back to indexThe Science of How to Optimize Testosterone & Estrogen | Huberman Lab Podcast #15
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Welcome to the Huberman Lab Podcast,
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where we discuss science and science-based tools
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for everyday life.
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I'm Andrew Huberman, and I'm a professor of neurobiology
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and ophthalmology at Stanford School of Medicine.
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This podcast is separate from my teaching
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and research roles at Stanford.
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It is, however, part of my desire and effort
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to bring zero cost to consumer information
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about science and science-related tools
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to the general public.
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Before we begin today, just want to acknowledge
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that if you're watching this on YouTube,
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yes, I have a bandage on the left side of my face.
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I was trying to cook something for Costello and I,
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and I got burned, burned myself.
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It was a cooking accident, I'm fine,
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no need to dwell on it, we can move on.
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But I just wanted to let you know,
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everybody's going to be okay.
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He got a great meal, I got a burn and a great meal.
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Today's episode is brought to us by Four Sigmatic.
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Four Sigmatic is a wellness company
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that makes mushroom coffee.
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For those of you that haven't heard
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of mushroom coffee before, just want to make clear,
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these are not psychedelic mushrooms,
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and no, the coffee does not taste like mushrooms at all.
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It tastes amazing, and it tastes like coffee.
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I started using Four Sigmatic coffee a few years ago,
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and then we actually stocked it in my lab,
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we still stock it in my lab, because it tastes really good.
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And it also happens to have two types of mushrooms in it
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that I particularly like because of their supplement
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and medicinal qualities.
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And those two are lion's mane mushroom,
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which has been shown in several research studies
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to have a mild anxiolytic, meaning anti-anxiety effect,
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and mood elevating effect.
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Those are from research studies done independently.
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As well, it has chaga mushroom.
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Chaga mushroom has been shown to increase growth factors
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that impact the nervous system, like nerve growth factor.
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So that's the reason I drink it,
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and that's the reason we stock it in the lab,
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and that's the reason why I drink it at home.
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If you'd like to try Four Sigmatic,
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you can go to foursigmatic.com slash Huberman.
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That's F-O-U-R-S-I-G-M-A-T-I-C.com slash Huberman,
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and you'll get up to 40% off your order,
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plus free shipping on their mushroom coffees.
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That's foursigmatic.com slash Huberman
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for up to 40% off and free shipping.
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Today's episode is also brought to us by Blinkist.
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Blinkist is an app that has thousands of nonfiction books
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condensed down to just 15 minutes of key takeaways
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that you can read or listen to.
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For me, I really like listening to books on Blinkist,
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even books that I've already read.
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Typically, the way I consume information
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is unless it's fiction, I'll listen to a nonfiction book
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or I'll read the actual physical hard copy
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of a nonfiction book, and then at the end,
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I like to take some notes about things
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I'd like to read the book.
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Blinkist has some terrific science category books.
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I read the full length book
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and I've listened to it on Blinkist
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That's in there, David Sinclair's book, Lifespan.
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Many of you probably know that David Sinclair,
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His book, Lifespan is terrific.
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I've read the full length book, I've listened to it
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and I've listened to it on Blinkist.
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Today's episode is also brought to us by Theragun.
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Theragun is a handheld percussive therapy device
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that releases deep muscle tension.
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I was introduced to Theragun on a dive expedition
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for my laboratory a few years ago.
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On that expedition, we were working very hard,
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we were diving all day,
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we were carrying Pelican cases with equipment,
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we were carrying tanks, very sore,
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very tired by the end of the day as was everybody else.
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Someone brought along a Theragun
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and pretty soon that thing was getting passed around
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and it became the most coveted device on board
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because it really works to relieve the soreness
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and deep muscle tension that accumulates
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with physical work, exercise,
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even just sitting too long throughout the day.
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So when I got back, I got a Theragun,
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I still use the Theragun daily.
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It's terrific because it's very quiet
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so you can use it while watching a movie
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or even while having a conversation
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without it feeling intrusive.
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It really gets down into the meat of the muscle if you want
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or you can use it more superficially if you like.
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If you want to try Theragun,
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you can go to theragun.com slash Huberman.
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They have several models available.
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The first one starts at $190,
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except that unlike a professional massage,
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you can use the Theragun for as long as you want
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throughout the day and for as many days as you like.
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That's theragun.com slash Huberman
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and I should mention that there's also
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a 30-day money back guarantee.
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So if you don't like the product, you send it back,
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you get your money back.
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This month on the Huberman Lab Podcast,
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we're talking all about hormones,
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these incredible chemicals that can impact our mood,
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our behavior, our feelings of optimism or pessimism.
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The amazing thing about hormones
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is that hormones impact all those things,
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but all those things, how we feel and what we do
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and what we think also can impact our hormones.
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And so it's a really fascinating area of biology
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that impacts every single one of us every day,
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both in wakefulness and in sleep and throughout the lifespan
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Today, we're going to be talking about hormone optimization
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and we're mainly going to be focusing on estrogen
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and testosterone and their derivatives.
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Last episode of the Huberman Lab Podcast,
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we talked about sexual development.
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That is how the chromosomes, the gonads and hormones
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impact what we call sexual development
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leading all the way up to puberty.
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Today, we're mainly going to talk about processes
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that happen from puberty onward.
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Although we might talk a little bit
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about development as well.
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So today we're going to talk a lot about basic biology,
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but we're going to weave in a lot of practical tools
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along the way for how to optimize
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these incredibly powerful things that we call hormones.
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Before we dive into our discussion
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about hormone optimization,
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I want to raise what I think is a very important point
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that at least I hadn't heard of until recently,
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which is the concept of salutogenesis.
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Many of us are familiar with the concept of pathogenesis,
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the idea that there are all these scary diseases
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like dementia and heart disease and stroke
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and all these things that await us
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if we don't take good care of ourselves
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and that might await us even if we do.
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That's the pathogenic model.
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Salutogenesis is something I learned about
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from one of my Stanford Medicine colleagues,
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which is a different orientation toward health
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and wellbeing where you're taking on particular behaviors,
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you're taking on a particular stance towards nutrition
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and exercise, supplementation, et cetera,
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in order to promote wellbeing above where you would be
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if you were not doing those behaviors.
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If you think about these two things,
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salutogenesis and the pathogenic model
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are really two sides of the same coin,
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but I'll just give an example
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of how this might affect you in a real way.
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If you like exercise because it feels good, great,
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but many people exercise or eat well for that matter
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in order to avoid heart disease or to avoid dementia,
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to avoid negative changes in body composition.
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And while that's powerful and certainly is the case,
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that exercise will help you move away from all those things,
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the salutogenesis model differs in that
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it involves a mindset and an orientation
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towards doing those things in order to feel good,
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in order to enhance your level of energy,
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in order to improve endocrine function
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and metabolic function.
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So it's really part of the pathogenic model
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and yet salutogenesis is really more of a mindset
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toward why you would do these particular behaviors.
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And really the most powerful mindset is going to be one
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where you are thinking about the pathogenic model,
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doing things so that you don't end up sick, et cetera,
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and to move away from sickness,
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as well as the salutogenic model,
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where you're doing things
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in order to move towards health and wellbeing.
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We think of health and wellness nowadays
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or the wellness community or wellness practices,
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that is the essence of the salutogenic model,
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but I found it very interesting to know
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that within the field of allopathic medicine,
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these two models exist,
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but we don't hear about the salutogenic model
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So it's just something to keep in mind,
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especially because of some of the mindset effects
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that were discussed in previous episodes.
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I'm not going to go into these in detail again right now,
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but if you might recall from the episode on food and mood,
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we talked about some of these incredible studies
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that were done by Alia Crum's group at Stanford and others,
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showing that if you tell people
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that the behavior that they're about to do,
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in this case, it was people cleaning up hotel rooms
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because that was their job,
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if you tell them that it's good for them,
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then you see much greater positive health effects
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than if they aren't aware of that information,
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that it's good for them.
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So we should really be thinking about
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not just moving away from disease and negative things,
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but also why certain things are good for us,
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because it's well-established now
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from really good scientific studies,
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that keeping in mind the positive effects of things
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can really have an outsized effect on wellbeing
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right down to the level of our physiology.
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So let's talk about hormone optimization.
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Today, we're going to talk about hormone optimization
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in reference to estrogen and testosterone
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and their derivatives.
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Now, estrogen and testosterone and their derivatives
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are what we call sex steroids.
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Now, the sex steroids immediately call to mind sex,
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for obvious reasons,
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and steroids, meaning anabolic steroids.
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But I just want to emphasize that estrogen and testosterone
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are present in everybody.
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It's their ratios that determine their effects.
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So today, we're going to talk about
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how you can optimize their ratios
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depending on your particular life goals,
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because the ratio of estrogen and testosterone
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in every individual has profound influence
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on feelings of wellbeing, feelings of optimism,
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feelings of anxiety or lack of anxiety,
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on reproduction, on sexual behavior
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independent of reproduction.
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They are profoundly powerful molecules,
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and we all make these molecules to some degree or another,
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but there are also important behavioral tools,
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supplementation tools, as well as prescription drugs
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that can impact the ratios of testosterone and estrogen
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in really powerful ways.
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So we're going to cover all of that.
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I want to emphasize that when you hear sex steroids
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or steroid hormones,
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most people think about anabolic steroids.
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And of course, anabolic steroids
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are derivatives of testosterone or testosterone itself.
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And they are heavily used and abused
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in the sports community,
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as well as outside the sports community.
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But there, of course, are many steroids
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that are not anabolic steroids
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that are also abused in sports.
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Today, we're not talking about drugs and sports,
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but I think that it carries such a heavy weight
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when people hear the word steroids,
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they think about anabolic steroids.
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So while today's discussion will certainly be relevant
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to physical performance, in fact,
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we're going to talk about how specific types of exercise,
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particular patterns of cold exposure,
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as well as particular patterns, believe it or not,
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of breathing can impact sex steroid hormones,
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both estrogen and testosterone.
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The discussion isn't really geared
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towards performance enhancement in sport,
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although we will do an entire episode,
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perhaps even an entire month
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related to performance enhancement in physical enterprises.
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So one of the first things to understand
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if you want to optimize your hormones
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is where they come from.
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There are a lot of different glands in the body
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that produce hormones.
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There's the pineal gland.
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Some hormones are made in the hypothalamus.
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Hormones are made by the gonads,
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the ovaries or the testes.
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You've got the thyroid gland.
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There are a bunch of different glands
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that make these different hormones,
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but when we're talking about the sex steroid hormones,
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estrogen and testosterone,
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the major sources are ovaries for estrogen
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and the testes for testosterone,
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although the adrenals can also make testosterone.
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Now, there are also some enzymes.
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Enzymes are things that can change chemical composition,
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and the enzymes that we're going to talk about today
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are the aromatases mainly.
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The aromatases convert testosterone into estrogen.
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So in a male, for instance, that has very high testosterone,
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some of that is going to be converted
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into estrogen by aromatase,
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and aromatase is made by body fat.
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It's also made in the testes themselves.
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A lot of people don't realize this,
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but the testes actually have the capacity
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to manufacture estrogen and aromatase, albeit at low levels,
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but this turns out to be important
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for optimizing hormone levels in males at later points,
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and we'll discuss that.
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It's important to note that there's a huge range
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in terms of the levels of hormones,
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testosterone and estrogen, between individuals,
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and it actually occurs
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within individuals across the lifespan.
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I'm not going to throw out specific numbers
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of X picograms per deciliter, et cetera, today,
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because that's going to vary a lot.
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It's going to depend on whether or not
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you're measuring in picograms or nanograms
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and that sort of thing.
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If you want to examine your hormones,
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you should do that in conjunction with a medical doctor,
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ideally an endocrinologist,
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can help you sort out that information,
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but the important thing to know is that
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prepubescent females make very little estrogen,
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and when we talk about estrogen,
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we mainly talk about estradiol,
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which is the most active form of estrogen
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in both males and females.
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So prepubescent females, very low levels of estrogen.
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During puberty, levels of estrogen,
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AKA estradiol, basically skyrocket,
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and then across the lifespan,
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estrogen is going to vary
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depending on the stage of the menstrual cycle,
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but as one heads into menopause,
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which typically takes place nowadays,
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somewhere between age 45 and 60,
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levels of estrogen are going to drop,
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and then post-menopause levels of estrogen are very low.
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As well, testosterone will fluctuate across the lifespan.
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Testosterone is going to be relatively low,
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pre-puberty in males.
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During puberty, it's going to skyrocket,
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and then the current numbers are that it drops off
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at about a rate of 1% per year,
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although we're going to talk about some data
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that show that there's actually
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tremendous variation in testosterone levels.
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There's actually a lot of examples of men in their 90s,
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their 90s, who still have testosterone levels
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that mimic pubertal levels, which is remarkable
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and speaks to the huge variation in testosterone levels
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across individuals.
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So let's talk about other sources of these hormones,
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and then it will make clear what avenues
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you might want to take in order to optimize these hormones.
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The other glands and tissues in the body
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that make these hormones, testosterone and estrogen,
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as I mentioned briefly, are the adrenals.
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So the adrenals right up top the kidneys,
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and the release of these steroid hormones from the adrenals,
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in particular testosterone
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and some of its related derivatives,
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are mainly activated by competition.
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So let's talk about competition,
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because it turns out that competition
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is a powerful influence on the sex steroid hormones,
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and the sex steroid hormones
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powerfully influence competition.
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So most people don't realize this,
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but most males of a given mammalian species
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never get to reproduce.
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In fact, they never even get to have sex at all.
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And we don't often think about that,
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but testosterone plays a powerful role
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in determining which members of a given species
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will get to reproduce,
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which ones of that species
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will actually get access to females.
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And so here I'm not talking about humans specifically,
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but it's well-known in species like elephant seals,
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in species like antlered animals and rams, for instance,
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that the higher levels of testosterone
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correlate with access to females.
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Now, one interpretation of this
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is that the females are detecting
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which males have high testosterone and selecting them.
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They're more receptive to them.
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We're going to talk about receptivity for mating
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But it's actually more so
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that the males that have higher testosterone
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forage further and will fight harder for the females.
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And this is really interesting
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because there's very good evidence now
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that testosterone can reduce anxiety,
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promote novelty seeking,
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and promote competitive interactions.
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And so before you leap too far with this in your mind
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and think about all these human behaviors,
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because there's a little bit of biology here
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that makes it all make sense.
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And it turns out to be pretty simple.
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We have a brain region called the amygdala.
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In Latin, that just means almond.
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But the amygdala is most famous for its role in fear.
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We hear a lot about fear and the amygdala.
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But the amygdala is really involved in threat detection.
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It sets our thresholds for anxiety
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and what we consider scary or too much.
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Testosterone, secreted from the gonads
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and elsewhere in the body,
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binds to the amygdala
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and changes the threshold for stress.
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So I've said before on previous versions of this podcast
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and on other podcasts,
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that testosterone has this incredible effect
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of making effort feel good.
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But what I was really referring to
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is the fact that testosterone lowers stress and anxiety,
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in particular, in males of a given species.
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Now, this is important
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because we often think of testosterone
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as creating whatever,
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masculinization or it's, you know,
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virilization or all these terms are thrown around.
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But what's it really doing
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when it comes to mate choice and competition?
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What it's doing is it's reducing the threshold for anxiety.
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it selects individuals of a given species
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being willing to, you know, suffer more,
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although it also reduces pain,
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so maybe they also suffer less,
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in pursuit of reproduction in females.
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Now, it's well-known in humans
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that both males and females
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who have elevated levels of testosterone
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will engage in more novelty seeking.
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And I do want to point out
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that even individuals without testes have testosterone
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and peaks in testosterone have similar effects,
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regardless of whether or not someone has ovaries or testes.
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Testosterone increases
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generally lead to more foraging,
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more novelty seeking,
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increases in libido and increases in desire to mate.
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So it is the case that increases in testosterone
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promote competitive and foraging type behaviors
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in humans and in non-human mammals.
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But it's also true that competition itself
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can increase androgens such as testosterone.
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I want to repeat that.
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Competitive environments themselves
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can increase testosterone.
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Now, some people have come to the conclusion
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that if you win, your testosterone goes up,
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and if you lose, your testosterone goes down.
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And to some extent that's true,
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but that's not a direct effect on the gonads.
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That's actually mediated by the neuromodulator dopamine.
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We talked about dopamine in the episode
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on motivation and drive.
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And dopamine and testosterone
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have a remarkable interplay in the body.
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Dopamine is actually released in the brain
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in ways that has the pituitary,
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this gland that sits over the roof of your mouth,
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release certain hormones that then go on
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to promote the release of more testosterone.
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And indeed, winning promotes more dopamine
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and later more testosterone.
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However, in the short term,
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just competing increases testosterone
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independent of whether or not you win or lose.
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So the short version of this
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is that competition increases testosterone.
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And this may be an ancient mechanism
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whereby the androgens such as testosterone
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are feeding back to encourage
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more competitive type behaviors.
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Because every species,
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whether or not you're talking about reproduction
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or other resource allocation,
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is involved in competition.
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Not every individual of a species
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gets access to the same number of mates
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or the same quality of mates.
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And this is true in both directions
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for males and females and everything in between.
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So I just want to emphasize once more,
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in case I went through it too quickly,
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that increases in testosterone in females
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are also going to lead to increase in reproductive behavior
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or seeking out reproductive behavior.
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They increase libido.
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In fact, there's a particular phase of the menstrual cycle
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where testosterone peaks just before ovulation
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that on average leads female humans to seek out sex
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more than they would otherwise during their cycle.
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And this is all by self-report,
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but this is also while measuring things like testosterone,
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estrogen ratios, and so forth.
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So it's really interesting that a single molecule,
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regardless of chromosomal or gonadal background,
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is increasing seeking of mates across individuals,
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increasing desire to compete or willingness to compete,
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and lowering the threshold for stress and anxiety.
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It's important to point out
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that while increases in testosterone
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promote seeking of mates and reproduction
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in both males and females,
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in females, it's actually increases in estrogen
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that promote receptivity to mating.
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So testosterone is driving the seeking of sex
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and estrogen is promoting the actual act of sex
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from females, so-called receptivity, consensual receptivity.
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In males, it's interesting to point out
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that testosterone is promoting seeking of sex,
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but it's also estrogen in males that's important for libido.
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If estrogen levels are brought too low,
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then men will completely lose their libido.
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This is often not discussed or overlooked
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in the discussion about testosterone therapy
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and performance-enhancing drugs.
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People think that hyperandrogenized individuals,
link |
meaning people that have very high levels of androgen,
link |
will have very high levels of libido,
link |
and they will provided estrogen is available
link |
in sufficient ratios to match that testosterone.
link |
So it's not simply the case
link |
that high levels of testosterone
link |
produce a lot of sex and mating behavior
link |
and low levels of estrogen are good across the board.
link |
You actually need both in both males and females.
link |
It's just that in females,
link |
the testosterone levels are always going to be lower
link |
than the estrogen levels.
link |
And in males, the estrogen levels
link |
are always going to be lower than testosterone levels.
link |
So testosterone promotes sex-seeking behavior.
link |
And the real question then is,
link |
does sex itself promote testosterone?
link |
And the answer is somewhat complicated,
link |
but the short version is yes.
link |
And as you recall, sex has multiple stages.
link |
So there's the physical act of sex,
link |
there's the seeking of sex,
link |
and then there's orgasm and ejaculation.
link |
Now, it's important to distinguish between these
link |
because whether or not sex itself increases testosterone
link |
depends on whether or not the male ejaculates.
link |
And this is very important to understand
link |
because on a previous episode,
link |
I mentioned how dopamine increases with sexual activity.
link |
Remember, dopamine and testosterone
link |
tend to increase linearly with one another.
link |
But then after ejaculation, there's a release of prolactin,
link |
and prolactin actually sets the refractory period in males
link |
during which he can't have sex again.
link |
And the duration of the refractory period
link |
will vary tremendously depending on how much
link |
and how long that prolactin release occurs.
link |
I also described in a previous episode
link |
how some people take vitamin B6,
link |
I'm not suggesting anyone do this,
link |
but take vitamin B6 in order to reduce prolactin levels
link |
and thereby reduce the duration of the refractory period.
link |
But getting at this question
link |
about testosterone and sexual behavior,
link |
it's important to distinguish
link |
between these different phases of reproduction
link |
or reproductive behaviors.
link |
So there are studies showing
link |
that sexual behavior itself can increase testosterone.
link |
There was a study published in 2011 from Escasa et al.,
link |
E-S-C-A-S-A, this is the stuff of textbooks,
link |
this is on PubMed, these are quality studies,
link |
showing that men who observe sex,
link |
so I guess this would be observing pornography,
link |
will have slight increases in testosterone
link |
during the observation.
link |
These people actually were willing to have blood draws taken
link |
while watching pornography.
link |
They had increases in testosterone
link |
that were very modest of about 10%.
link |
Whereas when people participated in sex,
link |
they actually did this study where people had blood draws
link |
and they had real sex with their partners,
link |
and they had 70% increases in testosterone.
link |
So there are increases in testosterone
link |
that are quite significant during the physical act of sex
link |
and far less so during observing sex.
link |
Now, the question that I often get,
link |
in fact, it's one of the questions I get most often
link |
in the comments on YouTube, I don't know why that is,
link |
is whether or not ejaculation adjusts testosterone levels.
link |
And it turns out there are two studies that I could find
link |
that were quality studies on PubMed that addressed this,
link |
that sex and ejaculation itself
link |
does not reduce testosterone levels,
link |
although it will increase prolactin levels
link |
for the reasons I described a moment ago.
link |
However, abstinence or sex without ejaculation
link |
for a week or more will increase testosterone levels
link |
So the answer is actually complicated.
link |
It's not straightforward.
link |
What it means is that sex itself increases testosterone.
link |
However, abstinence also increases testosterone
link |
So it's a nuanced answer.
link |
And I hope this is satisfactory, no pun intended,
link |
to those of you that have been asking me
link |
what is the relationship between sex and ejaculation
link |
and testosterone and dopamine?
link |
And you have to understand that nuance
link |
if you want to understand how certain behaviors
link |
impact hormones and how hormones impact those behaviors.
link |
As I mentioned before, in females,
link |
testosterone also primes the motivation to seek out sex.
link |
And sex itself also increases testosterone,
link |
but it also increases prolactin.
link |
So in both men and women,
link |
sex increases prolactin post-sex.
link |
It's just the way that the system works.
link |
It's that testosterone and dopamine increase
link |
in the seeking out and the behavior of sex.
link |
And then after sex, prolactin levels go up.
link |
There's kind of a quiescence.
link |
The whole nervous system is promoted towards calm.
link |
And this may actually have something to do with pair bonding
link |
and the encouragement of individuals
link |
to spend more time together to exchange different smells
link |
and hormones and maybe even pheromones.
link |
And we're going to talk about pheromones in a moment.
link |
A few years ago, there was a lot of excitement
link |
about the hormone DHEA,
link |
which is mainly made by the adrenals.
link |
DHEA has been promoted as kind of a catchall
link |
for increasing testosterone and estrogen
link |
in males and females.
link |
And indeed, DHEA will increase
link |
both testosterone and estrogen.
link |
This is something to be mindful of
link |
if you're thinking about taking DHEA
link |
or you're taking DHEA already.
link |
DHEA will increase both testosterone and estrogen
link |
and the extent to which it increases one or the other
link |
will depend on whether or not you're starting off
link |
with more estrogen than testosterone
link |
or whether or not you're starting off
link |
with more testosterone than estrogen
link |
and whether or not you have a lot of aromatase.
link |
So for individuals that have a lot of aromatase
link |
being made by the testes or by body fat,
link |
if you take DHEA, there's a good chance
link |
that a fair portion of that is going to be shuttled
link |
towards estrogen production
link |
and not towards testosterone production.
link |
Whereas in individuals that have low levels of testosterone
link |
to begin with, high levels of estrogen,
link |
there's a good chance that the DHEA
link |
is going to promote mainly estrogen production.
link |
At least that's what I could find
link |
from the research studies that I examined.
link |
So the way to think about DHEA,
link |
it's a kind of global promoter of the sex steroid hormones
link |
and its specific effects are going to depend
link |
a little bit on where you started
link |
and whether or not you have ovaries or testes.
link |
So just as there are behaviors
link |
that can increase testosterone,
link |
there are behaviors that can decrease testosterone.
link |
And one of the most well-characterized ones in humans
link |
is becoming a parent.
link |
So expecting fathers have an almost 50% decrease
link |
in testosterone levels, both free and bound testosterone.
link |
As well, their cortisol levels, a stress hormone,
link |
drop by almost threefold, which is incredible.
link |
And their estradiol levels double,
link |
so their estrogen levels double.
link |
So expecting fathers, many people have known,
link |
put on additional body weight.
link |
Everyone always thought that it's because they're eating
link |
in parallel with their pregnant wife,
link |
but it turns out that these effects of reduced testosterone,
link |
increased estradiol, and reduced cortisol
link |
can all be explained by an increase in prolactin.
link |
So not just in humans, but in other species as well.
link |
When the male and female of that species
link |
are expecting young, they lay down more body fat.
link |
The assumption is that this is to prepare
link |
for long nights of no sleep,
link |
which occurs in many species, not just in humans.
link |
So it's really interesting that this hormone prolactin
link |
can start suppressing whole categories of hormones,
link |
sex steroid hormones,
link |
and can start increasing whole categories of other ones.
link |
So we hear about the dad bod.
link |
There are a lot of explanations for the dad bod
link |
that extend well beyond this podcast episode,
link |
but it is a well-known phenomenon
link |
that testosterone is going to drop,
link |
prolactin's going to increase,
link |
estradiol's going to increase in males and females
link |
that are expecting children.
link |
Now, how long that lasts is very interesting.
link |
It actually has to do with how much contact
link |
and how much contact with the smells of the baby,
link |
of the offspring the father happens to have.
link |
So how available or unavailable he is
link |
will actually impact his level of hormones.
link |
Now, I am definitely not promoting the idea
link |
that fathers or mothers take time away from their offspring
link |
in order to keep their testosterone levels high
link |
or to restore them.
link |
That's not what I'm saying at all.
link |
It's just interesting to point out
link |
that these evolutionary mechanisms push us toward
link |
or bias us toward particular categories of behaviors
link |
by influencing our hormones,
link |
which then feed back and promote more
link |
of that particular behavior.
link |
Because as I mentioned before,
link |
peaks in testosterone in males and females
link |
cause individuals to seek sex, not promote parenting.
link |
Whereas reductions in testosterone, increases in prolactin,
link |
and decreases in cortisol move individuals of both sexes
link |
toward parenting behavior
link |
and less toward reproductive behavior.
link |
The other behavior that markedly reduces testosterone
link |
in both males and females
link |
and markedly reduces the desire for seeking sex
link |
and sex itself is illness.
link |
And many of you might say, well, duh,
link |
when people don't feel sick,
link |
they don't feel like seeking out mates
link |
and they don't feel like having sex.
link |
But have you ever wondered why that actually is?
link |
Well, it turns out that it can be explained by the release
link |
of what are called inflammatory cytokines.
link |
So cytokines are related to the immune system.
link |
They travel in the lymph and in the blood
link |
and they attack invader cells like bacteria and viruses.
link |
And under conditions of illness,
link |
we make a lot of different cytokines.
link |
Some of them are anti-inflammatory,
link |
but some of them are pro-inflammatory.
link |
And the best known example of a pro-inflammatory cytokine
link |
And it's known that IL-6 when injected into individuals
link |
will decrease the desire for sex
link |
and eventually will reduce levels of testosterone
link |
and estrogen independent of feeling lousy.
link |
So the reason why people don't want sex when they're sick
link |
is because levels of IL-6 are increased.
link |
Now, this is important because as we start to think about
link |
the different ways to modulate the sex steroid hormones,
link |
so-called optimize the hormones,
link |
keeping levels of IL-6 low is going to be important
link |
for them to exert their effects.
link |
Now, IL-6 doesn't just travel to the gonads
link |
and shut down the gonads.
link |
It actually has ways to interact
link |
with some of the receptors that the steroid hormones,
link |
estrogen and testosterone bind to,
link |
and impact those receptors
link |
so that the sex steroid hormones can't have their effect.
link |
In short, and put simply,
link |
inflammatory cytokines like IL-6
link |
are bad for sex steroid hormones.
link |
And so we're going to talk about how to modulate IL-6
link |
in the direction that you would want
link |
and how to increase another cytokine called IL-10,
link |
which is anti-inflammatory in ways that can help promote
link |
or at least support the sex steroid hormones.
link |
So as we move forward,
link |
we're going to now start to consider
link |
what sorts of behavioral practices,
link |
as well as other things,
link |
can modulate the sex steroid hormones
link |
in the directions that you want them to go.
link |
But before we do that,
link |
and in order to set the stage for that,
link |
you should be asking yourself,
link |
how is it or why is it at a mechanistic level
link |
that behaviors can modulate hormones at all?
link |
If you think about it,
link |
it's kind of strange that just the mere act
link |
of being a parent or parenting
link |
can change testosterone levels so dramatically
link |
or estradiol levels so dramatically.
link |
Is it the sweat of the baby?
link |
Is it their saliva?
link |
Is it the sight of the baby?
link |
Is it holding the baby?
link |
Or is it all those things?
link |
It turns out that many of those effects
link |
are because of smell,
link |
or in some cases, even possibly pheromones.
link |
Now I talked about hormones.
link |
Hormones, again, are a chemical,
link |
travels in the body,
link |
impacts tissues and cells elsewhere in the body.
link |
A pheromone is a chemical that's released
link |
by one member of a species
link |
that goes and impacts members elsewhere,
link |
but of the same species or even of other species.
link |
Now pheromone effects are absolutely well-established
link |
in lots of animal species,
link |
but they are very controversial in humans.
link |
Today, I'm going to talk about
link |
some of the well-established ones in animals.
link |
I've mentioned one or two of these before
link |
on previous podcasts,
link |
but I haven't mentioned several of them.
link |
And I'm going to talk about the evidence
link |
for pheromones in humans that are well-established.
link |
So the main ones in animals that are discussed
link |
are called the Leibniz effect,
link |
the Witten effect, the Bruce effect,
link |
and the Vandenberg effect,
link |
named after the people that discovered them.
link |
The Leibniz effect is when you house females
link |
of a given species together with no males,
link |
they start displaying longer,
link |
what are called estrous cycles.
link |
In many species, they don't have menstrual cycles,
link |
which are 28 days.
link |
They have estrous cycles,
link |
which tend to be four days or some variant thereof.
link |
It's an interesting phenomenon
link |
because what it means is that the presence of the male
link |
itself is changing the ovulation cycle.
link |
Now, many people out there,
link |
imagine mostly the people that are ovulating out there,
link |
will say, of course, I notice I ovulate differently
link |
or my cycle changes
link |
when I'm in the presence of my partner or I'm not.
link |
But the pheromone effect
link |
that mirrors this Leibniz effect in humans
link |
has still not really been identified.
link |
Nobody knows what the exact chemical is,
link |
but nonetheless, this is a strong effect in some animals.
link |
The other one is the Bruce effect,
link |
and this is a very dramatic effect
link |
whereby a pregnant animal will abort or reabsorb her fetus
link |
if the dad of those animals,
link |
the father that sired the litter,
link |
because these are animals, they're litters,
link |
is removed and a novel male is placed in her vicinity
link |
for about 48 hours.
link |
And what's interesting is the way that this happens
link |
is a pheromone that comes from male urine
link |
activates the gonadotropin-releasing hormone system
link |
and causes a reintroduction of the estrous cycle
link |
and a spontaneous abortion of the fetus.
link |
Now, a lot of people have taken the Bruce effect
link |
kind of to its extreme
link |
and asked whether or not in humans miscarriages are caused
link |
by detecting the pheromones or odors of novel males,
link |
meaning the non-dad male,
link |
and that's still an open question.
link |
Nobody knows if that's true or not,
link |
so I want to emphasize that.
link |
The other one is the Vandenberg effect,
link |
and this is one I alluded to
link |
in a previous episode of the podcast,
link |
which is that puberty in females can be accelerated
link |
by placing a novel sexually competent male
link |
in with a young female who has not undergone puberty.
link |
There's also a version of this, which I haven't described,
link |
which is delay of puberty,
link |
where you take juvenile female animals
link |
that have not undergone puberty
link |
and you put them with more mature females
link |
of the same species,
link |
and that introduction of more females will cause a delay,
link |
a significant delay in the onset of puberty.
link |
So these are all pheromone effects,
link |
and we know they're pheromone effects
link |
because they're not conscious.
link |
They also don't require actual contact
link |
with the other members of a given species.
link |
These are all effects that can be mediated
link |
by the urine from a given species
link |
or by the sweat of a given species,
link |
and speaking of sweat,
link |
the one pheromone effect that I'm very aware of
link |
from the published literature
link |
is a paper that was published in 1998
link |
by Stern and McClintock,
link |
which was getting at this question
link |
of synchronization of menstrual cycles.
link |
Now, the whole idea of synchronization of menstrual cycles
link |
is pretty controversial.
link |
For a long time, people said,
link |
oh, this is absolutely a well-characterized phenomenon,
link |
people living in dormitories,
link |
their menstrual cycles would synchronize,
link |
people living in environments together
link |
with their menstrual cycles would synchronize,
link |
and then some studies came out
link |
that kind of undercut those data
link |
and said, no, this actually doesn't happen,
link |
and it was kind of controversial,
link |
but there is a very clear effect
link |
that was described by Stern and McClintock.
link |
What they did actually
link |
was they took females, they charted their cycles,
link |
and then they had other females wear pads in their armpits,
link |
and they collected sweat from those females,
link |
and then they took the sweat from those pads
link |
in those females' armpits,
link |
and they introduced them to women
link |
who had never had contact with the people who had sweated.
link |
They only had contact with their sweat.
link |
In fact, they swabbed it underneath their nose,
link |
but if that sounds gross,
link |
they dilute it in alcohol,
link |
so much so that they can't actually detect
link |
the odor of the sweat.
link |
That's actually very important because it's not the smell,
link |
it's the pheromone chemical itself,
link |
and it turns out the pheromone chemical itself
link |
can modulate the menstrual cycle,
link |
although it doesn't necessarily synchronize it
link |
What it does is it changes the duration
link |
and the pattern of ovulation
link |
relative to so-called follicular phase.
link |
Long and short of this is that the sweat and pheromones
link |
of females can modulate the menstrual cycle patterns
link |
of other adult females.
link |
It's just a question of whether or not they synchronize,
link |
and if you're kind of rolling your eyes now and saying,
link |
well, of course they do, and this is really detailed,
link |
this is how the science is done,
link |
and the reason why people are so skeptical
link |
about the presence of pheromone effects in humans
link |
is that there's no well-identified pheromone organ.
link |
We have an area of our nose that's responsible for smelling,
link |
that's well-established, it's been observed in MRIs
link |
many, many times in cadavers, many, many times
link |
in pretty much all individuals,
link |
but the vomeronasal organ,
link |
which is the pheromone detecting organ,
link |
hasn't really been found in humans.
link |
There's something called Jacobson's organ,
link |
which is thought to be the organ in the nose.
link |
It's actually on the top of the roof of the mouth,
link |
and in the kind of back of the nose,
link |
there's a few wine tasters, I never can pronounce this,
link |
what are they called?
link |
Sommelier, whatever, it's the people that are excellent
link |
at drinking and detecting the essences of wine
link |
that you have to go through all these tests
link |
in order to get certified as one of them.
link |
They are using probably a similar mechanism
link |
of mixing taste and smell, and Jacobson's organ,
link |
if it exists, the vomeronasal equivalent in humans
link |
is thought to be a combination of smell and taste.
link |
Now, it gets even weirder and cooler
link |
when you think about a given study that was done in humans,
link |
where if you take hundreds of t-shirts from boyfriends,
link |
keep them separate, you take those t-shirts,
link |
you wash them many times separately,
link |
and then you offer them to the girlfriends,
link |
the longtime partners of those guys,
link |
and what you'll find is that the girlfriend
link |
can pick out her boyfriend's t-shirt
link |
among hundreds of other t-shirts,
link |
not because it smells different,
link |
but because something about it seems different.
link |
It might smell different to her
link |
in some way that's kind of imperceptible even to her,
link |
and the level of accuracy in detecting that t-shirt,
link |
her partner's t-shirt,
link |
is way above statistical significant thresholds,
link |
so much so that you almost have to say
link |
there's something about these effects
link |
that are real pheromone effects,
link |
although people still argue
link |
that there are no pheromone effects in humans,
link |
that it's all through olfaction.
link |
I think these are interesting and important to understand
link |
because it means that a lot of things
link |
coming through our nose,
link |
whether or not it's pheromones or smells,
link |
are impacting hormones and our ability to attach memories
link |
and kind of recognition of mates and other people,
link |
including our children, not just our mates.
link |
And of course, perfume manufacturers
link |
have really picked up on the idea of pheromones
link |
and have entire laboratories set up
link |
to build chemical compounds into perfumes
link |
that are designed to attract other mates.
link |
This is a well-established and well-documented phenomenon.
link |
And the last point I'll make about pheromones
link |
is that this combination of taste and smell
link |
is such a real thing in the animal world
link |
that there's something called the flemming response.
link |
During the mating season for different animals,
link |
you can actually even see this in horses,
link |
but for animals that are seasonal maters,
link |
they'll do something called the flemming response
link |
where they actually open their lips and their mouth
link |
and they expose their gums
link |
so that they can capture pheromones
link |
that are floating in the wind and the environment.
link |
They actually are looking for mates using their mouth
link |
and kind of sniffing around.
link |
If you own a dog and you watch the way
link |
that the dog will sniff around,
link |
selecting where they want to urinate, males and females,
link |
there's often, they're bringing molecules into their nose.
link |
I know it sounds kind of gross sniffing urine,
link |
but there are a lot of pheromones in urine of animals.
link |
A lot of pheromones are traveling in the wind.
link |
Again, whether or not this is happening in humans,
link |
I don't know, but then you think about the perfume thing
link |
and here people are putting these scents on themselves
link |
that contain putative pheromones, human pheromones,
link |
and walking around hoping that their scents
link |
are going to evoke mate-seeking behavior
link |
from other individuals of the same human species.
link |
So we are among the animals in this behavior
link |
independent of whether or not
link |
you believe pheromone effects exist.
link |
So let's get back to behaviors
link |
that can help optimize hormone levels.
link |
One of the main behaviors
link |
that's been shown to be associated
link |
with poor levels of estrogen
link |
relative to age match controls for people with ovaries
link |
or lower levels of testosterone
link |
compared to age match controls for people with testes
link |
Apnea has everything to do with underbreathing
link |
and the buildup of too much carbon dioxide in the body.
link |
There are other effects of apnea as well,
link |
but if there's a consistent literature
link |
in this whole story about aging and reductions in hormones
link |
and general health and reductions in hormones, it's apnea.
link |
I went deep into the literature on advanced menopause
link |
or when menopausal symptoms are exacerbated.
link |
And I went into the literature on andropause
link |
or early onset andropause,
link |
so levels of testosterone that are far lower
link |
than they should be for a given age.
link |
And in every case, you could find multiple papers
link |
that showed that apnea or poor efficiency of breathing
link |
and buildup of too much carbon dioxide in the body
link |
was a problem, mostly sleep apnea,
link |
although apnea in general was shown to be an issue
link |
negatively impacting hormones.
link |
Now, the directionality of this effect isn't entirely clear.
link |
It could be that reductions in estrogen cause apnea.
link |
And actually there's some reason
link |
to believe that might be the case.
link |
I found at least one paper showing
link |
that there are estrogen receptors on some of the neurons
link |
that actually innervate the lungs
link |
and allow for the perception
link |
of how full or empty the lungs are.
link |
In other words, reductions in estrogen may adjust breathing
link |
by changing our sensitivity to our own lungs.
link |
Now, that was true for males and females.
link |
Remember, estrogen in both males and females.
link |
But as well, I found papers in which testosterone reductions
link |
were associated with apnea
link |
and testosterone receptors are also found
link |
on a lot of cells in the so-called viscera,
link |
including the lungs.
link |
So again, the directionality of the effect isn't clear.
link |
But what's really interesting is that
link |
there are very clear ways in which patterns of breathing,
link |
especially patterns of breathing in sleep,
link |
can modulate hormones in ways that are immediately actionable
link |
and can serve to optimize both estrogen and testosterone,
link |
regardless of whether or not you have ovaries or testes.
link |
Apnea is underbreathing
link |
or mainly cessation of breathing during sleep.
link |
So people are holding their breath
link |
and then they'll suddenly wake up.
link |
Actually, I've talked about the physiological sigh
link |
on previous episodes of this podcast
link |
of this pattern of double inhales followed by exhales
link |
that one can do consciously
link |
to reduce stress and anxiety and offload carbon dioxide.
link |
That pattern of breathing
link |
is actually what kicks in spontaneously
link |
anytime we have an apnea episode in sleep,
link |
although in many people who have apnea,
link |
they don't engage the physiological sigh.
link |
People who are dramatically overweight
link |
also suffer a lot from apnea during sleep.
link |
There's actually a lot of buildup
link |
of carbon dioxide in the body,
link |
and that can lead to excessive sleepiness during the day,
link |
inability to access the deeper phases of sleep,
link |
and it's well-established that going into deep sleep
link |
and getting the proper patterns of slow wave sleep
link |
and REM sleep are important for hormone optimization.
link |
I talked about how to modulate sleep and optimize sleep
link |
in the first month of the Huberman Lab Podcast,
link |
so please check out those episodes if you have sleep issues
link |
or you want to work on your sleep.
link |
Also check out Matt Walker's terrific book,
link |
"'While We Sleep,"
link |
and that will help you find various protocols
link |
to help you optimize your sleep.
link |
But the issue of breathing itself
link |
can be adjusted in the daytime waking hours
link |
in ways that can powerfully impact both sleep,
link |
reduce incidents of sleep apnea,
link |
and apparently from some emerging literature
link |
can also help to optimize various hormones
link |
even just by breathing in particular ways while awake.
link |
So here's how this works.
link |
There's now a lot of literature showing
link |
that breathing through the nose, not through the mouth,
link |
is powerful for improving lots of things.
link |
First of all, it improves cosmetic features
link |
of the jaw and face.
link |
This was first well-established by my colleagues at Stanford
link |
in a book called, Jaws, the story of a hidden epidemic.
link |
This is by Sandra Kahn and Paul Ehrlich,
link |
who are both faculty at Stanford,
link |
has a foreword by Robert Sapolsky,
link |
the great Robert Sapolsky,
link |
and it also has a heavy endorsement up front
link |
by Jared Diamond, the author of,
link |
"'Guns, Germs, and Steel,' the Pulitzer winner."
link |
So a lot of heavy hitters on this book, Jaws.
link |
It's not a book that a lot of people know about, unfortunately
link |
but it really describes the benefits of nasal breathing
link |
and the terrible things that happen
link |
when people, in particular children,
link |
but adults also, are heavy mouth breathers.
link |
So mouth breathers have changes
link |
in the cosmetics of their face and jaw
link |
that are really bad in terms of attractiveness,
link |
and this was done in twin studies.
link |
You can look in the book and see some of this.
link |
It's really dramatic how being a mouth breather
link |
tends to make the chin drop back behind the upper mandible.
link |
There's a lengthening in the face, a drooping of the eyes.
link |
It can be quite dramatic or modest
link |
depending on how much mouth breathing.
link |
Now, sometimes we have to breathe with our mouths
link |
but there's also a lot of data and studies
link |
described in this book, Jaws,
link |
that describe how nose breathing in wakefulness
link |
and in sleep promotes all sorts of positive things
link |
related to not just cosmetics
link |
but also the improvement of gas exchange
link |
with carbon dioxide and oxygen in the body.
link |
And as well, it can modify levels
link |
of different neurotransmitters and neuromodulators
link |
in ways that positively can impact hormones.
link |
So believe it or not, being a nasal breather
link |
and avoiding being a mouth breather
link |
can actually positively impact hormones,
link |
and in particular, the hormones testosterone and estrogen,
link |
although the way that it does that
link |
is by making you a better sleeper,
link |
which allows you to produce more testosterone
link |
and the appropriate amounts of testosterone and estrogen.
link |
But it does that in part through indirect mechanisms
link |
because deep sleep supports the gonads,
link |
the ovaries and the testicles,
link |
and the turnover of cells and the production of cells.
link |
Remember, in the ovary, particular cells
link |
and the egg follicles themselves make estrogen,
link |
and in the testicle that the sertoli cells
link |
and the lytic cells are important
link |
for the formation of sperm and for testosterone respectively.
link |
So what does this all mean?
link |
This means we have to be breathing properly.
link |
It almost sounds kind of like kind of new agey,
link |
like, oh, you have to breathe properly,
link |
get your hormones right.
link |
But no, you have to breathe properly
link |
to get your breathing and sleep right
link |
so that your sleep can actually be deep enough
link |
and you're not entering apnea states,
link |
and then that will support gonad function.
link |
And I wouldn't be putting this out
link |
as one of the main behavioral tools upfront
link |
if it weren't for the fact that the effects of apnea
link |
on these hormones are dramatic and terrible,
link |
and the positive effects of getting breathing right
link |
on these hormones, testosterone and estrogen,
link |
are dramatic and wonderful.
link |
So let's talk about a few of those studies briefly
link |
so I can underscore the value of proper breathing
link |
in order to optimize hormones.
link |
So I was able to find at least four quality studies
link |
showing that when apnea is reduced in sleep or eliminated,
link |
there are significant increases
link |
in testosterone in males and in proper estrogen
link |
to testosterone ratios in females.
link |
And the way that it works is very interesting.
link |
Apparently, it works by reductions in cortisol.
link |
Now, cortisol is a stress hormone
link |
that is released early in the day as we wake up
link |
and serves healthy roles in protecting us against infection,
link |
reducing inflammation, et cetera.
link |
But you don't want cortisol to be too high,
link |
and you certainly don't want to elevate it too long
link |
throughout the day and night.
link |
And so we all know, because now we've been told a lot
link |
in the last decade or so, that getting proper sleep
link |
is important for all these aspects of health.
link |
Getting proper sleep can really offset all the reductions
link |
in testosterone and estrogen and reductions in fertility
link |
that occur if we don't get enough sleep.
link |
But seldom is it discussed how sleep actually adjusts
link |
things like testosterone and estrogen,
link |
and it does it by modifying cortisol.
link |
So the molecule cholesterol can be converted
link |
into testosterone or estrogen,
link |
but there's a competition whereby the cholesterol
link |
will turn into cortisol and not testosterone,
link |
or it'll turn into cortisol and not estrogen
link |
if stress levels are too high.
link |
So the simple version of this
link |
is getting your breathing right during the waking hours,
link |
meaning primarily, unless you're working out really hard
link |
or there's some other reason why you're maybe eating
link |
or speaking that you need to be breathing
link |
through your mouth, you should be a nose breather.
link |
There's really good evidence for that now.
link |
And in sleep, you also want to be a nose breather
link |
because that's going to increase the amount of oxygen
link |
that you're bringing into your system
link |
and the amount of carbon dioxide that you're offloading.
link |
There are other positive effects of it as well,
link |
but you're basically reducing apnea.
link |
Breath holding in sleep leads to buildup of carbon dioxide
link |
and leads to increases in cortisol,
link |
which then decrease testosterone and decrease estrogen
link |
in negative ways across all sexes, okay?
link |
So the simple version of this is get your breathing right.
link |
So how do you do that?
link |
How do you get your breathing right?
link |
Well, for some people that have severe sleep apnea,
link |
they're going to need the CPAP machine.
link |
This is a machine that you actually put on your face
link |
and it helps you breathe properly in sleep.
link |
Many people, however, are starting to do this thing
link |
of taping their mouth shut.
link |
Now, this sounds a little bit extreme
link |
and you certainly don't want to do this
link |
in any way that's dangerous.
link |
James Nestor talked about this in his book,
link |
"'Breath, The New Science of a Lost Art,"
link |
that simply taping shut the mouth
link |
with some tape that will allow you to open your mouth
link |
if you really need to.
link |
During sleep can allow people to shift over
link |
from being mouth breathers and snorers to nose breathers.
link |
In the daytime, the best way to get good at nasal breathing
link |
is to dilate the nasal passages
link |
because a lot of people have a hard time
link |
breathing through their nose.
link |
And one way to do this
link |
is to just breathe through your nose more.
link |
And one way to do that is that when you exercise,
link |
in particular cardiovascular exercise,
link |
most of the time, provided you're not in maximum effort,
link |
you should be nasal breathing.
link |
Now, for a lot of people,
link |
nasal breathing during exercise is hard at first,
link |
because the sinuses have a capacity to dilate over time,
link |
you'll get better at it.
link |
The sinuses, if you haven't ever held a skull,
link |
because of my job as a neuroscientist,
link |
I've held a lot of skulls,
link |
taken a lot of brains out of a lot of skulls,
link |
teach neuroanatomy and have done that for, goodness,
link |
God knows how many species I've done that for,
link |
But what the sinuses are is they're actually,
link |
what you've got are you've got these little portals
link |
in the bone that run up here and down here
link |
behind the nose and into the jaw.
link |
If you ever had a cold and your sinuses are stuffed up,
link |
you feel like you have congestion here and here
link |
and around your ears and in your cheeks and in your face.
link |
And that's because the sinuses are actually portals
link |
where the bones are fused together,
link |
kind of interdigitate like this,
link |
but they're lined, of course, with mucous membranes.
link |
And as you start to nasal breathe more,
link |
the nasal passages will start to dilate more.
link |
Don't worry, you're not going to get giant nostrils.
link |
But what's going to end up happening
link |
is you're going to have an easier time breathing
link |
through your nose just from waking.
link |
So my advice would be breathe through your nose
link |
while exercising, unless you're in maximum effort.
link |
Pretty soon, what you'll find is you actually can
link |
create more output than you would
link |
if you were breathing through your mouth.
link |
And of course, there are exceptions to this.
link |
If you're swimming, follow that breath protocol.
link |
For fighters and martial artists,
link |
there's reason to do the kind of exhale breathing
link |
through the mouth, the shh kind of thing.
link |
There are reasons to do that sort of thing
link |
for particular sports, but for most people
link |
who are kind of recreational athletes or exercisers,
link |
learn to be a nasal breather.
link |
It has positive cosmetic effects, it reduces apnea,
link |
it offloads more carbon dioxide, it increases lung capacity,
link |
it dilates the sinuses, and it prevents apnea in sleep.
link |
So unless you have severe apnea and you need the CPAP,
link |
becoming a nasal breather can have all sorts
link |
of positive effects by reducing cortisol,
link |
reducing apnea, and indirectly,
link |
raising testosterone and estrogen in the proper ratios.
link |
So this might seem kind of foundational and indirect,
link |
but when you go into the scientific literature,
link |
it comes through as one of the most powerful things
link |
that you can do that is zero cost,
link |
takes a little effort, but at zero cost,
link |
and it has all these positive effects across the board,
link |
both cosmetic and in sleep and hormonal, et cetera.
link |
So that's the first piece of behavioral advice.
link |
The second piece of behavioral advice
link |
relates to the viewing of light.
link |
And many of you have heard me talk about this before,
link |
and I'm not going to belabor the point
link |
that viewing bright light within the first hour of waking,
link |
whether or not it's from artificial light
link |
or ideally from sunlight,
link |
has these powerful effects on sleep and wakefulness.
link |
But we have to return to this if you want to understand
link |
how light can impact hormones,
link |
because hormones, light and dopamine,
link |
have a very close-knit relationship,
link |
so much so that your light viewing behavior
link |
can actually have a direct effect
link |
on hormone levels and fertility.
link |
It can have a direct effect on hormone levels and libido.
link |
It can have a direct effect on hormone levels
link |
and your ability to heal quickly.
link |
And I'm not talking about shining light
link |
on particular injuries.
link |
That may or may not have positive effects.
link |
We can argue about that on a subsequent episode, it may,
link |
but what I'm talking about is viewing light with your eyes.
link |
So let's talk about that now
link |
because the scientific literature on this are robust
link |
and they extend back several decades,
link |
and yet I think most people don't really understand
link |
how powerful this relationship is
link |
between light, dopamine, hormones,
link |
and all the great things that the sex steroid hormones do
link |
when they're available in your body in the proper ratios.
link |
In order to understand the powerful effects
link |
that light can have on the sex steroid hormones,
link |
we need to understand seasonal breeding animals.
link |
Now, humans are not seasonal breeders,
link |
but if you understand the biology
link |
of how light impacts various neurotransmitters and hormones,
link |
you'll set yourself up for a deep understanding
link |
of what you should do with your light viewing behavior.
link |
So several species of animals,
link |
many species of animals, in fact,
link |
like rabbits and fox and various mustelids
link |
like ferrets and ermines,
link |
change their pelage color across the seasons.
link |
This might be kind of a duh,
link |
but fox in winter are often white or light gray,
link |
and those same animals will be brown or darker colored
link |
in the summertime and spring months.
link |
Now, those same animals breed in the spring,
link |
and they shut down breeding.
link |
They actually shut down ovulation.
link |
They often shut down testosterone production
link |
in the winter months.
link |
So right now I'm just correlating color of fur
link |
with tendency to breed.
link |
Tendency to breed, as we know,
link |
is going to be related to the levels of sex steroid hormones,
link |
estrogen and testosterone.
link |
Now, why would these two things be linked?
link |
Well, it turns out that dopamine is the link between them.
link |
So dopamine has a precursor.
link |
That precursor is tyrosine,
link |
which is an amino acid, comes from food.
link |
And when dopamine levels are high, as I mentioned before,
link |
there's a tendency for more gonadotropin-releasing hormone,
link |
luteinizing hormone, follicle-stimulating hormone,
link |
all the hormones that come
link |
from the hypothalamic-pituitary axis
link |
and stimulate estrogen and testosterone release
link |
from the ovary and testes.
link |
Dopamine basically increases all of that.
link |
The precursor to dopamine is tyrosine,
link |
but the precursor to a lot
link |
of the melanin-producing elements of cells
link |
that give pigmentation, including for the hair,
link |
is tyrosine and tyrosinase, an enzyme.
link |
So yes, the same amino acid-based pathway
link |
and many of the same enzymes
link |
that are devoted to dopamine
link |
and dopamine-increasing the sex steroid hormones
link |
are devoted to giving pigmentation to the hair and skin.
link |
And this is why in the summer months, when days are longer,
link |
animals are breeding more.
link |
And this is also why in the winter months,
link |
when days are shorter, animals are breeding less.
link |
This is also why in humans, many people, not all,
link |
feel an elevation and mood in the spring and summer months
link |
because of the amount of sunlight they're getting
link |
is increased relative to the winter months.
link |
Now, some of you may be saying,
link |
I love the fall, I love the winter.
link |
Sensitivity to light in these dopamine systems
link |
has a strong genetic component.
link |
So you go to some areas of the world,
link |
I have relatives who are Scandinavian,
link |
and in some areas of Scandinavia,
link |
people know that there's a kind of seasonal effect
link |
to the disorder, there's kind of a seasonal depression,
link |
and people get sadder and more quiescent in the winter,
link |
there's actually less going out,
link |
and therefore there's less sexual behavior,
link |
there's less partying and things of that sort.
link |
But other people will say, no, during the winter months,
link |
I feel great and I love the holidays around winter, et cetera.
link |
So there's a lot of variation.
link |
But in general, the pathway is the following.
link |
Increased viewing of sunlight,
link |
and it has to be to the eyes, it's not to the skin,
link |
increased viewing of sunlight,
link |
increases dopamine levels in the brain,
link |
increased dopamine levels in animals and humans,
link |
increases the amount of these melanocytes
link |
and the activity of these melanin-producing cells,
link |
which give pigmentation to the skin and hair,
link |
and indirectly increase the amount
link |
of testosterone and estrogen
link |
and thereby reproductive behavior, feelings of wellbeing,
link |
social interactions, reductions, anxiety, et cetera,
link |
all of which should make sense
link |
based on what we've talked about already
link |
in terms of the biology and the impact
link |
of these steroid hormones
link |
on various aspects of the mind and body.
link |
So how does this translate to a protocol?
link |
This translates to the protocol
link |
of if you want to optimize testosterone and estrogen,
link |
you need to get your light viewing behavior correct.
link |
It's not just about optimizing your sleep,
link |
which is also important,
link |
it's about getting sufficient amount of light in your eyes
link |
so you have sufficient levels of dopamine.
link |
So the simple protocols for that I've reviewed before,
link |
but it means getting anywhere from two to 10 minutes
link |
of bright light exposure in your eyes early in the day.
link |
It is not sufficient to do this with sunglasses
link |
unless you have to do that for safety reasons.
link |
It's fine to wear prescription lenses and contacts.
link |
If you can't get sunlight for whatever reason,
link |
you want to use bright artificial light,
link |
but that is absolutely critical
link |
for timing the cortisol release properly,
link |
limiting cortisol release to the early part of the day,
link |
getting increases in dopamine
link |
that are going to promote the production
link |
of testosterone and estrogen to healthy levels.
link |
The other aspect of light viewing behavior
link |
that's extremely important
link |
is to avoid bright light exposure to your eyes
link |
in the middle of the night.
link |
If you're viewing bright light in the middle of the night,
link |
you are suppressing dopamine release.
link |
If you're suppressing dopamine release,
link |
you are suppressing testosterone levels.
link |
So much so that I would wager that a major effect
link |
of sleep deprivation on reducing testosterone and estrogen
link |
is not necessarily because of the lack of sleep per se,
link |
it's because usually when people
link |
are not getting enough sleep,
link |
they're getting too much light in their eyes
link |
in the middle of the night as well.
link |
A study on this has not been completed yet,
link |
but there are two studies published in Cell and Neuron,
link |
both cell press journals, excellent journals,
link |
showing that viewing bright light with the eyes
link |
in the middle of the circadian night
link |
has a detrimental effect on dopamine,
link |
and therefore has a detrimental effect
link |
on things like testosterone and estrogen.
link |
So you can't even begin to talk about supplements
link |
and other ways to optimize testosterone, diet,
link |
and its effects on testosterone and estrogen
link |
and fertility and reproductive behavior, et cetera,
link |
until you get your breathing right,
link |
until you get things like your light viewing behavior right.
link |
So bright light early in the day
link |
and throughout the day is great.
link |
View as much bright light, ideally sunlight, as you can,
link |
as much as you safely can.
link |
You obviously don't want to burn your retinas
link |
or damage your retinas,
link |
so never look at any light that's so bright
link |
it's painful to look at.
link |
But getting a lot of light in your eyes
link |
is not just about adjusting your sleep-wake rhythms,
link |
it's also about optimizing your sex steroid hormones.
link |
And avoiding bright light in the middle of the night
link |
is not just about not disrupting your sleep,
link |
it's also about optimizing the sex steroid hormones.
link |
And now that you understand
link |
a bit of how the sex steroid hormones work
link |
and how powerful they are for reducing anxiety
link |
and all these other effects,
link |
this should be straightforward to do,
link |
or hopefully it's inspired you
link |
to get your light viewing behavior
link |
and your breathing behavior correct.
link |
In fact, in thinking about tools,
link |
for many people that are suffering from low levels
link |
of estrogen if they want higher levels,
link |
or low levels of testosterone if they want higher levels,
link |
just getting the breathing and light viewing behavior,
link |
which will indirectly support sleep behavior,
link |
can be a huge and positive effect
link |
on levels of sex steroid hormones.
link |
I can already anticipate that in hearing this,
link |
you might wonder whether or not viewing light
link |
is going to, for instance, increase your testosterone a lot
link |
when in fact you want your estrogen increased,
link |
or it's going to increase your estrogen a lot
link |
when you want your testosterone increased.
link |
Everything I'm describing here is for people,
link |
regardless of chromosomal or gonadal background.
link |
So I'm trying to basically offer all this information
link |
But basically, if you're somebody who naturally has ovaries
link |
and has higher levels of estrogen than testosterone,
link |
then viewing bright light early in the day
link |
because of dopamine's effects
link |
is going to promote more estrogen
link |
and subtle increases in testosterone.
link |
Whereas if you're somebody who starts off
link |
with more testosterone and lower estrogen,
link |
so somebody presumably who has testes,
link |
or maybe you're supplementing with testosterone
link |
through other sources for whatever reason,
link |
bright light viewing is going to increase testosterone
link |
and estrogen in parallel,
link |
but you're still going to maintain
link |
the ratio of testosterone to estrogen.
link |
In short, you don't have to worry
link |
that you're going to increase the wrong hormone.
link |
This is all about optimizing the ratios of hormones
link |
that you already have.
link |
Okay, so we've talked about breathing.
link |
We've talked about light.
link |
Let's talk about a third element
link |
that there seems to be some excitement about lately
link |
for other reasons,
link |
but that can actually have some pretty profound influences
link |
on hormone levels, and that's heat and cold.
link |
So as always, rather than just offer a tool,
link |
I'm going to tell you the underlying science
link |
as it relates to naturally occurring phenomenon,
link |
because in understanding that
link |
and understanding the mechanism,
link |
you're going to be in a far better position
link |
to understand the tools and mechanisms
link |
and how you might want to adjust them for your own life.
link |
So now you understand the relationship
link |
between light, day length, dopamine, and hormone levels,
link |
and everyone should realize
link |
that temperature and day length are linked,
link |
and I'm sure as I say that,
link |
you're probably thinking, oh, of course.
link |
In summer, when there's more sunlight,
link |
days are longer, nights are shorter.
link |
In general, it tends to be warmer out,
link |
and in winter, when nights are longer, days are shorter,
link |
it tends to be colder out.
link |
And in the winter months,
link |
testosterone and estrogen tend to be lower in many animals
link |
and in humans, and in the summer months,
link |
because of the role of dopamine
link |
in promoting the sex steroid hormones,
link |
when days are longer and it's warmer,
link |
humans tend to make more estrogen and testosterone
link |
relative to the other months of the year.
link |
Now, these effects can be somewhat weak and modulated,
link |
as opposed to in seasonally breathing animals
link |
where they're really dramatic, okay?
link |
But the point is that temperature and day length
link |
and sunlight, those are all intimately related
link |
because of the systems that we evolved in, right?
link |
So before we had artificial light
link |
and artificial heating and artificial cooling,
link |
our biology evolved under systems where temperature,
link |
day length, and the hormones
link |
were correlated with one another.
link |
So nowadays, there's a lot of interest
link |
in using cold as a way to stimulate testosterone.
link |
This is mainly because in the sports community,
link |
in particular in the bodybuilding community,
link |
they are always seeking ways to maximize testosterone,
link |
dihydrotestosterone, keep estrogen to its minimum required
link |
to still have libido and still have skin elasticity,
link |
but also walk around with saran wrap skin,
link |
then all this kind of extreme stuff that happens there
link |
has led to a recent movement where, believe it or not,
link |
I heard this and I couldn't believe I went and checked,
link |
although I didn't buy them, that on Amazon,
link |
you can actually find,
link |
people have their literally underwear that have ice packs,
link |
or I think they're ice pack underwear,
link |
so that people are making themselves cold
link |
at the level of the gonads
link |
in order to try and increase testosterone and libido.
link |
Sounds pretty crazy.
link |
But believe it or not,
link |
that and things like ice baths and cold showers
link |
can have positive effects on the sex steroid hormones,
link |
both testosterone, mainly in males,
link |
and estrogen, mainly in females.
link |
And you might say, wait,
link |
I thought cold makes the reproductive axis
link |
kind of shut down a bit or reduces testosterone and estrogen
link |
but it turns out it's not actually the cold
link |
that's having these effects in people.
link |
Things like the ice bath, cold showers, cold water swims,
link |
these ice underwear, whatever they are,
link |
can't believe that these actually exist, but they do exist.
link |
What happens is there's a rebound in vasodilation
link |
So cooling causes vasoconstriction.
link |
And then after the cooling,
link |
there's a rebound vasodilation
link |
and there's more infusion of blood into the gonads.
link |
There's also an effect that's neural.
link |
So let me explain how this works
link |
because there are only a few studies on this,
link |
none of which looking at the frozen underwear
link |
but that have looked at cold exposure
link |
and levels of androgens and estrogens.
link |
That's kind of interesting.
link |
So you have to remember that the gonad,
link |
the ovaries and the testes, are heavily vascularized.
link |
Remember, even at the level of the brain,
link |
GnRH, gonadotropin-releasing hormone,
link |
comes from neurons that, believe it or not,
link |
start off in your nose early in development,
link |
migrate into the hypothalamus.
link |
I'm not making that up.
link |
They started off in your nose,
link |
migrate into the hypothalamus.
link |
Those neurons extend processes,
link |
we call them axons, into the pituitary
link |
and release GnRH into the pituitary.
link |
There's a lot of vascularization within the pituitary,
link |
so now those hormones, or GnRH,
link |
can stimulate follicle-stimulating hormone,
link |
luteinizing hormone,
link |
which then are released and travel into the bloodstream.
link |
Then those hormones reach the ovary or testes
link |
and they have to get into the ovary and testes.
link |
And the way they do that is through the vascular system.
link |
And people forget, but the vascular system
link |
and how constricted or dilated vessels are
link |
is controlled by neurons, right?
link |
This is what we discussed this
link |
during the discussion about stress in the stress episode.
link |
But it's well-known to neuroscientists
link |
that the best way to shut down neurons is to cool them.
link |
So there are a lot of examples of this
link |
in the scientific literature,
link |
but most people aren't aware of it
link |
because you're not digging around
link |
in the methods section of these papers.
link |
But when we want to shut down neurons,
link |
we can do things like inject drugs
link |
that will do that like lidocaine,
link |
the stuff that makes you numb at the dentist,
link |
or you can use different inhibitors.
link |
But one of the best ways to do it experimentally
link |
is to just cool neurons.
link |
When you make neurons cold,
link |
because there's a temperature dependence
link |
of when neurons can be active and when they can't,
link |
the neurons shut down.
link |
So the most plausible explanation for why cold exposure,
link |
either through one to 10-minute ice bath or cold shower
link |
or the ice underpants thing,
link |
would increase testosterone or increase estrogen
link |
is that you're cooling the neurons
link |
that control vasoconstriction and vasodilation
link |
and shutting down the entry of blood,
link |
or at least reducing it, and hormones into the gonad.
link |
And then when the gonad and the surrounding area
link |
heats up again, you're getting a rebound hypervasodilation
link |
that delivers excessive levels of,
link |
not excessive, but increased levels of GnRH
link |
and other hormones and carriers and carrier proteins
link |
and so forth that would then stimulate the gonad
link |
to release more testosterone,
link |
or would stimulate the gonad to release more estrogen.
link |
That's the most plausible explanation I can come up with.
link |
There aren't a lot of studies looking at direct effects
link |
of temperature on the gonad.
link |
And it's going to be a difficult study to carry out
link |
in any case, because unless they were done in vitro
link |
in a dish, it's very hard to eliminate all the other things
link |
like vasoconstriction and vasodilation.
link |
Put simply, we don't know whether or not cold and heat
link |
directly affect the production of testosterone and estrogen.
link |
We only know that cold and heat can modulate those
link |
probably through indirect mechanisms
link |
like controlling the amount of blood flow
link |
by way of shutting down or activating the neurons.
link |
Now, there's a lot of lore
link |
around heating up the gonads too much.
link |
There's actually a whole set of pseudoscience web pages
link |
out there saying, well, if you want a girl,
link |
you should conceive the child at this room temperature.
link |
And if you want a boy,
link |
you should conceive the child at this room temperature.
link |
I don't think there's really any firm scientific evidence
link |
for that, for either one.
link |
But there's some interesting literature
link |
about temperature dependence of production of hormones.
link |
And I think that it probably relates to these mechanisms
link |
of vasodilation and neural control over vasodilation.
link |
And of course, excessively high heat is not good
link |
for the testes, for sperm production, or for sperm health.
link |
Sperm have all sorts of proteins in the cap,
link |
things like pentraxins and other things
link |
that cause them to swim faster
link |
when they're expressed properly and in the right locations.
link |
And heat actually alters the location
link |
and the function a lot of those proteins.
link |
They're very heat sensitive.
link |
And so that's why excessive heat
link |
is truly not good for fertility,
link |
which may be independent of heat's roles
link |
in promoting estrogen or testosterone.
link |
Okay, so now we've talked about breathing,
link |
light, and temperature.
link |
We talked about parenthood.
link |
We talked about competition.
link |
And we talked about some pheromone effects.
link |
Now let's talk about particular forms of exercise
link |
and how they modulate the steroid hormones.
link |
And then we're going to talk about various supplements,
link |
both in reference to testosterone
link |
and in reference to estrogen.
link |
So now let's talk about how exercise in its various forms,
link |
weight training, endurance work, weight training to failure,
link |
or less intense weight training,
link |
can impact testosterone levels.
link |
But I want to remind you
link |
that we're talking about testosterone
link |
both in males and females.
link |
And based on what you know from earlier in the episode,
link |
testosterone can have numerous positive effects
link |
in both males and females provided they're in optimal range.
link |
So if you look on the web, people will say,
link |
oh, you know, testosterone is increased by weight training.
link |
You want to do the big, heavy compound movement,
link |
squats and deadlifts and chins and things of that sort.
link |
But what about the scientific studies?
link |
Like what's the actual basis for this?
link |
Because if you just take a step back
link |
and look at this from the perspective of a scientist,
link |
you'd say, okay, what is a squat?
link |
A squat is loading up a bunch of weights on a bar
link |
and then, you know, sitting down essentially
link |
and standing up over and over again.
link |
What's a deadlift?
link |
It's lifting heavy weights from the ground.
link |
Why would that increase testosterone, right?
link |
This is what's often not discussed in the weight training
link |
or even the exercise science community.
link |
What would actually stimulate the release of testosterone
link |
from the adrenals and or testes?
link |
And which one is it, adrenals or testes or both?
link |
And that's often not discussed, but as a neuroscientist,
link |
this is the kinds of things we think about
link |
because we think always that genes don't create behavior,
link |
immune systems don't know when to be activated,
link |
lungs don't know when to inhale or exhale,
link |
hearts don't know when to beat
link |
except for the information that it gets from neurons.
link |
The nervous system controls all of that.
link |
And so really the answer has to be in the neural system
link |
that's related to these particular types
link |
of weight-bearing exercises.
link |
So when you go into this literature,
link |
it's kind of hard to find real mechanism.
link |
You see a lot of effects.
link |
You'll hear things like androgen receptor content,
link |
meaning testosterone and its derivatives,
link |
receptor content following heavy resistance exercise,
link |
and you'll find some examples that, for instance,
link |
you know, they do muscle biopsies,
link |
they can actually see receptor increases
link |
looking at either high volume or low volume,
link |
really intense exercise, and you can find a lot of that,
link |
but not a lot of mechanism
link |
about how the nervous system would do this.
link |
And the reason you'd want to know how it can do it
link |
is that you could potentially build better protocols
link |
or figure out exactly what about these movements
link |
is triggering increases in androgen receptors
link |
So what's interesting is when you start digging
link |
into the more mechanistic studies,
link |
what you find is that heavy weight training,
link |
so this is weight training where the sets are done
link |
with anywhere from kind of one to eight rep range,
link |
so this translates differently depending on ratio
link |
of muscle fiber type and so forth,
link |
but where basically people are working at anywhere
link |
from like 70% to 95% of their maximum
link |
or sometimes even going right down
link |
to their one repetition maximum,
link |
really kind of max effort,
link |
what you find is that using the nervous system
link |
in a way in which they're moving heavy loads,
link |
so that I would translate to recruitment
link |
of high threshold motor units for you muscle physiologists.
link |
And there's a rule in muscle physiology
link |
about the neuron recruitment for moving muscles
link |
where you basically use the minimum number of motor units
link |
of neurons to activate muscle as you possibly can,
link |
as loads increase, you have to recruit more and more neurons.
link |
You always hear about recruiting muscle fibers,
link |
but really it's recruiting more neurons
link |
to recruit more muscle fibers.
link |
And what you find is that heavy weight training,
link |
but not weight training to failure,
link |
where completion of a repetition is impossible,
link |
leads to the greatest increases in testosterone.
link |
Now I'm sure there are a bunch of exercise jockeys out there
link |
that are going to come at me with a bunch of things
link |
where, oh yeah, but high volume and this
link |
and training to failure and that, sure.
link |
If you're willing to kind of put things side by side,
link |
adjust for exogenous testosterone treatment
link |
and all the rest, which was done in these studies,
link |
what you find in general is that weight training
link |
with heavy loads, so anywhere from one rep maximum
link |
to somewhere in the six to eight repetition range
link |
in males or females increases testosterone significantly.
link |
And it does it for about a day, sometimes up to 48 hours.
link |
And the studies that I found,
link |
which seem to hold the most rigor or weight
link |
based on where they're published,
link |
as opposed to being published in the journal,
link |
never heard of it, they're published in
link |
good quality exercise physiology journals.
link |
For instance, the paper by Ratames, R-A-T-A-M-E-S-S et al,
link |
which was published in 2005,
link |
which talks about modulations in androgen receptor content
link |
after heavy resistance exercise,
link |
looks at going to failure, not to failure.
link |
The work of Sciardo et al, published in 2006,
link |
differential effects of strength training
link |
leading to failure versus not failure
link |
on hormonal responses, strength, and power gains.
link |
There are a lot of studies here,
link |
and I will certainly put the links to these in the caption.
link |
Many of these actually include Duncan French,
link |
who runs the UFC Training Center,
link |
who I've had the privilege of meeting
link |
and discussing some of this with before,
link |
as well as other authors, of course.
link |
But they all point to the fact that there's something
link |
about the engagement of the neurons
link |
that recruit high threshold motor units in muscle
link |
when moving heavy loads, but not to failure,
link |
that has to provide some sort of feedback signal
link |
either to the gonad to produce more testosterone
link |
or is increasing the activity of receptors in the body.
link |
Now, why do I say that?
link |
Well, this is the puzzle, right?
link |
How is it that a particular movement,
link |
just like how is it that interacting with your child
link |
is increasing or decreasing testosterone?
link |
This is the kind of fundamental question
link |
at the mechanistic level.
link |
And we answered the question for child rearing.
link |
It has probably something to do with smell and pheromones,
link |
although I'm sure there are other cues as well,
link |
but there's clearly a influence of hard work
link |
at the neural level and then at the muscular level
link |
for increasing testosterone.
link |
And there's also clearly an effect of working too hard
link |
and presumably increasing cortisol too much,
link |
although I'm speculating there,
link |
in terms of reducing testosterone.
link |
And so the reason we're getting nitty gritty about this
link |
is because ultimately we'd really like to understand
link |
what are the optimal protocols?
link |
Out there in the literature,
link |
you hear move heavy objects to increase testosterone.
link |
Some of that will be converted
link |
to the more powerful androgen DHT
link |
by 5-alpha reductase, et cetera.
link |
But we really don't understand yet
link |
how these particular behaviors increase testosterone
link |
and whether or not it's doing that
link |
by modulating the receptors
link |
or it's modeling testosterone release directly,
link |
presumably testosterone release directly
link |
and sensitivity of the receptors.
link |
That's what most of the muscle physiology studies
link |
that I was able to find point to.
link |
But this basically boils down
link |
to a particular set of protocols
link |
where if you want to increase testosterone
link |
for whatever reason,
link |
that weight training with heavy loads,
link |
but not to failure seems to be the best supported,
link |
at least scientifically supported solution to that.
link |
Now, it may not raise your testosterone levels
link |
as high as you want,
link |
but it's definitely taking things in the correct direction.
link |
Now, many of you might be endurance athletes
link |
or also enjoy exercise besides heavy weight bearing exercise
link |
and there are several studies exploring
link |
whether or not endurance activity
link |
can increase or decrease androgen levels
link |
and whether or not you combine endurance activity
link |
and weight training,
link |
whether or not that has any effect
link |
if you do the endurance activity first or second.
link |
And the takeaway from all of this
link |
was that endurance activity, if performed first,
link |
leads to decreases in testosterone
link |
during the weight training session
link |
as compared to the same weight training session done first
link |
followed by endurance activity.
link |
In other words, if you want to optimize testosterone levels,
link |
it seems to be the case that weight training first
link |
and doing cardio type endurance activity afterward
link |
is the right order of business.
link |
Now, when these are done on separate days,
link |
it doesn't seem to have an effect.
link |
They showed no statistical interaction,
link |
but it seems that if you're going to do these
link |
in the same workout episode,
link |
that it's move heavy loads first,
link |
then do cardiovascular exercise.
link |
So there's a little bit of data looking specifically
link |
at how endurance exercise impacts testosterone
link |
and its derivatives.
link |
And it's very clear that high-intensity interval training,
link |
sprinting, et cetera,
link |
which somewhat mimics the neural activity that occurs
link |
while moving heavy weight loads
link |
is going to increase testosterone.
link |
There's ample evidence for that in the literature.
link |
And that endurance exercise that extends beyond 75 minutes
link |
is going to start to lead to reductions in testosterone,
link |
presumably by increases in cortisol.
link |
But of course, the intensity of the exercise
link |
is going to be important too.
link |
I don't think anyone really believes
link |
that hiking for the three hours
link |
is going to reduce your testosterone.
link |
Whereas I think if one were to go out
link |
and run hard for three hours,
link |
that you can imagine there'd be reductions in testosterone
link |
by way of increases in cortisol.
link |
And so while this area certainly needs more research,
link |
it's pretty clear that limiting the endurance exercise
link |
to 75 minutes or less, not making it too intense,
link |
is one way to keep cortisol from going through the roof.
link |
But I've talked on previous episodes
link |
and there are a lot of others who have talked out there
link |
about how to clamp cortisol,
link |
how to keep cortisol more reduced.
link |
This is also one of the reasons why you can imagine
link |
that various individuals, either for competition
link |
or just for their own purposes,
link |
rely on testosterone therapy, exogenous testosterone,
link |
not just for weight training, but for endurance exercise.
link |
So this is one of the reasons why every once in a while
link |
professional cyclists will get popped
link |
for performance in hectic drugs,
link |
meaning they'll get caught.
link |
And it's not just that they're increasing red blood cells
link |
through EPO and things of that sort.
link |
Oftentimes they're also taking testosterone,
link |
not because they want to be large
link |
or have massively hypertrophied muscles,
link |
but because they're injecting testosterone,
link |
they don't have to worry about
link |
cortisol-induced reductions in testosterone.
link |
They can just clamp or keep their testosterone levels high.
link |
Not something I'm recommending,
link |
but I'm just justifying the rationale
link |
for why an endurance athlete would want to do that at all.
link |
So now let's switch over to talking about estrogen.
link |
So there are many people
link |
who are trying to optimize their estrogen levels.
link |
And one of the places where this shows up a lot,
link |
and I get a lot of questions about, is menopause.
link |
So menopause, as I mentioned earlier,
link |
is this fairly massive reduction in the amount of estrogen
link |
that is circulating in one's blood,
link |
mainly because the ovary is now depleted
link |
of some estrogen production of its own,
link |
the eggs are not being produced,
link |
they've been depleted, et cetera.
link |
So menopause is characterized by a variety of symptoms.
link |
And it's multifaceted,
link |
probably deserves an entire episode on its own,
link |
but things like hot flashes, things like mood swings,
link |
things like headaches, in particular, migraine headaches.
link |
There can be a lot of brain fog.
link |
It can be very, very disruptive for people.
link |
Now you sometimes hear about andropause,
link |
which is thought to be the kind of analog to menopause,
link |
but menopause has certain characteristics
link |
that make it a very robust phenomenon for most women.
link |
andropause is going to sometimes happen, sometimes won't.
link |
In fact, without going into the details
link |
of the graphs and the data,
link |
it's very clear, as I mentioned earlier,
link |
that some men maintain levels of circulating androgens
link |
that are quite high, even as similar as they were in puberty
link |
and their teen years and 20s,
link |
well into their 60s, 70s, and 80s,
link |
if they're optimizing a lot of other things,
link |
and probably genetics plays a role as well.
link |
Whereas some males won't,
link |
but within the female population
link |
or population of individuals that have ovaries,
link |
there's a very stereotyped and characteristic reduction
link |
in estrogen levels as the number of eggs becomes depleted.
link |
And that's what we think of as menopause.
link |
So what are the various things
link |
that one can do for menopause?
link |
Well, one of the most common ones
link |
is that physicians will prescribe supplemental estrogen.
link |
So this is hormone therapy
link |
where somebody takes either their oral estrogen
link |
or they'll use a patch or a pellet,
link |
some way to secrete estradiol into the system.
link |
And that has varying success, depending on the individual.
link |
Some people respond very well to it.
link |
Other people really have challenges with it.
link |
And there are a lot of side effects associated with it
link |
for some people, not others.
link |
In addition, there's a concern always
link |
about supplementing estrogen
link |
when there's a breast cancer background in the family,
link |
or there's concern about breast cancer for any reason,
link |
because a lot of those cancers are estrogen dependent.
link |
And that's why drugs like tamoxifen and anastrozole
link |
and drugs that block either aromatase
link |
or block, excuse me, estrogen receptors directly
link |
were initially developed.
link |
You see them a lot on the internet, again,
link |
for all the sports folks
link |
who are trying to increase testosterone and reduce estrogen.
link |
But remember, those drugs were initially developed
link |
as ways to prevent estrogen binding
link |
to the estrogen receptor as cancer treatments.
link |
So I want to be very clear, and I've said this many times,
link |
we always put in the caption of each episode, of course,
link |
that I'm not a physician, I'm not an MD,
link |
I don't prescribe anything, I'm a professor,
link |
I'm professed things,
link |
I'm here to translate the scientific literature
link |
and point to what might be some useful avenues
link |
But this is just for information purposes.
link |
You should definitely talk to your doctor
link |
about anything that I'm talking about now
link |
or in any episode for that matter.
link |
So if you look at the literature on menopause
link |
outside of just standard estrogen therapy,
link |
there are some very interesting compounds out there
link |
that have been used and that are supported
link |
by quality peer-reviewed studies.
link |
And again, I'll refer you once again
link |
to this amazing website, examine.com,
link |
where you can put in essentially any condition
link |
or any supplement,
link |
and it will point you to the human effect matrix,
link |
not animal studies,
link |
but human studies that have explored these things.
link |
Now, there are a huge variety of them here,
link |
so I won't go into all of them,
link |
but some of the pro-estrogenic compounds
link |
that have been shown to be powerful
link |
in the context of menopause,
link |
as well as other conditions
link |
where estrogen is lower than one would like,
link |
include a description and some of the literature,
link |
I'll get into this in a moment,
link |
of something like black cohosh.
link |
I think that's the correct pronunciation.
link |
It's literally the word black and then C-O-H-O-S-H.
link |
And it's very interesting.
link |
There are 13 peer-reviewed studies
link |
that have reached prominence
link |
in the kind of commercial landscape
link |
where this substance, black cohosh,
link |
has been promoted as a way to increase estrogen.
link |
Turns out that the effects are consistent,
link |
but are fairly minor,
link |
fairly minor increases in estrogen.
link |
So it does seem to be a real effect.
link |
It is significant over the placebo effect,
link |
but there's also a significant placebo effect
link |
in some of these studies as well.
link |
So what's interesting when you look at these studies
link |
is that many of them were carried out
link |
over a period of six plus months,
link |
they're double-blind studies, et cetera,
link |
and almost all of them led to modest increases in estrogen
link |
and modest decreases in menopause-related symptoms.
link |
Now, a few additional details about these studies,
link |
they were generally carried out on women age 45 to 64.
link |
In some cases, they look specifically at women
link |
that were clinically obese or overweight,
link |
although not always.
link |
The subject size pools are pretty big,
link |
anywhere from 50 to 87,
link |
these are decent size, 132 subjects, et cetera.
link |
So these look to be like quality studies,
link |
and they basically point to the fact
link |
that black cohosh can have a modest effect
link |
in improving menopause symptoms.
link |
The other one is Panax ginseng, so P-N-A-X, ginseng,
link |
has been shown to decrease some symptoms
link |
associated with menopause, mostly related to libido,
link |
although the other effects were unreliable.
link |
Other things like maca,
link |
which is known to increase dopamine actually,
link |
had minor effects, things like,
link |
the names here are a little hard to pronounce,
link |
so forgive me, things like Valeriana officionalis
link |
has shown that there can be some improvement
link |
in the hot flash symptoms
link |
and some of the insomnia associated with that,
link |
so that might be worth exploring,
link |
again, discuss with your doctor,
link |
but these were both 100 subject plus
link |
age 45 to 64 individuals,
link |
double-blind placebo-controlled studies
link |
that showed significant but modest effects.
link |
There was one substance in the gallery
link |
of the compounds that was looked at
link |
that turns out to be particularly interesting,
link |
and this one is also particularly difficult to pronounce,
link |
and it's Puraria mirifica,
link |
so I'm going to spell this out for you.
link |
It's P-U-E-R-A-R-I-A, Puraria mirifica, M-I-R-I-F-I-C-A,
link |
and there are four studies on this compound
link |
that show in every case it to be very potent,
link |
in fact, comparable to estrogen therapy,
link |
estrogen replacement therapy,
link |
in reducing the symptoms of menopause,
link |
so this was pretty striking
link |
because when you go through these studies
link |
and you look again, they seem to be pretty well controlled
link |
as far as I could tell,
link |
and they explored a pretty wide subject pool,
link |
and it seems that every single one of these studies
link |
when looking side-by-side at Puraria mirifica,
link |
which is also called,
link |
now this is really hard to pronounce, quaocuracao,
link |
I guess that's the name that they use in various countries,
link |
that it was comparable to estrogen replacement therapy,
link |
so I mention this because a lot of people contacted me
link |
and said, what about the insomnia in menopause?
link |
What about the headaches in menopause?
link |
Now, I'm not suggesting you run out
link |
and immediately start taking any of these compounds.
link |
Please talk to your doctor.
link |
Any hormone-related compound is a serious consideration
link |
because of the relationship to breast cancers,
link |
but just in general, these compounds are,
link |
estrogen and testosterone are exceedingly powerful
link |
in terms of controlling our mental and physical states,
link |
and so you want to approach them with caution,
link |
but I thought that that one in particular was interesting
link |
and for which there are quite a few PubMed-documented
link |
peer-reviewed studies in quality journals.
link |
Okay, so now let's talk about the role of specific compounds,
link |
some of which, many of which,
link |
can be taken in supplementation form
link |
or extracted from diet and nutrition
link |
in order to optimize sex steroid hormones,
link |
and again, I just want to emphasize
link |
that I'm not suggesting anyone take anything
link |
or stop taking anything.
link |
This is purely for informational purposes,
link |
but some of the data on these
link |
is quite striking and impressive.
link |
It's very clear that certain collections of nutrients
link |
are useful for promoting testosterone and estrogen production
link |
in their proper ratios,
link |
and those things are what I would call
link |
the sort of usual suspects.
link |
Vitamin D, which is important for so many biological
link |
functions, including endocrine functions,
link |
zinc, magnesium, et cetera,
link |
and if you want to look into this more deeply
link |
and you want to understand exactly what the negative effects
link |
are of not having sufficient zinc, magnesium,
link |
and what those levels might actually be,
link |
there's a paper that's available, you can go on PubMed,
link |
I can't pronounce this last name, I'm sorry,
link |
it looks to me like Wrozosek, but it's W-R-Z-O-S-E-K.
link |
I hope I didn't butcher that too badly.
link |
Wrozosek et al, 2020 in Endocrinology and Metabolism Review.
link |
So there's a recent paper in a good peer review journal
link |
that talks mainly about how the hypothalamic
link |
pituitary adrenal axis and the sex steroid hormones
link |
are negatively impacted by deficiencies in magnesium,
link |
deficiencies in vitamin D, and deficiencies in zinc.
link |
However, that doesn't point to the levels
link |
that one should take in order to optimize.
link |
So it doesn't say take X amount of zinc
link |
or X amount of magnesium or X amount of vitamin D.
link |
For that information, because it's so context dependent
link |
and individual dependent, I highly recommend
link |
you go to examine.com.
link |
You can put in zinc or magnesium or vitamin D,
link |
and they will give you ranges of dosages
link |
that are supported by specific studies.
link |
Again, that information is completely free to you,
link |
and it's very useful in figuring that out.
link |
I personally have supplemented with zinc, magnesium,
link |
and vitamin D for years,
link |
but many other people do that as well.
link |
And the question is always how much?
link |
And that's why I'm a proponent of getting blood work done
link |
because that's how you know whether or not
link |
your androgen levels, as well as things like
link |
vitamin D levels, et cetera, are sufficiently high.
link |
So the takeaway from these studies
link |
looking at what deficiencies cause
link |
in terms of deficits in testosterone and estrogen
link |
really point in the direction of
link |
make sure you're getting adequate zinc, magnesium, and D3
link |
unless you want these steroid hormone levels
link |
to be reduced for whatever reason.
link |
One of the things that's been shown time and time again
link |
to have very negative effects on sex steroid hormones,
link |
testosterone mainly in men, estrogen mainly in women,
link |
There's this whole issue, of course, of the opioid epidemic.
link |
It's deserving of an entire episode
link |
where you're going to talk about that
link |
with experts in addiction
link |
and people that treat pain and so forth,
link |
but the opioids dramatically reduce levels
link |
of testosterone and estrogen.
link |
And they do that mainly by disrupting the receptors
link |
on gonadotropin-releasing hormone neurons,
link |
these neurons within the hypothalamus
link |
that communicate to the pituitary.
link |
And in fact, people that take large amounts of opioids
link |
or even take low levels of opioids for long periods of time
link |
will develop all sorts of endocrine syndromes.
link |
That's been shown over and over again.
link |
Gynecomastia or male breast development in males,
link |
disruptions to the ovary in females.
link |
It's really a quite terrible situation.
link |
So excessive opioids are very problematic
link |
for sex steroid hormones.
link |
I don't think anyone will have any trouble
link |
finding any literature on that.
link |
You can just go into PubMed,
link |
you can put opioids, testosterone or opioids, estrogen,
link |
but the major effect is actually way up
link |
in the hypothalamus to shut down the production of GnRH,
link |
the very hormone that stimulates
link |
testosterone and estrogen release.
link |
Now there's an entire industry devoted to supplements
link |
and various things that people can take
link |
to increase testosterone.
link |
Some of which have scientific data to support them,
link |
some of which do not,
link |
and some of which have anecdotal support
link |
and some of which do not.
link |
This ranges so broadly.
link |
I mean, things like the material off deer antlers,
link |
which is high in supposedly IGF-1,
link |
which is in the growth hormone pathway,
link |
all the way to actual consumption of bull testes.
link |
You can go on Amazon right now,
link |
I certainly don't suggest that you do this,
link |
and you can actually buy ground-up testes from cows,
link |
and you can consume those.
link |
Now, a lot of that's going to be broken down in the gut.
link |
I'm certainly not suggesting you do that,
link |
but just to point out, this is a huge and vast literature,
link |
and it actually dates back hundreds of years,
link |
even though testosterone wasn't discovered that long ago
link |
as a specific hormone molecule
link |
and characterized and then resynthesized,
link |
it has a huge industry
link |
because of the powerful effects that it has.
link |
Likewise with estrogen,
link |
the development of the birth control pill
link |
was only made possible by understanding the structure
link |
of estrogen and estradiol,
link |
and we're going to talk all about birth control
link |
and how it works and its influence on various other pathways
link |
in a future episode.
link |
But there are these supplement compounds
link |
that are supported by the scientific literature
link |
in terms of their ability to adjust androgens,
link |
things like testosterone and dihydrotestosterone.
link |
One of the ones that has really good evidence for it
link |
It's very clear that something about creatine,
link |
although the mechanism isn't exactly clear,
link |
either increases 5-alpha reductase
link |
or makes the testosterone molecule more susceptible
link |
to certain enzymatic reactions
link |
that leads to increases in DHT.
link |
DHT, dihydrotestosterone,
link |
as I mentioned in the previous episode,
link |
has this dramatic role in creating
link |
a kind of masculinization of the brain prenatally.
link |
It also defines the primary sex characteristic
link |
of the growth of the penis, et cetera,
link |
and beyond infancy and early childhood and later in life,
link |
it has powerful effects in creating balding
link |
and beard growth, et cetera,
link |
and it has a much higher affinity for the androgen receptor
link |
than does testosterone.
link |
So creatine can increase DHT,
link |
which means that if you take creatine
link |
and you're very DHT susceptible,
link |
then you might experience some hair loss.
link |
This has been heavily debated.
link |
Does creatine cause baldness?
link |
It's going to depend.
link |
It's going to depend on how much 5-alpha reductase you have
link |
and how prone to hair loss you are.
link |
Some people can take creatine without any problem
link |
in terms of hair loss.
link |
Some people cannot.
link |
They start losing their hair to levels
link |
that, at least for them, aren't comfortable.
link |
There are a few other things that can increase testosterone,
link |
and it has to do with the way that testosterone exists
link |
in its free and its bound form.
link |
So testosterone, the molecule,
link |
is got a total testosterone.
link |
That's usually what's measured.
link |
This is the kind of levels
link |
that are typically thrown around
link |
of anywhere from 300 to 900,
link |
being the kind of natural range,
link |
and then super physiological,
link |
getting up into 1200, 1600 range.
link |
But testosterone isn't just roaming around free
link |
in the blood, at least most of it isn't.
link |
Most of it is bound
link |
to either sex hormone binding globulin, SHBG,
link |
They're needed as transporters
link |
to get testosterone into cells
link |
so that testosterone can have its effects
link |
on gene expression,
link |
as well as other pathways within the cells.
link |
So people talk about that the level of free testosterone
link |
is really what's important
link |
and that you want to optimize free testosterone.
link |
That's a little bit of a tricky statement.
link |
That's kind of like it's true,
link |
and yet it's not really reflective
link |
of a thorough understanding
link |
of how these binding globulins work.
link |
Remember, these binding globulins
link |
aren't there to soak up all your testosterone
link |
just to make it hard for you to free up testosterone
link |
and make gains in the gym or whatever it is,
link |
or have increases in libido.
link |
They're there to actually transport testosterone
link |
to specific tissues,
link |
to shuttle them to specific tissues,
link |
and to set the rate of bound and unbound testosterone
link |
so that it's not all unbound at once.
link |
And it's always interesting to look in the literature
link |
and see how everyone wants to free up their testosterone
link |
so that it can work.
link |
But sex hormone binding globulin
link |
can bind up too much testosterone
link |
to the point where it's having negative effects on libido
link |
or on muscle growth and fat loss and things of that sort.
link |
This is true in males and females.
link |
Or it can be doing exactly what it's supposed to do,
link |
which is shuttling testosterone to the proper tissues
link |
and organs where it has all these effects,
link |
including the brain.
link |
So there are supplements, in particular, Tonga Ali,
link |
which has this other name.
link |
It's something I've called Tonga Ali.
link |
Sometimes it's called, and forgive me,
link |
that's hard to pronounce,
link |
but uricoma longifolia jack.
link |
They always seem to have these names
link |
that kind of allude to androgenic features,
link |
like I don't know why longifolia jack.
link |
I think it's kind of obvious
link |
why that sounds sort of androgenic.
link |
This has been shown in several studies,
link |
and you can find these on examine.com,
link |
or you can go to PubMed if you like.
link |
I've looked at these.
link |
That it does seem to have some pro-fertility,
link |
pro-free testosterone and subtle aphrodisiac effects.
link |
It does also seem to be a slight anti-estrogen.
link |
So the reports of this are people take this
link |
anywhere from 400 to 800 milligrams a day.
link |
Again, I'm not suggesting you do that,
link |
but that's kind of what's out there.
link |
And there is some decent scientific literature
link |
to support the fact that it liberates
link |
some of the bound testosterone
link |
and allows more free testosterone to be available.
link |
Some of the reported quote-unquote side effects
link |
are things like excessive alertness and insomnia
link |
if it's taken too late in the day and so forth.
link |
But I encourage you to explore that further
link |
if increasing free testosterone
link |
is something that you're interested in doing.
link |
examine.com includes a lot of other things
link |
that can increase testosterone.
link |
One of the things that's been purported
link |
to free up testosterone in the blood
link |
are things like nettles, stinging nettles.
link |
Although I should point out that the literature points
link |
to stinging nettle also having some fairly potent effects
link |
on the prostate and on the liver.
link |
And so it might be a tricky molecule,
link |
maybe not an attractive one for people to take.
link |
So we talked about creatine, we talked about Tonga Ali.
link |
It's clear that boron, which is really interesting,
link |
believe it or not, I think boron comes from,
link |
I think these were like meteors that landed on earth
link |
that now they extract boron.
link |
It's one of these crazy stories that when you look at it,
link |
you go, how could that possibly be?
link |
But there's actually, that's how it works.
link |
That boron, there's some scientific support for it
link |
freeing up more testosterone.
link |
And again, freeing up testosterone
link |
may be exactly what you want.
link |
I just don't think that we should demonize
link |
these carrier proteins like albumin and SHBG.
link |
In fact, albumin is very important for testosterone
link |
to be able to make it into the brain
link |
to have some of the pro-androgenic effects
link |
on the cognitive effects of testosterone,
link |
because in both males and females,
link |
testosterone can shift these behaviors
link |
like mate-seeking, reductions in anxiety and so forth
link |
that we talked about before, only by making it
link |
And there is this thing called the blood-brain barrier,
link |
which is fascinating and deserving of an entire episode also
link |
and getting molecules across the blood-brain barrier,
link |
even if they're sex steroid hormones,
link |
which are lipophilic and can pass through cell membranes,
link |
requires carriers.
link |
And those carriers often are bound to or include albumin.
link |
And so it's not the goal to free up all your testosterone,
link |
but getting free testosterone into a range
link |
that works for your particular goals and needs
link |
is an attractive one.
link |
And that's why we're discussing these particular tools.
link |
The amounts of boron that people take,
link |
and you can find this again on PubMed or Examine,
link |
but people take a couple grams of it a day.
link |
I'm not aware of any specific side effects,
link |
but you always, always, always want to examine
link |
for the particular side effects.
link |
And people with different backgrounds and conditions,
link |
as we talked about for menopause and estrogen,
link |
have to be careful,
link |
because when you're starting to modulate hormones,
link |
you're starting to modulate not just the tissues
link |
that thrive on binding of those hormones,
link |
but remember, the reason why there's so much breast cancer,
link |
and there's a reason why there's so much testicular cancer,
link |
is that any tissue that undergoes
link |
rapid reproduction of particular cells,
link |
so there's a lot of reproduction of cells
link |
and shedding of uterine lining,
link |
and the reproduction of cells and eggs in the ovary,
link |
and in the testes, there's the production
link |
of Leydig and Sertoli cells,
link |
and there's this kind of ongoing production of sperm,
link |
that's why those tissues are particularly vulnerable
link |
to the development of cancers.
link |
And many of those cancers are androgen-sensitive.
link |
That's why one of the major treatments
link |
for prostate overgrowth or prostate cancer
link |
is to give antiandrogenic drugs, okay?
link |
It's not just a shutdown,
link |
all things related to being androgenized,
link |
it's really about trying to prevent testosterone
link |
from encouraging growth of tumors.
link |
So I want to really emphasize the caution there,
link |
because it is easy when thinking about
link |
optimizing estrogen and testosterone to just think,
link |
oh, more is better, more is definitely not better,
link |
and it's not just because they can aromatize
link |
or convert into other things,
link |
it's because cancers or any tissue
link |
that has a lot of turnover of cells
link |
is going to thrive on androgen,
link |
anything that promotes growth,
link |
it's going to thrive on estrogen.
link |
Remember, brain tissue doesn't turn over that much,
link |
there isn't really much production of new neurons,
link |
brain cancers happen, but they're kind of rare,
link |
and when they do happen, they tend to be glial cells,
link |
which have a lot of proliferation.
link |
Glial cells can proliferate,
link |
adult neurons don't create more of themselves,
link |
they don't create more neurons in general,
link |
except in a few places in the brain and body.
link |
So any tissue that recycles itself is prone to cancers,
link |
and those tissues thrive on androgens and estrogens
link |
to create more tumors,
link |
so you have to be careful
link |
anytime you're modulating hormones,
link |
especially androgens and estrogens.
link |
And in my scouring of the literature
link |
and looking at kind of what's out there
link |
and what people are talking about,
link |
and I also mean in the scientific literature,
link |
one of the things that is new to me anyway,
link |
probably not new to a lot of the gym rats out there,
link |
or the people that spend a lot of time on YouTube videos
link |
talking about androgens,
link |
are these, forgive me for butchering the name again,
link |
are these ectosteroids.
link |
So ectosteroids are molecules
link |
that come from things like spinach, believe it or not,
link |
that have a lot of similarity to the cholesterol molecule.
link |
The one that's being discussed a lot out there right now
link |
is something called turkisterone.
link |
I wish I knew why it was called turkisterone.
link |
Someone tell me why it's called turkisterone.
link |
Does it have anything to do with turkeys?
link |
I don't know why it's called turkisterone.
link |
Perhaps someone will know.
link |
In any case, these ectosteroids
link |
are similar enough to cholesterol.
link |
Remember, cholesterol is the precursor
link |
to testosterone, cortisol, and estrogen.
link |
And it appears that some of these ectosteroids
link |
do have bioavailability,
link |
or their metabolites are bioavailable.
link |
And this was something that for many years,
link |
people talked about whether or not insect hormones
link |
or hormones from other species
link |
could actually be used by humans,
link |
or whether or not it would have any effect at all.
link |
And it's pretty clear,
link |
based on a study that I was able to find,
link |
there's a paper that came out in 2019.
link |
It's a comparative study in the archives of toxicology.
link |
This is Isenman et al., I-S-E-N-M-A-N-N et al.,
link |
that talks about the ectosteroids
link |
and was given in conjunction with strength training
link |
or no strength training.
link |
This is a 10-week intervention.
link |
And their conclusion is that these ectosteroids
link |
had a fairly significant, above placebo controls,
link |
increases in muscle mass, strength, hypertrophy effects,
link |
all the sorts of things that one would expect
link |
with increases in androgen.
link |
Their conclusion of this study is not my conclusion,
link |
although I may or may not agree with them.
link |
This isn't about my opinions.
link |
It's just, I want to be clear,
link |
these are their words, not mine.
link |
But they say that, in their words, quote,
link |
"'Our results strongly suggest the inclusion of ectosteroid
link |
in the list of prohibitive substances.'"
link |
So they're saying these things are so powerful
link |
that they should be on the list of banned substances,
link |
which might be upsetting to some,
link |
or some of you might be thinking, well, who cares?
link |
The whole issue of augmenting hormones in sports
link |
is a very interesting issue.
link |
In fact, if you just want a little anecdote about that,
link |
I can't reveal names here, of course,
link |
but what I learned recently was very surprising to me,
link |
which is that many athletes in pro sports
link |
are taking testosterone,
link |
and they are able to do that legally,
link |
not just because it's available by prescription,
link |
but they are allowed to do that
link |
under the rules of their sport,
link |
in the fine print that no one, including me, had ever seen,
link |
if they've had an injury.
link |
So if athletes are injured,
link |
then it opens up the door for certain forms
link |
of testosterone augmentation,
link |
and other types of augmentations
link |
that are not available to them if they're not injured,
link |
which always makes me wonder now,
link |
when I see them getting injured,
link |
whether or not that's an attempt to get some of the support,
link |
because there's absolutely no question
link |
that estrogens and testosterone modulate gene expression,
link |
modulate strength, modulate the way the brain works,
link |
modulates our relationship to effort and anxiety, et cetera.
link |
And while we're talking about supplementation,
link |
the effects of supplementation,
link |
I would say in some individuals can be quite dramatic,
link |
but they're always, always, always,
link |
except in extreme cases, going to be far subtler,
link |
excuse me, far more subtle, to use the proper English,
link |
far more subtle than would be, for instance,
link |
just in injecting testosterone
link |
or injecting estrogen, et cetera.
link |
So I think we should just be honest and upfront about that.
link |
So thus far, in terms of talking about optimizing hormones,
link |
and in the discussion of supplementation,
link |
I haven't really talked about things
link |
that actually affect the brain directly,
link |
that increase the pituitary output and things of that sort.
link |
We've mainly been talking about things
link |
that free up testosterone,
link |
or that increase estrogen at the level of the periphery.
link |
But if you remember way back to the beginning
link |
hormones are made in different locations in the body,
link |
and there are hormones that promote the release
link |
and the production of hormones
link |
from other tissues in the body.
link |
And one of the main hormones for that is luteinizing hormone.
link |
Luteinizing hormone, again,
link |
comes from the pituitary, circulates,
link |
and either goes to the ovary
link |
to promote various aspects of egg maturation,
link |
as well as production of estrogen,
link |
and to the testes to promote testosterone and sperm production.
link |
And the prescription version
link |
of increasing luteinizing hormone is something called HCG,
link |
or human chorionic gonadotropin,
link |
which has been synthesized
link |
and is now available as a prescription drug.
link |
It's taken in various contexts for increasing fertility,
link |
both by males and by females.
link |
It can increase, for all the reasons that now make sense,
link |
it can increase sperm production,
link |
it can produce ovulation frequency,
link |
it can produce the number of eggs even that are deployed
link |
in a given ovulation,
link |
although that's not always a good thing.
link |
It basically is pro-fertility, pro-testosterone,
link |
pro-estrogen, depending on your background.
link |
And what's interesting is HCG was initially synthesized,
link |
collected and synthesized from pregnant women's urine,
link |
and believe it or not, before it was synthetically made
link |
and sold as a prescription drug,
link |
there was actually a black market for pregnant women's urine
link |
where people would buy the urine.
link |
I don't know, I'm guessing that they probably
link |
just consumed it, which is weird.
link |
But in any case, human chorionic gonadotropin
link |
is now available as a prescription drug,
link |
and it's one of the things that many people use
link |
to increase testosterone or estrogen
link |
for increasing fertility.
link |
In some cases, I think it's used
link |
to increase sports performance
link |
or when people have shut down their gonads
link |
for whatever reason, because of excessive hormone therapies
link |
or they have some sort of,
link |
sometimes they're actually lesions to the pituitary.
link |
Sometimes people have a tumor in the pituitary.
link |
It's actually not common,
link |
but among brain tumors and neural tumors,
link |
it's one of the more common ones.
link |
And then you get deficiencies in LH and FSH,
link |
and so people will take HCG to stimulate the gonads.
link |
So there are a variety of reasons
link |
why these drugs were created.
link |
But there are certain supplements, not many,
link |
that apparently can increase luteinizing hormone
link |
and thereby can increase testosterone and estrogen.
link |
And one of the more well-documented ones
link |
is Fadogia agrestis, that's F-A-D-O-G-I-A,
link |
separate word A-G-R-E-S-T-I-S,
link |
which, at least according to the literature
link |
that I was able to find,
link |
can increase levels of luteinizing hormone
link |
and thereby levels of testosterone or levels of estrogen.
link |
And again, if an individual were to take Fadogia agrestis,
link |
what they would probably find is that
link |
testosterone and estrogen would increase
link |
in any one of any chromosomal or gonadal background.
link |
But remember, it's the ratio of both.
link |
So both, if someone has low estrogen, high testosterone,
link |
let's say they have testes just by way of example,
link |
then both of those would be expected to increase.
link |
And if someone has high estrogen and low testosterone,
link |
and let's just say has ovaries,
link |
then both of those would increase
link |
by taking Fadogia agrestis.
link |
The side effect profile of Fadogia agrestis
link |
hasn't really been documented, so it's a little unclear.
link |
I just want to emphasize
link |
that anytime someone's going to start taking supplements
link |
that, or modifying sex steroid hormones,
link |
getting blood work done is extremely important
link |
for safety reasons,
link |
and also just to know whether or not things are working.
link |
And because all of these things
link |
are subject to negative feedback,
link |
talked about this previously,
link |
but if testosterone goes high or too high,
link |
it can feed back and shut down luteinizing hormone,
link |
which will then shut down for the testosterone production.
link |
Likewise, if estrogens are going too high
link |
or they're going too high at various phases of the cycle,
link |
that can start to throw off various other hormones,
link |
including FSH, progesterone, LH.
link |
The menstrual cycle itself
link |
is a just absolutely exquisite balance
link |
of feedback of luteinizing hormone kept low and constant,
link |
at least for the first 14 days of the cycle.
link |
Then mid-cycle, there's a peak,
link |
and that's typically when ovulation occurs.
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That's why pregnancy is most likely
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during the middle of the 28-day cycle.
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FSH kind of goes up and then down across the first 14 days.
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So taking anything or really modifying one's estrogens
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or testosterone on that background of the menstrual cycle
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is really going to disrupt the way those things interact,
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and it's just such an exquisite feedback loop.
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So I'm not saying don't do that,
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but you definitely want to be aware of what you're doing,
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and blood draws are one way to do that.
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Monitoring cycles for ovulating females
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is another way to do that.
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And in males, having a good window
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into what's going on with testosterone,
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DHT, aromatase, estradiol, LH, et cetera, is just vital.
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And it's really part and parcel
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with the practice of thinking about optimizing
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these incredible things that we call sex steroid hormones,
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estrogen, and testosterone, and their derivatives.
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The list of supplements and molecules
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that can adjust estrogen and testosterone is vast,
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and I only touched on a few of these.
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I really tried to emphasize the ones
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for which there are human studies
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or that have mostly human studies,
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or maybe even just one human study.
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There are other things out there
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for which there are scientific data,
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things like bulbine natalensis,
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which definitely has support for increasing testosterone,
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but all the studies were in rats.
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I think there is some evidence in humans,
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but the evidence mainly comes in the form
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of what we call sponsored research,
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so companies paying for research,
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which is different than independent research
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by people who are not biased in terms of the outcome.
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And the reason I didn't throw out things
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like bulbine natalensis is they seem to have liver toxicity
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similar to high levels of anabolic exogenous steroids.
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There's some problems associated with them
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that make them important to think about
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if you're curious about this area and the endocrinology,
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but also somewhat precarious.
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And that's one category,
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so stuff that doesn't have a lot of evidence in humans
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might actually be dangerous.
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The other category of things that has been shown to improve
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or levels of, or increase, I should say,
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I don't want to say improve because it's up to you
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whether or not you want to increase
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or decrease estrogen and testosterone.
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That's highly individual, how could I know,
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are the things that are kind of housekeeping
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for production of estrogen and testosterone,
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things like magnesium, things like D3, things like zinc.
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Those are the things that are going to create
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an overall milieu of opportunity
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to produce normal endogenous levels
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rather than increasing endogenous levels further.
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And so I really want to highlight that there's a difference
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between taking something to create a kind of backdrop
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of general support and taking something
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that's going to create a big inflection
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in the levels of a given hormone.
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So once again, we covered a tremendous amount of information.
link |
We covered some basic science of hormones and pheromones,
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estrogen and testosterone and their derivatives.
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We talked about supplementation and behaviors,
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competition and parenting,
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and how all these things interact.
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And I hope that you'll come away from this
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with a deeper mechanistic understanding
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of how the brain and body are interacting
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to control the output and the ways
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in which these incredible things
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that we call sex steroid hormones work and influence us.
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I hope you'll also come away with some ideas
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of things that you can do
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in particular behavioral practices that can improve sleep
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and your relationship to light, et cetera,
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because those things really set the foundation
link |
not just for healthy steroid hormone output,
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but for all sorts of health effects
link |
and for both the psychology and the biology
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of your nervous system.
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So I'm sure there'll be many questions.
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There are many things that I couldn't get to today.
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I do try and limit these episodes to about 90 minutes,
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which is the optimal ultradian cycle for learning.
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It's a lot of information,
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but we've timestamped everything for you.
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So feel free to look over it in parts or circle back
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where you might want deeper understanding.
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And please put your questions in the comment section below.
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Please put suggestions for future episodes
link |
and things that relate to hormones
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in the comment section below.
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We do look at those and we do use them
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to inform the content for subsequent episodes.
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If you're enjoying and learning from this podcast,
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please subscribe on YouTube,
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or if you prefer, please subscribe on Apple and or Spotify.
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At Apple, you have the opportunity also
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Please also inform your friends, family, coworkers,
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from the information that we're covering.
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That really helps us grow our audience
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and bring more information to you.
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As well, please check out our sponsors
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mentioned at the beginning of each episode.
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And we also have a Patreon.
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That's patreon.com slash Andrew Huberman.
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At the Patreon, you can help support the podcast
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at any level that you like.
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As well, we've partnered with Thorne, T-H-O-R-N-E,
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which is a supplement company.
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The reason we partnered with Thorne
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is that they have the highest levels of stringency
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in terms of the quality of the supplements that they make
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and the quantity of the individual ingredients.
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Some things that's not always the case
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with various supplement companies,
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but Thorne is exquisitely good
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about the stringency of their products.
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They partner with the Mayo Clinic
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and all the major sports teams.
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If you want to check out Thorne
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you can go to thorne.com slash you slash Huberman.
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That's thorne, T-H-O-R-N-E dot com
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to get 20% off any Thorne supplements.
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In closing, I hope you'll leave today's episode
link |
with a much richer understanding of the mechanisms
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that control the endocrine and nervous system
link |
in the context of estrogen and testosterone,
link |
as well as take away various tools
link |
that you might choose to apply.
link |
And next week, we'll be back with another episode
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about the role of hormones
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and its important interactions with the nervous system.
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And that will, of course,
link |
include both mechanisms and tools as well.
link |
And as always, thank you for your interest in science.
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And as always, thank you for your interest in science.