back to indexHow Our Hormones Control Our Hunger, Eating & Satiety | Huberman Lab Podcast #16
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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,
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and I'm a professor of neurobiology and ophthalmology
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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 about science
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and science-related tools to the general public.
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In keeping with that theme,
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I'd like to thank the sponsors of today's podcast.
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Our first sponsor is Inside Tracker.
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Inside Tracker is a personalized nutrition platform
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that analyzes data from your blood and DNA
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to help you better understand your body
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and help you reach your health goals.
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I've long been a fan of getting blood work done.
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And the simple reason for that
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is that most of the things that you want to know
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about your health, such as hormones, metabolic factors,
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blood sugar levels, et cetera,
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can only be analyzed from blood.
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And nowadays, there are also excellent DNA tests
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that can also give you valuable information
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about what's going on at the cellular, molecular,
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even the neural circuit level within your brain and body.
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Inside Tracker makes getting blood and DNA tests easy.
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You can go to a testing site where they draw your blood,
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they take your DNA sample,
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or they can come to your home if you prefer that.
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As well, they have a really amazing dashboard.
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The dashboard lets you understand
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what your levels of various hormones
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and metabolic factors, et cetera, mean
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and what you should do about them.
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And I think that that's one of the main things
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that really separates Inside Tracker
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apart from other blood and DNA tests.
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Most tests, you get the results back,
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but there are no directives about what to do specifically
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in order to bring the numbers into the ranges
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that you would like for your goals.
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Inside Tracker makes all of that extremely simple
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and extremely clear.
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If you'd like to try Inside Tracker,
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you can go to insidetracker.com slash Huberman.
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And if you do that,
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you'll get 25% off any of Inside Tracker's plans.
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Use the code Huberman at checkout.
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That's insidetracker.com slash Huberman
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to get 25% off any of Inside Tracker's plans.
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Today's episode is also brought to us by Athletic Greens.
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Athletic Greens is an all-in-one
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vitamin mineral probiotic drink.
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I started taking Athletic Greens back in 2012
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and I've taken it ever since.
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So I'm delighted that they're sponsoring the podcast.
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The reason I started taking Athletic Greens
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and the reason I still take it now
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is that Athletic Greens really lets me cover
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all my nutritional bases in terms of vitamins,
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minerals, and probiotics.
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There's so much data now pointing to the fact
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that the gut microbiome and the gut brain access
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is important for metabolism and for endocrine health.
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The vitamins, minerals, and probiotics in Athletic Greens
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I do take other supplements, but with Athletic Greens,
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I know that I've got all the foundational stuff handled.
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It also tastes really good, tastes fine on its own.
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You can mix it with water, which is what I do.
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I add a little bit of lemon juice or lime juice
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because I like a little tartness flavor in there as well.
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But most people just mix it with water.
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It mixes up super easily.
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I drink it once or twice a day, usually once mid-morning
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and once again in the afternoon.
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If you'd like to try Athletic Greens,
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you can go to athleticgreens.com slash Huberman.
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And if you do that, you can claim their special offer,
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There is now a ton of evidence that vitamin D3
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hormonal processes that are important for overall health
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So if you go to athleticgreens.com slash Huberman,
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you'll get the Athletic Greens,
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So once again, it's athleticgreens.com slash Huberman
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to get Athletic Greens, the vitamin D3K2,
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that's a year supply plus the five free travel packs.
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Today's episode is also brought to us by Monk Pack.
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Monk Pack is a company that makes keto-friendly snacks
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that taste incredible,
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but have just one gram of sugar or less.
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And indeed, they taste incredible.
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In fact, my production team here
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at the Huberman Lab Podcast teases me
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because I actually have to keep the boxes
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of Monk Pack bars in my basement,
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because otherwise I'll tear through all of them.
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I remember the first time I tasted it,
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I was like, all right, here we go, a keto bar.
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I'm not a big fan of bars in general.
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Most of them don't taste good to me.
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And I tasted the Monk Pack bars
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and they are absolutely awesome.
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They come in a lot of different flavors.
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I'm partial to the caramel sea salt one,
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but they also have sea salt dark chocolate,
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peanut butter dark chocolate.
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They have a bunch of flavors.
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They're all incredible.
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I've tried them all, which is why I keep them in my basement.
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As I've mentioned previously on this podcast,
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I'm neither keto nor carbo.
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I don't really follow a particular diet in that sense.
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I eat in a way that maximizes my alertness
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and my levels of focus during the day when I want to work,
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and that maximize my transition to sleep at night.
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So I basically eat low carb keto-ish during the day.
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And I know the ketonistas will say that I'm not in ketosis
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and I can manage to get into ketosis.
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But the main idea is I keep my carbohydrates low
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And then at night I do eat carbohydrates.
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So for me, the Monk Pack bars are a really good snack,
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usually in the afternoon, maybe with a cup of coffee,
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especially if I'm going to train soon after that,
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or if I just want a snack and I'm going to continue working.
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As I mentioned before, they're absolutely delicious.
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They also don't have any of the stuff that's bad for you.
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No soy, trans fat, sugar alcohols, artificial colors,
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all that stuff that we know we should avoid.
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you can go to Monk Pack, that's M-U-N-K, monkpack.com,
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and enter the code Huberman at checkout,
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and you'll get 20% off your first purchase
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of any Monk Pack product.
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and enter the code Huberman at checkout
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to get 20% off your purchase.
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This month, we're talking all about hormones.
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Hormones are incredible,
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and they control so many processes in the brain and body.
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Last episode, we talked about the role
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of estrogen and testosterone.
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Today, we're going to talk about how hormones
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impact feeding and hunger, as well as satiety,
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the feeling that you don't want to eat
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or that you've eaten enough.
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Now, it's important to understand
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that hormones don't work alone in this context.
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Today, I'm going to describe some hormones
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that have powerful effects on whether or not
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you want to eat more or less or stop eating altogether,
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but they don't do that on their own.
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They do that in cooperation with the nervous system.
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So today, I would say as much,
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or perhaps even more than any other episodes,
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we're going to hear a lot of biology,
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but there are multiple what I'm going to call entry points
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for tools that you can apply
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in order to regulate your levels of hunger,
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your meal timing, your levels of satiety,
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of not wanting to eat more,
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and many of this is actionable with behaviors,
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but of course, we're also going to talk about supplements,
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and we're actually going to talk about
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a little bit of brain machine interface,
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devices that can actually be involved
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in manipulating these incredible things
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that we think of as hunger and appetite and satiety.
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So the first thing that you need to know
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about the nervous system side,
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the neural control over feeding and hunger,
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is that there's an area of your brain
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called the hypothalamus.
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It's in the forebrain,
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which tells you it's in the front of your brain,
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and it's at the base of the forebrain.
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Now, the hypothalamus contains
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lots of different kinds of neurons
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doing lots of different kinds of things.
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There are neurons in your hypothalamus
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controlling sexual behavior,
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controlling body temperature,
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controlling circadian rhythms,
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the desire to sleep or be awake,
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even neurons controlling rage.
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There are actually neurons that if we were to stimulate them
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would send you or anyone into a rage.
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They're just powerful control centers
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for the brain and body.
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There's a particular area of the hypothalamus
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called the ventromedial hypothalamus.
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And it's one that researchers have been interested
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for a long time now in terms of its relationship
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to hunger and feeding.
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And the reason is it creates these paradoxical effects.
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What do I mean by that?
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What they found was that sometimes lesioning
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or disrupting the neurons in the ventromedial hypothalamus
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would make animals or people hyperphagic.
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They would want to eat like crazy.
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And other lesions in other individuals or animals
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would make them anorexic,
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would make them not want to eat at all.
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It would make food aversive.
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So that means that the ventromedial hypothalamus
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is definitely an interesting control station
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for hunger and feeding and satiety,
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but it doesn't really tell you what's going on
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at a deeper level.
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In fact, it's a little bit confusing or paradoxical.
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It turns out that there are multiple populations
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of neurons in there.
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We're going to talk about those.
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Some are promoting feeding
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and some are promoting not feeding or not eating.
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Now, the other neural component of all this
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that you need to know about
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actually has to do with your mouth.
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So there's an area of your cortex.
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So that's a little bit further up in your brain
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called the insular cortex.
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And it processes a lot of different kinds of information,
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mostly information about what's going on inside you,
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so-called interoception.
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The insular cortex has neurons that get input
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from your mouth, from the touch receptors in your mouth.
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An insular cortex has powerful control
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over whether or not you're enjoying what you're eating,
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whether or not you want to avoid what you're eating,
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whether or not you've had enough
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or whether or not you want to continue eating more.
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And that has to do, believe it or not,
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with the touch or sensation of eating.
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I'm very familiar with this.
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I'm one of these people I love eating so much
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that I just like the mere act of chewing.
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I like celery sticks enough.
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I'm not crazy about them, but they taste fine to me
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and I like chewing on celery sticks,
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but I actually just like chewing on them.
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I could eat all day long,
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except that it's not healthy to do that.
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But the mere act of chewing for me is very pleasurable.
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People who chew gum feel this way as well.
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And just as a point about gum or chewing,
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if you chew something like celery or cucumber slices
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or chew gum, provided it doesn't have any sugar
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or caloric content,
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it's not going to drive increased hunger.
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That generally isn't the case.
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But if you eat something with sugar,
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as we'll find out,
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it has a very specific action in the insular cortex
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and in other areas of your nervous system
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that promotes the desire to eat more.
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But the key point right now is to know
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you've got these two brain areas,
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the ventromedial hypothalamus,
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that's involved in hunger and lack of hunger,
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sort of an accelerator and a brake on feeding.
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And you have this insular cortex
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that gets input from your mouth
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and cares about chewing and the consistency of foods
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and all sorts of interesting things
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that are just very tactile.
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And I think most people think about the touch receptors on,
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excuse me, the taste receptors on the tongue,
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but we often don't think about
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the touch or tactile essence of food.
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The thing that comes to mind just now
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is I've gone to sushi several times
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and some people really like the urchin.
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I don't like the urchin, there's something about it
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that kind of creeps me out about the consistency.
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Other people love it.
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So it's highly individual and it's probably learned
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and there's some probably cultural background to this
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if you were raised eating urchin.
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Some people love that consistency or that touch.
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So touch has a lot to do
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with whether or not you want to eat or not.
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Now let's get back to the ventromedial hypothalamus.
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Sometimes it makes animals or people want to eat more,
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So what's going on there?
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There's a classic experiment that was done
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in which researchers took two rats
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and so-called parabios to them to each other.
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What that meant is that they did a little surgery
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and they linked their blood supply
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so that they were forever physically linked to one another
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and could exchange factors in the blood,
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but their brains were separate,
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their mouths were separate,
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and they essentially did everything separately
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except that they were linked to one another.
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So they had to walk together and go to the same places
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in order to do it.
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This parabiosis experiment
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revealed something really important.
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When they lesioned the ventromedial hypothalamus
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in one of the rats that was connected to the other rat,
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that rat got very, very fat.
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It's just really obese, huge rat, super rat, jumbo rat.
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The other one, however, got very thin.
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It actually lost weight
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despite consuming the same amount of food that it had
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prior to the other one getting the lesion.
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So what does this tell us?
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This tells us that there's something in the blood
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that's being exchanged between the two animals
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because it was their blood supply that was linked,
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and that tells us that there's hormone or endocrine signals
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that are involved in the desire to eat
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and hunger and appetite.
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And so next, we're going to talk about
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what those endocrine signals are,
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and then I'm going to immediately point
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to some entry points that you can use,
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and you can use these
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even if you're not parabiosed to anything,
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and that can allow you to time your meal frequency
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and predict when you're going to be hungry or not,
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as well as drive up appetite.
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Believe it or not, there are people out there
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who are trying to eat more,
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although I think far many more people are trying to eat less
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because nowadays, the data just point to the fact
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that there is essentially an epidemic of diabetes,
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type 2 diabetes, and obesity.
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And most everyone agrees now
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that maintaining a healthy body weight
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and body weight composition
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is one of the best paths to longevity
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and to just feeling very good
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and actually being able to think.
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Cognitive functioning is actually linked
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to levels of adipose tissue and so forth.
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So let's talk about the endocrine factors
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that regulate feeding, hunger, and satiety.
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One of the really exciting things to emerge
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in the science of feeding and appetite in the last 20 years
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is the discovery of another brain area,
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not just the ventromedial hypothalamus,
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but it's an area of the brain called the arcuate nucleus.
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And the arcuate nucleus
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has some really fascinating sets of neurons
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that release even more incredible molecules
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and chemicals into the blood.
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And these chemicals act as accelerators
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on feeding and appetite or breaks.
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And the really cool thing
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is that you can actually control these molecules
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through simple behaviors.
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And once you understand what these molecules are,
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you'll start to understand why that's the case
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and the control points that you have right now
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in order to control your appetite in either direction,
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increase or decrease.
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So first of all, there are a set of neurons
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in this arcuate nucleus called the PMOC neurons, okay?
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I don't want to get into what the acronym stands for,
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but I'll do it anyway.
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It's the pro-opiomelanocortin system, okay?
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So these are PMOC neurons, pro-opiomelanocortin.
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And if you heard melano,
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that should tell you it has something to do with pigmentation
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in skin cells or in hair cells,
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pigmentation of some sort because of melanin.
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Last episode, I talked a little bit
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about the relationship between light, dopamine, and melanin.
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So you should already be thinking, wait,
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melano means it probably has something to do
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with that system, and indeed it does.
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Now, the POMC neurons make something called alpha-MSH,
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melanocyte stimulating hormone.
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Alpha melanocyte stimulating hormone.
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If you don't want to remember any of the other acronyms
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and terms I've talked about this episode so far,
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do try and remember MSH, okay?
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Mouse, Sam, hamster, MSH, okay?
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MSH reduces appetite.
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And it's a powerful molecule, all right?
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So just put that on the shelf, MSH reduces appetite.
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Now there's another population of neurons
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in the arcuate nucleus called the AGRP neurons.
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And there, I'm truly not going to read you
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what that stands for because it's related
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to the mouse strain it was first identified in,
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but humans have these cells as well, but AGRP neurons.
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The AGRP neurons stimulate eating.
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And anytime you are approaching food
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or you feel some excitement about food or anxiety,
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because some people actually experience
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a kind of heightened anxiety,
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some people actually get a little bit of a resting tremor
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before they eat, even if they don't have
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any sort of eating disorder,
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there's kind of a ramping up of autonomic activity.
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That's largely due to the activity of these AGRP neurons.
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So the activity in these AGRP neurons goes way up
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when animals or people are starved.
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And I don't mean starve for long periods of time,
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but I mean, when they haven't eaten for a while.
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And the activity of MSH,
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the release of MSH goes up when we've eaten.
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However, there are other things that will stimulate
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the release of things like MSH.
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So just briefly, the experimental evidence.
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If you kill AGRP neurons, animals and people stop eating.
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There are people who have lesions, they just stop eating.
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They become anorexic.
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That's actually, I know you're familiar with anorexia
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as a clinical term, but that's actually a term
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that's used in the scientific literature
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about a pattern of behavior, okay?
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As well as a clinical term, of course.
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If you were to stimulate the AGRP neurons,
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animals or people eat like crazy.
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They will eat to the point where they burst,
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which just sounds horrible, but it just tells you
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this is the accelerator on eating.
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And yes, as relationship to the ventromedial hypothalamus
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I talked about earlier,
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but I don't want to go back there just yet.
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We will circle back.
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So melanocyte stimulating hormone,
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such an interesting hormone.
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This thing can shut down the desire to eat.
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The melanocyte stimulating hormone
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is released from the medial pituitary.
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We talked about the pituitary last time.
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This is a gland that is very closely positioned
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to the hypothalamus.
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Actually, some of the hypothalamus neurons
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actually project their neural connections
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directly into the pituitary to release things
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like gonadotropins and luteinizing hormone,
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stuff we talked about last time
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in reference to testosterone and estrogen.
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But MSH is released from the medial portion
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of the pituitary, and it stimulates the desire
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to not eat, to cease eating.
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What's really interesting is that melanocyte
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stimulating hormone is activated by ultraviolet light.
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And it's not activated by ultraviolet light to the skin
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or directly to the pituitary.
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It's activated by ultraviolet light to the eyes.
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Now, if you've been watching this podcast
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or listening to this podcast for any period of time,
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or you've heard me on other podcasts,
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or you follow my Instagram,
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I am a big fan of this whole thing of getting morning light
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in order to synchronize circadian rhythms, et cetera,
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avoiding light in the middle of the night.
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This is yet another reason why getting ample light,
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ideally sunlight, but it could be other sources of UV light
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to the eyes, stimulates MSH,
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this has been shown over and over again,
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and keeps the desire to eat or appetite in check
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in healthy ranges.
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This is also why in the spring and summer months,
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animals and people eat less.
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Now, for hibernating animals, it's different
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because the bear hibernating,
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actually bears don't truly hibernate technically
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by scientific criteria, they don't hibernate,
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but they go into a kind of torpor.
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The hibernating animals, they don't eat much
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because they're in burrows or dens
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or they're just wrapped up in a little ball
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or whatever it is that hibernating animals do.
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So they're of course going to eat far less in the winter,
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but that's a unique scenario.
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We are not hibernating animals,
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but humans generally have greater appetite
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in the cold winter months.
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It's not just because of the holidays
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and the abundance of food that we're presenting ourselves
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with, but when we get a lot of sun,
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our appetite is reduced or at least it's easier to control.
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And that is due in part,
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because if you're getting ample sunlight to the eyes,
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it's converted into a signal for the MSH neurons,
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the neurons that release MSH, excuse me,
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these POMC neurons release MSH,
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and then MSH can bind its receptors
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and can keep the brake on appetite in check.
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So the takeaway tool from this
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is make sure you're getting enough light,
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not just in the morning, but throughout the day.
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And yes, it has to be light to your eyes
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and blasting your eyes with sunlight or artificial light
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to the point where it's damaging or painful
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won't accelerate or improve this process.
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It's about getting photons, ultraviolet light to the eyes
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consistently throughout the day.
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That's best accomplished by not wearing sunglasses
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provided you can do that safely.
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And if you don't have access to enough sunlight,
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then you can do this with artificial light.
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This also points again to our old friends, the blue blockers.
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Many people know I'm not a huge fan of blue blockers,
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especially not during the daytime
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because they block a lot of the UV
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and shorter wavelength light that you want
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and need to create alertness,
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but also to create release of MSH from the medial pituitary.
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Now, there are people out there, subcultures,
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that actually inject MSH,
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that are taking MSH or things similar to it.
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I am not suggesting people do that,
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but there are three main consequences of doing that.
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First of all, it reduces appetite, no surprise there.
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They're actually using it as a dieting drug.
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This is kind of in the underground.
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I don't know what the legal status is.
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And again, I'm not promoting that people do it.
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Two, it makes them very, very tan, which makes sense, right?
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Melanocyte stimulating hormone.
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And the third is it purportedly, never tried it,
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purportedly sends libido through the roof
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to the point where it's actually distracting
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for other activities.
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It actually can create priapism,
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which is a kind of chronic erection in males
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to the point where it actually can be physically damaging
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So this is a drug of,
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or I don't know whether or not to call it a drug.
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It's a substance that one can regulate with healthy levels,
link |
with sunlight and perhaps artificial UV light.
link |
I have not heard much about treatments for obesity
link |
involving getting ample sunlight or getting ample UV light,
link |
but to me, the logic is just very clear.
link |
And so if you're pursuing those avenues,
link |
you certainly should talk to your physician,
link |
but you might want to think about
link |
how some of those logic hangs together.
link |
Absolutely fascinating hormone.
link |
I think most people aren't aware of it.
link |
And the subcultures that are aware of it
link |
are using it to very particular endpoints,
link |
and they're using it at super physiological levels.
link |
That's enough about that, because I really don't know.
link |
I've talked to a few people in research,
link |
believe it or not, for this podcast.
link |
I reached out to a few people and asked whether or not
link |
these side effects, in air quotes,
link |
that I've heard about are true, and indeed they're true.
link |
But again, that's super physiological.
link |
Controlling MSH, it's actually alpha MSH levels
link |
through viewing ultraviolet light seems like an interesting
link |
and mechanistically logical thing to do
link |
if your goal is to keep appetite in check.
link |
So MSH inhibits hunger.
link |
Next, let's talk about a hormone peptide
link |
that activates hunger.
link |
And this is a really interesting one,
link |
because it relates to when you get hungry,
link |
in addition to the fact that you get hungry at all.
link |
And it's called ghrelin.
link |
It's spelled G-H-R-E-L-I-N.
link |
Ghrelin is released actually from the GI tract.
link |
And its main role is to increase your desire to eat.
link |
And it does that through a variety of mechanisms.
link |
Part of that is to stimulate some of the brain areas,
link |
the actual neurons that make you want to eat.
link |
In addition, it creates food anticipatory signals
link |
within your nervous system.
link |
So you start thinking about the things
link |
that you happen to like to eat
link |
at that particular time of day.
link |
This is fascinating.
link |
Ghrelin is sort of like a clock, a hormonal clock
link |
that makes you want to eat at particular times.
link |
Now, the signal for ghrelin
link |
is reduced glucose levels in the blood.
link |
We're going to talk a lot today about glucose and insulin,
link |
ways to manage glucose and insulin.
link |
But for now, the simple version of this
link |
is you normally want your glucose
link |
to be in a kind of modest range.
link |
And I'll explain what that range is in a little bit.
link |
But if it drops too low, ghrelin is secreted from your gut.
link |
It activates neurons in your brain at various locations,
link |
including the PMOC neurons
link |
and the other neurons of the arcuate.
link |
It also activates the VMH in particular ways.
link |
And it might even activate some of these neurons
link |
that are in the periphery in your mouth
link |
that actually make you kind of salivate
link |
and want to eat, right?
link |
We all know about the famous Pavlovian experiments
link |
the Pavlov's dogs, they start salivating to the bell
link |
after the bell was presented with food, you remove the food
link |
and then just the bell can stimulate the salivation.
link |
We become Pavlovian at times,
link |
but rarely has it ever discussed
link |
what the neural pathways for that are.
link |
And it turns out that these hormones
link |
that are secreted from the gut
link |
can stimulate the neurons to create a sensation
link |
and a desire for certain foods at certain times of day.
link |
You've done this experiment.
link |
If you are somebody who eats breakfast at more or less
link |
the same time each day,
link |
let's say 8 AM plus or minus 20 minutes,
link |
and then you eat lunch 1230 plus or minus 20 minutes,
link |
or let's say you're somebody like me
link |
who typically skips breakfast and just eats lunch
link |
usually around 1130 or 12 or something like that,
link |
your ghrelin secretion will start to match
link |
when you typically eat.
link |
And it does that and it's able to override
link |
the low levels of glucose in your bloodstream
link |
because the ghrelin system also gets input
link |
from a clock in your liver
link |
that is linked to the clock in your hypothalamus
link |
And what this means is if you eat at regular meal times,
link |
you will start to get hungry a few minutes
link |
before those meals times.
link |
If you've ever wondered why
link |
your stomach kind of starts to growl
link |
because it's a particular time of day,
link |
you're like, oh, I must want to eat.
link |
Well, that's ghrelin.
link |
And for those of you that don't know
link |
why your stomach growls,
link |
I'll also tell you that today.
link |
It's actually really interesting.
link |
It's not at all what you expect.
link |
And it's not just the gurgling of liquids in your stomach.
link |
That's not what it is.
link |
It's actually a muscular phenomenon.
link |
So ghrelin is secreted as a kind of food anticipatory signal
link |
to get you motivated to go eat at regular times.
link |
So nowadays there's a lot of interest
link |
in intermittent fasting.
link |
There's also a lot of interest in just what meal plans
link |
and schedules and what to eat in general
link |
in order to maximize one's health and wellbeing.
link |
And people have all sorts of cosmetic reasons
link |
and brain reasons and metabolic reasons
link |
for wanting to control this kind of stuff.
link |
So let's make it really simple
link |
by first looking at the extremes.
link |
Some people need to eat every two or three hours.
link |
They feel this, I need to eat every two or three hours
link |
or else their blood sugar drops.
link |
In general, blood sugar doesn't drop so low
link |
that they truly need to eat
link |
in order to alleviate a blood sugar issue.
link |
Although sometimes that can happen.
link |
Some people are truly hypoglycemic, low blood sugar.
link |
But most people, as the blood sugar starts to head down
link |
towards the low-ish ranges, ghrelin is secreted.
link |
And so for those people, not eating on the clock
link |
is very disruptive to them
link |
because it activates these neurons in the brain.
link |
For people who eat once a day or twice a day
link |
or tend to shift their meals, they might eat a lot,
link |
but during a limited so-called feeding window,
link |
it's kind of interesting, humans now eat
link |
and talk about foods in ways that for years
link |
I used to hear about in classes and courses
link |
and research lectures about feeding animals,
link |
restricted feeding windows.
link |
And we owe a great deal of gratitude to Sachin Panda,
link |
who was a colleague of mine when my lab was in San Diego
link |
at the Salk Institute, who really is one of the pioneers
link |
of this restricted feeding window work
link |
and has done a beautiful work.
link |
He has a book that's excellent called the Circadian Code
link |
that I highly recommend.
link |
And he's done a lot of important work on neurons
link |
in the retina that control circadian timing,
link |
but also the relationship
link |
between feeding windows and health.
link |
And he's sort of the major proponent out there,
link |
among the major proponents, I should say, of circadian eating
link |
that means eating during the daytime, not at night,
link |
or intermittent fasting, restricting feeding windows
link |
to anywhere from four to six to eight hours.
link |
I'll use myself as an example of the transition
link |
from regular feeding schedule to more intermittent-ish
link |
fasting, although I don't really fall
link |
into true intermittent fasting.
link |
So I was one of these people that just got so accustomed
link |
to waking up and eating about an hour after I woke up
link |
that to go from eating every three or four hours
link |
to eating twice a day, lunch and dinner,
link |
maybe a couple of snacks in the afternoon or something,
link |
at first was excruciating.
link |
I remember thinking like,
link |
this is really brutal, pushing out, feeding.
link |
I didn't think I could exercise unless I had eaten first.
link |
We now know that during most all forms of exercise,
link |
unless you're really focused on optimal performance,
link |
like you've got to hit key lifts
link |
or you have to sprint at your maximum speed,
link |
and maybe even then, that you can exercise faster just fine
link |
because you're mainly relying on sources
link |
like glycogen from the liver,
link |
some undigested food sometimes,
link |
as gross as that might seem, it's true,
link |
as well as body fat if the exercise bout is extremely long.
link |
But what that means is that if you suddenly go from eating
link |
on a very regular schedule to skipping a meal
link |
or pushing your meal timing out or shifting at all,
link |
you're going to have ghrelin in your system.
link |
And that ghrelin is going to stimulate the desire to eat
link |
by acting at the level of your brain.
link |
And it is indeed at that point, just mental.
link |
When we hear about just mental, just physical,
link |
it's really kind of the same thing
link |
because it's all chemicals, brain and body,
link |
but it's the stimulation of neurons that anticipate feeding.
link |
You're stimulating the arcuate nucleus neurons
link |
that make you want to eat those AGRP neurons.
link |
So ghrelin stimulates the AGRP neurons,
link |
which makes you want to eat.
link |
So what can you do with this?
link |
What this means is if you want to start shifting
link |
your feeding schedule to one where you're not eating
link |
quite as frequently, and there are some advantages to that
link |
that aren't just in the biochemistry and health related,
link |
cellular health related things,
link |
but some of them include not having to think about
link |
or buy food, right?
link |
You actually don't have to think about food all day
link |
if you're not eating so often.
link |
The other is it gives you a far more social flexibility.
link |
You can go to a noon meeting if you have to,
link |
or you can go out to dinner at a particular time.
link |
And I guess it makes it kind of tough
link |
if you want to meet somebody for breakfast,
link |
because then you're the dork who's just like
link |
sipping black coffee and like refusing everything.
link |
But anyway, I've been that dork.
link |
So it's one of those things you just kind of work with.
link |
But the fact of the matter is ghrelin secretion,
link |
because of its relationship to the nervous system,
link |
can be shifted by about 45 minutes per day.
link |
Now it's going to vary.
link |
Some of you have more so-called willpower, you know,
link |
but if you really want to just start pushing
link |
that first meal out or shifting it in any direction,
link |
some people might want to eat in the early part of the day
link |
and not in the evening,
link |
trying to shift the meal times out,
link |
the spacing by about 45 minutes
link |
is what the neural circuits that link the ghrelin system
link |
to the neural circuits that control feeding
link |
really can handle, because it's a form of neuroplasticity.
link |
And so what this would look like is
link |
if you normally you eat breakfast at eight o'clock,
link |
plus or minus 20 minutes,
link |
and you want to start eating your first meal at noon,
link |
you would take maybe four or five days
link |
and just start pushing the meal out
link |
by about 45 minutes to an hour each day,
link |
so it's not quite as painful.
link |
Or you can just take the plunge and just do it all at once.
link |
I have a colleague who was a neurosurgeon at Stanford,
link |
came up through my lab, he's now at Neuralink,
link |
and he has a great practice.
link |
He keeps his ghrelin system at random.
link |
What he does is he skips one meal per day,
link |
and he makes his external schedule dictate that.
link |
So sometimes he skips breakfast,
link |
sometimes he skips lunch,
link |
sometimes he skips dinner,
link |
he just skips one of the three major meals per day.
link |
And in doing that,
link |
the ghrelin system is always kind of kept off kilter,
link |
and it probably also allows him
link |
to have a lot of neural flexibility,
link |
what we call top-down control,
link |
just the knowledge,
link |
oh, the hunger I'm feeling isn't necessarily hypoglycemia,
link |
and in his case, it's almost certainly not,
link |
and therefore what I'm feeling here
link |
is an activation of these AGRP neurons,
link |
and therefore I can push my meal schedule
link |
around however I want.
link |
Now, I should mention that top-down mechanisms
link |
are powerful, belief, motivation,
link |
these things can really shift neural circuits.
link |
We're going to talk more about that a little bit later.
link |
But there are also people who are genuinely hypoglycemic
link |
and that need to take really good control
link |
of their blood sugar levels and try and keep them stable.
link |
And so, of course,
link |
you want to do what's medically safe for you.
link |
I'm not at all recommending that people
link |
that suffer from hypoglycemia suddenly
link |
disrupt their blood sugar patterns in any direction.
link |
That wouldn't be healthy.
link |
But for most people out there
link |
who have reasonable blood glucose levels,
link |
it's kind of interesting and kind of fun
link |
to play with these parameters
link |
in order to optimize what you want to do.
link |
And sometimes that might change
link |
across the year with schedules.
link |
Many people find great benefit in having flexibility
link |
over when they eat.
link |
Regularity of eating equals regularity of ghrelin secretion
link |
equals regularity of activity of these AGRP neurons,
link |
meaning you will be hungry at very regular intervals.
link |
So that's something that you can work with.
link |
It's grounded in deep mechanism of hormone
link |
and neural systems.
link |
And there's a lot of modern research
link |
to support what I just said.
link |
So if MSH inhibits feeding, makes us want to eat less,
link |
and ghrelin makes us want to eat more,
link |
there's another hormone called CCK, cholecystokinin,
link |
that is potent in reducing our levels of hunger.
link |
Now, I learned about CCK back when I was an undergraduate,
link |
so well over 20 years ago, when it was first discovered,
link |
and there was a lot of excitement about CCK at that point
link |
Anytime there's a molecule or a chemical
link |
discovered in the brain or body that can suppress feeding,
link |
the diet industry just goes wild.
link |
They think, okay, this is going to be the thing
link |
that's going to allow people to move from being obese
link |
to losing all sorts of unhealthy weight, et cetera.
link |
A similar phenomenon was observed with leptin.
link |
Leptin is a hormone that's made by body fat
link |
that signals to the brain when there's a lot of body fat,
link |
and in animals, injections of leptin
link |
can make fat animals thin.
link |
They lose a lot of adipose or fat.
link |
In humans, it didn't work out that way.
link |
It just, the studies were done,
link |
and leptin was successful in treating a certain rare form
link |
of diabetes, but it really wasn't very potent
link |
as an anti-obesity drug.
link |
Similarly, CCK has been looked at as an obesity drug,
link |
something to reduce obesity,
link |
but it had some pretty unhappy side effects,
link |
actually caused some pretty serious side effects.
link |
Now that's as a drug.
link |
However, CCK, when released at normal levels by your gut,
link |
has a powerful effect in suppressing appetite
link |
for a period of time, and there are healthy
link |
and direct ways to activate CCK.
link |
Now, CCK is in the GI tract.
link |
It's released from the GI tract,
link |
and its release is governed by two things.
link |
One is a subset of very specialized neurons
link |
that detect what's in the gut,
link |
the specific contents of the gut,
link |
and by certain elements of the mucosa,
link |
the mucus lining of the gut and the gut microbiome.
link |
So what's really interesting is that CCK is stimulated
link |
by fatty acids and particular fatty acids
link |
that we'll talk about, amino acids
link |
and particular amino acids that we'll talk about,
link |
as well as by sugar.
link |
Now let's put sugar on the shelf for a moment.
link |
We're going to talk a lot about sugar
link |
because if CCK inhibits appetite and reduces feeding,
link |
and it can be triggered by fatty acids, amino acids,
link |
or sugars, then you might say,
link |
well, then eating a lot of sugar
link |
should make us not want to eat more,
link |
but we all know that eating sugar
link |
makes us want to eat far more.
link |
That's the role of a lot of sugars,
link |
and that has to do with a separate mechanism
link |
we'll talk about today.
link |
So which fatty acids in the gut stimulate the release of CCK?
link |
It turns out it's the omega-3 fatty acids,
link |
the ones that come from algae or krill or fish oil.
link |
I talked about this in the episode on nutrition
link |
and some of the things related to the gut microbiome,
link |
but I'm going to revisit that now.
link |
Omega-3 fatty acids and conjugated linoleic acid, CLA,
link |
either from food or from supplements,
link |
stimulate the release of CCK,
link |
which then reduces or at least blunts appetite.
link |
And I'm not talking about blunting appetite
link |
to anorexic levels where you don't want to eat at all.
link |
I'm talking about regulating appetite
link |
to the point where animals and people don't over-consume.
link |
So it's keeping appetite at a healthy level.
link |
The other thing that stimulates CCK that I mentioned
link |
So when we eat, we have the ability
link |
to break down different macronutrients,
link |
you know, carbohydrates, fats, or proteins
link |
into sugars and glucose that then we can convert to ATP
link |
and all that stuff from the Krebs cycle from high school.
link |
We're not going to go into that today.
link |
That's for a future episode.
link |
But amino acids are one of the things
link |
that we are eating for.
link |
Amino acids both can be used as energy
link |
through a process called gluconeogenesis
link |
of converting proteins into energy,
link |
or those amino acids can be broken down
link |
and then rebuilt into things like preparing, excuse me,
link |
repairing muscle tissue,
link |
as well as other forms of cellular repair.
link |
They're involved in all sorts of things
link |
related to protein synthesis.
link |
What does this mean?
link |
If we eat the proper amino acids at the proper levels,
link |
if we ingest omega-3s and CLAs, conjugated linoleic acids,
link |
at the proper levels, or get them from supplements,
link |
there is a blunting of appetite.
link |
Appetite is kept clamped and we don't become hyperphagic.
link |
We tend to eat within healthy or normal ranges.
link |
So this is very important
link |
because most people don't understand
link |
that when we're eating,
link |
we are basically fat foraging and amino acid foraging.
link |
And there are several studies now have shown
link |
that people and animals will essentially eat
link |
until they feel they've consumed enough omega-3s,
link |
omega-6s, CLAs, and certain amino acids.
link |
In other words, even if it's not conscious,
link |
we are eating until we trigger the activation of CCK.
link |
Now, there are other reasons why we shut down eating too.
link |
Literally, the volume of food in our gut can be large
link |
and we can feel very distended.
link |
That's the physical reason, obviously.
link |
There are other reasons.
link |
Maybe we just have top-down control.
link |
We have knowledge that this is the end of the meal
link |
and we stop because we have to go back to work
link |
or to a meeting, or we tell ourselves that we've had enough.
link |
But at a subconscious level,
link |
the gut is informing the brain via CCK and other mechanisms
link |
when we've ingested enough of what we need.
link |
And these omega-3s and CLAs and certain amino acids
link |
are vital for sending out that signal
link |
that we've had enough.
link |
Now, which amino acids is actually really interesting?
link |
We have essential amino acids
link |
and we have non-essential amino acids.
link |
Among the essential amino acids,
link |
there's one in particular that can trigger the release
link |
of CCK very potently, and that's glutamine.
link |
Glutamine is a very interesting amino acid.
link |
First of all, it's been shown in a few studies
link |
to play a role in bolstering the immune system.
link |
It can increase the number of killer cells
link |
in the immune system.
link |
It is consumed in supplement form.
link |
People can take a teaspoon of glutamine
link |
or some people take glutamine throughout the day
link |
if they're really into it or for whatever reason
link |
they think they're battling off an infection
link |
or something of that sort.
link |
Glutamine can also, of course, be derived from foods.
link |
And you can just put into the internet,
link |
do an internet search and find out
link |
what foods are rich with glutamine.
link |
Some of the ones that I'm aware of off the top of my head
link |
are like cottage cheese and things of that sort,
link |
but other foods have glutamine as well.
link |
Once a threshold level of glutamine
link |
and other essential amino acids are reached,
link |
once the threshold level of these Alpha-3,
link |
excuse me, Omega-3 fatty acids and CLAs are reached,
link |
CCK is released and it helps reduce the activity
link |
of those AGRP neurons that promote feeding.
link |
So as you can see, feeding is an interplay
link |
between brain and body.
link |
And it's some of the micronutrients
link |
and even the breakdown of particular nutrients
link |
that's putting the accelerator
link |
or the brake on the feeding process.
link |
It's not just one thing.
link |
So from an actionable standpoint,
link |
you, we should probably all be trying to get
link |
our Omega-3, Omega-6 ratios correct anyway,
link |
because they are antidepressant.
link |
I talked about the peer-reviewed studies on that.
link |
They are healthy for the gut microbiome
link |
and we should be seeking sufficient glutamine.
link |
Now, whether or not you decide to supplement
link |
with glutamine or not is up to you.
link |
One of the reasons why one might want to do that,
link |
and again, you should always check with a doctor,
link |
especially if you have any predisposition to cancers
link |
or you have cancer, many cancers and tumors like glutamine.
link |
So that's something to note.
link |
But one reason why you might want to supplement
link |
with glutamine or consider eating foods
link |
that are rich in glutamine,
link |
isn't just to keep your appetite in healthy ranges,
link |
but as well, glutamine can actually reduce sugar cravings.
link |
So this is very interesting.
link |
I have a friend, he's an absolute chocolate sweets addict.
link |
He's a grown adult, but he eats candy and chocolate
link |
as if it was, you know, as if he was like a 14 year old kid
link |
hanging out at the local convenience store.
link |
It's really incredible.
link |
And he has probably a sugar addiction,
link |
but he's very aware of this
link |
and he's managed to kick all other addictions.
link |
So for whatever reason, it stimulates his brain and body
link |
in the ways that make him want more, but he hates this.
link |
It's actually quite frustrating for him.
link |
And he's somebody who cares a lot about his health.
link |
He took the approach that I know many other people have
link |
who know about this role of glutamine
link |
of taking a teaspoon or a couple of teaspoons of glutamine
link |
several times throughout the day,
link |
or anytime he craves sugar.
link |
And indeed, glutamine will reduce sugar cravings.
link |
Some people who are really on the kind of ketogenic front
link |
will mix it with a little bit of half and half
link |
and down that, because I guess it makes it taste better,
link |
it's a little bit chalky.
link |
So glutamine has some very interesting properties,
link |
but I think for most people that aren't suffering
link |
from adverse levels of craving,
link |
making sure you're getting the right omega-3s,
link |
that can come from a variety of sources.
link |
Check out the episode we did on nutrition
link |
if you want to learn more about that, and CLAs,
link |
and making sure that you're getting enough glutamine
link |
is going to be important for making sure
link |
that the CCK signal gets through.
link |
The one thing I do want to mention about glutamine,
link |
it's a minor effect, but it alone can have a small increase,
link |
excuse me, it alone can increase blood sugar.
link |
It's not a huge increase in blood glucose,
link |
but because the gut takes proteins
link |
and breaks them down into these amino acids
link |
and essentially looking for glutamine and things like it,
link |
other essential amino acids as well,
link |
when you ingest glutamine or branched-chain amino acids,
link |
there is a small but real increase in blood glucose,
link |
and that's because they are essentially food,
link |
and there I'm talking about the supplemental version.
link |
So just know glutamine can increase blood sugar slightly,
link |
especially diabetics should know that.
link |
It can reduce sugar cravings,
link |
and just know that what your gut is doing at a core level
link |
is it's forging, it's waiting,
link |
and it's trying to assess levels of omega-3 fatty acids,
link |
conjugated linoleic acid,
link |
and glutamine and other essential amino acids.
link |
You are essentially trying to eat to get these nutrients,
link |
and then a signal can be deployed up to your brain
link |
that you're not really interested in eating that much more.
link |
Whenever preparing an episode for this podcast,
link |
I'm always faced with a particular challenge,
link |
which is how many tools should I offer
link |
that involve doing something new,
link |
you know, a new behavior or a new exercise,
link |
supplements, something, things of that sort,
link |
and how many should be related to not doing things,
link |
It's never really fun to talk about all the things
link |
that we're supposed to avoid,
link |
but some of them are so powerful
link |
in light of the mechanisms of a given topic
link |
that I'd be remiss if I didn't mention them.
link |
So now you understand how hormones and peptides
link |
like CCK and ghrelin impact appetite.
link |
There's one particular aspect of food
link |
that can powerfully impact CCK,
link |
and I think most people,
link |
I'm guessing 99.9% of people out there
link |
are not aware of this,
link |
and it has to do with highly processed foods.
link |
There's a lot of reasons why one would want
link |
to avoid highly processed foods.
link |
In fact, if you're interested in that topic
link |
and the history of whole foods
link |
transitioning to highly processed foods in this country,
link |
I highly recommend you listen to a YouTube video
link |
by Dr. Robert Lustig.
link |
He's at University of California, San Francisco.
link |
It's very easy to find.
link |
Put Stanford, Robert Lustig.
link |
It was a talk hosted by Stanford.
link |
Gives a beautiful description of the history of this
link |
and why the food industry started packing in
link |
additional sugars and salts
link |
and turning foods into commodities.
link |
It's really fascinating.
link |
It has no conspiracy theory.
link |
It's just all scientific facts.
link |
It's really a wonderful lecture.
link |
It has millions of views, should be very easy to find.
link |
We can provide a link to that and we will.
link |
There's another reason to avoid
link |
highly processed foods, however,
link |
and that has to do with what's called emulsifiers.
link |
Now, many of you are familiar with emulsifiers
link |
even though you don't know it.
link |
When you put detergent in the laundry,
link |
that contains emulsifiers.
link |
The goal of that detergent is to bring together
link |
fatty molecules with water molecules
link |
and be able to dissociate them and break them up
link |
to get the stains out of clothes and things of that sort.
link |
There are a lot of emulsifiers put into processed foods.
link |
And those emulsifiers allow certain chemical reactions
link |
to occur that extends the shelf life of those foods.
link |
So it's like candy bars and cereals
link |
and all sorts of things that are in processed foods.
link |
The worst of which are the typical kind of pastries
link |
that you see at the convenience store,
link |
but this extends into chips of various kinds
link |
and even some meats of various kinds.
link |
They pack this stuff into meats.
link |
They have names like soy lecithin and other things.
link |
Why are emulsifiers bad?
link |
Okay, there are a lot of reasons why they're bad,
link |
but the reason why they're bad for the mechanisms
link |
that we've been talking about today
link |
is that when you ingest those foods,
link |
you're bringing those emulsifiers into your gut.
link |
And those emulsifiers strip away
link |
the mucosal lining of the gut,
link |
and they actually cause the neurons that innervate the gut
link |
that extend those little processes
link |
that we call axons into the gut
link |
to retract deeper into the gut.
link |
And as a consequence, you're ingesting a bunch of food
link |
and the signals like CCK never get deployed.
link |
The signals that actually shut down hunger
link |
are never actually triggered.
link |
And so as a consequence, you want to eat far more
link |
of these highly processed foods.
link |
In addition, if you then go from eating
link |
a highly processed food to non-highly processed foods,
link |
you're not able to measure the amounts of amino acids,
link |
sugars, and fatty acids in those foods as accurately.
link |
You've actually done structural damage at a micro level,
link |
but structural damage, excuse me,
link |
to the mucosal lining of the gut.
link |
Now, this can all be repaired if you stay away
link |
from highly processed foods for some period of time,
link |
but the negative effects of these emulsifiers
link |
So to make it really clean and simple,
link |
emulsifiers from highly processed foods
link |
are limiting your gut's ability
link |
to detect what's in the foods you eat
link |
and therefore to deploy the satiety signals,
link |
the signals that shut down hunger.
link |
In addition to that, there's a parallel mechanism at play
link |
that I talked about in a previous episode,
link |
but I'll remind you again that you have neurons in your gut
link |
that are sensing sugar and are sending a subconscious signal
link |
up to the brain via the vagus nerve.
link |
And those neurons trigger the release of dopamine,
link |
which makes you crave more of that food.
link |
So now you've got parallel signals
link |
making you want to eat more sugar,
link |
making you unaware of how much sugar you've eaten
link |
and that are disrupting the inputs to the nervous system
link |
that signal to the rest of your brain and body
link |
that you've obtained enough fatty acids
link |
and you've obtained enough amino acids.
link |
So these highly processed foods are really terrible.
link |
And I'm not out here to say,
link |
never enjoy a processed food of any kind.
link |
I'd be a hypocrite
link |
because I do eat processed foods from time to time.
link |
Although the ones that I tend to eat,
link |
I try and make of the healthier variety,
link |
but eating whole foods has tremendous value
link |
and eating highly processed food
link |
has tremendous negative impact on the gut
link |
and on the gut brain axis.
link |
And so recently there was a paper that came out in Cell,
link |
Cell Press Journal.
link |
It's kind of the apex of cell journals, which is phenomenal.
link |
This paper showed that ingesting highly processed food
link |
leads to more intake of not just highly processed foods,
link |
but other types of food in general.
link |
There was kind of an overeating compensation
link |
generally across foods
link |
for people that consume these highly processed foods.
link |
And there are a lot of other reasons
link |
to avoid highly processed foods.
link |
So again, I don't like to focus too much on the do nots.
link |
I like to arm you with tools to do,
link |
but I think this visual of certain foods
link |
and these emulsifiers actually stripping away
link |
some of the critical lining of your gut
link |
and disrupting the hormone signaling
link |
to the brain controlling feeding
link |
is important enough and cryptic enough,
link |
meaning it hasn't been talked about,
link |
it works at a subconscious level,
link |
and that it's important that people are aware of it
link |
so they can make decisions
link |
about what they do want to eat
link |
or not want to eat for themselves.
link |
Before moving on, I just want to say one more thing
link |
about highly processed foods.
link |
There was an absolutely beautiful study
link |
done by my colleague, Chris Garner at Stanford,
link |
exploring whether or not certain diets
link |
were better than others.
link |
They looked at vegan, vegetarian, omnivore.
link |
I don't know if they looked at all meat or not,
link |
but they looked at the different forms of diets,
link |
intermittent fasting, et cetera.
link |
And they essentially found
link |
that whichever diet people adhered to,
link |
whichever one they followed,
link |
was equivalent to the others,
link |
provided that they followed it,
link |
they lost the equivalent amount of weight.
link |
There really wasn't a strong effect of the food type
link |
or the pattern of eating, et cetera.
link |
However, in a study like that,
link |
adherence is very high because people are a part of a study.
link |
And for many people,
link |
the ability to adhere to a certain eating plan
link |
is one of the most, if not the most powerful determinants
link |
of whether or not a given diet,
link |
meaning nutritional plan, works.
link |
Now, this thing about highly processed foods, however,
link |
is really diabolical because it truly says,
link |
and I think the recent data in cell metabolism
link |
and other journals really proves
link |
that a calorie is not a calorie.
link |
That's absolutely absurd because of these emulsifiers
link |
and the content of these highly processed foods.
link |
In fact, the data in humans points to this.
link |
So what they did is they took inpatient adults,
link |
so they had total control over their food intake,
link |
and they received either ultra processed or unprocessed
link |
diets for 14 days as a short study.
link |
The diets were matched for calories, sugar, fat,
link |
fiber, and macronutrients.
link |
So everything else was matched,
link |
just processed or non-processed is the major variable.
link |
And basically what they found is that the people
link |
who were eating the processed food diet
link |
happened to eat much more, right?
link |
This was after this period of putting them on either diet
link |
and clamping for all other variables.
link |
Then they would eat much more,
link |
and the body weight changes were much more.
link |
And those body weight changes were such
link |
that they couldn't be accounted for
link |
by just increased calories.
link |
So the bottom line is that highly processed foods
link |
are just bad for you.
link |
They increase weight gain.
link |
They disrupt the lining of your gut in a way
link |
that disrupts things like CCK and proper satiety signals.
link |
And they contain a bunch of things in particular sugars,
link |
but other things as well,
link |
that disrupt not just the hormonal systems,
link |
but also the neural systems that control the desire to eat
link |
after the diet is done.
link |
So there's just so many reasons
link |
why these highly processed foods are terrible.
link |
And they can explain a lot of the ill health effects
link |
that we've seen in the last 50 years,
link |
not just in the United States, but all over the world.
link |
The enormous increase in diabetes, juvenile diabetes.
link |
It's just remarkable how far down the path of bad
link |
And it's clear, it's almost a smoking gun
link |
what the cause of this is.
link |
If you'd like to learn more about that,
link |
please refer to the Lustig lecture.
link |
He also spells out why non-processed foods
link |
is far more economical in terms of just at the level
link |
of the household or individual,
link |
as well as at the societal level.
link |
Really interesting stuff.
link |
I highly recommend you check it out.
link |
So now let's move on to some other hormones
link |
that regulate hunger and satiety.
link |
In particular, insulin.
link |
Now you've probably heard of insulin before.
link |
Insulin is the thing that's lacking in type one diabetics.
link |
That's why they have to inject insulin whenever they eat.
link |
The reason they have to do that is because when they eat,
link |
their foods are broken down into glucose.
link |
And in order to shuttle glucose
link |
to the appropriate tissues in the body,
link |
and also to keep glucose levels in check, you need insulin.
link |
So the simplest way to think about insulin and glucose
link |
is that when you eat,
link |
that food is broken down into sugars.
link |
That's true whether or not it's fats or it's sugars,
link |
or eventually if it's proteins.
link |
They are oxidized into fuels, as we say.
link |
And those fuels can be used, as the name fuel implies,
link |
They're eventually made into ATP.
link |
There's a bunch of biochemical steps
link |
that we're not going to go into today,
link |
but that's essentially how it works.
link |
You break down food into glucose.
link |
Now, if you're ketogenic,
link |
we'll talk about that in a little bit,
link |
but in general, you eat, food is turned into glucose.
link |
Your blood sugar needs to be kept in a particular range.
link |
Hypoglycemic means too low.
link |
Hyperglycemic means too high.
link |
And what they called euglycemic, E-U-glycemic,
link |
is the healthy range.
link |
Now, what those healthy ranges are,
link |
in general, the healthy range, the euglycemic range,
link |
is about 70 to 100 nanograms per deciliter,
link |
but most of you aren't walking around
link |
with a glucose monitor.
link |
Some of you are, but most of you are not.
link |
The more important question for us to address right now
link |
is why is it important that glucose
link |
be kept at a particular level?
link |
Once you understand that, keeping glucose in check
link |
starts to have a rationale behind it,
link |
and the ways to do that start to make a lot more sense.
link |
So the reason is, if glucose levels get too high,
link |
because of the way that our cells, in particular neurons,
link |
interact with glucose,
link |
high levels of glucose can damage neurons.
link |
It can actually kill them.
link |
You can start getting what are called peripheral,
link |
excuse me, neuropathies.
link |
One of the symptoms of some forms of diabetes
link |
is that people start losing the sensation of touch
link |
in their fingers or their hands or their feet,
link |
and they can start going blind.
link |
There's diabetic retinopathies.
link |
So it's very important
link |
that insulin manage your glucose levels.
link |
Now, there's also type 2 diabetes,
link |
where there's insulin secreted from the pancreas,
link |
but people are insulin insensitive.
link |
There's a disruption in the receptors,
link |
and insulin insensitivity
link |
isn't quite the same as having no insulin at all,
link |
but it parallels some of the same mechanisms.
link |
Now, type 1 diabetes is often picked up
link |
because someone has a sudden weight loss
link |
because they're not processing blood sugar
link |
the same way they were before.
link |
Type 2 diabetes is often, although not always,
link |
associated with being overweight and with obesity.
link |
Both of them are challenging conditions.
link |
Type 2 diabetes almost always can be managed
link |
by managing one's weight.
link |
And of course, there are prescription drugs
link |
and supplements that can help manage those.
link |
We're going to talk about all of that.
link |
But for most people that don't have diabetes,
link |
the important thing is to manage glucose,
link |
to keep it in that euglycemic range.
link |
And there are a number of different ways to do that.
link |
Some of them are behavioral, some of them are diet-based,
link |
and some of them are based on supplements
link |
or prescription drugs.
link |
So let's talk about those now.
link |
So if you eat, and in particular, if you eat carbohydrates,
link |
blood glucose goes up.
link |
If you eat fats, blood glucose goes up
link |
to a far less degree.
link |
And if you eat proteins, depending on the protein,
link |
it'll eventually be broken down for fuel
link |
or assembled into amino acid chains for protein synthesis
link |
and repair of other tissues and bodily functions.
link |
But glucose goes up and then is kept in range.
link |
When you are hungry, you secrete a different hormone,
link |
and that's called glucagon.
link |
And glucagon's main role is to pull stores of energy
link |
out of the liver and the muscles.
link |
And once those are depleted,
link |
you'll eventually tap into body fat, okay?
link |
So, and this is for people
link |
that have a typical blood glucose range,
link |
so that 70 to 100 euglycemic range.
link |
So the two kind of push and pull systems
link |
that we're going to think about now to keep this simple
link |
is that you have the insulin system managing glucose,
link |
and you've got the glucagon system pulling energy
link |
out of your liver and muscles for immediate fuel.
link |
And eventually you'll pull fuel out of body fat
link |
if you've been active for a very long time
link |
and all your glycogen stores are depleted
link |
or close to depleted.
link |
So what does this all mean?
link |
There's a lot of important biochemistry
link |
and a lot of important cellular processes involved
link |
in whether or not you're anabolic or catabolic,
link |
whether or not you're breaking things down
link |
or building things up.
link |
Let's talk about feeding in a simpler way, however,
link |
and let's weave the tools to manage blood glucose
link |
to keep it in check as we do that.
link |
So let's say you had a meal
link |
and that meal consisted of rice, a carbohydrate,
link |
some meat or fish, let's say a piece of salmon,
link |
and some vegetable, some fibrous vegetable
link |
like asparagus or cabbage or something like that.
link |
If you were to eat all of that at once,
link |
you take a bite of one, a bite of the other,
link |
you mix it up, one of these,
link |
it all ends up in the same place kind of people,
link |
mix it all up, then you will experience an increase
link |
in insulin and increase in blood glucose
link |
that's moderately fast.
link |
It's going to increase pretty quickly.
link |
What's remarkable is that the order
link |
that you consume each macronutrient
link |
has a pretty profound influence
link |
on the rate of insulin and glucose secretion
link |
into the blood and how quickly those levels rise.
link |
So if you, we'll make it really simple,
link |
if you were to eat the rice first,
link |
your glucose would rise in a sharp spike,
link |
especially if it doesn't contain any fats
link |
to slow the absorption.
link |
Now, that might be good if you're very hungry
link |
and you want to get an increase in glucose.
link |
In fact, this is the reason
link |
why you're often served bread before meals
link |
because it's, and sometimes it's bread and butter,
link |
but, or chips before meals or appetizer
link |
are designed to get your blood glucose going up high
link |
because big steep increases in blood glucose
link |
tend to promote the desire to consume more glucose.
link |
And this also relates to the dopamine system
link |
and the way that something tasty in the mouth
link |
and sugar in the gut and fats and sugars in the mouth
link |
trigger the activation of a lot of systems
link |
in the brain and body to consume more of whatever you have
link |
or whatever is available to you.
link |
So the basic idea is that eating carbohydrates and or fats
link |
early in a meal will give a steep rise in blood glucose.
link |
However, if you were to eat the fibrous thing first,
link |
so a lot of chewing, but not a big rise in blood glucose,
link |
because in general there's,
link |
unless it's laden with sugar or something,
link |
we're just talking about some vegetable, fibrous vegetable,
link |
that will actually blunt the release of glucose
link |
until you eat the fish and the rice,
link |
but believe it or not, it will actually blunt
link |
the glucose increase that the rice would cause.
link |
Now I'm not talking about neurotically
link |
eating each macronutrient separately in sequence,
link |
I'm just trying to give you a picture
link |
of what's happening ordinarily.
link |
So what this means is if you feel
link |
a lot of food-related anxiety,
link |
or you feel you're one of these people
link |
that you can kind of sense like your blood sugar
link |
increasing very quickly, a lot of people can sense this,
link |
some people can't, has a lot to do
link |
with how well they manage their blood sugar,
link |
as well as some of the psychological factors.
link |
And yes, there are family and historical reasons
link |
where I've got friends who had a lot of siblings,
link |
and when they sit down to eat,
link |
they have to really suppress the desire
link |
to not beat up everyone else at the table
link |
and take all the food, it's sort of like not,
link |
it's hard for them to understand
link |
that there's plenty to go around because of their upbringing,
link |
so there are psychological top-down effects.
link |
A lot of the psychology around food
link |
is geared towards getting people to be relaxed
link |
when they eat and these sorts of things,
link |
but these blood sugar effects are real,
link |
just cellar and basic biochemistry
link |
of how the body manages sugars ingested into the blood.
link |
So what does this all mean?
link |
It means that if you want a steep increase in glucose,
link |
you are very, very hungry,
link |
then you should eat the carbohydrate-laden food first,
link |
or you should eat a bunch of macronutrients combined,
link |
so that would be like the hamburger or the sandwich,
link |
the bread, the whatever's in that sandwich altogether,
link |
usually that's protein and vegetables as well.
link |
If you want to have a kind of more modest
link |
increase in glucose or you want to blunt
link |
the increase in glucose,
link |
then have at least some of the fibrous thing first,
link |
and then the protein, and then the carbohydrate,
link |
you will notice that your blood glucose
link |
will rise more steadily,
link |
and that you'll achieve satiety earlier in the meal,
link |
or at least you won't get this huge peak,
link |
it's sort of the Thanksgiving meal effect,
link |
some of you are international,
link |
so if you don't celebrate Thanksgiving,
link |
it's a time of year where,
link |
used to be the one time of year or two times a year
link |
where Americans would give themselves permission
link |
to eat enormous meals,
link |
now that seems to happen a lot more often,
link |
but there is this effect of you're full
link |
and yet you're hungry for more,
link |
that's because your blood glucose has gone through the roof
link |
and it's triggered a number of other mechanisms.
link |
There's also usually a lot of alcohol consumption,
link |
and alcohol itself, because it's a sugar,
link |
will increase blood glucose very, very sharply,
link |
it depends on the alcohol,
link |
some alcohols have more sugar than others,
link |
but basically what you're trying to avoid
link |
are steep increases in blood sugar,
link |
and the order that you eat foods
link |
has an enormous impact on that,
link |
the other thing that has an enormous impact
link |
on how long and shallow or how steep
link |
that curve of glucose is,
link |
depends on whether or not you recently were moving,
link |
are moving, or start moving after you eat,
link |
so it turns out that your blood glucose levels
link |
can be modulated very, very powerfully by movement,
link |
if you did any kind of intense exercise,
link |
or even just walking or jogging or cycling,
link |
anything before you eat,
link |
your blood glucose levels will be dampened somewhat,
link |
and that has to do with the release of something called,
link |
some people call it GLUT4, which sounds like glutton,
link |
other people call it GLUT4,
link |
these are things that are involved in shuttling glucose
link |
to particular cells in the body,
link |
namely toward muscle and glycogen stores
link |
and away from body fat stores,
link |
it has to do a sequestering of glucose from the blood,
link |
the point is that if you're somebody
link |
who struggles with blood sugar regulation,
link |
in addition to getting your body weight in a healthy range,
link |
doing all the other sorts of things that you should be doing,
link |
the key thing is to try and get some movement,
link |
sometime circa meal,
link |
now very few people can actually eat and walk
link |
at the same time, although I do it all the time,
link |
not because I'm trying to regulate my blood sugar,
link |
but just because I tend to be busy, I eat and drive,
link |
so basically if I'm not giving this podcast or sleeping,
link |
I'm eating, except the early part of the day when I fast,
link |
but the bottom line here is that if you, for instance,
link |
take a 30 minute walk after a meal,
link |
your blood glucose will be blunted
link |
in ways that are beneficial,
link |
if you have exercised in the recent hours before a meal,
link |
that can be beneficial,
link |
the order that you consume foods is beneficial,
link |
and there are a few things that you can consume
link |
that can also adjust blood glucose levels,
link |
so let's talk about those,
link |
but I thought it was important to really tamp down
link |
that it's not just what you eat,
link |
we talked about that before,
link |
but also the order that you eat those things,
link |
believe it or not,
link |
whether or not you combine macronutrients,
link |
carbohydrates, proteins, and fats, and fibrous vegetables,
link |
and whether or not you've moved recently,
link |
the higher intensity of the movement,
link |
the greater the Glut4 increase,
link |
and the more that the blood glucose will be blunted,
link |
and you'll shuttle more of that
link |
to glycogen and muscle stores,
link |
and even just moving after a meal,
link |
even just a calm, easy walk,
link |
can really adjust the ways
link |
in which blood sugar regulated for the better.
link |
I don't want to perseverate
link |
on this processed foods, hidden sugars thing too much,
link |
but understanding now a little bit
link |
about how insulin and glucose work,
link |
you can probably imagine why hidden sugars
link |
are such an attractive thing
link |
from the standpoint of processed food manufacturers,
link |
because if they can put sugar in that you can't even taste,
link |
that sugar is going to amplify the amount of glucose,
link |
it's going to increase the rate of glucose increases
link |
into your bloodstream,
link |
and it's going to promote more feeding.
link |
So in that case, you're really being tricked,
link |
it's not that you're actually reaching
link |
for the additional appetizer,
link |
and your blood glucose is going up,
link |
the food that you ate
link |
is actually increasing your appetite as you eat it,
link |
it's a positive feedback loop.
link |
So don't want to demonize those any more than I already have,
link |
but you should be aware that these things are happening
link |
at the level of your bloodstream and brain.
link |
The other thing I'd like to address for a moment
link |
is this notion of stable blood sugar
link |
versus labile blood sugar, or unstable blood sugar.
link |
Some people just have stable blood sugar,
link |
they can go long periods of time without eating
link |
and feel fine, other people get really shaky,
link |
really jittery, and or when they do eat,
link |
they feel really keyed up, sometimes they'll even sweat,
link |
sometimes their vision will go blurry,
link |
and some of that can actually be
link |
because they've become hyperglycemic.
link |
And those effects that you experience
link |
when you are hyperglycemic are the early warning signs
link |
of the kinds of things that damage neurons
link |
and lead to the really terrible stuff
link |
they talked about before, like peripheral neuropathies.
link |
Now it takes some time for those things to occur,
link |
those neuropathies to occur,
link |
but whether or not your blood sugar is all over the place
link |
or whether or not it's stable
link |
can be impacted by a number of things.
link |
One of those things is exercise.
link |
So these days there's a lot of interest
link |
in what they call zone two cardio,
link |
which is that kind of steady state cardio
link |
where you can just nasal breathe,
link |
even at pretty high output,
link |
where you could maybe have a conversation,
link |
although I'm such a huge proponent
link |
of nasal breathing during exercise,
link |
most forms of exercise, especially zone two cardio,
link |
that you probably shouldn't be talking
link |
while you're doing that cardio
link |
unless it's absolutely essential.
link |
But periods of zone two cardio
link |
that last anywhere from 30 minutes to an hour
link |
or sometimes more for you endurance athletes
link |
can create positive effects on blood sugar regulation
link |
such that you, people can sit down
link |
and enjoy whatever it is, the hot fudge sundae
link |
or whatever the high sugar content food is.
link |
And blood glucose management is so good,
link |
your insulin sensitivity is so high, which is a good thing,
link |
that you can manage that blood glucose
link |
to the point where it doesn't really make you shaky,
link |
it doesn't disrupt you.
link |
And to say nothing of the weight related issues
link |
or the adipose fat gain, et cetera,
link |
that's a separate issue because people vary there.
link |
But basically doing zone two cardio
link |
for 30 to 60 minutes three to four times a week
link |
makes your blood sugar really stable.
link |
And that's an attractive thing for a variety of reasons.
link |
On the flip side, high intensity interval training
link |
or resistance training, AKA weight training,
link |
are very good at stimulating the various molecules
link |
that promote repackaging of glycogen.
link |
So sprints, heavy weightlifting, circuit type weightlifting
link |
provided there's some reasonable degree of resistance.
link |
Those are going to trigger all sorts of mechanisms
link |
that are going to encourage the body
link |
to shuttle glucose back into glycogen,
link |
convert into glycogen into muscle tissue,
link |
restock the liver, et cetera.
link |
Depleting one's glycogen actually takes some time.
link |
If you do a couple sets of tricep extensions
link |
and some crunches, you're not depleting your glycogen.
link |
Glycogen depleting workouts are very high intensity.
link |
Generally they're less than an hour or so,
link |
but those are the sort that are going to lead
link |
to big increases in the kinds of enzymes
link |
and metabolic pathways that are going to repack glycogen
link |
and shuttle most things towards restorage of foods,
link |
not into adipose tissue, not into fat,
link |
but taking glucose and making it into fuels
link |
that you can access later for more of that high intensity
link |
And I should mention that one of the advantages
link |
of high intensity interval training
link |
or weightlifting of various kinds is that it also,
link |
it causes long standing increases in basal metabolic rate.
link |
I don't want to go too far down this path
link |
because we're going to do an entire month
link |
on human performance and athletic performance,
link |
but it's not just the increases in muscle
link |
that increase metabolism because muscle burns more energy
link |
than other types of tissues, except your brain,
link |
which truly burns the most energy
link |
and is the main reason why your basal metabolic rate
link |
Well, high intensity training, so it could be sprints,
link |
it could be a high intensity interval training
link |
of different kinds, it could be weight training,
link |
also has an effect of increasing thermogenesis
link |
even long after you've completed the exercise.
link |
So there's a long tail,
link |
there's a kind of post-exercise metabolic effect
link |
that's also beneficial.
link |
So it's not an either or,
link |
it's really that high intensity interval training
link |
and resistance training and things of that sort
link |
are very good for one reason.
link |
And the zone two cardio is very good for other reasons.
link |
And now you can see why it's just a healthy thing
link |
and why most people should probably be doing exercise
link |
most days of the week, if not every day of the week.
link |
If your goal is to manage blood glucose
link |
and your goal is to manage some of the metabolic factors
link |
that control repackaging of glycogen
link |
and encouraging excess glucose
link |
to not get diverted into body fat stores.
link |
We haven't talked a lot about lipids today.
link |
That's because most of today's discussion is about hormones
link |
and insulin is the dominant hormone
link |
in terms of mobilizing and managing glucose in the body,
link |
at least for most people.
link |
But fats are very important
link |
and there's just a little anecdote about fats
link |
that I think will be useful
link |
in thinking about why you want to manage
link |
what they call the LDL or HDL ratios.
link |
And this is deserving in an entire episode,
link |
many perhaps even several episodes,
link |
but some of you may be familiar with LDLs and HDLs.
link |
Some of you may not.
link |
The LDL is low density lipoprotein.
link |
This is the one that you don't want it to be too high.
link |
Costello's dreaming.
link |
He doesn't, he loves all forms of cholesterol,
link |
but that's just Costello dreaming.
link |
So LDLs are the ones that you want to keep low.
link |
You don't want those to go excessively high.
link |
HDLs, the high density lipoproteins
link |
are the ones that are the so-called healthy lipoproteins.
link |
That's all fine and good,
link |
but you might ask yourself, what are they doing?
link |
What is the actual role of these things?
link |
And why would you want healthy levels of HDL
link |
and not too much LDL?
link |
Well, one of the reasons is that fats don't like water.
link |
They are hydrophobic
link |
and yet you need to move fats in your bloodstream,
link |
all tissues in your body need fats.
link |
They need cholesterols.
link |
Last episode, we talked about how cholesterol
link |
is a precursor to the sex steroid hormones,
link |
estrogen and testosterone and other hormones as well.
link |
Well, HDL and LDL actually coat fats
link |
to allow them to be transported through the bloodstream.
link |
They do a number of other things as well,
link |
but HDL is a key component of the delivery system
link |
that brings those fats to the liver,
link |
ovaries, testes and adrenals.
link |
In other words, having adequate levels of HDL is good
link |
because it allows fats to be delivered to the tissues
link |
that manufacture testosterone, estrogen, cortisol
link |
in healthy levels and the liver.
link |
So this is why when LDLs are too high,
link |
what's happening is you're not getting fats
link |
to the correct tissues and you can get buildup
link |
of fats like fatty liver disease
link |
and some of these things can happen.
link |
High sugar content can even lead
link |
to some of these fatty liver conditions
link |
that are starting to happen.
link |
This is actually the first time in human history perhaps
link |
that we're aware of anyway,
link |
that we're starting to see liver conditions
link |
that normally were associated only with severe alcoholism
link |
starting to come from sugar content.
link |
So what does this mean?
link |
This means keep your LDL and HDL ratios proper.
link |
You want those HDLs in order to deliver fatty molecules
link |
to the very tissues that use cholesterol
link |
in order to manufacture hormones.
link |
So how do you keep LDLs and HDLs in their proper ratios?
link |
Well, a lot of people don't realize this,
link |
but the debate about dietary cholesterol
link |
and its relationship to LDL and HDL ratios
link |
is a barbed wire debate.
link |
I don't want to get into it right now.
link |
There are still a lot of open questions
link |
as to how much dietary cholesterol
link |
impacts LDL and HDL ratios.
link |
I don't want to get into that now.
link |
I'm not taking a stance either way.
link |
But what is very clear
link |
is that having highly elevated glucose
link |
consuming too much sugar or not managing glucose
link |
in your body through some of the mechanisms
link |
that we've been talking about up until now
link |
can also negatively impact LDL, HDL ratios.
link |
So managing glucose goes way beyond
link |
just managing blood sugar
link |
and making sure that you don't lay down too much body fat,
link |
making sure your metabolism stays high,
link |
making sure you're not getting jittery at meals.
link |
It also has to do with making sure
link |
that you're creating enough of the molecules, HDL,
link |
and not too many of the molecules, LDL,
link |
that are going to disrupt the delivery of things
link |
to the organs of your body
link |
that allow you to make healthy levels
link |
of testosterone, estrogen, and so forth.
link |
If that wasn't clear, let me make this ultra simple.
link |
You want healthy levels of HDL
link |
and you want low levels of LDL
link |
because if you have ovaries,
link |
it will allow the fats that need to get to the ovary
link |
to produce estrogen to get there.
link |
And if you have testes,
link |
it will allow the fats and the cholesterol molecules
link |
that you need in order to manufacture testosterone
link |
to get to the testes.
link |
As well, in order to have proper adrenal function
link |
and proper liver function,
link |
you want HDL and LDL in the healthy, correct levels.
link |
So now we've talked a lot about behavioral tools
link |
and the underlying biological mechanisms
link |
that justify those tools in particular circumstances.
link |
Now I'd like to turn to supplements and prescription drugs
link |
that regulate the hormone systems
link |
controlling feeding and satiety.
link |
There are a huge number of these.
link |
Some have more powerful effects than others.
link |
There are two that I want to describe
link |
because they've been getting a lot of attention recently.
link |
First of all, there's a prescription drug metformin,
link |
which was developed as a treatment for diabetes
link |
and it works potently to reduce blood glucose.
link |
It has dramatic effects in lowering blood glucose.
link |
Metformin involves changes to mitochondrial action
link |
That's its main way of depleting or reducing blood glucose.
link |
And it does so through the so-called AMPK pathway
link |
and it increases insulin sensitivity overall.
link |
Metformin is a powerful drug.
link |
In fact, I'm surprised that so many people
link |
have sought it out,
link |
given that most of the people that I'm aware of
link |
that sought it out are not diabetic.
link |
I think for diabetics, it seems to be a useful drug.
link |
For non-diabetics, it can also,
link |
of course, lower blood glucose.
link |
It also has the potential to make people hypoglycemic,
link |
genuinely hypoglycemic.
link |
So you really need to approach metformin with caution.
link |
I get a little concerned when I hear about people
link |
blasting metformin simply because fasted states
link |
or low blood sugar states are healthy.
link |
Doing that pharmacologically can have longstanding effects.
link |
You really want to approach that with caution.
link |
Now there's a comparable drug.
link |
It really should be called a drug,
link |
but it's non-prescription
link |
that's also in fairly prominent use out there
link |
called berberine, B-E-R, B-E-R-I-N-E, berberine, correct.
link |
So berberine is a really interesting compound.
link |
Its actions very much mimic metformin.
link |
So let's talk about berberine for a second.
link |
Berberine actually comes from various plants
link |
It is sold in supplement stores.
link |
It is, as far as I know, unregulated.
link |
If you're going to experiment with berberine,
link |
you definitely want to talk to your doctor
link |
and you want to approach it with caution.
link |
It also works to activate the so-called AMPK pathway.
link |
AMPK, by the way, stands for adenosine monophosphate
link |
activated protein kinase, AMPK,
link |
and it inhibits a protein tyrosine phosphase, 1B pathway.
link |
I think that's enough nomenclature.
link |
It activates a certain pathway that's associated
link |
with fasting and low blood glucose.
link |
The effects of berberine are, as far as I can tell,
link |
when looking at the literature, are very similar,
link |
if not identical, to metformin.
link |
Now, the number of studies out there on this are many.
link |
So I'm just going to review a few of them
link |
and their major effects.
link |
As always, I invite you to check out examine.com.
link |
It's a wonderful website where you can put in
link |
any supplement or compound or biological goal
link |
for that matter, and it will list out the various effects
link |
in the human effect matrix, so studies on humans,
link |
if they're available, and it will tell you
link |
whether or not there's strong effects or weak effects
link |
or modest effects, and it will point
link |
to the specific subject population, a wonderful resource.
link |
So berberine, not surprisingly, has very strong effects
link |
in lowering blood glucose.
link |
There are four studies on this.
link |
In fact, they say that berberine is one of the more,
link |
if not the most effective supplements
link |
for lowering blood glucose.
link |
It talks about dosages there,
link |
although I'll just mention that I've tried berberine,
link |
and the dosages that are typical on the bottle
link |
of most supplements is much higher than I needed.
link |
So when I took berberine, two things happened.
link |
First of all, I got a pretty splitting headache.
link |
It gave me pretty vicious headache.
link |
So for me, it was a no, almost immediately.
link |
The other thing is I became so hypoglycemic
link |
that in order to get my blood sugar back up,
link |
I think I ate something like 10 donuts,
link |
and I didn't feel like I had ingested all that much sugar.
link |
It was really kind of weird.
link |
I was hyperphagic for sugar.
link |
I was craving sugar, craving sugar,
link |
and I was very thirsty as well.
link |
And so I don't want to promote any bad behavior,
link |
but I know that certain people use this
link |
when they've overeaten sugars
link |
or they're doing their cheat days,
link |
something that I'm personally just not a fan of,
link |
and they want to keep their blood sugar in check
link |
or they know they're going to consume a huge meal,
link |
they'll take berberine to keep blood glucose clamped.
link |
And it does do that.
link |
It has very strong effects,
link |
three peer-reviewed studies on HbA1c levels.
link |
HbA1c is something that can be measured in a blood test
link |
that is sort of an average readout
link |
of your blood sugar levels
link |
over the previous two or three months,
link |
sometimes shorter period,
link |
but that's mostly what HbA1c is about.
link |
So it radically decreases your blood sugar levels.
link |
It actually lowers cholesterol.
link |
It acts, remember, on the liver,
link |
and the liver is involved in cholesterol metabolism.
link |
And remember, it's both sugars, blood glucose,
link |
and dietary fats, perhaps.
link |
It's still heavily debated
link |
in terms of how your blood total cholesterol,
link |
HDL and LDL are regulated.
link |
So it seems to lower total cholesterol,
link |
and it seems like it lowers HDL and LDL in parallel.
link |
So that's interesting.
link |
One study showed a minor increase in HDL,
link |
the so-called good cholesterol.
link |
Insulin levels drop, not surprising.
link |
Another study showed a slight decrease in LDL.
link |
Those seem to be kind of minor.
link |
Here's a kind of interesting one,
link |
just to help you remember berberine,
link |
as if the fact that it comes from tree bark
link |
isn't trigger enough to remember it.
link |
Direct contact of berberine on canker sores
link |
seems to eliminate canker sores very quickly,
link |
which is kind of cool.
link |
I haven't had canker sores in a few years,
link |
but when I did get them, they are extremely painful.
link |
So that's kind of interesting,
link |
and there's some study references there.
link |
I find it amazing that these compounds exist.
link |
You've got this prescription drug metformin,
link |
and then you've got berberine, the stuff from tree bark,
link |
and they have effects
link |
that are essentially equivalent to one another.
link |
So again, I'm not promoting their use
link |
or even their exploration,
link |
but those compounds do exist.
link |
They're out there.
link |
And check out examine.com if you'd like to learn more.
link |
Certainly do your reading, do your homework
link |
before you start just popping the stuff.
link |
And if you have hypoglycemia or hyperglycemia,
link |
be especially careful.
link |
And also do understand that dosages
link |
and dose requirements vary.
link |
So if you do go down this path,
link |
really approach things carefully.
link |
Always start with the lowest amount
link |
that you could get away with.
link |
For me, the headache thing just made it a no-go.
link |
I do keep a bottle of it in full disclosure
link |
in the odd chance that I feel like eating
link |
It's not so much about not ingesting the calories.
link |
It's just that I don't like the feeling
link |
of being hyperglycemic, the blurry vision,
link |
just feeling lousy.
link |
Other things that impact blood glucose
link |
in supplement form, chromium has been shown
link |
in 29 studies to have a minor,
link |
I want to emphasize a minor effect
link |
on reducing blood glucose.
link |
Things like L-carnitine,
link |
something we've talked about here on the podcast before
link |
in terms of its relationship to power output
link |
and ATP production for both aerobic and anaerobic exercise
link |
as well as sperm quality and egg quality.
link |
We talked about that long ago.
link |
Things like panache ginseng can have positive effects on,
link |
I should say can have effects
link |
of reducing blood glucose slightly.
link |
I don't want to give a valence to or judgment
link |
to whether or not it's positive or negative.
link |
Here's something that's interesting
link |
that you should know about.
link |
Caffeine has very reliably been shown
link |
to increase blood glucose just a little bit, okay?
link |
So I always thought that caffeine would drop blood glucose
link |
but it actually can increase blood glucose just slightly.
link |
Things like magnesium, talked about magnesium
link |
as a tool for enhancing the passage into sleep,
link |
in particular magnesium threonate and biglycinate.
link |
Magnesium can also have a modest reduction
link |
You're starting to get the impression
link |
everything reduces blood glucose
link |
but that's certainly not the case.
link |
And then a couple episodes ago
link |
when we were discussing nutrition
link |
we talked about artificial sweeteners,
link |
sucralose, aspartame, nutra-sweet.
link |
Some of those are generic names.
link |
Some of those might be brand names
link |
and how they have negative effects on the gut microbiome
link |
and that's supported by a number of studies.
link |
There's one artificial sweetener, it's Stevia, S-T-E-V-I-A
link |
which seems to lower blood glucose just slightly.
link |
And I still can't find data on whether or not
link |
Stevia impacts the gut microbiome in either direction.
link |
Many of the things that I consume
link |
do have small amounts of Stevia in them.
link |
So I'd love to know if anyone out there
link |
is aware of quality peer-reviewed research
link |
as to whether or not Stevia impacts the gut microbiome
link |
similarly or differently from other artificial sweeteners.
link |
Please let me know, please send me the references.
link |
I'd really appreciate it.
link |
You can put it in the comment section
link |
on YouTube or elsewhere, comment section on YouTube
link |
would be the best place.
link |
So Stevia seems to lower blood glucose a little bit
link |
which makes it kind of an attractive artificial sweetener
link |
if one is going to use artificial sweeteners.
link |
But remember sweet taste itself stimulates the desire to eat
link |
which will increase more blood glucose.
link |
So I'm guessing that they probably cancel each other out.
link |
So you have to think logically about these things.
link |
Vitamin B3, so some of the B vitamins
link |
do indeed stimulate appetite
link |
by triggering increases in blood glucose.
link |
Vitamin B3 in particular, I don't know if B6 does.
link |
Things like zinc seem to lower blood glucose.
link |
And then there've been an enormous number of other things
link |
that have been tested for their roles in blood glucose.
link |
Apple cider vinegar, anything acidic.
link |
This is well-known now that any kind of acidity,
link |
so it could be lemon juice or lime juice
link |
or apple cider vinegar lowers blood glucose slightly.
link |
Some of those can also have other effects
link |
that we're not talking about today.
link |
So that's kind of interesting because there's a movement now
link |
towards creating sort of people talk
link |
about becoming more alkaline.
link |
I hate to break it to you
link |
but you don't really want your body to be too alkaline.
link |
You want to stay in the right pH or else you start,
link |
there are conditions that make you more alkaline.
link |
You don't want to be too acidic or too alkaline.
link |
If you see a beverage or something that purports
link |
that ingesting that beverage
link |
is going to make you more alkaline,
link |
that is absolutely false.
link |
There's no evidence for that.
link |
It's impossible biochemically, it's just marketing.
link |
But nonetheless, ingesting foods that are acidic
link |
can make some slight adjustments to the pH of the gut
link |
in ways that can slow or alter the absorption of foods
link |
and can blunt blood glucose.
link |
You can try this sometime if you want.
link |
If ever you're feeling kind of over sugared out
link |
like you ate something with too much sugar,
link |
you can drink a small amount of lemon juice
link |
mixed with water or lime juice.
link |
And you'll notice that it will blunt
link |
that kind of hyperglycemic effect just a little bit.
link |
Again, you don't want to use this as a medical tool
link |
but the effect is fairly potent.
link |
And then, excuse me.
link |
And then there are a number of other things
link |
like capsaicin and hot chili peppers
link |
that will lower blood glucose.
link |
The list goes on and on.
link |
The most powerful one is absolutely berberine and metformin
link |
but that's really heavy caliber stuff.
link |
And the other ones I mentioned have more minor effects.
link |
I do want to mention,
link |
because I'm sure some of you out there
link |
are curious about the ketogenic diet.
link |
I'm going to do an entire episode
link |
about ketosis and the brain and the body.
link |
But the ketogenic diet has been shown in 22 studies
link |
to have a notable decrease on blood glucose.
link |
And that is not surprising
link |
because the essence of the ketogenic diet
link |
is that you're consuming very little or zero of the foods
link |
that promote big spikes in insulin and glucose.
link |
If you consume enough protein,
link |
some of that protein can be converted into glucose,
link |
of course, through gluconeogenesis.
link |
But the ketogenic diet has very strong support
link |
for its role in regulating blood sugar, which is glucose.
link |
But the specific effects of the ketogenic diet
link |
and one particular effect that I'll address later
link |
but I'll mention now,
link |
which is the ability of the ketogenic diet
link |
to adjust thyroid hormone levels
link |
in ways that make it such
link |
that if you return to eating carbohydrates
link |
after being in ketosis for too long,
link |
you don't manage thyroid and carbohydrates as well.
link |
That has been shown as well.
link |
So we're going to dive deep into ketosis
link |
in a future episode.
link |
So for you ketonistas out there, don't worry.
link |
I certainly have nothing against ketogenic diet.
link |
I actually don't have anything for
link |
or against any particular nutrition plan.
link |
I know it works for me, at least at this stage of my life,
link |
and I'll update it if I need to.
link |
I'm simply trying to get you as much information
link |
as I possibly can so that you can navigate
link |
through that landscape in a way
link |
that's in keeping with your particular goals.
link |
So now you understand a lot about blood sugar
link |
and how it's managed and the ways
link |
that you can manage it better
link |
depending on your particular needs.
link |
This is also a good opportunity for us to look back
link |
at some of the medical literature
link |
because it really points to just how far we've come
link |
in terms of understanding these important mechanisms.
link |
And it points us in the direction of some actionable
link |
So diabetes, which is these huge increases
link |
in blood glucose because there's no insulin,
link |
was known about as early as 1500 BC,
link |
which is just incredible.
link |
And the way physicians then understood
link |
that certain people had high blood glucose
link |
without actually knowing what blood glucose was
link |
is that they would take the urine of particular patients
link |
and they'd find that ants preferably moved toward
link |
and consumed the urine of certain patients and not others.
link |
And they understood that there was something in that urine
link |
that was correlated with the sudden weight loss
link |
and some of the other probably very unfortunate
link |
health symptoms that these people were experiencing.
link |
So they knew that there was something in blood and urine.
link |
But you might not be asking yourself, wait, that's urine.
link |
But as I tell every kid that I meet, two things,
link |
I tell a kid, your brain is here.
link |
I make them point to their head.
link |
And then I tell them, do you know what?
link |
Do you know that your urine is actually filtered blood?
link |
And they usually go, I get parental permission
link |
But most adults don't realize that your urine
link |
is actually just filtered blood.
link |
And that's why if you see blood in your urine,
link |
You want to filter the blood, but urine is filtered blood.
link |
Now, this business of measuring blood sugar from the urine
link |
has been something that lasted way beyond
link |
these early stages of 1500 BC.
link |
Turns out that as late as 1674,
link |
physicians at Oxford University were figuring out
link |
who had pathologically high levels of blood glucose
link |
by analyzing their urine.
link |
And again, they were measuring the sweetness of their urine.
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But, and this is medical fact, they would do this
link |
by taking urine samples from different patients
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And they developed an intuitive sense
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of what excessively sweet urine was relative
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to the other urines that they had tasted.
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So for those of you that are in the medical profession
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or those of you that are seeking out the medical profession,
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do understand this is not done anymore.
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And you can also just reflect on how far we've come
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in terms of the medical profession itself
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in our ability to measure things from the blood
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and measure things from urine without having to ask ants
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which urine is sweeter or ask oneself which urine is sweeter
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so indeed we are making progress as a species.
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Before we close out today, I want to talk about
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one more tool that many of you will probably find useful.
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I certainly have, I'm a big consumer of caffeine,
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although I don't consume a ton of it,
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I consume it very consistently.
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So I'm big on consuming mate,
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which is a strong caffeinated tea
link |
and I generally do that early in the day.
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Although I do delay about two hours after I wake up
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for reasons I've talked about in previous episode
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to maintain that nice arc of alertness and focus.
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I do drink black coffee as well, mushroom coffee as well,
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I love that stuff.
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But mate, also called yerba mate,
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is an interesting compound because unlike coffee,
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it has been shown to increase something called
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glucagon-like peptide, GLP-1 and increase leptin levels.
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Now we didn't talk a lot about glucagon today.
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Glucagon is really elevated in the fasting state.
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I mentioned that it's sort of the opposite of insulin
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in kind of rough terms, that's one way to think about it.
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But GLP-1 or glucagon-like peptide one
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is increased by ingesting mate
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and it acts as a pretty nice appetite suppressant.
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Now I'm not trying to suppress my appetite.
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I like to eat, as I mentioned before,
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but it works really well to stimulate the brain
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and to give you a level of alertness
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and to do a lot of the things that coffee does.
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It also contains electrolytes.
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So we, meaning our neurons and our brain
link |
run on a variety of factors, electrical activity
link |
and chemical transmission, et cetera,
link |
but they require adequate levels of sodium,
link |
potassium, and magnesium.
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Actually, if you were to learn the biology
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or the physiology of the action potential,
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the firing of a neuron,
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something we teach every first year neuroscience student,
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and I'd be happy to teach you if you're interested,
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you'll hear about sodium rushing into cells
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and potassium entering and leaving cells
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in order to allow neurons to communicate.
link |
Electrolytes are critically important
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for the function of the nervous system.
link |
And many things that act as diuretics
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that promote excretion of water, like caffeine,
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can also take electrolytes out
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along with, in particular, sodium.
link |
And sometimes the lightheadedness
link |
or the brain fog that people experience
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isn't just because electrolytes are low,
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but because they're kind of out of balance.
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So I like mate because it has electrolytes, it has caffeine.
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It stimulates the release of this glucagon-like peptide,
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GLP-1, and it's been a big help to me
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in extending that early morning fasting window
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out to about noon or so when I eat my first meal.
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It also just tastes really good.
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I don't drink it out of the gourd,
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even though I have Argentine lineage.
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The gourd to me is, it's just kind of an inconvenience.
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I drink it out of a mug.
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There's no promotional here.
link |
I have no relationship to any yerba mate plantations
link |
I just happen to really like the stuff.
link |
And the fact that glucagon-like peptide-1 is enriched
link |
or is released more when you drink mate,
link |
and the fact that GLP-1 can regulate blood sugar
link |
in ways that keep your blood sugar
link |
in that we called you got glycemic,
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not too high, not too low mode
link |
is one reason why ingesting mate is attractive to me.
link |
If you go to South America,
link |
what you'll see, especially among Uruguayans,
link |
but also Argentines is people actually carry a thermos
link |
of this stuff with them around
link |
and bring it to meals in restaurants.
link |
And that's just considered cultural convention.
link |
It's not unusual to see that.
link |
So we don't see that so much here in the States,
link |
but I happen to really love this stuff.
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because that's the most economical way to do it.
link |
And I really enjoy it.
link |
It can be a little bitter for some people.
link |
The real key there, if you want to know the mate trick
link |
is to not use water that's really boiling hot.
link |
You go just shy of boil
link |
and then it doesn't have that same kind of tobacco-like
link |
or really acidic flavor to it.
link |
It's a little bit, just a little bit sweeter,
link |
although not quite sweet.
link |
So Yerba Mate GLP-1 can manage in healthy ways,
link |
leptin levels, glucose levels, and glucagon levels
link |
in ways that if it serves you, you might want to try.
link |
So once again, we covered an enormous amount of material
link |
focused on how hormones regulate feeding, hunger,
link |
and when one feels they don't need to eat,
link |
so-called satiety that you've had enough.
link |
As always, we covered a lot,
link |
but I could not be exhaustive about all the information
link |
related to this topic.
link |
It's just so vast.
link |
For instance, we did not talk about thyroid hormone,
link |
an extremely important hormone and pathway
link |
in the body and brain.
link |
We are going to do an episode related to thyroid
link |
and tools to regulate thyroid, I promise.
link |
Having seen this episode,
link |
you will be able to digest that material with far more ease.
link |
We also didn't talk about the fact
link |
that testosterone and estrogen can impact blood glucose
link |
in ways that are opposite to one another,
link |
that when estrogen levels are high,
link |
appetite tends to be reduced.
link |
When testosterone levels are high,
link |
appetite tends to increase.
link |
So there are all sorts of interesting interplays
link |
between the various hormones,
link |
but that's much too much of a deep dive for now.
link |
Right now, we've just focused today mainly
link |
on things like ghrelin,
link |
on things like melanocyte-simulating hormone,
link |
incredible, powerful hormone that can suppress appetite,
link |
on things like cholecystokinin that comes from the gut
link |
and can suppress appetite,
link |
on things like food emulsifiers,
link |
on the fact that when you're eating,
link |
you are amino acid seeking,
link |
even though you might not realize it,
link |
that you are also seeking out particular fatty acids,
link |
in particular, the conjugated linoleic acids and omega-3s.
link |
So I've tried to give you a number of actionable tools.
link |
Many of them are behavioral.
link |
Some of them are based on supplements
link |
or even prescription drugs.
link |
Again, always do what's best for your health
link |
and do that in company with a healthcare professional.
link |
I'm not a physician.
link |
I don't prescribe anything.
link |
I profess a lot of things.
link |
And I try and share with you what I think
link |
to be the best high quality peer-reviewed literature.
link |
So that's what I've done today.
link |
Really appreciate your time and attention.
link |
Many of you have continued to ask
link |
how you can help support the podcast,
link |
and we really appreciate the question.
link |
There are several ways to do that.
link |
The first is to like a video that you've seen
link |
and please subscribe to the YouTube channel.
link |
That's perhaps the most important thing
link |
about the YouTube channel.
link |
As well, leave us a comment.
link |
If you leave us a comment in the comment section,
link |
And please ask questions.
link |
Those questions and your comments do inform content
link |
of future episodes.
link |
Except the negative ones, we don't read.
link |
In addition, please subscribe on Apple and or Spotify
link |
or both if you like.
link |
And on Apple, you have the opportunity
link |
to leave us up to a five-star review
link |
if you feel we deserve that.
link |
Apple also lets you leave a comment,
link |
some feedback for us as well.
link |
Please do check out our sponsors
link |
that we mentioned at the beginning of the podcast.
link |
That's the best way perhaps to support the podcast.
link |
As well, we have a Patreon account.
link |
It's patreon.com slash Andrew Huberman,
link |
and there you can support the podcast
link |
at any level you like.
link |
And today, as well as in previous episodes,
link |
I've mentioned various supplements.
link |
If you're interested in seeing what supplements I take
link |
and you want to explore for some other supplements as well,
link |
you can go to Thorne, T-H-O-R-N-E.com slash U,
link |
the letter U, slash Huberman.
link |
Thorne is a supplement company that we believe
link |
to have the highest stringency in terms of what they put
link |
in the various supplements that they make
link |
and the amounts that they put are very accurate.
link |
They've partnered with the Mayo Clinic.
link |
They've partnered with all the major sports teams
link |
and we've partnered with them because we believe
link |
in their levels of stringency and accuracy.
link |
If you go to Thorne.com slash U slash Huberman,
link |
you can see what I take and you'll also get 20% off
link |
any of those supplements or any of the other supplements
link |
that Thorne makes.
link |
So that's where you can find out more about supplements
link |
and the ones that I take.
link |
And again, you get the 20% discount on any supplements
link |
that Thorne makes.
link |
And last but not least, thank you for being with us.
link |
I hope you learned a lot.
link |
I hope you explore some of the tools
link |
and that the mechanistic information that you learned today
link |
will serve you well.
link |
If you know anyone that's interested in this topic
link |
or you think that someone could benefit from it,
link |
please suggest the podcast to them as well.
link |
And most of all, thank you for your interest in science.
link |
And I'll see you in the next one.