Shadowing Practice: Essentials: Micronutrients for Health & Longevity | Dr. Rhonda Patrick - Learn English Speaking with Video

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Welcome to Huberman Lab Essentials, where we revisit past episodes for the most potent and actionable science-based tools for mental health, physical health, and performance.
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I'm Andrew Huberman, and I'm a professor of neurobiology and ophthalmology at Stanford School of Medicine.
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And now for my discussion with Dr. Rhonda Patrick.
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Rhonda, welcome.
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I am so excited to be here having a conversation with you.
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Thank you.
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I have so many questions, but I want to start off with a kind of a a new but old theme that you're very familiar with.
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So temperature is a powerful stimulus, as we know for biology, and you've covered a lot of material related to the utility of cold,
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but also the utility of heat.
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And as I learn more and more from your content and from the various papers,
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it seems that cold can stimulate a number of things like increases in metabolism, brown fat, etc etc
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but heat seems to be able to do a lot of the same things
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and i wonder whether or not the discomfort of cold deliberate cold exposure
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and the discomfort of heat might be anchoring to the same pathway
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so would you mind sharing with us a little bit about what happens
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when we get into a cold environment on purpose and what happens
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when we get into a hot environment on purpose let's take a step back
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and i think you brought up a really important point here you know we evolve to intermittently challenge ourselves.
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And before we had Instacart, where you could basically just get your food delivered to you, we were out hunting, gathering,
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we were moving, and we had to be physically fit.
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You couldn't catch your prey if you were a sedentary slob, right?
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Physical activity was a part of everyday life.
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And caloric restriction or intermittent fasting was also a part of it.
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This is another type of challenge.
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We didn't always have a prey that we caught or maybe temperatures were such that, you know, there was nothing for us to gather, right?
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So food scarcity was something common as well as eating plants.
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So getting these compounds that I mentioned.
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So this is, these, these are all types of stress, intermittent challenges that activate genetic pathways in our bodies.
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These are often referred to in science as stress response pathways because they respond to a little bit of stress.
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You know, physical activity is strenuous.
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Fasting is a little bit stressful.
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Heat, cold, these things are all types of little intermittent challenges.
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There is a lot of crosstalk between these stressors and the genetic pathways that they activate.
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And these genetic pathways that are activated help you deal with stress.
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And they do it in a way that is not only beneficial to help you deal with that little stressor,
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exercise or heat, it stays active and it helps you deal with the stress of normal metabolism, normal immune function happening, just life, aging, right?
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So this concept is referred to as hormesis, right?
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This has a very profound antioxidant, anti-inflammatory response, or, you know, or whatever the response is.
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It could be the production of more stem cells or something like autophagy.
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These stress response pathways are activated, like, by a variety of stressors.
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So for example, one pathway is called heat shock proteins.
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And as their name would apply, one would go, oh, they're activated by heat.
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Well, correct.
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They are activated very robustly by heat, but you can eat a plant like broccoli sprouts, which is high in something called sulforaphane,
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and it activates heat shock proteins, among other things.
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It also activates a very powerful detoxification pathway called NRF2, which helps you detoxify things like carcinogens that you're exposed to.
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Cold also activates heat shock proteins.
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Now, you're going to more robustly activate heat shock proteins from heat versus cold, but there is some overlap.
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You mentioned plants as a route to creating intermittent challenge.
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There's a lot of debate, mostly online, about whether or not plants are our friends or plants are trying to kill us.
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The extreme version from the carnivore types, pure carnivore diet types, is that plants are trying to kill us.
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These generalizations are kind of, they're just not useful.
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And I think that a lot of people online in the blogosphere, they gravitate towards them because it's easier and it's a lot more sensational.
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But I do think with respect to plants, there's just evidence that sulforaphane is a very powerful activator of the NRF2 pathway.
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And this is a pathway that regulates a lot of genes
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and a lot of genes that are related to like glutathione production, genes that are involved in detoxifying compounds that we're exposed to from our food, like heterocyclic amines.
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In fact, There have been GWAS studies.
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So these are genetically, these are studies that are genome-wide associated studies for people listening that aren't familiar.
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People have a variety of versions of genes.
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And we have a gene that's able to make heterocyclic amines to basically detoxify it so it's not as harmful.
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And people that don't have a certain version of
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that that's doing it well are very prone to like colon cancer and increased cancer risk.
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But if they eat a lot of broccoli and cruciferous vegetables, it negates that risk because they're getting sulforaphane,
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which activates glutathione transferase and synthase genes.
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So glutathione is a major antioxidant in our brain and in our vascular system and our body, basically.
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There's evidence eating things like, you know, compounds that are like sulforaphane or broccoli or broccoli spouts,
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which have like 100, or up to 100 times more sulforaphane than broccoli, are activating glutathione in the brain.
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There's human evidence of that.
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Can we cook the broccoli and still get these nutrients, or do we have to eat it raw?
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I confess, eating raw broccoli is really aversive to me.
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So you do somewhat lower the sulforaphane levels when you cook the broccoli.
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However, there was a study a few years back
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that showed adding one gram of mustard seed powder ground to your cooked broccoli increases the sulforaphane by fourfold.
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Are you eating this every day or most days of the week?
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Well, I had shifted to supplementation with sulforaphane.
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There's another compound, and it's actually called moringa.
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It's like a cousin, and it activates the NRF2 pathway similarly to sulforaphane.
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And so I've been buying this Kuli Kuli moringa powder, and I add it to my smoothies.
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So if you had to do your kind of top three, your superstars of nutrients for the brain and body, sounds like we've got one set.
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What would you put in alongside them?
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Omega-3, the marine omega-3 fatty acids.
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So these are found in marine types of, you know, animals, fish, cold water fish, fatty fish.
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So there's three fatty acids.
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There's ALA, EPA, and DHA.
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If you get a high quality one, it's in a triglyceride form.
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So you've got like a glycerol backbone with three fatty acids and that's attached.
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And those are either DHA or the EPA.
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And, or if you have a lower quality fish oil supplement, then you have what's called ethyl ester form.
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And it's not that ethyl ester is bad.
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It just means take it with food.
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What's the dosage that you recommend people get?
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I think two grams is, is a good threshold.
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Now, the International Fish Oil Standards, IFSO, they have a website where they do third party testing
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of a ton of different fish oil supplements from around the world.
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and they measure the concentration of the omega-3 fatty acids in the actual supplement
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because nothing is ever what it says on the bottle.
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And then they also measure contaminants, so mercury, PCBs, dioxins, things that you'd find potentially in fish that are harmful to humans.
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And they also measure mercury and then oxidized fatty acids.
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So these omega-3 fatty acids are polyunsaturated fatty acids which are extremely prone to oxidation.
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So please keep your fish oil in the refrigerator.
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They give you a total oxidation number.
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It's called TOTOX.
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TOTOX is what we call it for short.
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And I like it to be at the least under 10, ideally under six.
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It's really hard to find all the right mixtures of things.
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But people can go to this website and they can browse through the products.
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What are some things
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that getting two to four grams of EPA per day is going to help with in our brain
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and the rest of our body?
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I personally think it is one of the most powerful anti-inflammatory dietary lifestyle things
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that we can get easily that is going to powerfully modulate the way you think, the way you feel, and the way you age.
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So there's been lots of work by Dr. Bill Harris and his collaborators looking at what is called the omega-3 index.
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So this is actually the omega-3 level in red blood cells.
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So red blood cells turn over about every 120 days.
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So it's a long-term marker of omega-3 status.
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He's done a variety of studies, observational studies, measuring the omega-3 index in people and then looking at their mortality risk, for example, or their cardiovascular disease risk.
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And what he has found is that most, first of all, standard American diet has omega-3 index of 5%.
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Japan, by contrast, has an omega-3 index of around 10 to 11%.
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Big, big difference there.
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And they also have about a five-year increased life expectancy compared to people in the US.
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What he showed in his data was that people that had a omega-3 index of 4% or lower, so close to what the standard American is, but a little bit lower,
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they had a five-year decreased life expectancy compared to people that had an 8% omega-3 index.
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People that are in the 4% omega-3 index range, in order to get to the 8%, right, the five-year increased life expectancy, if we're comparing the two groups,
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was to supplement with at least two grams.
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It was about two grams a day.
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And I think it was a little bit less if it was triglyceride form, but I think two grams is a good, safe number.
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So most Americans that are not eating a lot of fish
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and they're not supplementing are probably around a four to five percent omega-3 index.
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Where and how can somebody measure their omega-3 index?
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The omega-3 index is actually in the red blood cells and red blood cells take 120 days to turn over.
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So if you're going to do a baseline test, if you want to know before supplementing what your level is,
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you have to wait 120 days before doing the second test after supplementing to know how much you went up because
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that's how long it takes for your red blood cell to turn over.
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How is omega-3 and some of these other related lipids, how are they having these positive effects?
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What are some of the purported, reported, and known mechanisms?
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Some of the most well-known mechanisms do have to do with
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the omega-3 fatty acids being very powerful regulators of the inflammatory process in some way, shape, or form.
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Whether that has to do with resolvins that are produced, So from the metabolites of like DHA,
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for example, resolvins play a role in resolving inflammation.
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Like you want your inflammatory response to be activated when it's supposed to be, but you want to resolve that inflammation and inflammatory response in a timely manner, right?
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And resolvins help do that.
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And so resolvins are one.
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And then there's these specialized pro-mediating molecules, the SPMs, that also help resolve the inflammation.
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just so many different ways and inputs.
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And so when we talk about inflammation, honestly, that's a big general term, but you're talking about, when you're talking about serotonin release, you know, at the level of neurons,
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you know, we know that these inflammatory molecules cross the blood brain barrier.
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It's known that omega-3, actually specifically EPA, is able to help serotonin, inflammation inhibits the release of serotonin.
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And so EPA is actually able to blunt, inflammatory responses along with DHA as well.
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DHA does that through resolvins and stuff.
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And this then helps more serotonin be released because you're not having
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so much inflammation getting into the brain and affecting serotonin release, right?
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That's one mechanism.
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And then another would be, well, DHA itself has been shown.
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It's a very important fatty acid that makes up cell membranes, many cell membranes, including in our neurons.
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And as you very well know, Andrew, the structure
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and function of receptors of transporters these membrane bound proteins on
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the surface of our cells including neurons are affected by the membrane fluidity you know like how rigid
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and how fluid the cell membrane is and dha plays a role in
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that and so for example in animal studies if you make an animal deficient in dha their serotonin receptors dopamine receptors
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they're affected because the structure of them is affected through the fluidity of the membrane.
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There's been some animal studies in piglets and rodents as well showing that consuming
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phospholipid DHA during fetal brain development gets 10 times more DHA in the brain.
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If you're supplementing with your two to four grams of fish oil, I mean, you're going to get phospholipid form anyway because your body's going to make it.
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So we have these plant-based compounds.
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We have the omega-3s, so you pay a DHA.
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And then you mentioned there's a third category.
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What would you place in your third category of foods
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or supplement-based nutrients that brain and or body health can really benefit from?
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I mean, I think the most obvious would be vitamin D.
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70% of the US population has inadequate vitamin D levels, 70 of the whole US.
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So this is everyone.
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And so I think that insufficient levels defined as less than 30 nanograms per milliliter.
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And that's sort of defined by the endocrine society.
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There's been a lot of different meta-analyses of all cause mortality studies where vitamin D levels
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are really seem to be ideal between 40 to 60 nanograms per milliliter.
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So basically the point is that vitamin D is a steroid hormone,
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meaning it actually binds to a receptor and another receptor dimerizes with it, the retinoid receptor.
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And that complex goes into the nucleus of a cell where your DNA is.
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And it recognizes little sequences of DNA called vitamin D response elements.
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They're called VDREs.
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They're specific sequences of DNA that this complex vitamin D bound, the vitamin D receptor goes inside and recognizes and turns on a whole host of genes,
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turns off a whole host of genes.
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I mean, this is important stuff.
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What sorts of things is it stimulating?
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Okay, so first of all, it's regulating more than 5% of the protein-encoded human genome.
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One of the important things that you'll find interesting
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that I published on back in 2014 was that the VDREs and tryptophan hydroxylase 2,
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so for people listening, tryptophan hydroxylase is an enzyme that converts tryptophan into serotonin.
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So tryptophan is an amino acid that we get from our food.
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you convert serotonin you convert tryptophan into serotonin into the gut in the gut
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but you also do it in the brain however serotonin does not cross the blood brain barrier
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so tryptophan has to get into your brain
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and then you have to convert it to serotonin in your brain well the enzyme
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that does that in your brain is called tryptophan hydroxylase 2
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and it's activated by vitamin d
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but most people i mean this is regulating our immune immune cell immune system it's regulating our blood pressure,
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you know, all that water retention, you know, I mean, bone, of course, homeostasis, 5%, more than 5%.
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I mean, I can't tell you, like, so much.
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Where and what is a good starting range for people to think about D3 supplementation and, again, foods that can increase D3?
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So vitamin D3 is a good way to supplement with it.
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Their vitamin D2 would be a plant source you often find it fortified in like foods like milk.
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Yeah, vitamin D is naturally to some degree in fatty fish, but you're not going to correct a deficiency with eating fish for your vitamin D.
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Like you're either going to correct it with sun exposure, being in the right area, having the right amount of sun and being the right age.
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Because as you get old, you become very inefficient at making vitamin D3 in your skin.
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There have been a lot of these Mendelian randomization studies.
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So these are studies where scientists will look at people
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that have these common variations of a gene that's a little more than 1% of the population.
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So it's not a random mutation.
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It's actually found in a sizable percent of the population.
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A lot of times they'll look at genes
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that are also involved in SNPs
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that basically make the conversion of either vitamin D precursor into D3
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or D3 into 25-hydroxyvitamin D or into the active steroid hormone, which is 125-hydroxyvitamin D.
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So you're not looking at vitamin D levels at all.
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You're looking at just the SNPs.
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And you know if they have it, they have low vitamin D.
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People randomly have these genes and it's not like there's no health status.
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So these Mendelian randomization studies have found that people that can't convert into the precursor,
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the 25-hydroxy vitamin D, which is usually what's measured.
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It's the most stable form of vitamin D in the body.
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They have a higher all-cause mortality if they can't do it.
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So people that don't have it have a lower all-cause mortality.
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They have a higher respiratory related mortality.
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They have a higher cancer related mortality.
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They also are more likely to get multiple sclerosis.
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This has all been done with Mendelian randomization.
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And so it really does hammer home the importance of measuring your vitamin D levels and being very proactive about that.
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I mean, you can get it done anyway.
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Your doctor will do it.
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You ask him to do it, you know.
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So supplementation-wise, typically, if you don't have one of those SNPs,
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for the most part, taking 1,000 IUs of vitamin D will raise blood levels by around 5 nanograms per milliliter.
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So let's say you're deficient, you're 20 nanograms per milliliter, and you want to get to 40.
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You're going to need at least 4,000 IUs.
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So for people who are going to be stubborn and not get their D levels tested and simply say, oh, I'll just take some D3.
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Is that reasonable?
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1,000 to 5,000 IUs for most people will be reasonably safe.
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If we look at the literature, the scientific literature, it is extremely hard to get like hypercalcemia,
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which would be the major concern with really high levels of vitamin D3 supplementation.
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I mean, we're talking like hundreds of thousands of IU a day for a long time.
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And by the way, there have been studies looking at people that are deficient in vitamin D In this case,
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it was African-Americans that were given a 4,000 IU a day vitamin D supplement to bring them back to sufficient levels.
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And this was a smaller study than I would like, but it reversed their epigenetic aging by like three years.
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Because, again, it's a hormone.
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It's regulating more than 5% of your protein encoding human genome.
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So if I'm taking vitamin D3, I still need to get out into the sun, correct?
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Absolutely.
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Okay, so we've talked about these plant-based compounds, the omega-3s and D3.
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Is there anything that fit to supplement-based or food-based compounds that you think are especially useful for brain and or body health?
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I do think magnesium is important in there as well.
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I mean, I think, you know, again, About 40% of the U.S population doesn't get enough magnesium.
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It's an essential mineral we're supposed to be getting from our diet.
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Magnesium is also involved in making ATP, the energetic currency of our cells.
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Basically, all of our cells need ATP to do anything.
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And it's also involved in utilizing ATP as well as DNA repair enzymes.
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These are enzymes that are involved in repairing damage to our DNA.
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I personally think that magnesium insufficiency causes an insidious type of damage.
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daily that you can't look in the mirror and see.
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Like when you're deficient in vitamin C, you're like, my gums are falling apart.
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I have scurvy, right?
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But like, you can't see DNA damage.
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You can't see it, but it's happening.
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It's happening right now in my body and it's happening in your body.
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It's happening.
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Normal metabolism is happening, you know, every day.
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But we repair that damage.
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We have repair enzymes in our body called DNA repair enzymes.
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They require magnesium.
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Magnesium is a cofactor for them.
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Well, magnesium is at the center of a chlorophyll molecule.
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Chlorophyll is what gives plants their green color.
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So dark leafy greens are high in magnesium.
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Basically, what is the 40% insufficiency in the US tell us?
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People aren't eating their greens.
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They're eating their packaged food, they're eating their processed food.
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The standard American diet isn't really high in dark leafy greens.
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So kale, what are some other examples?
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Kale, spinach, chard, like Swiss chard, rainbow chard, romaine lettuce.
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So supplementation with magnesium, it can cause GI distress at like high doses.
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I personally like to take around 130 or 135 milligrams.
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That way it's not like a huge bolus to my gut.
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You can take like magnesium three and eight, for example, and it doesn't affect the gut as much.
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I would say malate would be the best.
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That has to do with the short chain out fatty acids being good for the gut.
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I think malate's awesome.
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And I always try to eat green apples.
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They're really high in malic acid.
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Oh, good to know.
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And tart cherries, tart cherries are really high in it as well.
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You've talked a lot about the use of deliberate cold exposure.
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What sort of activity or stimulus do you think is a reasonable and particularly potent one to use in terms of cold?
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So today I did three minutes at 49 degrees Fahrenheit.
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I have a cold tub.
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I definitely do cold when I'm going to do a podcast, when I'm going to give a talk, or when I'm anxious.
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I feel good.
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I feel more focused, which is why I usually do it before any type of public speaking.
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So the mood enhancing effects that you report, those are almost certainly a consequence of having slowly elevating, but significantly elevated dopamine that goes on for hours.
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That's almost a dreamlike profile for dopamine because most everything else, like an Adderall, a Ritalin, a cup of coffee and a pre-workout drink
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or something is gonna give you a big spike in adrenaline and dopamine and a big crash.
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But the advantage of not doing it too often is that you're not cold adapted.
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Now it's very hard for anyone to get truly cold adapted.
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Some people start to look forward to the cold.
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And what I think they're looking forward to is the feeling afterward, that dopamine rush.
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But if you get cold adapted, then it certainly blunts some of the effect.
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But I want to be cold adapted because that means I have more mitochondria in my adipose tissue and perhaps even muscle, like that's been shown.
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Shivering is a very inefficient way to produce heat, which is what your body's trying to do and it's exposed to cold.
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And your muscles are basically contracting and producing heat from that, but that's just not very efficient.
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So the more eloquent way to do it, or elegant, I guess, way to do it is,
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you know, to basically have your mitochondria produce tons and tons of heat.
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So mitochondria are these little organelles inside of your cells that are responsible for producing energy.
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Usually that's in the form of adenosine triphosphate,
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ATP, And that's what lets everything function inside your body from your neurotransmitter production to your heart beating,
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etc. Basically, your mitochondria, they're like a little battery.
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So they have a double membrane, first of all, their structure.
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But they have a negative charge on the inside and they have a positive charge on the inner membrane.
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Basically, you can uncouple that charge.
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And so that positive charge, protons start leaking out of the mitochondria.
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And your mitochondria freak out.
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So this is called uncoupling it.
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and they start to, it's maximum respiration as we call it.
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They try to make as much energy.
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They're like, I got to get that proton back, that gradient, the electrochemical gradient.
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And so they just go insane.
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And in this case, it's uncoupled energy.
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So the energy they're making is actually heat, not ATP.
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But heat is, but you're essentially burning substrate.
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So who cares?
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You're burning glucose, you're burning lipids, you're basically burning things and making heat.
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And so that's what uncoupling does.
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And that is a much more efficient way of producing heat than shivering.
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So as you become more adapted, maybe the longer duration that you've stayed in the cold or the more times you've done it, you'll no longer shiver anymore.
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You will start to then just do this uncoupling type of thermogenesis, as it's called.
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And another type of adaptation that occurs is you actually produce more mitochondria in your adipose tissue.
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And that actually happens also regulated by norepinephrine or noreadrenaline through a protein called PGC1-alpha.
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And what that protein does is it makes more mitochondria in your adipose cells.
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So per adipose cell, you're getting more mitochondria.
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It's a beautiful way to basically make more heat when you're, it's one of those things where it's like, it's, it's, your body's going, okay, I'm going to be exposed to this cold next time.
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How can I make sure I don't die?
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Oh, I can have more mitochondria and I'm going to make more heat.
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And so you're making more mitochondria in your adipose tissue.
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And, and this is often referred to as like the browning of fat.
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And the reason for that is because if you look under a microscope at a lipid droplet, basically a fat cell, not a lipid drop,
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but an adipocyte, you'll find that it looks darker because there's more mitochondria in there.
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So it's referred to as browning fat.
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That's awesome.
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You want more mitochondria in your muscle.
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It's associated with improved muscle mass, improved endurance.
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I mean, mitochondria are essentially either the making energy in your cell.
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And we don't make more mitochondria normally.
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Like you have certain inputs, high-intensity interval training, exercise can do it.
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Your cells are turning over, you make new cells, you replace old ones.
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With your mitochondria, you don't really do that for the most part.
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You can.
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Mitochondrial biogenesis does happen, but you have to stimulate it to happen.
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And what happens with your mitochondria is they essentially are bobbing around inside of your cells
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and then they fuse with other mitochondria, exchange all their content, mitochondrial DNA, and then fizz back apart.
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And that's how they kind of stay young-ish.
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But as you age, you keep doing that with the same pool of mitochondria, and you're going I'm gonna get a bunch of old mitochondria mixing old stuff together, right?
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So why wouldn't you wanna like bring up new, healthy, young mitochondria into that pool, right?
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So in my mind, when I hear mitochondrial biogenesis, I'm like aging.
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Like that's the first thing I think of.
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So anyways, cold exposure does that.
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What sort of cardiovascular or other types of training do you do?
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Do you do HIIT?
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I imagine you are doing high intensity interval training.
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I do a lot of high intensity interval Tabata's on a stationary cycle three times a week.
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And I do a 10 minute, just 10, because it's efficient and I push my ass.
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I push myself really hard.
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That's the Tabata.
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It's 20 seconds on, 10 seconds off.
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And it's 10 minutes.
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And on means you're pedaling like your life depended on it.
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You're maxing it.
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And then I always have my sauna on preheating up.
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I get it to about 189 degrees Fahrenheit.
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I hop right in the sauna after my Peloton.
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I literally like down a bunch of water and then I get in and then I like either read a science paper, prepare for a presentation or a podcast,
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or I hash over things in my mind.
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And it's interesting because I would use the sauna to memorize things.
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I don't know if it has to do with the stress response.
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Like when you have an emotional trigger, like you remember things better, right?
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Absolutely.
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The idea that being in this semi-stressful environment would aid in the learning
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and retention of information is really well substantiated by this.
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Beautiful work by a guy named James McGaw.
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He was at UC Irvine for a while.
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And then I think at University of Arizona as well.
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They have a great memory group at both places, very strong in learning and memory, both places.
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And he was the one that really defined this kind of inverted U-shaped function for the relationship between adrenaline and memory.
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Basically, if you're too relaxed and not stressed enough, you're not going to remember any information.
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At peak levels of stress, you actually are a memory machine, at least within the context of whatever it is you're trying to learn.
392
So what you're describing very well matches with that.
393
And then of course it tapers off as you really increase
394
adrenaline to the point where people are starting to lose autonomic function, where they're panicking basically.
395
The other thing that I'd like to ask you about is in the sauna, of course, there's vasodilation and perfusion of blood to the brain is a wonderful way to enhance cognition.
396
The vasodilation does occur.
397
So there's a lot of overlap between moderate intensity, aerobic exercise and heat stress.
398
And as you can imagine, when you're exercising, you're elevating your core body temperature, you're sweating.
399
When you're actually in the sauna, blood does get redistributed to the skin to facilitate sweating.
400
But much like exercise, blood flow in general is improved to the brain, to the muscles, everywhere.
401
So, you know, I think generally speaking that, and this, you know, there's studies showing
402
that sauna use is associated with a much lower risk of dementia
403
and Alzheimer's disease like people
404
that use it four to seven times a week have greater than 60% reduction in dementia risk
405
and Alzheimer's disease risk compared to people that use it only one time a week.
406
People that use it two to three times a week have something like a little greater than 20% reduction in risk.
407
There's a dose-dependent effect on dementia risk and Alzheimer's disease risk.
408
It also has a profound, like there's a big link between the cardiovascular system and the brain.
409
Obviously blood flow, a big one, right?
410
You need to get blood to your brain.
411
But cardiovascular mortality, so mortality from cardiovascular disease, if people use, or actually this was men, if men use the sauna four to seven times a week,
412
it's a 50% reduction in cardiovascular-related mortality compared to one time a week.
413
Again, dose-dependent manner two to three times a week is something like 24% lower death from cardiovascular disease.
414
There's also lower, you know, sudden cardiac death, like a heart attack.
415
That's like 60-something, greater than 60% lower if men use it four to seven times a week versus once.
416
Again, a dose-dependent thing.
417
And this is all work from Dr. Jari Laukunen.
418
He's in the University of Eastern Finland and just one of the world experts on sauna use.
419
The more you do the sauna or any sort of heat stress, whether it's a hot tub
420
or jacuzzi, you become adapted you're basically start to sweat at a lower core body temperature to cool yourself down.
421
All these sort of physiological changes start to happen earlier.
422
And so I stay in for like 30 minutes.
423
I mean, so I stay in a long time.
424
That's a lot.
425
You have to listen to your body.
426
Most of the studies that I just talked about were from the duration, the time spent in the sauna when I said 50% reduction in cardiovascular disease related death.
427
What was shown was that men that were in the sauna for only 11 minutes, even if they used it four to seven times a week
428
that reduction was only like eight percent instead of 50 it had to be greater than 19 minutes
429
so like 20 minutes is the sweet spot at about 174 degrees fahrenheit to me that's a very strong data
430
that this is more causal than some you know corollary thing
431
because that's always the problem with observational studies including these
432
which they corrected for a whole host of factors like cholesterol you know exercise just everything everything under the sun.
433
I mean, they correct it for those.
434
And on top of that, you have the dose-dependent nature of the duration, the time spent in the sauna, and the frequency.
435
So to me, it's like something's going on here.
436
Plus there's been studies, intervention studies where it's like,
437
you know, comparing directly head-to-head moderate intensity aerobic exercise on a stationary cycle to 20 minutes in a sauna.
438
They're physiologically the same things happen.
439
So heart rate elevates while you're doing the activity.
440
blood pressure increases while you're doing the activity
441
but then after heart rate decreases resting heart rate decreases below baseline blood pressure is improved
442
so it decreases below baseline this is happening the same in moderate intensity cycling versus sauna
443
so again the sauna like this heat stress there's something about it
444
that really mimics this moderate intensity aerobic exercise
445
which is really great for people that can't go for a run that can't even get on a bike So, you know, disabled people, granted, there are some safety concerns,
446
they're pretty mild, but they do exist.
447
You know, so people that had a recent heart attack or have some rare kind of heart disease or problem, drinking alcohol, never do that.
448
Elderly people prone to low blood pressure, always talk to a physician before doing the sauna.
449
It is stressful.
450
Pregnant.
451
Pregnant women.
452
Oh, yeah, I definitely avoided saunas when I was pregnant.
453
So for those healthy fit people out there already exercising, there's a synergistic effect by also adding a sauna into that routine.
454
And to me, that's great.
455
And there's so many beneficial things happening with the heat stress.
456
In addition to like mimicking aerobic exercise, there's the heat shock proteins that we talked about earlier.
457
Many animal studies have been done looking at Alzheimer's disease,
458
a human-like Alzheimer's disease in a rodent and heat shock proteins protecting from it.
459
So heat shock proteins are robustly activated in humans.
460
This has been shown to even 50% higher over baseline levels after just 30 minutes at 163 degrees Fahrenheit in the sauna.
461
and they stay activated at least in rodents for 48 hours at least.
462
So having these heat shock proteins around, making sure they're properly taking care of our proteins
463
so they're not aggregating in our brains
464
and in our plaques could be another potential way that sauna is protecting from Alzheimer's disease
465
and other cardiovascular health as well as longevity.
466
I know people are probably desperate to know what if they don't have a sauna.
467
I could imagine that a hot bath would work almost as well.
468
Yeah, so there's been some studies looking at, for example, activation of heat shock proteins, also brain drive neurotrophic factor increases with heat stress.
469
And so the hot bath at around 104 degrees Fahrenheit, which is typically what studies will use for temperature, and it's 20 minutes from the shoulders down.
470
And that is like a very robust activation of heat shock proteins and in brain drive neurotrophic factor.
471
And then heat shock proteins are also protecting against muscle atrophy.
472
So that's also having to do with the protein structure and the muscle tissue as well.
473
And this has been studies in animal, you know, animal data, as well as some recent human data as well.
474
It was local hypothermia or local heat treatment, but essentially it showed that it protected.
475
I mean, it was like, there was a study where they were looking at muscle disuse and it was,
476
it was something like the local heat treatment prevented like almost 40% of the muscle atrophy from disuse.
477
We covered a lot of territory, but I just want to thank you again.
478
It was extremely thorough and extremely informative on behalf of the listeners and just directly from me.
479
Thank you so much for your time.
480
I learned a ton.
481
My pleasure.
482
Thanks for having me on.
483
It was really awesome conversation.
484
So I enjoyed it a lot.
485
Let's do it again.
486
Totally.
487
Great.

Vocabulary and speaking notes for this lesson

This video has 487 sentences and 6195 words to shadow. The speech runs for 35:32. The speaker talks at a natural 174 words per minute, close to everyday conversation. Only 79% of the words are among the 3,000 most common in English, so the vocabulary is demanding.

Key vocabulary in this video

15 words from the video worth learning, with pronunciation and meaning:

WordPronunciationMeaning
vitamin noun/ˈvɪt.ə.mɪn/Any of a specific group of organic compounds essential in small quantities for healthy human growth, metabolism, development, and body function. They are found…
omega noun/oʊˈmeɪ.ɡə/The twenty-fourth letter of the Classical and the Modern Greek alphabet, and the twenty-eighth letter of the Old and the Ancient Greek alphabet, i.e. the last…
acid noun/ˈæsɪd/A sour substance.
shock noun/ʃɔk/A sudden, heavy impact.
gene noun/d͡ʒiːn/A theoretical unit of heredity of living organisms which may take several values and (in principle) predetermines a precise trait of an organism's form…
pathway noun/ˈpæθˌweɪ/A footpath or other path or track.
activate verb/ˈæktɪˌveɪt/To encourage development or induce increased activity; to stimulate.
muscle noun/ˈmʌs.əl/A contractile form of tissue which animals use to effect movement.
mortality noun/mɔɹˈtælɪti/The state of being susceptible to death.
cardiovascular adjective/ˌkɑːdi.əʊˈvæskjʊlə(ɹ)/Relating to the circulatory system, that is the heart and blood vessels.
broccoli noun/ˈbɹɑ.kə.li/A plant, Brassica oleracea var. italica, of the cabbage family, Brassicaceae; especially, the tree-shaped flower and stalk that are eaten as a vegetable.
compound noun/ˈkɑmpaʊnd/Anything made by combining several things.
intensity noun/ɪnˈtɛnsɪti/The quality of being intense.
supplement noun/ˈsʌp.lɪ.mənt/Something added; especially, such an addition added to make up for a deficiency.
receptor noun/ɹɪˈsɛp.tə/A protein on a cell wall that binds with specific molecules so that they can be absorbed into the cell in order to control certain functions.

Phrasal verbs you will hear

WordPronunciationMeaning
turn over verbTo flip over; to rotate uppermost to bottom.
bring up verbTo mention.
look forward to verbTo anticipate, expect, or wait for, especially with a feeling of approval or pleasure; to be excited or eager to.
fall apart verbTo disintegrate, to break into pieces.
go up verbTo move upwards.
make up verb/ˌmeɪk ˈʌp/To constitute, to compose.
step back verb/stɛp ˈbæk/To stop what one is doing and evaluate the current situation.
turn off verbTo power down, to switch off, to put out of operation, to deactivate (an appliance, light, mechanism, functionality etc.).

Pronunciation to watch

The speaker uses 115 contractions and reduced forms, such as you're, they're, I'm. Say them the short way, as you hear them.

  • The “th” sounds: pathway /ˈpæθˌweɪ/, bath /bɑːθ/, gather /ˈɡæðɚ/, threshold /ˈθɹɛʃ(h)oʊld/, thorough /ˈθʌɹoʊ/
  • The “sh” and “zh” sounds: shock /ʃɔk/, inflammation /ɪnfləˈmeɪ̯ʃən/, reduction /ɹɪˈdʌk.ʃən/, exposure /ɪkˈspəʊ.ʒə(ɹ)/, essentially /ɪˈsɛnʃəli/
  • Long words — get the stress right: mortality /mɔɹˈtælɪti/, cardiovascular /ˌkɑːdi.əʊˈvæskjʊlə(ɹ)/, intensity /ɪnˈtɛnsɪti/, inflammatory /ɪnˈflæmət(ə)ɹi/, inflammation /ɪnfləˈmeɪ̯ʃən/

How to practise with this video

  1. Listen to the whole video once without speaking and note the words you do not know.
  2. Start at 0.75× speed, shadow it sentence by sentence, then go back to normal speed once it feels easy.
  3. Record yourself and compare with the original, paying attention to words like vitamin, omega, acid.

Grammar in this video

The structures the speaker uses most, with the exact words from the video:

StructureIn the video
Present perfect have/has + past participle — a past action that still matters nowyou've covered · have been · has found
Passive voice be + past participle — the focus is on what happens, not who does itare often referred · are activated · is referred
Relative clauses who / which + clause — extra information about a person or thingsprouts, which is · acids which are · hormone, which is

What is the Shadowing Technique?

Shadowing is a science-backed language learning technique originally developed for professional interpreter training and popularized by polyglot Dr. Alexander Arguelles. The method is simple but powerful: you listen to native English audio and immediately repeat it out loud — like a shadow following the speaker with just a 1–2 second delay. Unlike passive listening or grammar drills, shadowing forces your brain and mouth muscles to simultaneously process and reproduce real speech patterns. Research shows it significantly improves pronunciation accuracy, intonation, rhythm, connected speech, listening comprehension, and speaking fluency — making it one of the most effective methods for IELTS Speaking preparation and real-world English communication.

Shadowing technique: read the full step-by-step guide →