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[@hubermanlab] Behaviors That Alter Your Genes to Improve Your Health & Performance | Dr. Melissa Ilardo

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@hubermanlab - "Behaviors That Alter Your Genes to Improve Your Health & Performance | Dr. Melissa Ilardo"

Link: https://youtu.be/ijdpvG24IkE

Short Summary​

Number One Action Item/Takeaway: Explore the mammalian dive reflex by safely experimenting with breath-holding and facial immersion in cold water to potentially improve oxygen availability and potentially explore long-term benefits in immune system function.

Executive Summary: This Huberman Lab podcast episode explores the influence of behavior on human genetics and gene expression, featuring Dr. Melissa Ardo. The discussion highlights examples of how behavior, such as breath-hold diving in specific populations, can rapidly alter gene expression and even lead to inheritable changes. The episode also delves into the ethical considerations of gene editing and touches on human mate selection based on immune system compatibility, as indicated by body odor.

Key Quotes​

Here are 5 direct quotes from the provided transcript that I found particularly insightful or interesting:

  1. "Everyone with blue eyes descends from the same person." - This surprising statement highlights the remarkable origin of a common physical trait.

  2. "...the more different they were in that um the more attracted they were to that smell. It's kind of amazing, right? Like that smell, which we just think of as I like this body odor. I don't like this body odor. I love this body odor is um kind of a proxy for gene expression related to the immune system of the offspring that you haven't even had yet with this smelly t-shirt owning person. It's kind of wild." - This illustrates the unconscious and complex selection mechanisms at play in human mate choice.

  3. "It's about 10% in in most of us." (Referring to the oxygen boost from spleen contraction during the mammalian dive reflex) - This highlights the significant physiological impact of the dive reflex, revealing a previously unappreciated adaptation.

  4. "I think that like is there something to being in water that just generally is good for us? I would imagine I shower, I bathe. But, you know, is there something good about swimming or floating or diving just for our general human physiology that we're aware of?" - Huberman poses an interesting question about the potential benefits of water immersion beyond basic hygiene.

  5. "I think it's it's interesting how much the idea that we're genetically predisposed to something or um you know we're genetically better at something can actually influence how we are at that thing." - This speaks to the powerful impact of belief and mindset on performance, even independent of actual genetic potential.

Detailed Summary​

Here's a detailed summary of the YouTube video transcript, excluding advertisements:

  • Introduction to Human Genetics and Epigenetics:

    • Dr. Andrew Huberman introduces Dr. Melissa Ardo, an expert in human genetics and epigenetics.
    • The video explores how behavior and environment can modify gene expression across generations.
    • The goal is to make complex genetic concepts accessible and practical.

  • Nature vs. Nurture:

    • The question of how much of our DNA is modifiable by our environment and choices is explored.
    • The understanding of how we can modify gene expression is constantly evolving.
    • While some aspects are genetically determined, there is a significant amount that can be changed.

  • Mendelian Genetics and Heritability:

    • Eye color is used as an example of Mendelian genetics and heritability.
    • While eye color is largely determined by parents' genes, there are exceptions and possibilities.
    • Dr. Ardo's work focuses on genetic expression that changes based on behavior or environmental selection.

  • Evolution of Eye Color:

    • All blue-eyed people are believed to descend from a single individual with that mutation.
    • Green eyes likely arose from multiple individuals due to different genes.
    • UV exposure darkens eyes.

  • Rapid Changes in Gene Expression and Epigenetics:

    • Genes are constantly changing expression based on environmental stimuli.
    • Epigenetic changes, modifications to the genome, can be passed down through generations.
    • Trauma and famine can leave epigenetic marks influencing subsequent generations.

  • Hybrid Vigor and Mate Selection:

    • Humans and mice select mates with immune systems that are most different from their own.
    • Smell plays a role in mate selection, signaling immune system differences.
    • Globalization leads to unique genetic combinations with potential benefits and risks.
    • Nature discourages reproducing with people that are too close genetically.

  • Human Evolution Continues:

    • Humans are still evolving as they travel, meet people from different backgrounds, and have children with people from origin populations that presumably have never mixed before in the course of human evolution.
    • Introduction of new genetic material is a driver of adaptation.
    • The Tibetan high-altitude adaptation originated from interbreeding with the hominid group, Denisovans.

  • Homo Sapiens and Other Primates:

    • Homo sapiens were able to reproduce with other species of primates.

  • Evolution's "Best Fit" over "Fittest":

    • Evolution is not a linear trajectory towards perfection.
    • It's about fitting in with the environment, not being the "most fit."
    • It's easier to lose a trait than to evolve one.

  • Spontaneous Mutations:

    • Most mutations are delotterious and do not result in improvements in a particular species.

  • X-Men and Real-Life Super Abilities:

    • There's variation in all human genomes, and occasionally, mutations provide incredible abilities.
    • Underwater free divers are studied as an example of behavior shaping fixed body properties.

  • The Bajau and Moken People of Southeast Asia

    • These groups of people are excellent free divers.
    • Some learn to swim before they learn to walk
    • Cultural knowledge is integrated into the practice and that's passed on from you know generation to generation.
    • The experts in the village are those that keep the traditional diving alive.

  • The Bajau Divers and the Mammalian Dive Reflex:

    • The Bajau are sea nomads skilled in breath-hold diving.
    • They can hold their breath for extended periods and dive to great depths.
    • The mammalian dive reflex is activated by breath-holding and cold water immersion.

  • Spleen Contraction and Oxygen Boost:

    • The dive reflex causes the heart rate to slow, blood vessels in extremities to constrict, and the spleen to contract.
    • Spleen contraction releases oxygen-rich red blood cells into circulation, providing a ~10% oxygen boost.
    • Horses and greyhounds have large spleens due to bouts of extreme exercise, but horses and greyhounds may incorporate breath holds as a way to deploy red blood cells.
    • The facial immersion is crucial to triggering this response which you know runs through your face.

  • Origin of the Dive Reflex:

    • The precise origin of the dive reflex in humans is unknown.
    • Aquatic ape hypothesis vs ancient mammalian ancestors.

  • Babies underwater have an innate response to hold their breath.

    • Some bajau would pass their infants under the canoe to test this response.

  • The Bajau Divers and Spleen Size:

    • The Bajau have larger spleens compared to a nearby farming population (50% larger on average).
    • This is likely genetic, though diving might increase spleen size.

  • Thyroid Hormone and Spleen Function:

    • A gene evolving in the Bajau population correlates with higher than average thyroid hormone levels.
    • Higher thyroid hormone levels increase red blood cell production and spleen size.
    • This is an erythropoietin (EPO)-independent mechanism.

  • Spleen Benefit for Robustness of the Immune System

    • Sticking one's face in a bowl of cold water, 50° as long as you can hold your breath may afford advantage to the immune system.

  • Women Divers and Cardiovascular Health:

    • Henyo (sea women) in Korea dive in cold water without wetsuits, often throughout pregnancy.
    • Averages ages of these sea women are 70 years old.
    • This has significantly shaped this population.
    • The average dive of these women are 30 feet.
    • May be the females better for diving in cold temperatures
    • Genetic selection that happens during pregnancy can change evolution rapidly.

  • Henyo Adaptations:

    • Diving in extremely cold water throughout pregnancy.
    • This has created very fast examples of evolution.
    • A cultural observation is that Women are generally more cold tolerant, at least in terms of being willing to embrace it the first time around.

  • Cardiovascular Adaptations of Korean Divers

    • Slows heart rate even more to conserve oxygen
    • Lower blood pressure with diastolic

  • Benefits of Exercise Like the Korean Divers

    • More people are continuing to dive and there is seeming health and robustness.

  • Evolution Can be Seen as a Driver of Diet

    • The Greenlandic Inuit had a huge part of their diet was marine mammals that have really high lipid content. And so they actually evolved to be able to better metabolize those lipids so that it wouldn't, you know, kill them from heart disease or something like that.

  • Vision of Underwater Divers Can Adapt

    • Mochin children had better eyesight underwater than European children.
    • With training the European children can achieve the same eyesight underwater.
    • Just because one can train someone to be at the same level of someone else does not mean that that person didn't have an advantage.

  • Super Performances can be Influenced by Genetics

    • Elite runners from Ethiopia may come from high altitudes.

  • Human Super Performance of Cognitive Performance

    • Correlation of people who are in STEM fields come from a line of people with autism.
    • People with autism have ability to hyperfocus.
    • There are advantages despite any other disadvantages.
    • There may be faster processing speeds with those who have tourettes.

  • The Ethics of Genetics and Genetic Engineering

    • The use of crisper to modify the genome of babies is explored.

    • In one case, an HIV gene was mutated in babies.

    • CRISPR is still a relatively blunt tool that isn't as precise as we would like it to be for this type of gene editing.

    • Ethically, it is important to think about enhancement versus correction, where one finds the line between the two.

  • The Power Genes Have

    • Genes and natural selection has power we need to underestimate.

  • Admixing

    • When different ancestry populations mix.

This bullet point list captures the main points of the video transcript. It highlights the key topics, arguments, and information discussed, providing a useful summary of the content.