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Behaviors That Alter Your Genes to Improve Your Health & Performance | Dr. Melissa Ilardo

Episode 230 May 26, 2025 1h 54m 16 insights
My guest is Dr. Melissa Ilardo, Ph.D., professor of biomedical informatics at the University of Utah. We discuss the interplay between genes and behaviors, including how certain behaviors can improve resilience by changing gene and organ function, as well as natural selection events happening in humans today. We also discuss the immune system–related reasons people find the smells of potential mates attractive—or not. We explore how physical and psychological traits are passed from one generation to the next, and the specific behaviors that can influence gene expression to improve health and performance. Melissa explains her lab’s pioneering research on breath-hold training and how activation of the dive reflex through breath holding can significantly improve oxygen availability by changing spleen size and function. We also delve into the medical uses and ethics of gene editing to cure disease in both babies and adults. For those interested in genes and inheritance, human performance, immune system function, and natural selection, this episode illustrates the remarkable interplay between human nature and nurture. Read the episode show notes at hubermanlab.com.
Actionable Insights

1. Safe Breath-Hold Diving Practice

Never attempt to test your breath-hold limits or free dive without expert instruction and supervision. Pushing past the natural urge to breathe underwater can lead to sudden unconsciousness and death due to unreliable oxygen sensors.

2. Prioritize Healthy Nighttime Breathing

Be aware of the dangers of sleep apnea, which involves holding your breath during sleep and can lead to low oxygen levels (hypoxemia) and other health complications. Ensure you are breathing properly at night, especially if you snore or have a large neck.

3. Leverage Mindset for Performance

Understand that your mindset significantly impacts your health and performance. Believing that stress is beneficial, or that you are capable of improving, can lead to better health outcomes and measurable biological changes, regardless of actual genetic predispositions.

4. Activate Mammalian Dive Reflex

To potentially boost oxygen availability, hold your breath and immerse your face in cold water (around 10°C/50°F). This triggers a physiological response that slows heart rate, constricts blood vessels, and contracts the spleen, releasing oxygen-rich red blood cells into circulation for an oxygen boost of about 10% during the breath hold.

5. Unconscious Mate Selection via Smell

When choosing a partner, be aware that your attraction to their natural body odor may unconsciously signal genetic compatibility. Humans tend to be drawn to mates whose immune system composition is most different from their own, which is beneficial for offspring diversity.

6. Prevent Disease Through Diverse Mating

Avoid reproduction with closely related individuals (e.g., siblings, cousins) to prevent the increased risk of offspring inheriting deleterious genetic variants and developing diseases.

7. Embrace Swimming for Health

Consider incorporating swimming or other water-based activities into your routine, especially as you age. It is a low-impact and natural way to move and exercise, contributing to overall fitness and health.

8. Darken Eyes with Sunlight Exposure

Eyes can darken with increased sunlight exposure, particularly to ultraviolet light, due to changes in pigmentation.

9. Understand Skill Specialization Trade-offs

Recognize that dedicating intense focus and training to become highly proficient in one specific skill or area often means less development in other potential abilities due to neuroplasticity’s inherent trade-offs.

10. Reject Genetic Determinism

Do not subscribe to the belief that your genes alone predetermine all aspects of your capabilities, potential, or life outcomes. Human traits are a complex interplay of genetic, environmental, and behavioral factors.

11. Personal Intelligence Not Inherited

Do not let the perceived intelligence of your family members dictate your own intellectual potential. Current scientific evidence suggests that intelligence is not highly heritable.

12. Redefine Evolutionary Fitness

Shift your understanding of ‘fitness’ in an evolutionary context from being ’the most capable’ to being ’the best adapted to your specific environment.’ Evolution favors the best fit, not necessarily the strongest or fastest.

13. Understand Epigenetic Inheritance

Be aware that significant environmental stressors, such as trauma or starvation, can induce epigenetic changes (modifications to gene expression) that may be passed down through generations. These changes can be adaptive in the original environment but potentially maladaptive in new conditions.

14. Recognize Diet’s Evolutionary Impact

Understand that diet is a powerful driver of natural selection. Historical dietary patterns have led to rapid genetic adaptations in human populations, influencing metabolic abilities and overall health over generations.

15. Acknowledge Genetic Mixing Effects

Recognize that increased globalization and inter-population mating are leading to novel genetic combinations in humans. This can result in both enhanced resilience and the emergence of new disease susceptibilities in offspring.

16. Grasp Mutation’s Deleterious Nature

Understand that the vast majority of genetic mutations are harmful or neutral, with beneficial mutations being rare and taking a very long time to become established within a population.