How to Enhance Your Immune System | Dr. Roger Seheult
Here are the top 20 key takeaways from Andrew Huberman's fascinating conversation with Dr. Roger Seheult about evidence-based strategies to enhance your immune system and optimize your health.
1. The NEW START framework for health
Dr. Seheult introduces the NEW START framework as a comprehensive approach to health and immune system function. This mnemonic stands for Nutrition, Exercise, Water, Sunlight, Temperance, Air, Rest, and Trust.
Each element contributes to overall health and immune function in different but complementary ways. This framework provides a holistic approach to health maintenance rather than focusing solely on medications or isolated interventions.
2. Sunlight's profound effects through infrared light
Sunlight provides far more benefits than just vitamin D production. About 52% of the sun's energy comes in the infrared spectrum, which can penetrate deeply into the body's tissues—up to 8 centimeters.
This infrared light interacts with mitochondria, improving their efficiency and triggering on-site production of melatonin, which serves as a powerful antioxidant. This process helps combat oxidative stress and supports cellular health throughout the body, not just at the skin's surface.
3. Intracellular melatonin production
Mitochondria produce melatonin on-site in concentrations orders of magnitude higher than what's produced in the pineal gland. Unlike pineal melatonin, which regulates sleep, this intracellular melatonin functions as a powerful antioxidant.
This mitochondrial melatonin helps neutralize reactive oxygen species produced during energy production. It supports the glutathione system and helps maintain mitochondrial function, which declines with age and is implicated in many chronic diseases.
4. Green spaces enhance infrared light exposure
Plants and chlorophyll highly reflect infrared light, making green spaces beneficial for infrared light exposure. In green environments, you might receive 2-4 times more infrared light compared to non-green settings.
A study in Louisville showed that planting 8,000 mature trees in a four-square-mile area resulted in a 13% reduction in residents' C-reactive protein (an inflammation marker) after 2-3 years. This reduction occurred without changes in income, exercise programs, or other variables.
5. Mitochondrial dysfunction underlies many chronic diseases
After age 40, mitochondrial ATP production drops by approximately 70%, contributing to numerous chronic diseases. Conditions like diabetes, hypertension, heart disease, and dementia all have mitochondrial dysfunction at their root.
Improving mitochondrial function through sunlight exposure and other interventions may help prevent or mitigate these conditions. The "mitochondrial theory of aging" suggests that maintaining mitochondrial health is crucial for longevity and disease prevention.
6. Indoor environments lack beneficial light wavelengths
Modern indoor environments often lack the full spectrum of light we evolved with, especially red and infrared wavelengths. LED lights are energy-efficient because they don't produce infrared or ultraviolet wavelengths, but this creates a biologically incomplete light spectrum.
Additionally, low-E glass windows filter out infrared light to improve energy efficiency. This combination means people indoors are missing crucial light wavelengths that support biological processes, particularly mitochondrial function.
7. Sunlight exposure reduces influenza risk
Harvard Kennedy School research showed that sunlight strongly protects against influenza. This was demonstrated during the 2009 H1N1 pandemic, which provided a unique opportunity to study influenza patterns outside the typical winter season.
A study of COVID-19 surges in Europe found that latitude perfectly predicted surge dates, with northern countries experiencing surges earlier as daylight hours shortened. Temperature and humidity showed no correlation, suggesting sunlight's protective effect against respiratory viruses.
8. Just 15-20 minutes of sunlight daily is beneficial
Studies suggest that just 15-20 minutes of daily sunlight exposure can significantly benefit health. A Brazilian study showed that COVID-19 patients receiving 15 minutes of near-infrared light (940nm) for seven days were discharged from the hospital four days earlier than the control group.
Dr. Seheult recommends taking lunch breaks outside to get sunlight exposure, even in winter when outdoor time is limited. For those in regions with limited natural sunlight, specific red light therapy devices can provide similar benefits, especially during winter months.
9. Heat therapy boosts immune function through interferon
Raising body temperature to around 38-39°C (100.4-102.2°F) can trigger a 10-fold increase in interferon production. Interferon is a powerful immune molecule with broad antiviral properties that can combat numerous viral variants.
Heat therapy was used successfully during the 1918 Spanish flu pandemic in sanatoriums that emphasized hydrotherapy and sunlight. These facilities reported significantly lower rates of pneumonia compared to conventional hospitals. Heat therapy can be applied through hot baths, saunas, or even hot compresses.
10. Cold exposure enhances white blood cell circulation
Brief cold exposure following heat therapy causes vasoconstriction that triggers demargination of white blood cells. This process knocks white blood cells off the blood vessel walls and into circulation, enhancing immune surveillance.
Cold exposure also helps "lock in" the heat built up during heat therapy, allowing the elevated temperature to persist longer. The combination of heat followed by brief cold exposure may maximize immune benefits while minimizing the discomfort of prolonged heat exposure.
11. N-acetylcysteine (NAC) reduces flu symptoms
A placebo-controlled study showed that taking 600mg of N-acetylcysteine (NAC) twice daily during flu season significantly reduced symptom severity, particularly for runny nose and sore throat. While it didn't reduce infection rates, it dramatically reduced symptom severity.
NAC works as a mucolytic (breaks down mucus), supports glutathione production, and may help prevent the formation of blood clots by breaking disulfide bonds. NAC is particularly helpful during infectious disease seasons when oxidative stress increases.
12. Importance of darkness at night for melatonin production
Complete darkness at night is crucial for proper melatonin production and metabolic health. Even dim light (100 lux) during sleep can disrupt glucose regulation, and just 15 seconds of artificial light exposure can significantly suppress melatonin.
For navigating at night, it's better to use indirect lighting or red lights rather than looking directly at screens. Using phone flashlights pointed away from the eyes or dim red lights allows for safe movement without disrupting melatonin production.
13. The flu shot reduces symptom severity rather than preventing infection
The flu shot doesn't necessarily prevent infection but can significantly reduce symptom severity. Dr. Seheult explains that the vaccine gives the immune system advance notice of the antigen, allowing for a more efficient response if infection occurs.
He recommends the flu shot particularly for those who are immunocompromised or frequently exposed to flu, using a "Swiss cheese model" of protection where multiple interventions provide layered defense. The ideal approach combines immune-supporting practices like proper nutrition and sunlight with targeted medical interventions when appropriate.
14. Forest environments contain immune-enhancing phytoncides
Trees release substances called phytoncides that can positively affect the innate immune system. Japanese research on "forest bathing" showed that walking in forests for three days produced beneficial changes in immune markers that lasted for seven days.
These effects were partially replicated by infusing phytoncides in hotel rooms, though urinary cortisol levels were only reduced during actual forest walks. This suggests multiple beneficial mechanisms from time spent in natural environments beyond just the chemical compounds in the air.
15. Eucalyptus oil stimulates immune cell activity
Laboratory studies show that even small amounts of eucalyptus oil can significantly enhance phagocytosis—the process by which immune cells engulf foreign particles. Dr. Seheult cautions that eucalyptus oil should never be taken internally but can be beneficial when used as an inhalant.
Traditional practices like adding a few drops of eucalyptus oil to steam inhalation may help with respiratory symptoms. This aligns with the historical use of eucalyptus in various therapeutic contexts and may partially explain why certain traditional remedies have persisted.
16. Long COVID involves mitochondrial dysfunction
Research indicates that many long COVID symptoms may stem from mitochondrial dysfunction, particularly in the pathways that metabolize fatty acids. Patients with long COVID showed significant downregulation in beta oxidation compared to those who recovered without lingering symptoms.
Dr. Seheult has found that approaches targeting mitochondrial health, such as intermittent fasting (not eating after 5:30 PM) and increased sunlight exposure, have helped some patients with long COVID. This suggests that metabolic rehabilitation may be an important component of long COVID treatment.
17. The reductionist approach to health has limitations
Dr. Seheult points out that scientific reductionism—isolating single compounds or mechanisms—often fails to capture the complex interactions in health. Nature provides compounds in specific contexts and combinations that may be more effective than isolated substances.
For example, studies giving high-dose vitamin E and A supplements to lung cancer patients had to be stopped early because patients did worse than the control group, despite observational evidence that diets rich in these vitamins were beneficial. This highlights the importance of whole-food approaches and natural contexts for health interventions.
18. The innate immune system requires regular activation
The innate immune system, which provides broad protection against pathogens, requires regular activation to function optimally. Sunlight, temperature variations, and certain botanical compounds all help stimulate this system.
Modern indoor lifestyles may under-stimulate our innate immunity. The system includes interference, which has broad antiviral properties regardless of variants, but requires proper activation through environmental signals like temperature elevation and certain chemical triggers.
19. Trust and forgiveness impact physical health
Research shows that people who practice unconditional forgiveness experience less anxiety, fewer somatic complaints, and greater well-being compared to those who forgive conditionally. A strong predictor of unconditional forgiveness was whether people felt they had been forgiven themselves.
Dr. Seheult observes that addressing spiritual and emotional concerns can significantly impact patient outcomes, particularly for those facing serious illness. This highlights the importance of the mind-body connection and suggests that emotional resolution may influence physical recovery.
20. Hospitals should incorporate more environmental therapies
Despite strong historical and emerging evidence for the benefits of environmental interventions like sunlight exposure, many hospitals still don't incorporate these approaches. Dr. Seheult described a case where moving a gravely ill 15-year-old boy outside resulted in unexpected recovery from a severe fungal infection.
Getting hospital patients outside into natural light for even brief periods could significantly improve outcomes and reduce hospital stays. However, logistical challenges and the focus on medication-based interventions often prevent implementation of these simple, low-cost approaches to enhancing recovery.