Huberman LabHow to Enhance Your Immune System | Dr. Roger Seheult
CHAPTERS
- 0:00 – 28:20
Introduction, Dr. Seheult’s Background, and NEW START Framework
Huberman introduces Dr. Roger Seheult, a pulmonologist, critical care and sleep medicine physician, and founder of MedCram. They set the stage: how to avoid and recover from colds, flus, COVID, and other infections. Seheult presents the NEW START mnemonic as the core pillars of immune and overall health.
- •Dr. Seheult’s roles: ICU clinician at Loma Linda, MedCram educator, board-certified in pulmonology and sleep medicine.
- •NEW START: Nutrition, Exercise, Water, Sunlight, Temperance, Air, Rest, Trust.
- •Nutrition: minimally processed, as natural as possible.
- •Exercise: J-shaped relationship; mild–moderate lowers inflammation, extreme can increase susceptibility in athletes.
- •Water: internal hydration and external use (saunas, cold plunges) modulate innate immunity and interferon.
- •Sunlight, Temperance, Air, Rest, Trust previewed as major immune levers.
- 28:20 – 51:40
Sunlight Beyond Circadian Rhythms: Infrared, Melatonin, and Mitochondria
They move from circadian-focused morning sunlight to less-known effects of red and infrared light penetrating the body. Seheult explains how infrared light reaches deep tissues, how mitochondria generate huge amounts of local melatonin, and why this matters for oxidative stress, aging, and chronic diseases.
- •Only ~38% of solar output is visible light; ~52% is infrared, which penetrates well beyond skin.
- •Analogy: low-frequency sound and thunder travel far; likewise, long-wavelength infrared penetrates deeply.
- •Infrared images show light passing through hands, illuminating tissue without being blocked by bone.
- •Mitochondria produce massive amounts of melatonin in situ—orders of magnitude higher than pineal output.
- •This melatonin is not a hormone but a local antioxidant, upregulating glutathione and quenching ROS.
- •Mitochondrial theory of aging: ATP output falls ~70% after age 40; mitochondrial dysfunction underlies diabetes, CVD, dementia.
- •Infrared light improves mitochondrial efficiency via cytochrome c oxidase, nitric oxide interactions, and enhanced electron transport.
- 51:40 – 1:18:20
Evidence for Sunlight’s Systemic Benefits: Green Spaces, Mortality, and Metabolism
Seheult highlights epidemiologic and interventional data connecting sunlight and green environments to lower inflammation, better metabolic markers, and reduced mortality. They discuss tree-planting natural experiments and glaucoma/vision research showing red-light benefits.
- •Louisville, KY 4-square-mile experiment: planting ~8,000 trees lowered residents’ hs-CRP by ~13% without other interventions.
- •Green spaces are highly reflective in infrared, increasing IR exposure several-fold versus concrete.
- •Swedish cohort: women with higher sun exposure had lower all-cause, cardiovascular, and cancer mortality in dose–response fashion.
- •Sun-seeking smokers had mortality similar to sun-avoiding non-smokers, underscoring sunlight’s potency (though not endorsing smoking).
- •UK Biobank replication (400,000 subjects) using UVA as a proxy for sunlight found similar mortality benefits in men and women.
- •Glen Jeffery’s work: three minutes of 670 nm light in the morning improved elderly color sensitivity by ~17% for days.
- •Jeffery’s glucose study: red light (670 nm) on the back lower postprandial glucose peaks and raised CO₂ exhalation, indicating enhanced mitochondrial metabolism.
- 1:18:20 – 1:43:20
Seasonality of Flu and COVID: Latitude, Light, and Hospital Design
The conversation turns to why flu and COVID surge in winter and how sunlight explains patterns better than temperature or humidity. They revisit historic sun-based hospital design and reflect on how modern indoor life suppresses these benefits.
- •2009 H1N1 pandemic uncoupled influenza from winter-only seasonality, allowing analysis across temperatures, humidities, and sun levels.
- •Harvard study: sunlight strongly predicted influenza infection risk; more solar radiation preceding infection correlated with lower incidence.
- •COVID autumn surge in Europe: temperature and humidity showed no pattern; latitude and day-length perfectly matched surge timing.
- •In the Northern Hemisphere, flu and natural-cause deaths peak 1–3 weeks after the shortest day; inverse pattern in Australia; non-seasonal pattern near the equator (e.g., Singapore).
- •Historical TB sanitariums used high-altitude sunlight and outdoor rest; older hospitals were architected with sun decks and large windows.
- •Scientific reductionism over-focused on UV and skin cancer, neglecting the protective IR that always accompanies natural sunlight.
- •Practical recommendation: especially in winter, consciously budget at least ~15 minutes outdoors daily; otherwise weeks can pass with essentially zero sun exposure.
- 1:43:20 – 3:00:00
Practical Light Protocols: Winter Exposure, Artificial Red Light, and Dark Nights
Huberman presses for concrete sunlight prescriptions and strategies for those in cloudy, high-latitude regions. They also address indoor lighting, artificial red/IR devices, and the critical role of darkness and melatonin preservation for metabolic health.
- •Target: ~15–20 minutes/day of outdoor daylight exposure; exact time of day less important for mitochondrial IR than for circadian blue light.
- •If midday UV is a skin concern, cover skin with clothing but still go outside; IR penetrates clothing and skin.
- •In very low-sun environments, low-power red/IR devices (~2–3 mW/cm²) can partially substitute, especially in winter.
- •Study: four hours/day of low-level red+IR lighting in winter (at a desk) improved wellbeing only in winter, not summer.
- •Population data: natural-cause mortality and major chronic disease deaths peak after the shortest day, trough after the longest day—tracking light, not weather.
- •Night light: even dim 100-lux light in a corner of the room can impair morning glucose; true darkness or eye masks are strongly recommended.
- •15 seconds of nighttime light exposure can significantly suppress melatonin; use phones as flashlights pointed away, or red light modes for nighttime navigation.
- 3:00:00 – 3:41:40
Flu Risk, Vaccination, and Masking: Nuanced Risk–Benefit Discussion
Huberman and Seheult tackle flu severity, the flu shot, and masks. Seheult explains why he vaccinates given his ICU exposure, outlines known risks and benefits, and frames vaccination as one more ‘slice of Swiss cheese’ rather than a magic shield.
- •Flu can be lethal in metabolically compromised or immunosuppressed people (e.g., poorly controlled diabetics with serious fungal co-infections).
- •Flu vaccine protects primarily by reducing severity, hospitalization, and complications, not by fully preventing infection.
- •Seheult gets the flu shot yearly due to high ICU exposure; he started vaccinating his children in their teen years.
- •Rare side effects: anaphylaxis; historically one formulation in Europe associated with narcolepsy was pulled from the market.
- •He emphasizes weighing benefits vs. risks for each individual, especially those immunocompromised or frequently exposed.
- •Surgical masks help prevent droplets from leaving or entering mouths; N95s protect wearers by filtering inhaled air but increase breathing resistance.
- •He and his clinic institute universal masking when flu rates rise; he used masks meticulously to avoid illness before this podcast recording.
- 3:41:40 – 4:00:00
NAC, Zinc, Eucalyptus, and Supportive Therapies for Colds and Flu
They catalog pharmacologic and natural tools to reduce symptom severity and support recovery from respiratory infections. NAC stands out with strong data; zinc, eucalyptus/steam, and forest volatiles get mechanistic and practical context.
- •NAC: clinical mainstay for acetaminophen overdose (recharges glutathione) and sometimes in liver failure; mucolytic via breaking disulfide bonds in mucus.
- •Randomized trial: 600 mg NAC twice daily in winter didn’t reduce flu infections but greatly reduced symptomatic illness (runny nose, sore throat), with NNT ~2.
- •NAC may also interrupt von Willebrand factor polymerization and white-clot formation relevant in viral pneumonias and COVID-associated microthrombosis.
- •Zinc: cofactor in immune enzymes; typical safe supplemental level ~40 mg elemental zinc/day; chronic high dosing requires monitoring copper levels.
- •Eucalyptus oil: in vitro, tiny amounts greatly enhanced phagocytosis (cells morphed into active ‘pseudopod’ states and engulfed beads); do not ingest eucalyptus oil—use topically or in steam.
- •Steam inhalation (hot water + towel over head) can thin mucus and ease congestion; adding a drop or two of eucalyptus can be soothing.
- •Forest bathing research: phytoncides from trees increase natural killer cell activity and chromogranin A markers for up to 7 days; diffused tree oils replicate some, but not all, benefits (higher cortisol reduction in actual forests).
- 4:00:00 – 4:48:20
Heat, Fever, Hydrotherapy, and Cold: Turning Temperature into Therapy
They dive deep into how body heating and brief cooling affect interferon, white blood cells, and overall antiviral defense. Historical data from 1918 influenza sanitariums and Nobel-winning fever therapy contextualize modern sauna and hot–cold practices.
- •Water’s high heat capacity makes it ideal for transferring heat into the body: saunas, hot baths, and hot towel ‘fomentations’ raise core temperature efficiently.
- •Lymphocytes exposed to LPS in vitro secreted ~10x more interferon at 39°C (~102.2°F), showing temperature alone can supercharge innate immunity.
- •1918 sanitarium data: early hydrotherapy and sun exposure reduced progression from early flu to pneumonia by ~6-fold versus Army hospitals; mortality became similar once pneumonia was established, pre-antibiotics.
- •Jules Wagner-Jauregg’s 1927 Nobel Prize: cured neurosyphilis by inducing high fevers via malaria, then treating the malaria—illustrating therapeutic hyperthermia.
- •Modern mouse/hamster data: even 38°C (100.4°F) boosts transcription of multiple interferon signaling components; temperature itself accelerates nuclear transcription.
- •Cold exposure after heat causes vasoconstriction, demarginating white blood cells into circulation and ‘locking in’ heat; it may be a mechanistic rationale behind Finnish/Russian hot-cold rituals.
- •Practical: brief hot showers or baths to sweating followed by very short cold exposure and vigorous toweling are accessible at home; caution in pregnancy, cardiovascular disease, and heat-intolerance.
- 4:48:20 – 5:22:30
Long COVID, ACE2, Clotting, and Mitochondrial Repair Strategies
Seheult explains long COVID’s diverse presentations and recurring theme: persistent mitochondrial and redox dysfunction. They connect ACE2’s true role in redox balance, the clotting findings in COVID, and interventions like time-restricted eating and light to support recovery.
- •Long COVID is defined as persistent symptoms ≥12 weeks post-infection; common complaints include fatigue, dyspnea, headaches, and dysautonomia.
- •Mechanistically, many patients show impaired beta-oxidation and downregulated mitochondrial metabolism, especially in fatty acid pathways.
- •ACE2’s primary job is converting pro-oxidant angiotensin II into antioxidant angiotensin 1–7; SARS-CoV-2 binding impairs this, increasing oxidative stress.
- •In COVID autopsies, many white clots and von Willebrand factor–platelet aggregates were found in pulmonary arteries; NAC plausibly disrupts relevant disulfide bonds.
- •Type O blood is modestly protective in COVID, likely because type O individuals have slightly lower von Willebrand factor levels.
- •Case: a patient with long COVID dyspnea but normal echo, PFTs, and CT improved dramatically with strict early time-restricted eating and daily sunlight exposure.
- •Exogenous interferon infusions have shown ~50% reduction in COVID hospitalizations in a New England Journal of Medicine trial; nasal interferon is under investigation.
- 5:22:30 – 5:39:10
Mold, Terrain vs. Germ Theory, and Pulmonary Nuances
They tackle mold toxicity, clarifying when mold is a real pulmonary threat versus a co-factor that exploits weakened host defenses. Seheult uses Aspergillus as a model and revisits the false dichotomy between ‘terrain’ and ‘germ’ theory.
- •Mold disease is real but multifaceted: fungi like Aspergillus can cause allergic bronchopulmonary aspergillosis (immune overreaction) or invasive aspergillosis (tissue destruction).
- •Invasive fungal disease is typically detectable on CT and via biopsy/culture; allergic forms often need steroids plus antifungals.
- •Biologics for autoimmune disease can unmask latent TB by suppressing immune containment, paralleling how terrain weakness allows mold to invade.
- •Terrain vs. germ theory: both matter. Some pathogens (e.g., Neisseria meningitidis) can overwhelm any terrain; many opportunists need compromised hosts.
- •Increased mold load from a damp home adds burden, but disease often appears when host immunity is impaired (e.g., via chemo, diabetes, biologics).
- •Hydrotherapy and sauna are not cures for true invasive mold infections; those require targeted antifungals and sometimes surgery.
- 5:39:10 – 5:57:10
Trust, Forgiveness, Spirituality, and Their Measurable Health Impacts
They close the NEW START loop by exploring ‘Trust’—faith, community, and psychological factors—and how these measurably influence anxiety, somatic symptoms, and even end-of-life peace. Seheult shares research on forgiveness and his ICU experience addressing spiritual distress.
- •Trust includes faith in a higher power for many, but also trust in community, clinicians, and a sense of support that lowers stress and cortisol.
- •Study on gratitude letters to mentors: even when letters weren’t delivered, simply writing them improved psychosomatic outcomes.
- •Survey of ~1,500 Christians: those who forgave unconditionally (not waiting for apology) had less end-of-life anxiety and fewer somatic complaints.
- •Strongest predictor of unconditional forgiveness: feeling forgiven by God; odds ratio was substantial, suggesting a powerful psychological/spiritual driver.
- •In ICU practice, Seheult gently explores spiritual and guilt issues; helping patients feel forgiven and at peace can markedly reduce their anxiety.
- •Hospitals routinely include chaplains and multi-faith spiritual support, reflecting longstanding clinical recognition that these factors matter for healing.
- 5:57:10
How to Navigate Hospitals and Advocate for Better Care
Responding to a direct question, Seheult explains what non-donor, non-VIP patients can do to get better inpatient care. The key lever is informed, respectful advocacy, not status, plus an understanding that some constraints are truly not negotiable.
- •You can’t control bed availability or exact room assignment; triage and logistics dictate those.
- •The most powerful lever for better care is demonstrating informed engagement—asking clear, specific questions about labs, imaging, diagnoses, and plans.
- •Families who understand basics of CBCs, metabolic panels, EKGs, and disease-relevant labs naturally prompt more thorough explanations and attention.
- •Hostility toward staff almost always degrades care quality and team morale; respectful persistence is far more effective.
- •Seheult’s MedCram content explicitly aims to educate patients and families so they can converse at a higher level with clinicians.
- •End of episode: Huberman plugs his book ‘Protocols’, thanks sponsors, and reiterates the importance of free, evidence-based tools like those discussed.
