#2516 - Rowan Jacobsen

Joe Rogan and Rowan Jacobsen discuss the complex and often misunderstood role of sun exposure in human health, unpacking both its benefits and risks and how public messaging has rarely embraced the nuance.

Sun Exposure Triggers Beneficial Responses, Contradicting Harmful Message

Sunlight Triggers Opioid Release, Enhancing Mood and Reward Sensations

Jacobsen explains that the body literally wants sunlight—it triggers the release of opioids in the brain. Sunlight exposure provides feelings of happiness and euphoria, underlining that mood enhancement is a central effect. Rogan describes returning to Los Angeles after a week of rain in Alaska and experiencing an overwhelming sense of joy from sun exposure, likening it to a natural and powerful drug. Jacobsen agrees, recalling visits to sunny places like L.A. in early spring, describing the rush as “an awesome drug.”

Sun Exposure Linked To Longevity and Heart Health

Jacobsen notes scientific studies suggesting sunlight exposure can lower blood pressure. He outlines his surprise in learning that, instead of shortening lifespan, sunlight seems to extend it. He questions why such positive findings are so rarely discussed publicly.

Body Produces Vitamin D Naturally Through Sun Exposure

Jacobsen details the discovery of vitamin D in the early 20th century, explaining that sun hitting the skin converts cholesterol molecules into vitamin D. This insight came after observations that city children—who saw much less sunlight—developed rickets, while farm children did not. Animal studies in Scotland confirmed that removing sunlight caused rickets, not just dietary factors. The body’s design is such that the most effective and healthiest way to get vitamin D is through sun exposure, not by taking supplements. Jacobsen emphasizes vitamin D from the sun comes in combination with related compounds, producing a combined, beneficial effect supplements cannot match.

Sun Boosts Cognition, Metabolism, and Health

Additional research cited by Jacobsen shows that sunlight improves cognition and metabolism. Light exposure on the skin can enhance brain function and make the body’s metabolic machinery work a little faster.

Complex Relationship: Uv Radiation and Skin Cancer

Uv Light Harms Dna, Causing Mutations and Skin Cancer

Jacobsen explains that ultraviolet (UV) light is the most energy-intense part of sunlight. When UV photons strike the skin, they can directly damage DNA or generate reactive oxygen species (“free radicals”) that kick off damaging chain reactions. Both effects increase the risk of skin cancers.

Melanoma Tied To Intermittent Burns; Outdoor Workers Less Affected Than Office Workers

Jacobsen clarifies that the deadliest skin cancer, melanoma, is strongly associated not with gentle, chronic daily exposure but with intermittent burning—such as office workers who suddenly get intense sun during vacations. By contrast, people with outdoor jobs and regular exposure tend to have lower than average melanoma risk.

Some Skin Cancers, Like the Melanoma on Bob Marley's Toe, Aren't Sun-induced

Jacobsen addresses common confusion, citing Bob Marley’s fatal melanoma on his toe—a site not typically exposed to the sun—and clarifies that not all melanomas are caused by UV light. There are forms of melanoma that strike regardless of sun, across all races.

Balance Skin Cancer Risk With Sun Exposure Benefits For Heart and Immune Health

While Jacobsen does not downplay the seriousness of skin cancer, including potentially disfiguring physical effects even when not life-threatening, he emphasizes that most issues arise from burning and overexposure rather than moderate sunlight. In Australia, where skin cancer rates are high, overall lifespan is greater than in less sunny environments like the UK—suggesting net benefits from sun exposure. He encourages weighing the genui ...

Skin Type and Heritage Affect Cancer Risk and Vitamin D Production

Dark skin provides powerful protection against sun-induced skin cancer. Rowan Jacobsen explains that melanin, produced by melanocytes in the deepest layer of the epidermis, absorbs 97–98% of UV rays, making it "almost perfect" at shielding cells. People of African ancestry or with very dark complexions almost never develop sun-induced skin cancer. However, this same melanin also reduces vitamin D production, so those with dark skin require five to ten times more sunlight to generate adequate vitamin D compared to people with lighter skin. Jacobsen notes that such individuals are evolutionarily designed for bright, tropical climates and can benefit from extensive sun exposure.

In contrast, individuals with very fair skin, red hair, freckles, and many moles possess a different type of melanin due to a mutation in the melanin gene. This condition, prevalent in Celtic-descended populations, means they produce pheomelanin instead of eumelanin, which is much less effective at blocking UV rays. As a result, they are extremely susceptible to skin cancer and rarely tan, regardless of sun exposure amounts. There is "no hope" for true redheads to safely build up a natural sun tolerance. For them, consistent, strong protection from sun exposure is critical.

The origins of pale skin trace back 4,000–5,000 years in Northern Europe. The dramatic genetic adaptation toward lighter skin was a desperate evolutionary attempt to maximize vitamin D synthesis from limited sunlight. Joe Rogan and Jacobsen affirm that skin tone gradations map neatly to ancestral latitude, reflecting local sunlight intensity over millennia. Thus, early humans’ migration away from the tropics led to lighter skin to compensate for lower UV levels. Today, pale-skinned people still process sunlight more efficiently for vitamin D, but are at much higher risk of DNA damage and cancer from overexposure.

The result is that fair-skinned people, especially those with the redhead "ginger" phenotype, must take extra care to shield themselves. While gradual morning and late afternoon sun exposure can sometimes help increase tolerance for some people, genetics place hard limits on tanning and safe exposure. For those with very dark skin, getting enough sunlight—especially in low-sun regions—remains a health challenge, and supplementation or adapted sun exposure schedules may be necessary.

Location and Uv Intensity Affect Sun Exposure Needs and Risks

Geographic location further shapes sun exposure requirements and risks. Australia represents an extreme mismatch, where many residents of Scottish and Celtic descent inhabit an environment with some of the world’s highest UV intensities and a thinned ozone layer. There, skin cancer rates are two to three times higher than the global average. Warning signs about skin cancer are common in public spaces, and public health recommendations emphasize sunscreen and protection, driven by this population-environment dissonance.

Conversely, in high-latitude northern regions like the UK or New York in winter, even fair-skinned people may struggle to produce enough vitamin D, especially when living and working mostly indoors. For dark-skinned populations, the risk of vitamin D deficiency is especially acute outside the tropics—Rogan notes that his doctor friend has seen dark-skinned patients in New York with undetectable vitamin D during winter.

The global gradation of skin pigmentation remains one of the clearest signs of adaptation to local light conditions, showing how humans have fine-tuned skin color over millennia to maximize health and ...

Aad Upheld Stance Against Unprotected Sun, Dismisses Health Benefit Data

Rowan Jacobsen describes official resistance from the American Academy of Dermatology (AAD) to research suggesting sun exposure may offer health benefits. The AAD has denounced Jacobsen multiple times, sending formal letters that label his claims about sunlight’s benefits as misrepresenting the evidence and dangerous to the public. The AAD maintains a strict stance: nobody should get sun exposure unprotected, regardless of potential upsides like vitamin D production or location and skin type. Their recommendations insist on sunscreen or clothing for everyone.

Efforts to engage dermatologists directly have been largely avoided by the AAD; they express unwillingness to revisit the data or consider opposing views. Jacobsen notes dermatologists focus exclusively on the sun–skin cancer connection, dismissing broader research from fields such as immunology and cardiology that demonstrate cardiovascular and metabolic benefits of responsible sun exposure. This narrow approach, he argues, is especially harmful for individuals with darker skin. While sun-avoidance recommendations may fit fair-skinned populations, their application to dark-skinned individuals—who have a low risk for sun-induced skin cancer but major potential health benefits from increased sun—can deny vital advantages like improved blood pressure and metabolic health.

Dermatological Guidance Emphasizes Skin Cancer Prevention Over Cardiovascular and Other Health Risks

Jacobsen and Rogan discuss that dermatology guidelines prioritize avoiding even minimal increases in skin cancer risk over acknowledging or exploring possible cardiovascular gains from sun exposure. Cardiovascular disease causes about 20 million deaths annually worldwide, while skin cancer causes far fewer. Even though observational studies show populations with greater sun exposure often have lower blood pressure and fewer cardiovascular events, the dermatological establishment dismisses such research as insufficient without controlled clinical trials.

The medical system largely insulates dermatologists from criticism when their recommendations to avoid sun exposure might contribute to broader public health risks—most notably increased cardiovascular or metabolic diseases. Research funding and career advancement remain tied to reinforcing established beliefs about skin and sun, making it extremely difficult for contrarian research to receive support. Jacobsen likens this dynamic to Max Planck’s observation that science advances “one funeral at a time,” requiring a generational shift to reassess deeply held assumptions.

Traditional Sunscreen Ingredients Are Absorbed Systemically More Than Believed, Raising Safety Questions

Traditional chemical sunscreen ingredients such as oxybenzone have come under suspicion for their potential to disrupt hormone function, as toxicologists now acknowledge these filters are absorbed through the skin at far higher rates than previously thought. While there is no definitive proof that these exposures cause disease in humans at typical use levels, the FDA has declined to confirm their safety and demanded additional testing—which manufacturers have yet to deliver. Consequently, some of these ingredients are in the process of being phased out.

There is further concern about product contamination from "forever chemicals," identified in many cosmetic products and sunscreens. Graham Peasley’s research at Notre Dame found that some of these chemicals come from the plastic containers themselves, which are coated with fluorine gas to impr ...

Scientific understanding of food and health has undergone dramatic reversals, overturning many longstanding expert recommendations. Rowan Jacobsen and Joe Rogan discuss how major staples like dietary fat, eggs, coffee, and chocolate have moved from being demonized to celebrated—and why science was slow to adapt.

Dietary Fat and Margarine: How Expert Consensus Can Be Wrong and Resistant to Correction

Scientists Wrongly Linked Dietary Fat To Heart Disease, Advising Margarine Over Butter

Jacobsen notes that a few decades ago, public health experts insisted that dietary fat—especially from animal sources—was the main villain responsible for heart disease. The recommended solution was to cut fat from the diet and substitute margarine for butter. The "margarine era" saw experts championing these low-fat, high-carb recommendations across the food pyramid.

Despite Evidence Fat Isn't Harmful and Margarine Is Detrimental, the Reversal Faced Decades of Resistance From Experts Defending Their Positions

Evidence gradually accumulated showing this advice was flawed—margarine, once promoted as the heart-healthy choice, was not a good substitute, while many dietary fats proved beneficial. Jacobsen recalls Gary Taubes’s influential journalism and the involvement of figures like Nina Teicholz in highlighting the errors. Despite mounting data, experts fought to defend their reputations and prior guidance, generating intense professional pushback and resistance to change.

Food Pyramid Overturned: Rare Self-Correction With Little Acknowledgment

Ultimately, public health guidance forced a rare self-correction, flipping the food pyramid: healthy fats from foods like milk and eggs, once discouraged, are now accepted and even recommended. Jacobsen marvels that this reversal, while long overdue, was accomplished with little official acknowledgment or ceremony.

Eggs, Once Demonized For Cholesterol, now Seen As a Perfect, Harmless Food

Warnings About Egg and Dietary Cholesterol Lack Evidence and Are Abandoned

Rogan describes how, through much of his adult life, he faced repeated warnings about the cholesterol in eggs and red meat, despite eventually displaying healthy cholesterol markers on a diet rich in both. He and Jacobsen agree that the scientific consensus on eggs has completely flipped: warnings against eggs and dietary cholesterol were unsupported by robust evidence, and have since been abandoned.

High-Egg Diets Improve Cholesterol and Health, Contradicting Anti-Egg Messaging

They note that, contrary to prior warnings, high-egg diets often correlate with good health and even improved cholesterol. Jacobsen names eggs “probably the perfect food,” easily supporting human health on their own.

Full-Fat Dairy Supports Health Despite Discouragement

Alongside eggs, healthy fats from milk and full-fat dairy—long discouraged—are now recognized as nutritionally sound, with no credible evidence that they are harmful when part of a balanced diet.

Coffee: From "Unhealthy" To Best Supplement

Caffeine Optimizes Mitochondrial Function, Enhancing Energy Efficiency With Less Wear and Tear

Jacobsen highlights the remarkable rehabilitation of coffee, once seen as a vice but now viewed as possibly “the best possible supplement.” He credits caffeine and coffee for optimizing mitochondrial function, giving efficient energy production and steady mental performance with minimal wear and tear on the body.

Plants Produce Caffeine As a Pesticide That Kills Insects By Causing Mitochondrial Overwork, While Humans Have Governors That Prevent Damage While Capturing Benefits

Caffeine’s evolutionary role is especially intriguing: plants evolved it as a pesticide that destroys insect mitochondria via overwork. Humans, however, have regulatory mechanisms that moderate the stimulant effect, letting us benefit from its energy-promoting properties without the metabolic damage insects experience.

Mediterranean Lifestyle: Moderate Alcohol, Coffee, Real Food, Centuries of Health Validation Despite Warnings

Jacobsen reflects on how the Mediterranean lifestyle—the gold standard in longevity—was once regarded skeptically for its inclusion of coffee, moderate wine, and real unprocessed foods. Studies suggest moderate alcohol in these contexts confers neither significant harm nor clear benefit, aligning with centuries of practical experience. Additional lifestyle factors, such as sunlight, reduced stress, tight-knit families, and communal meals, likely contribute to their robust health, outweighing worries about specific foods.

Heirloom Cacao Chocolate Contains Health-Supporting Polyphenols and Cannabinoids

Industrial Chocolate Lacks Aroma and Benefits of Wild Ama ...

Mitochondrial Function Explains Health Benefits of Sun Exposure and Red Light Therapy

Red light therapy has become increasingly popular, with dermatologists incorporating it despite mixed evidence. Rowan Jacobsen cites the work of Glenn Jeffery at University College London, who has shown in various animals and humans that red light improves mitochondrial function and enhances vision. The science suggests that red light's positive effects originate in its relationship to mitochondrial health, since mitochondria act as the energy factories of cells.

Red Light Boosts Cellular Energy By Enhancing Mitochondrial Function

Joe Rogan and Rowan Jacobsen discuss that the mitochondria in eye cells are particularly energy-intensive, firing at faster rates than anywhere else in the body due to the demanding task of processing visual information. Red light appears to benefit this rapid activity, making mitochondria more efficient.

Eye Cells' Fast-Firing Mitochondria Benefit From Red Light Therapy

Because eye cells rely so heavily on mitochondrial efficiency, red light exposure appears especially helpful for vision. Jacobsen notes that the lack of cancer risk from red light makes it an attractive therapeutic option for dermatologists and ophthalmologists alike.

Red Light Therapy Aids Macular Degeneration, Restoring Reading Vision and Eliminating Glasses

Joe Rogan shares a personal experience: he claims to have reversed his macular degeneration and eliminated his need for reading glasses by using a red light bed three times per week for twenty minutes. He saw improvements within a month, and reports that his vision, though not as perfect as in his youth, is vastly improved compared to before therapy. Rogan notes additional reports that even using red light therapy while blindfolded can benefit vision.

Sun-generated Vitamin D Is Superior to Supplement Pills

Trials Show Vitamin D Pills Don't Replicate Sun's Health Benefits

Jacobsen explains that large clinical trials administering vitamin D supplements to reduce chronic disease risk have shown no benefit—contrary to what was hoped based on observational studies linking high natural vitamin D levels with better health. He says that New England Journal of Medicine even recommended discontinuing vitamin D supplementation, as the trials showed no effect for any condition.

Optimal Vitamin D Production Requires Essential Co-factors

Rogan and Jacobsen discuss that supplementing with vitamin D alone may not be effective. For the body to use vitamin D efficiently, it needs to be taken alongside magnesium and vitamin K2, which help absorb and activate vitamin D and direct calcium to bones rather than arteries. Without these co-factors, the health benefits of vitamin D supplements remain unproven.

Vitamin D, Magnesium, and K2 Combination Necessary for Effects

The trio of vitamin D, K2, and magnesium work together synergistically to support bone and cardiovascular health. Vitamin D helps absorb calcium, magnesium helps activate vitamin D and supports bone structure, and K2 ensures calcium is deposited in bones and teeth rather than the arteries. This combination makes vitamin D use more efficient and may explain why some people see no effect from vitamin D supplementation alone.

Light Spe ...