For years dermatologists have been telling us that sun exposure is bad for us. Ultraviolet (UV) rays from the sun damage the skin and cause premature aging. We are warned that skin cancers, including basal, squamous and life-threatening melanoma, are caused by the sun. They also caution that UV radiation damages the eyes and the immune system.
The dermatological wisdom stresses sun avoidance. If people are exposed to sunlight, they must wear protective clothing, sunglasses and apply high SPF (Sun Protection Factor) sunscreen. But is this the whole story? Is a little sun exposure beneficial?
Balancing Between Good and Bad:
Americans like simplicity. They tend to classify things as good or bad. Just think politics as a prime example. American medicine also seems to overlook nuance in many situations.
Cholesterol:
Cholesterol, for example, is usually seen as bad. The lower you can get it, the better.
Ditto for blood pressure. Guidelines label half of all adults as hypertensive. Anything above 120/80 is considered too high.
Acid in the stomach is also perceived as problematic. No doubt this attitude helps account for the popularity of acid-suppressing drugs (proton pump inhibitors or PPIs), blood pressure pills and statins to lower cholesterol. In truth, though, humans could not survive without cholesterol. It’s the source of critical hormones and is a building block for cell membranes. Is it possible to have too low cholesterol? Read about the risks here. What about “bad” LDL cholesterol? Most cardiologists insist that the lower the LDL cholesterol, the better. Here is one risk that is rarely mentioned.
Hypotension:
Low blood pressure can make people quite uncomfortable. The resulting dizziness may lead to falls. Old people, in particular, sometimes retain their cognitive function better if blood pressure is a bit higher than “normal” (Alzheimer’s & Dementia, Jan. 16, 2017).
Achlorhydria:
Stomach acid is important for normal digestion. In addition, it helps protect the body from invading pathogens. People with very low stomach acid (achlorhydria) have trouble assimilating nutrients such as iron or vitamin B12. They may also be at risk for stomach cancer, hip fractures or bacterial overgrowth.
The list of PPI-related side effects keeps growing. It now includes kidney disease, C. diff infections, pneumonia, heart attacks, osteoporosis, dementia, gut dysbiosis and liver inflammation. Read more at this link.
Is All Sun Exposure Bad?
Another example of polarized thinking is the attitude of most dermatologists to sunlight. They perceive ultraviolet (UV) radiation as the enemy that causes skin cancer. The less sun exposure the better.
The only potential downside might be less vitamin D because the skin makes this essential hormone when exposed to sunlight. Many health care professionals recommend vitamin D supplements to solve that problem.
A dermatologist in Glasgow, Scotland, questions such a simplistic perspective. Dr. Richard Weller has challenged his American colleagues with an article titled “Sunlight: Time for a Rethink?” (Journal of Investigative Dermatology, Aug. 2024).
In it, he acknowledges that UV radiation is a known carcinogen, but he points out that avoiding sunlight doesn’t seem to help people live longer. In fact, epidemiologic data from Sweden links more sun exposure to a higher risk of melanoma but lower all-cause mortality. Melanoma is a very dangerous skin cancer, so this finding is unexpected. The reduction in mortality appears to be primarily due to fewer cardiovascular complications.
Low levels of vitamin D in the bloodstream have been linked to many health problems, including heart disease, high blood pressure, stroke, metabolic disease, multiple sclerosis and cancer. Dr. Weller suggests that vitamin D may be a marker for sun exposure rather than the simple causative mechanism. That’s because randomized controlled trials giving vitamin D supplements have not reduced these serious outcomes. You can read more about this unexpected finding at this link.
What Else Does Sun Exposure Do?
Sunlight on skin does more than make vitamin D. Moderate sun exposure leads to nitric oxide (NO) formation in the skin. As this chemical messenger is absorbed into the body, it relaxes blood vessels, improves circulation and lowers blood pressure. In addition, sunlight activates the innate immune system that helps us fight off infections.
Dr. Weller concludes his “rethink” of sun exposure this way:
“Multiple strands of evidence point to the importance of sunlight on health, but research in this field has been limited by the focus of the dermatology community almost exclusively on harmful effects and the absence of involvement of nondermatologists in considering wider health outcomes related to sun exposure. I would like to conclude by highlighting 2 areas.“All-cause mortality is markedly higher in winter than in summer. A Scot is 30% more likely to die during a week in January than during a week in July, and the same marked variation in mortality with a winter peak and summer nadir is seen for cardiovascular and noncardiovascular/noncancer mortality in all higher-latitude countries but not in equatorial countries…Hippocrates writing in the 5th century before Christ described this seasonal variation in disease.”
Final Words on Sun Exposure:
Too much sun, like too much water, is dangerous. Sunburns should always be avoided. Moderation in all things remains a motto for good health. Whether it’s cholesterol, stomach acid or some sun exposure, we need nuance instead of simplistic approaches.
How much sun exposure is enough? How much is too much? We asked Dr. Weller that precise question for an upcoming People’s Pharmacy radio show. He was cautious about making recommendations. For one thing, skin color makes a huge difference.
Here is what Dr. Weller has to say about that:
“Any advice on sun exposure must take skin color into account. A mismatch between skin color adapted to an ancestral UV environment and current residence is harmful, thus, for example, the high rates of skin cancer in people of White European heritage in Australia or the southern United States compared with those in Europe, which are not seen in Aboriginal Australians. Looking at the beneficial effects of UV, we see that in the United States Black Americans have a prevalence rate of hypertension 2.24 times as high as that in White Americans. However, West Africans have a prevalence of hypertension that is half that of Black Americans (hypertension prevalence of 16% in West Africans, 26% in Black Caribbean, and 33% in African Americans.”
Geography also matters. If you live in Portland, Oregon, your sun exposure is substantially less than if you live in Phoenix, Arizona. Ditto for people who live in Maine compared to those who live in Florida. Time of day also matters. Ten minutes of sun exposure at 9:00 am is very different from 10 minutes of sun exposure at 1:00 pm.
The bottom line is always: do not burn! We encourage you to discuss sun exposure with your dermatologist. See if there is a small amount that might be acceptable. That’s after it has been verified that you do not have any skin lesions that might be worrisome. You might take along a printout of Dr. Weller’s article in the Journal of Investigative Dermatology (August, 2024). It is one of the most prestigious journals in the field and cannot easily be dismissed.
Please share your thoughts about sun exposure in the comment section below. If you find our research-based articles of value, please pass them on to family and friends. We suspect that the data presented here will be shocking to many, but we are hopeful it puts this topic into perspective. You will also want to listen to our upcoming interview with Dr. Weller. The radio show will air on August 24, 2024. The podcast will be available on August 25, 2024.
