A recent article published in the Journal of Investigative Dermatology challenges the general recommendation by many dermatologists and doctors to avoid sunlight as it “causes skin cancer.” Professor Richard Weller, Chair of Medical Dermatology from the University of Edinburgh, authored the article. The main point of the article is that dermatology concerns about sun exposure concern only skin health and fail to consider the plethora of research demonstrating that sunlight reduces the risk of all-cause mortality (death).
Professor Weller reports that the many benefits of ultraviolet (UV) exposure to the skin go beyond vitamin D synthesis. These benefits include nitric oxide mobilization (improves circulation and blood flow) and regulate the immune system and inflammation. He also notes that UV reduces the risk of:
Blood pressure
Multiple sclerosis
Cancer mortality
Rickets
Weller states that all-cause mortality is much higher in the winter than in the summer months. For example, a person living in Scotland is 30% more likely to die during a week in January than in July. However, the same risk does not occur in countries near the equator with substantial year-round sunlight exposure. Weller is not the only person who has reported dermatologist's sun-phobic recommendations. A 2020 article in the International Journal of Environmental Research and Public Health states: “Studies in the past decade indicate that insufficient sun exposure may be responsible for 340,000 deaths in the United States and 480,000 deaths in Europe per year, and an increased incidence of breast cancer, colorectal cancer, hypertension, cardiovascular disease, metabolic syndrome, multiple sclerosis, Alzheimer’s disease, autism, asthma, type 1 diabetes and myopia.” The same authors note the benefits of ultraviolet B exposure from the sun that go beyond vitamin D, such as the direct benefit of genes for immunity.
Interestingly, Weller states that no epidemiological evidence exists that UV-induced skin cancer occurs in black skin. Since sunlight exposure reduces blood pressure, Weller points out that this may correlate to the increased rates of hypertension in Black Americans, who have 2.24 times higher rates than White Americans. Oppositely, West Africans have a prevalence of hypertension that is half that of Black Americans.
Weller recommends that clinicians reassess the general recommendations for sun avoidance and “take a more holistic view of UV exposure and human health.” He reports that the United Nations Environmental Effects Assessment panel and an Australian panel endorsed by the Cancer Council of Australia and Australasian College of Dermatologists have authored position statements recognizing that sunlight has beneficial effects that should be considered in formulating policy on sunlight exposure.
Excess sunlight for one’s skin type can cause burning and damage, which leads to an increased risk of skin aging and cancer. The most concerning skin cancer is melanoma. Sunburn is a strong risk factor for melanoma. However, the authors from the International Journal of Environmental Research and Public Health article report that chronic sun exposure does not appear to be associated with melanoma risk. Therefore, preventing sunburn and not total avoidance of sunlight should be the focus of good dermatology advice.
In light of all the information on the health benefits of sunlight, future medical recommendations of 15 to 30 minutes of direct sunlight may become normative medical recommendations (this is my current recommendation). Of course, one should take precautions for areas that burn easily and to protect the eyes from excess sunlight. If you have areas where you have had skin cancer, make sure to protect those areas. However, the general recommendation of avoiding sunlight, where people need to have all their skin covered by clothing and sunscreen whenever they go out, is bad medical advice.
Alfredsson, L., Armstrong, B. K., Butterfield, D. A., Chowdhury, R., de Gruijl, F. R., Feelisch, M., Garland, C. F., Hart, P. H., Hoel, D. G., Jacobsen, R., Lindqvist, P. G., Llewellyn, D. J., Tiemeier, H., Weller, R. B., & Young, A. R. (2020). Insufficient Sun Exposure Has Become a Real Public Health Problem. International journal of environmental research and public health, 17(14), 5014. https://doi.org/10.3390/ijerph17145014
Weller, Richard B. Sunlight: Time for a Rethink? Journal of Investigative Dermatology, Volume 144, Issue 8, 1724 – 1732 https://www.jidonline.org/article/S0022-202X(24)00280-X/fulltext
