A landmark study published Friday in the Journal Dermato-Endocrinology has world-renowned researchers calling insufficient sun exposure an emerging health problem in the United States. In their paper, The Risks and Benefits of Sun Exposure 2016, the authors reference major papers in the past five years in concluding that Americans are not getting enough sun exposure and that public health advice needs to be retooled to embrace moderate sun while focusing on sunburn prevention.
"The message of sun avoidance advocated by our government, and some within the medical community, should be changed immediately to a recommendation of regular non-burning sun exposure for most Americans," said lead author Dr. David Hoel, a member of the National Academy of Medicine and Distinguished University Professor at the Medical University of South Carolina. "The sun is essential for life and should be diligently pursued in moderation, not avoided."
The new study cites more than 100 studies demonstrating the benefits of non-burning sun exposure. Many benefits are related to vitamin D - produced naturally in the skin when exposed to UVB in sunlight. But new data show many benefits from sun are independent of vitamin D and may be related to other substances produced in sun-exposed skin. Just as important: New data suggest the significant risks associated with sun exposure are only related to sunburn or excessively large lifetime exposure, the study reports.
While recent public health guidance has encouraged people to avoid the sun out of concern that exposure will increase risk of skin cancer, the prevalence of vitamin D insufficiency in the United States - linked primarily to sun avoidance - is 70%. The study cites recent estimates that about 13% of all U.S. deaths (330,000 deaths per year) could be attributable to vitamin D insufficiency. Corresponding estimates for deaths linked to tobacco are about 20% (450,000 deaths).
The paper documents evidence that the health benefits of sun exposure are not limited to vitamin D, with nitric oxide and other sun-induced mediators identified with respect to reduced hypertension and other favorable health outcomes. Vitamin D supplements have not been shown to be an adequate substitute for sun exposure. Risks of insufficient sun exposure include increased risk of many types of cancer, cardiovascular disease, Alzheimer's disease/dementia, diabetes, multiple sclerosis, myopia and macular degeneration.
The paper's conclusions and call for a change in public policy are significant given the strong and diverse qualifications of its multi-disciplinary authors:
"Sunlight provides vitamin D, but it provides so much more. The UV from sunlight has other health benefits," Dr. Holick said. "Most public health agencies have ignored the indisputable evidence that sensible sun is good for you in moderation."
The authors are clear: sunscreen should be used as a tool to prevent sunburn, but the public should know that over-use of the product may have unintended consequences. They are calling for sunscreen labels to contain a statement explaining that sunscreen blocks vitamin D production in the skin. Labeling should also acknowledge that sunscreens have not been shown to be effective in reducing the risk of melanoma.