Exposure to sunlight is associated with lower blood glucose levels and a lower likelihood of type 2 diabetes, according to a new study published in the journal Scientific Reports.

Background

Type 2 diabetes is a chronic metabolic condition in which the body either cannot produce sufficient insulin or cannot use it properly, leading to the accumulation of glucose in the blood (hyperglycemia). The condition is a major public health concern, with substantial impacts on morbidity, mortality, and healthcare expenditure.

Several observational studies have linked lower circulating vitamin D levels to a higher risk of type 2 diabetes. However, current randomized controlled trials generally do not establish low vitamin D as a causal factor or support vitamin D supplementation for preventing type 2 diabetes in the general population.

Vitamin D is primarily synthesized in the human skin following exposure to the sun’s ultraviolet B (UVB) radiation. Existing evidence suggests that exposure to UV radiation can activate nitric oxide stored in the skin, which in turn can reduce blood pressure through vasodilation. Animal studies have also linked UV exposure to reductions in metabolic syndrome markers and weight gain. These observations suggest that sunlight may confer cardiovascular and metabolic health benefits independent of vitamin D.

Most dermatologists recommend shunning the sun to protect our skin. But Dr. Steve Feldman says that is probably bad for our health.

For decades, dermatologists have warned us to stay out of the sun. Shunning the sun was supposed to protect us from premature wrinkles and skin cancer.

It is true that spending a lot of time in the sun will damage our skin. Ultraviolet radiation can indeed accelerate wrinkling and contribute to squamous and basal cell skin cancer formation. Sunburn is unquestionably harmful and worth preventing.

But Could Avoiding Sunlight Altogether Also Carry Risks?

In this brief video, eminent dermatologist Dr. Steve Feldman describes a surprising study involving nearly 30,000 Swedish women who were followed for about 20 years.

In this presentation, Dr. Lyons-Weiler explains, in a way that is accessible even to those without a statistical background, how a single inferential mistake continues to influence vitamin D policy today. His bridge and truck analogy described below provides one of the clearest illustrations available for understanding why the Institute of Medicine’s original calculations underestimated the amount of vitamin D needed by most individuals.

Public health messaging about the sun tends to emphasize skin cancer risk, urging everybody to cover up and slather on sunscreen before going outdoors. But although it’s come to feel counterintuitive, research suggests small daily amounts of sun exposure confer an array of health benefits that outweigh the risks for most people, according to award-winning science and cultural writer Rowan Jacobsen. In an interview edited for clarity and length, Jacobsen digs into the findings from his new book, “In Defense of Sunlight: The Surprising Science of Sun Exposure,”