Bright Ideas

by Dish Staff

Today is the shortest day of the year, leading Brian Handwerk to examine the health benefits of sunshine:

Light treatments using both natural light and artificial lamps have some history as preventative measures and even as treatments for diseases linked to vitamin D deficiency. And moderate exposure to natural light usually produces an appropriate amount of vitamin D, although the exact amount varies greatly with climate, skin pigment and other factors. … “The most interesting recent development to me is the [number of] probable other beneficial effects of a bit of sun exposure or time outdoors,” says epidemiologist Robyn Lucas at the Australian National University. Lucas was lead author of a World Health Organization study about the global health burden due to UV exposure. “There are recent studies showing beneficial effects on blood pressure, development of obesity and modulation of immune function to be less autoreactive, so lower incidence of autoimmune disorders like multiple sclerosis.”

One recent study in the Journal of Investigative Dermatology suggested that exposing skin to sunlight can reduce the risk of stroke or heart attack, possibly because it alters levels of nitric oxide in human skin and blood. When the sun shines, small amounts of this messenger molecule are transferred from the skin to the circulatory system, dilating blood vessels and lowering blood pressure, the research posits. And in preliminary work in laboratory mice, nitric oxide released by UV exposure seemed to help curb weight gain and lower the risk of diabetes—although the researchers caution that they can’t yet be sure whether the effects translate to people.