Sun Exposure Can Lower Risk of Heart Attack

Exposure to sunlight alters the levels of nitric oxide in the skin and blood, reducing blood pressure and the risk of heart attack and stroke, according to a new study. Nitric oxide (NO), a messenger molecule, is “involved in the regulation of blood pressure. When exposed to sunlight, small amounts of NO are transferred from the skin to the circulation, lowering blood vessel tone,” according to Martin Feelisch, professor of experimental medicine and integrative biology at the University of Southampton. To test the effects of sun exposure on blood pressure levels, researchers exposed 24 healthy adults to ultraviolet tanning lamps in two 20-minute sessions. In the first session, participants were exposed to both the heat of the lamps and the UV rays. In the second session, participants were shielded from the UV rays and only exposed to the heat of the lamps. Results of the study suggested that exposure to ultraviolet light dilates blood vessels, lowers blood pressure, and alters nitric oxide metabolite levels in circulation without changing vitamin D levels. “These results are significant to the ongoing debate about potential health benefits of sunlight and the role of vitamin D in this process,” Feelisch concluded. “Avoiding excess sunlight exposure is critical to prevent skin cancer, but not being exposed to it at all, out of fear or as a result of a certain lifestyle, could increase the risk of cardiovascular disease.” –Michael Potts Feelisch M, Weller R. UVA Irradiation of Human Skin Vasodilates Arterial Vasculature and Lowers Blood Pressure Independently of Nitric Oxide Synthase. Journal of Investigative Dermatology doi:10.1038/jid.2014.27 http://www.southampton.ac.uk/mediacentre/news/2014/jan/14_09.shtml#.Ut6PNfYo6L0