Study: Exposing Skin to Sunlight May Help Lower Blood Pressure
Ultraviolet light affects nitrous oxide in skin and blood (January 20)
Exposing skin to sunlight may help reduce blood pressure (BP), thereby cutting the risk of heart attack and stroke, according to a study published in the Journal of Investigative Dermatology.
Researchers in the U.K. have found that sunlight alters levels of the small messenger molecule nitric oxide (NO) in the skin and blood, thereby reducing BP.
While limiting sunlight exposure is important to prevent skin cancer, the researchers suggest that minimizing exposure may be disadvantageous because it increases the risk of prevalent conditions related to cardiovascular disease.
During the study, the skin of 24 healthy individuals was exposed to ultraviolet (UVA) light from tanning lamps for two sessions of 20 minutes each. In one session, the volunteers were exposed to both the UVA rays and the heat of the lamps. In another session, the UVA rays were blocked so that only the heat of the lamps affected the skin.
The results suggested that UVA exposure dilates blood vessels, significantly lowers BP, and alters NO metabolite levels in the circulation without changing vitamin D levels. Further experiments indicated that preformed stores of NO in the upper skin layers are involved in mediating these effects. The data were consistent with the seasonal variation of BP and cardiovascular risk at temperate latitudes.
“We believe that NO from the skin is an important, so far overlooked contributor to cardiovascular health,” said lead investigator Professor Martin Feelisch.
Source: University of Southampton; January 20, 2013.