This may not be the most effective way to lower blood pressure, but it’s definitely the most cost effective: go outside. Researchers at the University of Southampton are convinced that sunlight can help lower blood pressure, because of the way that sunlight alters levels of the small messenger molecule, nitric oxide (NO) in the skin and blood. A university news release reports that researchers at the school tested the theory by exposing the skin of 24 healthy people 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, the UV rays were blocked so that only the heat of the lamps affected the skin. What did they learn? UVA exposure dilates blood vessels, significantly lowers blood pressure, and alters NO metabolite levels in the circulation, without changing vitamin D levels. Read more from the University of Southampton.