Study Finds Exposure to Sunlight May Help Reduce Blood Pressure

Posted on January 22, 2014

A new study has found that exposing skin to sunlight may help reduce blood pressure. It is well known that exposing skin to sunlight can cause skin cancer. If the researchers are correct sunlight may have both benefit and harm the body. The researchers found sunlight alters levels of the small messenger molecule, nitric oxide (NO) in the skin and blood, which reduces blood pressure. The study, carried out at the Universities of Southampton and Edinburgh, was published here in the Journal of Investigative Dermatology.

Martin Feelisch, Professor of Experimental Medicine and Integrative Biology at the University of Southampton, says in the announcement, "NO along with its breakdown products, known to be abundant in skin, 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; as blood pressure drops, so does the risk of heart attack and stroke."

During the study, the skin of 24 healthy individuals was exposed to ultraviolet (UVA) light from tanning lamps for two 20 minutes sessions. In one session, the volunteers were exposed to both UVA rays and the heat of the lamps. In the second session, the UV rays were blocked so that only the heat of the lamps affected the skin. Researchers say the results suggest UVA exposure "dilates blood vessels, significantly lowers blood pressure, and alters NO metabolite levels in the circulation, without changing vitamin D levels."

Professor Feelisch also says, "These results are significant to the ongoing debate about potential health benefits of sunlight and the role of Vitamin D in this process. It may be an opportune time to reassess the risks and benefits of sunlight for human health and to take a fresh look at current public health advice. 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. Perhaps with the exception of bone health, the effects of oral vitamin D supplementation have been disappointing. We believe that NO from the skin is an important, so far overlooked contributor to cardiovascular health. In future studies we intend to test whether the effects hold true in a more chronic setting and identify new nutritional strategies targeted at maximizing the skin's ability to store NO and deliver it to the circulation more efficiently."