By Stephen T. Sinatra, M.D., F.A.C.C., F.A.C.N., C.N.S., C.B.T.
A group of U.K. researchers have discovered a surprisingly new benefit of sunlight – lowering blood pressure! In a study published in the Journal of Investigative Dermatology, the researchers found that sunlight activates nitric oxide present in large quantities in the skin, which then enters the circulatory system and reduces blood pressure.
Nitric oxide is an important chemical produced by the body, including in blood vessel tissue where it maintains proper relaxation and dilation, key factors for good blood flow.
The researchers are continuing their studies to examine how the amount of sunlight exposure that might reduce high blood pressure, a major risk factor for cardiovascular disease, would affect skin cancer. Deaths from heart disease are far greater than the number attributed to skin cancer. The researchers believe that the benefits to heart health will outweigh the skin cancer risk.
My Viewpoint: One of the most persistent myths is that sunlight is bad for you. Excess sunlight is a problem, but everybody needs some exposure to the sun because it produces vitamin D in the body. This new finding is promising and shows that more than vitamin D is involved.
What this Means to You: A healthy level of nitric oxide is essential. Insufficient nitric oxide can result in constriction of blood vessels and increased risk of clotting. Low levels are associated with a number of disease states, including high blood pressure, obesity, diabetes, and atherosclerosis.
Recommendation: I have always recommended that people get enough sunlight to keep up their vitamin D level, which is important for immune function, calcium absorption, and cardiovascular health. Now there appears to be another good reason for sunlight exposure. Avoiding sunlight is not in the interest of your health. For more information on how to do it safely, check out my sunscreen Myth-Buster.
References:
- Liu D, et al. UVA Irradiation of Human Skin Vasodilates Arterial Vasculature and Lowers Blood Pressure Independently of Nitric Oxide Synthase.J Investig Dermatol. Jan 2014. Published online at http://www.nature.com/jid/journal/v134/n7/full/jid201427a.html
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