Sunlight Protects Against Heart Attack and Stroke

Sunlight Through Broken GlassAdequate exposure to sunlight may help reduce blood pressure, which consequently reduces the risk of heart attack and stroke, suggests a new study by researchers from the University of Southampton and the University of Edinburgh in the United Kingdom. As published in the Journal of Investigative Dermatology, the study examined a possible link between exposure of the skin to sunlight and reduced blood pressure levels.

Blood pressure refers to the force of blood pushing against the walls of the arteries as the heart pumps blood. When the pressure becomes and remains too high, the resulting serious condition known as high blood pressure can lead to coronary heart disease, heart failure, stroke, kidney failure, and other health problems. Approximately one out of every three adults in the United States suffers from high blood pressure.

However, exposure to sunlight may help lower blood pressure levels.

The researchers in the present study discovered that sunlight exposure reduces the levels of small messenger molecules and nitric oxide (NO) in the skin and blood.

Martin Feelisch, professor of Experimental Medicine and Integrative Biology at the University of Southampton, explains how nitric oxide affects blood pressure:

“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.”

To study the possible link between sunlight and blood pressure, the researchers exposed the skin of 24 volunteers to ultraviolet (UVA) light using a tanning lamp over two sessions lasting 20 minutes each.

After exposure to the UVA light, the blood pressure of the volunteers was significantly lowered.

The researchers believe that the effect of UVA light on blood pressure is the result of pre-formed stores of NO in the upper layers of the skin. States Prof. Feelisch, “We believe that NO from the skin is an important, so far overlooked contributor to cardiovascular health.”

Prof. Feelisch also believes that the results of the study may contribute to a new discussion about public health advice on exposure to sunlight. Current advice is to avoid the sun or use sunscreen in an effort to avoid risk of skin cancer. Unfortunately, being overly cautious in avoiding the sun to avoid skin cancer may increase the risk of other diseases.

For example, Prof. Feelisch explains the importance of sunlight for vitamin D production. Vitamin D is thought to offer protection from osteoporosis, high blood pressure, cancer, and several autoimmune diseases.

“These results are significant to the ongoing debate about potential health benefits of sunlight and the role of vitamin D in this process. 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.”

Further studies need to be conducted on the link between adequate exposure to sunlight and a reduce risk of heart attack and stroke via reduced blood pressure levels.


Can sunlight protect against heart attack and stroke?:
Sunshine lowers blood pressure and slashes risk of heart attacks and strokes:

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