Exposure to sunlight lowers blood pressure levels naturally, thereby reducing risk of heart attacks and strokes, according to a University of Southampton study. Researchers said that sunlight regulates levels of the 'messenger molecule' nitric oxide (NO) in the skin and blood that is responsible for lowering 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," Martin Feelisch, Professor of Experimental Medicine and Integrative Biology, said in a statement.

Feelisch said that right amount of sunlight is necessary for the body. Since increased exposure is related to skin cancer, people avoid the light. But insufficient amount of sunlight to the skin can cause other health problems including heart conditions.

Every year, around 30 percent of global deaths is caused due to cardiovascular diseases.

For the study, the researchers exposed 24 healthy individuals to ultraviolet (UVA) light from tanning lamps in two sessions of 20-minutes each. In the first session, the volunteers were exposed to both the UVA rays and the heat of the lamps. In the second session, only the heat of the lamps was exposed to the skin.

They found that UVA exposure alters blood vessels, reducing blood pressure. It also dilates NO levels without affecting the vitamin D levels. Researchers said that NO present in the upper skin is believed to trigger these effects.

"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," Professor Feelisch said.

The finding has been published in the Journal of Investigative Dermatology.

Previous studies showed that being physically fit during teenage years, regular exercise routine (including walking 2,000 extra steps) and consumption of apples lowers the risk of heart attack and stroke.