The fear of getting premature wrinkles and skin cancer has had some people avoiding sun exposure. Too much bad publicity about the damaging effects of getting scorched by the sun has also got some people to overlook the health benefits of sunlight. A new study, however, could encourage people to bask again under the sun as sunlight apparently reduces one's risks of heart attack and stroke by helping reduce high blood pressure.
In the study published in the Journal of Investigative Dermatology Jan. 20, a team of researchers at the universities of Southampton and Edinburgh in UK examined the effects of Ultraviolent-A (UVA) radiation on 24 volunteers whose exposure to UVA sun lamps in a lab is equivalent to what they would receive if they stayed under the sun for half an hour during summertime in Europe.
The researchers observed that the volunteers' blood vessels dilated and their blood pressure decreased. "Small amounts of NO [nitric oxide] are transferred from the skin to the circulation, lowering blood vessel tone," said study author Martin Feelisch, a professor of experimental medicine at the University of Southampton in southern England. "As blood pressure drops, so does the risk of heart attack and stroke."
High blood pressure is known as a silent killer because it is one of the main factors of cardiovascular disease, which the World Health Organization reported as the number one cause of death worldwide. "Blood pressure is a continual risk factor for cardiovascular disease, so even a small reduction is significant," Feelisch said.
Sunlight is known to aid in the production of Vitamin D but Feelisch said this isn't the reason why people in sunny parts of the world have lower blood pressure and lower risk of cardiovascular disease. "We know it is not the effect of vitamin D, as this takes longer to be made in the body than the time frame of the experiment," he said.
The researchers acknowledged the risks of getting exposed to too much sunlight as well but pointed out that while excess sunlight can be damaging, too little exposure also carries some risks. "While we appreciate that excess sunlight carries a very real risk to develop skin cancer, too little may increase the risk for cardiovascular disease by elevating blood pressure and if you look at the numbers, we're talking about 20 times higher numbers of chronic disease mortality, of cardiovascular disease compared to death as a consequence of melanoma," Feelisch told AM.
