Sunlight – the newest medicine for hypertension

From the results of a study conducted in early 2014, it was found that exposing the skin to sunlight can help lower blood pressure and thus limit the risk of heart attack and stroke.

The study was carried out by British scientists from the Universities of Southampton and Edinburgh and showed that sunlight alters the levels of the small signaling molecule nitric oxide in the skin and blood, lowering blood pressure.

Martin Feelish, Professor of Experimental Medicine and Integrative Biology at the University of Southampton and lead scientist on the study, says that nitric oxide and the compounds that break it down are most abundant in the skin, affect blood pressure regulation.

When exposed to sunlight, small amounts of nitric oxide molecules penetrate the skin into the bloodstream, lowering the tone of the blood vessels.

Thus, in fact, they contribute to lowering blood pressure, and the probability of heart attack and stroke decreases almost to 0.

Although limiting exposure to the sun is consistently recommended by all dermatologists to prevent skin cancer, the authors of the study suggest that limiting exposure as much as possible contributes to the formation of factorsthat increase the risk of cardiovascular disease.

These clinical conditions, which are often associated with hypertension, account for 30% of deaths worldwide each year.

High blood pressure and cardiovascular disease have been found to vary with latitude and their incidence increases in the winter months and in countries far from the Equator where ultraviolet radiation is significantly lower.

When exposed to sunlight, natural substances that lower blood pressure are released.

During the study, which was published as an abstract in the Journal of Investigative Dermatology, the skin of 24 healthy subjects was exposed to ultraviolet light from tanning lamps for 2 sessions of 20 minutes each.

In the first session, UVA rays and heat from the lamps were directed against the skin of the participants. In the second, the ultraviolet rays were blocked, so that only the heat from the lighting fixtures was directed against the skin of the participants.

Results show that UVA exposure dilates blood vessels, resulting in significantly lower blood pressure and altered levels of circulating nitric oxide metabolites without altering vitamin D concentrations.

Further experiments show that pre-formed nitric oxide deposits in the upper layers of the skin mediate the achievement of these effects.

The results are consistent with seasonal changes in blood pressure and cardiovascular risk in people living in temperate latitudes.

Professor Feelish adds that the results of the study he led are essential to the ongoing debate about the potential beneficial effects of sunlight on human health, as well as the role of vitamin D in this process.

The study may be appropriate to reassess the risks and benefits of sunlight exposure to human health and to take a new approach to formulating recommendations for public health protection.

Avoiding excess exposure to sunlight is essential for skin cancer prevention, but insufficient exposure due to fear of the sun or certain lifestyles can increase the risk of developing heart -vascular diseases.

And the effect of vitamin D in the form of a dietary supplement is disappointing, being useful only for maintaining bone strength.

Scientists who conducted the study believe that nitric oxide in the skin, which penetrates when exposed to sunlight into the bloodstream, is an important but overlooked factor in reducing the risk of cardiovascular disease.