Wearing sunscreens and other topical skin creams is highly advisable to protect ourselves against skin cancer, but this new research also shows that sunlight alters levels of the small messenger molecule, nitric oxide (NO) in the skin and blood, reducing blood pressure.
The research was carried out at the Universities of Southampton and Edinburgh, and published in the Journal of Investigative Dermatology, and the authors suggest that minimising sun exposure completely may be disadvantageous by increasing the risk of prevalent conditions related to cardiovascular disease.
Test
In their study, Dr Richard Weller of the University of Edinburgh and Professor Martin Feelisch at the University of Southampton, exposed the skin of 24 healthy individuals to ultraviolet (UVA) light from tanning lamps for two sessions of 20 minutes each.
In one session, the volunteers were exposed to both the UVA rays and the heat of the lamps. In another, the rays were blocked so that only the heat of the lamps affected the skin.
The results suggest that UVA exposure dilates blood vessels, significantly lowers blood pressure, and alters NO metabolite levels in the circulation, without changing vitamin D levels.
Debate
"These results are significant to the on-going debate about potential health benefits of sunlight and the role of Vitamin D in this process,” says Professor Feelisch.
“It may be an opportune time to reassess the risks and benefits of sunlight for human health and to take a fresh look at current public health advice. 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.”
The Professor of Experimental Medicine and Integrative Biology continues: "We believe that NO from the skin is an important, so far overlooked contributor to cardiovascular health.”
In future studies Feelisch and the team 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.