Good news for those with high blood pressure (HBP): exposure to sunlight could be able to modify the levels of nitric oxide in the skin, causing vasodilation, and thus reducing blood pressure levels.
Sunlight is beneficial to your bones and mood. Furthermore, the sun could be an excellent tool for lowering the risk of serious events such as heart attack and stroke.
This is the major finding of a study conducted by Southampton and Edinburgh Universities and published in the Journal of Investigative Dermatology.
The British researchers claim that small quantities of nitric oxide make the difference. According to Dr. Martin Feelisch, professor of experimental medicine at the University of Southampton, these small quantities of nitric oxide are transferred from the skin to the blood, reducing the contraction of the muscular wall of blood vessels. This results in an improvement in blood pressure values for hypertensive subjects (subjects with HBP) and therefore a reduction in the risk of heart attack or stroke. The researchers looked at 24 volunteers exposed to UVA rays through tanning beds. Each session lasted about 20 minutes in total and two sittings were carried out with a slight difference: in the first session, the tanning beds emitted heat as well as light while in the second they only emitted UVA rays.
Feelisch states that nitric oxide and its products, known for being abundant in the skin, are involved in the regulation of blood pressure, and during exposure to sunlight, small quantities of nitric oxide are transferred to the bloodstream, reducing the contraction of blood vessels.
These results also seem to suggest that UVA ray exposure could alter the levels of nitric oxide metabolites, without negatively impacting levels of vitamin D.
Dr. Feelisch adds that these results are significant in terms of the current debate on the possible benefits of exposure to the sun. He stresses the importance of avoiding excessive exposure in order to prevent skin cancer, but also claims that avoiding the sun entirely could increase the risk of heart disease. Feelisch states his belief that nitric oxide (NO) provides a great contribution towards cardiovascular health, and that future studies will aim to investigate this effect and identify nutritional strategies aimed at maximizing the skin’s ability to store nitric oxide and transfer it to the blood.
Once again we find that nature can benefit our health, but remember that exposure should be gradual and moderate in order to provide beneficial results for you and your HBP.
Scientific articles below:
- UVA Irradiation of Human Skin Vasodilates Arterial Vasculature and Lowers Blood Pressure Independently of Nitric Oxide Synthase (Journal of Investigative Dermatology (2014) 134, 1839–1846) http://www.nature.com/jid/journal/v134/n7/full/jid201427a.html
- An unexpected role: UVA-induced release of nitric oxide from skin may have unexpected health benefits
(J Invest Dermatol. 2014 Jul;134(7):1791-4) http://www.nature.com/jid/journal/v134/n7/full/jid201433a.html
- Whole body UVA irradiation lowers systemic blood pressure by release of nitric oxide from intracutaneous photolabile nitric oxide derivates. (Circ Res. 2009 Nov 6;105(10):1031-40) http://circres.ahajournals.org/content/105/10/1031.long
- Mechanism and biological relevance of blue-light (420-453 nm)-induced nonenzymatic nitric oxide generation from photolabile nitric oxide derivates in human skin in vitro and in vivo. (Free Radic Biol Med. 2013 Dec;65:1363-77) http://www.sciencedirect.com/science/article/pii/S0891584913006254