From Science Daily, research is reported on the ability of sunlight exposure to effectively lower blood pressure.[i] The research, reported earlier by Dr. Richard Weller, is not really new, but it is good to see that it is receiving more press. Even more important is the fact that Dr. Weller is a dermatologist. The study was conducted by exposing the skin of 24 healthy volunteers to ultraviolet light from tanning lamps for two sessions of 20 minutes each. In one session, they were exposed to both ultraviolet A (UVA) and the heat from the lamps; in another, the UVA rays were blocked so that only the heat was applied. Blood pressure was lowered by UVA exposure, but not by heat alone.
It has been known for some time that nitric oxide (NO) is produced by the skin in response to sunlight. NO is a potent vasodilator that relaxes the vessels and allows blood pressure to drop. Therefore, the sunlight, or tanning lamps, both of which emit UBA, become useful tools for lowering blood pressure.
It is important to note that these results were achieved with no increase in vitamin D levels. Therefore, sunlight stands on its own in reducing blood pressure. This is not to negate the positive influence of vitamin D; it is a critical factor in reducing the risk of myriad diseases. My ongoing searches of the medical and scientific literature, however, have persuaded me that most studies that assess the influence of sunlight alone are more impressive in preventing disease than those that assess only vitamin D blood levels or supplementation.
Dr. Feelisch, one of the investigators, stated the following: “These results are significant to the ongoing debate about potential health benefits of sunlight and the role of Vitamin D in this process. 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.”
More on this subject will follow. In the meantime, allow yourself safe, non-burning exposure to the sun.
[i] University of Southampton (2014, January 17). Here comes the sun to lower your blood pressure. Science Daily. Retrieved January 18, 2014, from http://www.sciencedaily.com /releases/2014/01/140117090139.htm.