Ultraviolet B light reduces mild hypertension. Researchers have determined that regular, brief exposure to ultraviolet B (UVB) light reduces blood pressure while increasing blood levels of Vitamin D, according to a study published in the August issue of the British medical journal Lancet.
Michael Holick, a professor of medicine, dermatology, and physiology at the School of Medicine and chief of endocrinology, nutrition, and diabetes at Boston Medical Center, conducted the study on women between the ages of 26 and 66 years, all of whom were diagnosed with mild essential hypertension (high blood pressure for which there is no other known cause).
In the randomized study, one group was exposed to full-body ultraviolet A (UVA) treatment three times per week, the other to UVB treatment at comparable intervals. Blood pressure levels were reduced on average by 6 mmHg in the UVB group -- essentially, a return to normal level.
"The study clearly showed that exposure to an artificial UVB source can reduce blood pressure in patients with mild, untreated hypertension," says Holick. "And the UVB group's Vitamin D blood levels were also increased by 40 times in comparison with the UVA group."
He suggests that walking for 15 to 20 minutes in the spring, summer, and fall would have a threefold effect: a reduction in blood pressure due to UVB exposure, increased cardiovascular conditioning (which also helps keep blood pressure down), and increased levels of Vitamin D.