A recent and fascinating Ted Talk featured dermatologist Richard Weller who talks about the science of UV light and how it affects our health. With humour and eloquence and simplicity, his talk demonstrates why people do not trust the media’s representation of medical discoveries sometimes.
Although our skin creates Vitamin D from cholesterol when exposed to UV light from the sun, sunlight may give us another unexpected benefit too. New research by his team shows that nitric oxide is a chemical released from relatively enormous stores in our skin. When UV light interacts with nitrates/nitrites that are concentrated in the skin from green leafy vegetables in our diet, it produces nitrous oxide that in turn circulates into the body and reduces blood pressure, and as Dr. Weller agues, likely reduces our risk for cardiovascular disease. Nitrous oxide is currently a common medical treatment for heart pain (angina) by causing dilation of blood vessels in the heart (and elsewhere).
Higher blood pressure due to lack of sun exposure may begin to explain why, Dr. Weller says, after adjusting for all other lifestyle risk factors, people who live in more northern geographic areas have more heart disease.