In this week’s article we are discussing a TED talk titled “could the sun be good for your heart?” delivered by Richard Weller, a dermatologist with a history in general medicine.
“A Gradient of Health”
In Britain, research shows there to be a “gradient of health” with your cardiovascular related mortality risk being higher the further north you live. Differences in lifestyle factors have been suggested as the reasons for this, however this is still the case even after taking into account smoking, social class, diet and other known risk factors.
So, what causes this? Sunlight exposure. It is important to note that this is independent to Vitamin D levels. Vitamin D is a signal for high levels of sunlight exposure, but it is actually that level of sunlight exposure which has been found to reduce the risk of cardiovascular disease.
Introducing Nitric Oxide
Nitric oxide dilates your blood vessels and your coronary arteries, therefore reducing blood pressure and preventing angina. The skin has huge stores of nitric oxide, which is suspected to come from diet (in the forms of leafy vegetables and beetroot, for example). These stores are in fact 10 times bigger than that in your circulatory system and is waiting to be activated and released by sunlight.
Vegetables high in nitrates
Unlocking Nitrates Through UV
The study presented in the Ted talk, used UV-A rays (in the form of ultra-violet lamps) as they did not want to increase Vitamin D stores (which is activated by UV-B rays). After the equivalent of 30 minutes of sunshine, they saw a rise in circulating nitric oxide and a decrease in blood pressure during exposure and up to an hour afterwards.
Although the reduction in blood pressure was small, this is an important finding as even small changes in blood pressure can result in significant reductions in deaths from cardiovascular disease. There is a direct relationship between the reduction in blood pressure and the fall in mortality due to cardiovascular diseases, such as strokes and ischemic heart disease. A 20mmHg lower systolic blood pressure leads to a two-fold reduction in overall mortality in both men and women aged 40-69.
In summary, the equivalent of 30 minutes of sunlight exposure has been found to reduce blood pressure to a degree great enough to reduce your risk of cardiovascular disease. This is a result of unlocking the nitrate stores in the skin, which are influenced by correct nutrition. Please remember when exercising outside it’s best to do so first thing in the morning or later in the evening, to avoid the hottest part of the day. Also, drink plenty of water and use sun cream to protect yourself!