UV light which encourages the production of nitric oxide helps to lower blood pressure, according to scientists at Edinburgh University.

More than a billion people worldwide currently suffer from high blood pressure (hypertension), while some 9 million individuals die every year as a result of the consequences of this condition, which can include heart attack, stroke and kidney failure, the WHO says.

High blood pressure is often the result of a modern lifestyle involving too many fatty and salty foods, too much alcohol and nicotine, insufficient exercise and - as demonstrated by a recent study carried out by researchers in Scotland - not enough sunlight.

A team led by Dr Weller at the University of Edinburgh invited 24 volunteers to expose their skin to the UV light from a heat lamp for 20 minutes initially. During a second session, the UV light spectrum was filtered out and the volunteers exposed to the heat of the lamp only. While their blood pressure remained unchanged after exposure to heat only, it fell significantly following exposure to UV light. According to the researchers, this is due to an increased production of nitric oxide which is stimulated by UV light. Nitric oxide causes the blood vessels to expand, which in turn lowers the blood pressure. Dietary vitamin D supplements do not help in this respect, as the effect is triggered by sunlight only.

"Like Dr Weller, I believe that the health benefits of moderate exposure to sunlight outweigh the risks of developing skin cancer. The researchers have shown that the reduction in blood pressure is not linked to vitamin D levels, but instead to other effects of sunlight. So this study provides further evidence to support our recommendation in favour of moderate sun exposure", Ad Brand of the Sunlight Research Forum (SRF) explains.

The Sunlight Research Forum (SRF) is a non-profit organisation with its headquarters in the Netherlands. Its aim is to make the latest medical and scientific findings concerning the effects of moderate UV radiation on humans open to the general public.