London - A little sunshine could be good for your heart.
A short, sharp blast from a tanning lamp can cause blood pressure to fall, scientists have found.
The results suggest that well-meaning advice to avoid the sun to protect against skin cancer may in fact be raising the odds of heart problems.
With high blood pressure trebling the chance of heart attacks and strokes, researchers believe the benefits of sunlight may outweigh the risks of skin cancer.
The study by experts at Southampton and Edinburgh Universities exposed the skin of 24 healthy young men to a sun lamp for 20 minutes and measured their blood pressure.
Diastolic pressure – the lower of the two figures in a blood pressure reading – dropped significantly and remained low for at least half an hour after the lamp was switched off.
Studies into sunlight usually credit vitamin D with any health benefits, but in this case a different compound was at work. It is thought that the UVA rays emitted by the lamp triggered the release of a compound called nitric oxide from the skin.
It then travelled to the blood vessels and relaxed them, causing blood pressure to fall.
The researchers wrote in the Journal of Investigative Dermatology that even a small drop in blood pressure cuts the risk of heart attacks and strokes.
Martin Feelisch, professor of experimental medicine at Southampton University, said: “Every little change might help.” The findings could help explain why rates of heart disease go up in the winter – and why cardiac health is worse in countries further from the equator.
The professor said it will be important to check that the benefits are not limited to a quick blast of UV light in a lab but persist in the real world where people are exposed to sunlight every day.
If the sun’s rays do prove to be beneficial for the heart, the professor said health advice on tanning should be reviewed.
He said that despite concern about skin cancer, heart disease is a far bigger killer.
In Britain, skin cancer kills 2 800 people a year while heart disease and strokes claim more than 160 000 lives annually and every seven minutes someone in the UK dies from a heart attack.
Professor Feelisch said that fear of skin cancer has left some people scared of the sun. Others may not be getting enough sunlight because they spend their work and leisure time indoors.
He added: “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.
“We are concerned that well-meaning advice to reduce comparatively low numbers of deaths from skin cancer may inadvertently increase the risk of death from heart disease and stroke.”
He added that his research is too preliminary to advise people on how much sun they should be getting.
Sunshine can also ease the early stages of multiple sclerosis, a separate study found.
MS is a neurological condition affecting around 100 000 people in the UK, causing problems with vision, balance and the bladder.
Research by Harvard School of Public Health published in online journal JAMA Neurology found that boosting vitamin D could reduce the severity of MS.
Alberto Ascherio, professor of epidemiology and nutrition at Harvard, said: “Because low vitamin D levels are common and can be easily and safely increased by oral supplementation, these findings may contribute to better outcomes for many MS patients.” - Daily Mail