9th May 2013 - A small study by researchers at Edinburgh University has found sunshine may do more than boost vitamin D levels it could also help to reduce blood pressure, which in turn could cut the risk of heart attack and stroke.
The study showed that when skin is exposed to the sun’s rays, a compound called nitric oxide is released in our blood vessels which helps to lower blood pressure.
According to the researchers the findings suggest that exposure to sunlight improves health overall, because the benefits of reducing blood pressure outweigh the risk of developing skin cancer.
However some surprise has been expressed already at this conclusion and although the study will be presented at the International Investigative Dermatology 2013 conference it hasn't yet undergone the scrutiny of peer review.
For the study researchers examined the blood pressure of 24 volunteers who sat beneath tanning lamps for two sessions of 20 minutes each.
In one session, the volunteers were exposed to both the UV rays and the heat of the lamps. In the other, the UV rays were blocked so that only the heat of the lamps affected the skin.
The results showed that blood pressure dropped significantly for one hour following exposure to UV rays, but not after the heat-only sessions.
The researchers say this shows that it is the sun’s UV rays that lead to health benefits. The volunteers’ vitamin D levels remained unaffected in both sessions.
Dr Richard Weller, Senior Lecturer in Dermatology at Edinburgh University says in a press release: "We suspect that the benefits to heart health of sunlight will outweigh the risk of skin cancer. The work we have done provides a mechanism that might account for this, and also explains why dietary vitamin D supplements alone will not be able to compensate for lack of sunlight.
"We now plan to look at the relative risks of heart disease and skin cancer in people who have received different amounts of sun exposure. If this confirms that sunlight reduces the death rate from all causes, we will need to reconsider our advice on sun exposure."
Maureen Talbot, Senior Cardiac Nurse at the British Heart Foundation, told us via e mail: "This small but interesting study has shown that exposure to ultraviolet rays produces nitric oxide, which can lead to a slight decrease in blood pressure.
"However, far more research is needed before sunlight would ever be recommended as an effective way to treat high blood pressure.
"In the meantime, people with high blood pressure should continue to take prescribed medication, maintain a healthy weight and stay physically active, as these are all proven ways to keep blood pressure under control."
Yinka Ebo, senior health information officer at Cancer Research UK, said in a prepared statement: "This is interesting research but it’s yet to be published in a peer reviewed scientific journal.
"Overexposure to UV radiation from the sun or sunbeds is the main cause of skin cancer. We all need some sunshine to make vitamin D to keep us healthy, but most people can get a good balance by enjoying the sun safely and taking care not to burn. Sunburn is a clear sign that your DNA has been damaged, and over time this damage can build up and lead to skin cancer.
"The best way to protect your skin from sunburn when you’re out in strong sun is to spend time in the shade, pop on a t-shirt and use at least factor 15 sunscreen applied generously and regularly."
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