Rather known to cause skin cancer, the sun’s rays also seem to lower blood pressure, according to British doctors.
What if ultraviolet rays could do our body good? On the occasion of a international congress in Edinburgh, in Scotland, British dermatologists presented the preliminary results of their work. According to them, exposure to the sun would have the effect of releasing nitrogen monoxide, a molecule stored in the lower layers of the skin, into the blood. Once in the vessels, it dilates their walls and thus reduces the pressure therein, which would minimize the risk of developing cardiovascular disease or having a heart attack.
To achieve these results, the researchers followed sessions of UV rays to volunteers. In just twenty minutes, the spokes lowered their tension for about an hour. This decreases by 2 mm Hg, which ultimately corresponds to a 10% lower risk of cardiovascular accident.
Dr Richard Weller, dermatologist at the University of Edinburgh and lead author of this work, believes that “the benefits of sunlight for heart health outweighs the risk of skin cancer”.
On the part of a dermatologist, the assertion is enough to make people jump. Every year, UV rays cause numerous skin cancers, the latter even holding the sad record for the strongest progression over the last twenty years. They are responsible for around 1,300 deaths each year in France alone. This figure is admittedly very modest compared to the 150,000 annual deaths linked to cardiovascular diseases, the majority of which are due to hypertension.
So should hypertensive people throw away their bottles of sunscreen? Dr Weller prefers to put water in his wine: “UV rays will remain the number 1 risk factor in the appearance of skin cancer no matter what, it should not be forgotten. In addition, the drop in blood pressure remains succinct, and we do not know how it will evolve following repeated exposure, ”he confides to pourquoidocteur.
This is not the first time that links between the sun and blood pressure have been highlighted by doctors. Except that until now, they believed that it was vitamin D, produced under the action of UV-B rays, that lowered blood pressure. However, in this experiment, the lamps emitted only UV-A rays, which makes it possible to rule out any effect linked to vitamin D, the blood concentration of which did not increase in the volunteers. This proves that “the action of nitric oxide is completely independent of vitamin D, according to Richard Weller. The dermatologist specifies that this probably explains why food supplements fortified with vitamin D, supposed to lower blood pressure, never had the desired effect ”.
Although announced in a symposium of specialists, these results must be taken with caution. There is often a gap between the announcements and the results actually published, no doubt that they will be qualified by other researchers. In any case, if there is one area where everyone agrees, it is that the sun is good for morale, all the more reason to wait for its return in this very gloomy spring!
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