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Sunbathing reduces blood pressure

Tecno calor pressa~o adaniel buenoIt had already been noted that blood pressure can vary throughout the year, tending to be higher during the winter and lower during the summer.  This effect had been attributed to the temperature, but now another hypothesis has emerged: sunshine could help reduce blood pressure.  Nitric oxide metabolites appear to be able to modulate pressure after exposure to ultraviolet radiation (Journal of Investigative Dermatology, January 2014).  Martin Feelish and his team at the University of Southampton, England, have suspected this possible effect of sunlight for 20 years.  Now they have confirmed a reduction in nitrate levels and an increase in nitrite, both nitric oxide metabolites, and reduced blood pressure in 24 healthy volunteers subjected to 30 minutes of sun at noon on a clear day in southern Europe.  In 2009, a group from Edinburgh had already shown that nitric oxide in human skin, found in greater concentrations there than in the blood, could interact with ultraviolet radiation.  It is unclear exactly how the nitric oxide metabolites act to generate this effect.  The authors of the latest study note that the findings are important for public health and suggest a reassessment of recommendations that people spend less time in the sun, a measure that can prevent skin cancer, but, as is now supposed, could exacerbate cardiovascular disease.