Researchers from Edinburgh University found that when the skin is exposed to heat combined with UV rays (like direct sun exposure), blood vessels release an important chemical called nitric oxide. This prompts the lowering of blood pressure, which then leads to the reduction in the risk of heart attack, stroke and blood clotting. According to the team, headed by a senior lecturer in dermatology at Edinburgh, their findings imply that it is UV radiation, not heat, which is responsible for the beneficial effects.
Researchers argued that the benefits of UV ray exposure extend way beyond its negative effects. “We suspect the benefits to heart health from sunlight will outweigh the risk of skin cancer.” he said. Scientists have known for years that blood pressure is lower in summer than in winter. Research has also shown that people living in countries far from the equator and with less sunlight have lower blood pressure in general.
Getting some sunlight each day can have more positive effects than just lowering blood pressure. Vitamin D is synthesized by the body when the skin is exposed to UV radiation. Studies actually suggest that sunlight can help cancer outcomes, because Vitamin D is so beneficial in regulating cell growth. It influences more than 200 genes, many of which are involved in cell regulation – a process that is disrupted in cancer cells. Studies have shown that those who have lower blood vessels of vitamin D are more at risk of developing cancer.
However, this does not mean you should spend hours out in the sun without any protection. Depending on your skin, your location and the time of year (warmer climates are more subject to UV radiation than cooler ones), you still need to take adequate precautions to make sure that you protect yourself from skin damage. During summer, it may only take a few minutes a day for your skin to manufacture all the vitamin D it needs, but during winter, longer periods may be needed.
It is obviously very important to be aware of the detrimental effects of too much sun exposure, but in light of this new research, getting a little bit of sun every day can help lift our spirits and contribute to better health in the long term.
 Frranchi.L, 20 Minutes of Sunshine May Reduce Blood Pressure, New Research Reveals, NaturalTherapyForAll.com, May 2013.  Webb. Denise, Today’s Dietitian (TODAYS DIETITIAN), 2012 Oct; 14 (10): 58-61