Sunlight Can Help With Prostate Health

30 June 2005
Sunlight Can Help With Prostate Health
by George Atkinson

A research team from three cancer centers has measured sunlight exposure in men and found that increased exposure to sunlight may decrease the risk of prostate cancer. The study, published in the journal Cancer Research, found that men with high sun exposure had half the risk of prostate cancer than did men with low sun exposure. The researchers, led by Esther John, of the Northern California Cancer Center, said that in men with certain gene variants, the risk was reduced even further, by as much as 65 percent. "Reduced risk of advanced prostate cancer was associated with high sun exposure determined and high occupational outdoor activity," the researchers said.

"We believe that sunlight helps to reduce the risk of prostate cancer because the body manufactures the active form of vitamin D from exposure to sunlight," said John.

Previous research by co-researcher Gary G. Schwartz had shown that the prostate uses vitamin D to promote the normal growth of prostate cells and to inhibit the invasiveness and spread of prostate cancer cells to other parts of the body. "The genes involved are those that determine the type of vitamin D receptors a person has," said Schwartz. "These receptors, which function with vitamin D like a lock and key, vary in their ability to bind vitamin D and thus to influence cell behavior."

Sunlight is not the only source of vitamin D, and the researchers said that men should not try to reduce their risk of prostate cancer by sunbathing because of the increased risk of sun-induced skin cancer. "If future studies continue to show reductions in prostate cancer risk associated with sun exposure, increasing vitamin D intake from diet and supplements may be the safest solution to achieve adequate levels of vitamin D," they said.

"Further studies in large populations are warranted to confirm the combined effects of sun exposure and genotype and define the exposure period that is important in influencing prostate cancer risk," they concluded.