Catch Some Rays, Avoid Breast Cancer?
Reported October 22, 2007
(Ivanhoe Newswire) — While too much sun may be bad for your skin, increased exposure to sunlight may cut your risk of advanced breast cancer in half.
Researchers reveal women who had high exposure to sunlight had half the risk of developing advanced breast cancer — breast cancer that has spread beyond the breast — compared to women with low sun exposure. This only held true for women with naturally light skin color.
Exposure to the sun increases levels of vitamin D in the body. This difference was only seen in women with advanced stages of the disease, suggesting vitamin D may play a role in slowing the growth of breast cancer cells.
We believe that sunlight helps to reduce womens risk of breast cancer because the body manufactures the active form of vitamin D from exposure to sunlight, Esther John, Ph.D., lead researcher on the study from the Northern California Cancer Center, was quoted as saying. It is possible that these effects were observed only among light- skinned women because sun exposure produces less vitamin D among women with naturally darker pigmentation.
Researchers caution sunlight is not the bodys only source of vitamin D. Multivitamins, fatty fish and fortified foods, like milk, cereals and fruit juices, also contain the vitamin. Women should not try to reduce their risk of developing breast cancer by baking in the sun, the study authors write, due to the increased risk of sun-induced skin cancer. Rather, spending some time outside during the day or adding a vitamin D supplement to your diet could be beneficial.
SOURCE: The American Journal of Epidemiology, 2007;166