A Cedars-Sinai study found that chemicals in the skins and seeds of red grapes decreased estrogen levels slightly while increasing testosterone among premenopausal women who drank 8 ounces of red wine nightly for about a month.
The study, published online in the Journal of Women’s Health, challenges the widely held belief among doctors that all alcohol increases estrogen levels, thus nurturing the growth of cancer cells.
In the study, 36 women were randomized to drink either cabernet sauvignon or chardonnay every day for about a month, after which participants switched to the other type of wine. Twice each month blood was collected to determine hormone levels. The change in hormone patterns suggested that red wine might stem the growth of cancer cells, according to investigators.
Coauthor Glenn D. Braunstein, MD, said the results do not mean that white wine increases the risk of breast cancer. Instead, it shows the grapes used in those varieties of wine may not contain the same protective elements found in red grapes.
“There are chemicals in red grape skin and red grape seeds that are not found in white grapes that may decrease breast cancer risk,” said Braunstein, vice president for Clinical Innovation and the James R. Klinenberg, MD, Chair in Medicine.
Source: Cedars-Sinai.