How is drinking skim milk linked to the risk of developing prostate cancer?
Some studies suggest that heavy consumption of dairy foods is linked to prostate cancer, but other studies have not confirmed this. It has become a somewhat controversial issue in cancer research. A study in the December issue of the American Journal of Epidemiology found that intake of low-fat and nonfat milk increased the risk of localized prostate cancer, while whole milk decreased the risk. Another study in the same journal found a weak link between nonfat milk and advanced prostate cancer. But the bottom line is that no one really knows if there is an increased risk of prostate cancer from consuming dairy products.
Even less is known about how dairy intake would contribute to cancer risk. Some researchers think that high intake of dietary calcium decreases the function of vitamin D in the body; the nutrient is important in protecting against prostate cancer. Other scientists suggest that the hormonal composition of milk may play a role: Skim milk, they note, contains more androgens than whole milk.
Still others suggest that men who drink skim milk may be more health-conscious and more likely to get regular cancer screenings than men who drink whole milk -- and thus their cancers are more likely to be detected.
Yikyung Park, a researcher in the division of cancer epidemiology and genetics at the National Cancer Institute and the author of one of the recent studies, notes that skim milk only slightly raised the risk of advanced prostate cancer in his study. The risk was so small, he said, he can't rule out that the finding wasn't due to chance.
--Copyright © 2015, Los Angeles Times