P. L. Tate at Department of Nursing, Clemson University, Clemson, South Carolina and colleagues published a study in Nutrition and Cancer suggesting that drinking milk may promote prostate cancer growth.
Concern has been raised about the fact that milk contains estrogen, which is known to promote hormone-sensitive cancers like prostate cancer and breast cancer.
In the study, researchers tested organic cows' milk and two commercial products, almond milk and soy milk in prostate cancer cell lines and breast cancer cell lines to examine how they effect the growth of these cancer cells.
Cows' milk was found to stimulate the growth of LNCaP prostate cancer cells in all 14 experiments, boosting the growth rate by greater than 30 percent. In contrast, almond milk decreased the growth rate by more than 30 percent.
Cows' milk and almond milk did not affect the growth of breast cancer nor AsPC pancreatuc cancer cells signficantly. But soy milk was found to increase the growth of breast cancer cells.
The researchers concluded "These data indicate that prostate and breast cancer patients should be cautioned about the possible promotional effects of commercial dairy products and their substitutes."
