The November issue of the peer-reviewed scientific journal Nutrition and Cancer (2011 Nov;63(8):1361-6) includes this study performed at Clemson University: Milk stimulates growth of prostate cancer cells in culture

In their abstract, researchers wrote:

"Concern has been expressed about the fact that cows' milk contains estrogens and could stimulate the growth of hormone-sensitive tumors. In this study, organic cows' milk and two commercial substitutes were digested in vitro and tested for their effects on the growth of cultures of prostate and breast cancer cells. Cows' milk stimulated the growth of LNCaP prostate cancer cells in each of 14 separate experiments, producing an average increase in growth rate of over 30%. In contrast, almond milk suppressed the growth of these cells by over 30%..."

Robert Cohen
http://www.notmilk.com
http://www.Twitter.com/TheRealNotmilk