[tanysquirrel]

interesting:


http://www.nordesthetics.com/en/articles...necomastia
How is protein powder related to gynecomastia?

Casein and whey protein are extracted from cow milk. According to the Harvard Gazette, in modern farms cows are milked several hundred times a year. Inevitably, for much of that time cows are pregnant. During pregnancy cow endocrine system produces estrogen and this hormone gets into the milk. Milk from a cow which is in the late stage of pregnancy contains approximately 33 times more estrogen than milk from a cow which is not pregnant. There is a hypothesis suggesting that casein and whey protein powder contains estrogen and may cause gynecomastia. However, there is other opinion that estrogen levels in protein powder are too low to have physiological effect on human body. All in all, casein and whey protein powder may be related to gynecomastia but it depends on many circumstances including age and hormonal sensitivity.


anecdotal evidence:
http://www.elitefitness.com/forum/diet-b...95194.html
more research needed.