A couple of months ago, I addressed the question of whether eating meat affects your hormone levels. Since then, several of you have written to ask the same question about cow’s milk.
All milk (whether from cows, goats, humans, or porpoises) naturally contains small amounts of various hormones, including estrogen and progesterone. Because hormones like estrogen are fat-soluble, the level of hormones is higher in whole milk than in skim milk. Organic milk, however, contains about the same amount of hormones as conventionally produced milk.
Does Dairy Promote Breast Cancer?
Some worry that the hormones in cow’s milk could cause health problems in humans. People have suggested that estrogen in cow’s milk might promote the growth of hormone-sensitive cancers such as breast or ovarian cancer, for example. Others worry that hormones in milk might cause early puberty in children.