Conventional milk typically has tons of antibiotics, steroids and hormones because of the way they "factory" the cows by putting them in areas, where they almost touch, stand still, row after row, many times in the dark, and milk the cows on unnatural schedules in order to maximize the milk production. This maximization causes the dairy cows' udders to become very painful, heavy and infected. In response, producers have to put these poor animals on more drugs to lessen the pain, reduce disease, and keep that milk production going around the clock.
This terrible cycle causes large doses of antibiotics and hormones in the milk and meat. On top of that, they typically pasteurize and homogenize. Both procedures destroy vitally important health-giving compounds in the milk, destroying enzymes, vitamins, vitamins B12 and B6, and promote pathogens. However, unpasteurized milk may harbor harmful bacteria (thanks friends for point this out!), as the FDA states, so certain processes may be necessary.
There also has been talk about a link between milk and cancer, including ovarian cancer. According to research published in November 2004 in the American Journal of Clinical Nutrition, some Swedish researchers concluded that "our data indicate that high intakes of lactose and dairy products, particularly milk, are associated with an increased risk of serious ovarian cancer, but not of other subtypes of ovarian cancer." Although we really don't know what kind of milk they were drinking or have multiple, multiple studies, but it should cause us to think about it (especially for those who drink conventional milk with cereal for like every meal--I was one of those in college).
The other thing to really question is why kids hit puberty SO MUCH earlier than people 50+ years ago. Girls are wearing their first bra at younger ages. My theory, and personal opinion, is that this abnormality could be very seriously linked to the impact of all the hormones and antibiotics industry uses. Kids are fed milk from a very young age. I am sure multiple factors, but this might be one (and potentially big one).
It is vital to know where your food is coming from. I do drink milk every day for the most part, although I have learned that I can get calcium from many other foods such as kale and other vegetables. Remember cheese also comes from the cow, so this same practice also impacts the nutritional value of it (to learn more: Is That Really Cheese?). I drink Organic Valley milk. From my research, Organic Valley is a co-op of farmers who really care about pasturing their cows and don't use hormones. In addition, I have switched to whole milk; I was fat free for years. Since my diet has changed, I now use milk to get some of my saturated fat.
Source: 150 Healthiest Foods on Earth by Jonny Bowden
