In my book, The Omni Diet, I discuss the science-backed reasons not to drink milk, including these:
- Pasteurization—heating milk at high temperatures to kill bacteria—also kills the live enzymes that might have otherwise made milk slightly worth drinking. You may be shocked to learn that organic milk is even worse, because it requires ultrapasteurization, which kills even more of the beneficial enzymes.
- Bovine growth hormones commonly used to boost cows’ milk production end up in the milk you drink, then accumulate in your liver to produce IGF-1 (insulin growth factor). Excessive amounts of IGF-1 are strongly linked to increased risk for breast, colon and prostate cancer. There’s also some evidence that eating dairy products may magnify risk for ovarian cancer.
- Bovine growth hormones consumed in milk are suspected of contributing to early puberty in kids, due to elevated IGF-1.
- One hormone, rBGH, makes dairy cows more prone to infections, especially mastitis. As a result, the animals are often dosed with antibiotics that taint the milk in your glass. Overuse of antibiotics has fueled the growth of potentially deadly antibiotic superbugs, such as MRSA and C. difficile. Many countries have now banned milk from cows treated with rBGH.
- Most people have trouble digesting dairy products. After age two, fewer than 35 percent of us produce lactase, the enzyme that’s required to break down lactose (milk sugar) and digest milk. Without lactase, lactose remains undigested, triggering very unpleasant GI symptoms. And even if you can digest lactose, it’s still bad news because it’s converted to compounds that increase blood sugar and ignite inflammation.
- Dairy products have also been linked with increased risk for acne, joint pain and Parkinson’s disease. Nor does milk help you slim down, according to a 2012 Harvard analysis of earlier studies involving 2,101 people.
- Fortunately, there are plenty of healthy ways to get the calcium you need for strong bones without drinking milk. Calcium-rich foods include sardines with bones, spinach, collards and other leafy greens, and blackstrap molasses. Regular, weight-bearing exercise is also crucial for protecting bone health.