This week’s issue of the New England Journal of Medicine has a review article by Harvard’s Drs. David Ludwig and Walter Willett that tells us way more than we can possibly digest about “milk and health.” (1)
One piece of basic information that is not mentioned in this review is that an estimated 65% of the world’s adult population cannot digest lactose; they are lactose intolerant. Infants can drink milk, but as adults mostly only northern Europeans have evolved the ability to digest lactose. That’s probably because of an adaptation to the domestication of dairy animals 10,000 years ago. So all this information about milk is not going to pertain to more than half of the world, unless we think that milk is so wonderful that we should process out the lactose so everybody can drink it.
But for those of us who can drink milk, is it good for you? The bottom line is that while milk is good food. It has calcium and is fortified with added vitamin D. It also has high quality protein and lots of fat for energy. But even for kids it is not indispensable. You can get all that good stuff by other kinds of food. The bottom line is that it’s complicated and probably doesn’t matter much whether you drink the three 8 oz. glasses of milk, that Americans older than 9 should drink every day, according to the U.S. Department of Agriculture (USDA) nutrition guideline. Still there’s a lot of interesting weird stuff about milk that is explained here.
The first anomaly is the observation that contrary to popular belief, drinking a lot of milk when you’re young leads to a higher rate of hip fractures. They say that this might be because drinking a lot of milk makes you taller (for complicated reasons) and tho tall stature is associated with lower risk of cardiovascular disease there is a higher risk of hip fractures and also many kinds of cancer.
Regarding obesity, the best (but actually bad) observational evidence says that milk consumption has no effect on body weight and low fat milk consumption is actually associated with a higher rate of obesity than full-fat (3%) or 2% milk. This contradicts the recommendation of the American Academy of Pediatrics and the USDA that obese children should drink skim milk.
Canada and the European union have banned milk from cows treated with bovine growth hormone not because of any evidence of human health issues but instead because of health welfare problems in the cows.
The sex-hormone content of milk is increased if cows are milked while they are pregnant but this is done commonly by both conventional and organic milk producers.
The only reasonable reason not to be drinking milk is the same as the best reason not to eat meat. It causes more greenhouse gasses and water pollution, particularly by industrial scale production, than just ourselves eating the stuff we are feeding to the cows.
It’s going to be tough for me. I like milk and cheese. Except not skim milk tho, that’s nasty.
Parenthetically, remember those milk mustache commercials? Remember during the Trump impeachment trial the senators were only allowed to drink milk or water.
1. Milk ad health. N Engl J Med 2020;382:644-54.
John DiTraglia M.D. is a Pediatrician in Portsmouth. He can be reached by e-mail- firstname.lastname@example.org or phone-354-6605.