Milk: It Does a Body Good -- or Does It?

Medically Reviewed by Aman Shah, MD on October 13, 2000
From the WebMD Archives

Oct. 13, 2000 -- There are three kinds of people in the world: those who like milk and believe it offers a whole nutritional package, those who don't like milk, and those who not only don't like milk but also claim it is hazardous to your health.

The dispute was vividly illustrated recently when the People for the Ethical Treatment of Animals took the anti-milk message to a Times Square billboard with a picture of Mayor Rudolph Guilliani sporting a milk mustache next to the headline: "Got prostate cancer?"

The billboard has been pulled but the controversy lingers: The Physicians Committee for Responsible Medicine (PCRM) says that there are good data to suggest that consumption of milk and other dairy products does increase the risk of prostate cancer. It makes that claim based on research from the landmark Physicians' Health Study suggesting that men who consume more than 2.5 servings of dairy products daily have a 30% increased risk of prostate cancer. That, says PCRM staff dietician Brie Turner, MS, RD, is a good reason for "men to decrease or eliminate dairy products from their diets, especially because men don't have the same risk for osteoporosis as women."

Taking an opposing position, Ruth Kava, PhD, RD, director of nutrition at the American Council on Science and Health in New York, says there are "no good or bad foods. Just good or bad diets." Moreover, Kava says that in some studies "an increased risk of 30% does not easily translate into clinical significance."

Turner says most Americans have been raised to revere milk as a wholesome source of needed calcium and other proteins, but she says that even small children face health risks from consumption of cow's milk. For example, she says a majority of Asian, Native American, and African-American children are lactose intolerant and can't drink milk. Additionally, she says that some studies suggest that milk promotes the development of type 1 diabetes because a specific protein in dairy products may cause damage to the body's ability to regulate sugars in the blood and thus increases the risk for type 1 diabetes.

Several studies of a possible type 1 diabetes/milk link have been published and the results are ambiguous Hillary Wright, RD, MEd, nutritionist for Harvard Vanguard Medical Associates in Boston, tells WebMD. "I have two brothers with type 1 diabetes and so I am interested in this area. I have never seen firm evidence to suggest that cow's milk promotes diabetes."

However, a negative for milk is "the reports in some cancer prevention and cancer survivor literature that milk -- because of bovine growth hormones taken by cows -- can increase the risk of cancer or cancer recurrence. Many times oncologists will recommend that patients be taken off dairy products because of this fear," says Wright.

She says that she advises patients to carefully consider the options before removing dairy products. "I ask them, 'Ok, how are you going to replace this? What will be your other sources of calcium? Of vitamin D? Of protein?'" She says that a better approach is to use only "organic, hormone-free milk. You can find this readily available in supermarkets and specialty stores.""

Although Turner and the PCRM question milk consumption at any age, most groups support milk drinking by children younger than two, says Kava. "The brain is growing so fast at that time, that whole milk is really needed."

At the University of Vermont in Burlington, Rachel Johnson, PhD, RD, professor of nutrition and associate dean for research, has been studying calcium intake by children. Johnson tells WebMD that her work has convinced her that in order for children to meet the recommended daily requirement of calcium, "they need to drink milk."

She says she was sold on this idea when "we did a study of where teenagers consumed their noontime meals. We found that in terms of diet quality, those who ate the school lunch meal instead of bringing a bag lunch or eating elsewhere had higher calcium intake then the other children." She says that the "drink of choice with a school lunch is milk."

She then conducted a national study of children aged 5 to 17 and discovered "that a mother's milk consumption is a good predictor of both the amount and type of milk a child consumes." She says that if the mother regularly drinks milk, "chances are the child will be a milk drinker." And if the mother's milk choice is skim, the child is likely to pick skim as well, she says.

Johnson says she supports daily milk consumption by schoolchildren because it is such an easy source of calcium. "Certainly, it is possible to meet one's calcium needs without dairy products. However, for the most part, calcium in other foods is not as readily available. For example, it would take 10 cups of broccoli to equal the calcium in one cup of milk. ... I'm not saying it isn't possible to get calcium and other nutrients without dairy, but I will tell you that when you look nationwide at food consumption the data show that that those kids who are not consuming dairy products on a regular basis are not meeting their calcium needs."

And even Turner agrees with the pro-dairy camp, that calcium is probably needed for bone health. But she says that "a cup of cooked collard greens can give you the same amount of calcium as a cup of milk," and she says that the collard greens are a healthier source of calcium. She also recommends calcium-fortified orange juice, which she says "offers calcium that is almost as absorbable as calcium in milk."

Although the milk debate may seem confusing, Kava says there is a very clear take home message: "In a nutshell, the key is moderation in everything. When people say one food or food group causes or cures everything, a red flag should go up, because it is very unlikely to be true. The whole discovery of vitamins set us up to expect magic bullets -- there are none."