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Udder Confusion

Milk used to be considered a "perfect food"—indeed it is very nutritious. In recent years, however, "cow's milk is for calves" has become a rallying cry for several groups. There's even an Antidairy Coalition, which claims that milk is nothing less than a "deadly poison"—that's the title of a book it promotes. If you believe this group, milk is behind nearly all our major diseases. Here are some of the claims being made about milk and dairy products—and our responses.

Claim: Dairy products increase the risk of heart disease.

Facts: If you consume lots of whole milk and cheese, you're likely to raise your blood cholesterol levels. That's true, however, of any foods rich in saturated fat and cholesterol. Milk's opponents talk as if all milk is still whole milk. But more and more dairy products these days are nonfat or low-fat, and thus do not raise cholesterol levels significantly. In fact, there's some evidence that certain substances in milk may help lower cholesterol somewhat. (However, with whole milk, this effect is probably overwhelmed by the cholesterol-boosting effect of the fat.) And since milk is rich in calcium and magnesium, it can help reduce the risk of hypertension.

Milk opponents often quote a paper in Alternative Medicine Review that indicted milk, even nonfat milk, as a cause of heart disease. But that article was simplistic and misleading. It found an association between milk consumption and heart disease in population studies from 32 countries, but the data did not allowthe researcher to take into consideration many of the other factors that can affect the risk of heart disease. Nor do the data specify what kind of milk (full-fat vs. lower-fat) was consumed in the various countries.

Claim: Dairy products increase the risk of ovarian cancer.

Facts: A few studies have suggested that there's a link between lactose (milk sugar) and/or galactose (a related sugar) and ovarian cancer, while others have found no connection. However, a recent and well-done study in the American Journal of Epidemiology refuted this claim. It found that women with ovarian cancer had consumed less, not more, of these milk sugars than healthy women.

Claim: Dairy products boost the risk of cancer in general.

Facts: Milk is not the problem, but rather total fat intake. For instance, a high fat intake may increase the risk of lung, prostate, and colon cancer. But at the same time some studies have found that low-fat milk reduces the risk of lung cancer. In fact, animal studies have shown that compounds in milk may suppress cancer development. In addition, there's some evidence that dairy products reduce the risk of colon cancer. Both calcium and vitamin D (added to milk) may help protect colon cells.

Claim: Dairy products increase the risk of juvenile diabetes.

Facts: This was the most frightening claim made a few years ago by a group of anti-milk physicians, including the late Dr. Benjamin Spock. They actually were against consuming all animal products. It's true that a 1992 Finnish study suggested that a protein in cow's milk might trigger an abnormal response in children genetically predisposed to developing insulin-dependent diabetes. But other studies have not found a connection between milk and childhood diabetes, except that breast-fed children seem to have a lower risk of the disease. No reputable authorities have proposed that children avoid milk and dairy products.

Claim: Milk boosts mucus production in the throat.

Facts: The scientific evidence says no. This myth may persist because of whole milk's thick consistency and because it may coat the mouth briefly. In one Australian study, subjects (many of them believers in the milk-mucus link) were given either chocolate-flavored cow's milk or an indistinguishable soy milk. About one-third of them reported that the cow's milk coated their tongue and throat, made them swallow a lot, and/or made their saliva feel thicker. But a similar proportion of those who drank the soy milk reported these same sensations, so the dairy product wasn't to blame. If you don't like the way whole milk coats your tongue, or if it feels as if it makes mucus hard to swallow, this is yet another reason to switch to low-fat or nonfat milk.

Claim: Dairy products actually increase the risk osteoporosis.

Facts: This notion is based in large part on the fact that in certain countries, such as China, where dairy products are rarely consumed and calcium comes primarily from green vegetables, the rate of osteoporosis (weakened bones) is low. In fact, the studies present contradictory findings: many show that high calcium intake (mostly from dairy products, and particularly in early adulthood) does lead to stronger bones, but others find that dairy or calcium intake does not lower the risk of hip fractures. One possible problem is that dairy products are rich in protein, and a high protein intake slightly increases calcium excretion in urine, which might reduce bone density. The high levels of calcium in dairy products should, however, more than offset any effect their protein may have on your bones. Genetics also plays a big role. We continue to recommend dairy products (along with exercise and, if necessary, calcium supplements) as the best way to reduce the risk of osteoporosis.

Claim: People who have problems digesting lactose can eat or drink no dairy products.

Facts: Many people who believe they can't digest any lactose (milk sugar) without bloating and discomfort are not really lactose-intolerant. Moreover, as we've reported, studies show that even those who truly are lactose-intolerant are able to digest a cup or two of milk a day, if consumed at meals, with few if any symptoms. Beyond that, they can turn to lactose-reduced milk (store-bought or homemade).

The milky way: Milk and other dairy products are the best sources of calcium, which not only keeps bones strong, but also may help prevent hypertension, heart disease, colon cancer, and possibly even diabetes. They are also important sources of other nutrients, notably riboflavin, vitamins A and D, and several other minerals. Whole milk and products made from it are, of course, rich in fat. That's why children over the age of two, as well as adults, should rely on nonfat or low-fat (1%) milk, yogurt, and other dairy products.