You know it like the Pledge of Allegiance: "Milk helps build strong teeth and bones."
But does it really? Or, as nutrition researchers from Harvard and Cornell universities are radically suggesting: Have we all been duped by the dairy industry's slick, celebrity-driven "Got milk?" advertising campaign?
Milk, the sacred cow of the American diet, is under attack and not just by animal-rights activists. Though federal dietary guidelines and most mainstream nutrition experts recommend that people age 9 and older drink three glasses of milk a day, researchers are examining the role of dairy in everything from rising osteoporosis rates, Type 1 diabetes and heart disease to breast, prostate and ovarian cancer.
Last March, the journal Pediatrics published a review article concluding that there is "scant evidence" that consuming more milk and dairy products will promote child and adolescent bone health.
Some leading practitioners of integrative medicine, including best-selling author Dr. Andrew Weil, suggest eliminating dairy products from the diet to help treat irritable bowel syndrome, asthma, eczema and ear infections.
The late Dr. Benjamin Spock reversed his support of cow's milk for children in 1998 in his last edition of his world-famous book Baby and Child Care.
One fact is indisputable: Our bodies need the mineral calcium to build and maintain bones and teeth. Calcium also helps with blood clotting, muscle function and regulation of the heart's rhythm. The debate centers on whether milk is really the best - or even a necessary - source. Ten thousand or so years ago, cow's milk was not part of the human diet.
Whom do you believe?
For consumers, the issue is profoundly confusing, especially when it comes to osteoporosis. On one hand, we have had it hammered home since grammar school that milk is a health food. We are told that increasing calcium intake by drinking milk will prevent osteoporosis, the weakening of bones.
But researchers Walter Willett, chairman of the department of nutrition at the Harvard School of Public Health, and T. Colin Campbell, professor emeritus of nutritional biochemistry at Cornell University, say there is little evidence that shows boosting calcium intake to the currently recommended levels will prevent fractures.
Willett, who co-authored "The Nurses' Health Studies," one of the largest investigations into the risk factors for major chronic diseases in women, found that women with the highest calcium consumption from dairy products had substantially more fractures than women who drank less milk.
