Milk has long enjoyed a coveted place in refrigerators across the country.
Pediatricians, health experts and the dairy industry have promoted consumption of dairy products by touting the fact that they're high in calcium, protein and vitamin D.
But milk's status as nutritional beverage of choice for growing children has recently come under the microscope.
Prompted by concerns over a rise in milk allergies, links to obesity, the advantages of alternatives such as soy, and new research questioning milk's role in protecting bones, some experts are advocating for change.
It's a debate that has picked up in the past decade since Benjamin Spock, one of the world's best-known pediatricians, argued against milk and meat in children's diets.
The seventh edition of Dr. Spock's Baby and Child Care, published in 1998 shortly after his death at 94, says children shouldn't consume dairy products after age 2, and that other calcium sources, such as some dark leafy vegetables, have nutritional advantages.
Experts recommend that infants be fed breast milk. Otherwise, special infant formula is recommended. After that, usually beyond age one or two, babies will typically be given cow's milk. Last Friday, a panel of experts assembled by U.S. government agencies called for research into soy-based formulas. The panel said that while soy is safe for consumption, there has never been a comprehensive study of the effects of a soy diet on babies.
Such studies could pave the way for greater inclusion of soy-based beverages in the diets of children, and of adults who consume dairy for its perceived health benefits. And it's long overdue, according to some experts.
"I think [milk] is not necessary for good health, good nutrition," said Lawrence Kushi, associate director for etiology and prevention research at Kaiser Permanente in California.
Dr. Kushi notes that many cultures that consume few dairy products have much lower rates of osteoporosis than North America, where consumption of milk and other types of dairy is higher. Japan, for instance, is well known for having a low rate of fractures related to osteoporosis despite the country's low dairy consumption.
In addition, a growing body of research is casting doubt on the role dairy plays in protecting bones. One of the strongest pieces of evidence came from the Nurses' Health Study, a multi-year investigation of women's health conducted in the early 2000s.
Co-authored by Walter Willett, chairman of the department of nutrition at the Harvard School of Public Health, the study found that women who consumed the highest amounts of dairy suffered more fractures than those who drank less milk.
Studies have also found other potential risks of high milk consumption, including increased incidence of ovarian or prostate cancer.
And there are growing fears that milk consumption could play a role in childhood obesity. A 2005 study led by a researcher at Harvard Medical School and Brigham and Women's Hospital in Boston found that children who consumed more than three dairy servings a day were at risk of being overweight.
A registered dietitian employed by the Dairy Farmers of Canada said people shouldn't draw conclusions from individual studies.
"The weight of evidence suggests that milk products are a good source of nutrients that are to the benefit of Canadians' health," said Joanne Gallagher, assistant director of nutrition with the farmers' group. "Milk is great."
Dr. Kushi said a major part of the problem is that people in Canada and other Western countries tend to view milk consumption as the only way to meet calcium requirements.
However, scientists know that consuming sodium and acidic foods can interfere with the body's ability to absorb calcium, and actually result in calcium loss.
That's part of the reason Dr. Spock, Dr. Kushi and others have advocated for diets heavy on plants and free of processed foods.
