I suspect your mother’s diet beyond dairy, and perhaps most significantly, her genetics and vigorous lifestyle, had much to do with her good health. I suspect that is the case for most; though the evidence does not appear to support the claim that calcium from dairy builds or maintains strong bones over the course of a lifetime.
In one study, funded by the National Dairy Council, a group of postmenopausal women were given three 8-ounce glasses of skim milk every day for two years, and their bones were compared to those of a control group of women not given the milk. The dairy group consumed 1,400 mg of calcium per day and lost bone at twice the rate of the control group. According to the researchers, “this may have been due to the average 30 percent increase in protein intake during milk supplementation. … The adverse effect of increases in protein intake on calcium balance has been reported from several laboratories, including our own” (they then cite 10 other studies). Says McDougall, “Needless to say, this finding did not reach the six o’clock news.” This is one study that the dairy industry won’t be repeating any time soon.
After looking at 34 published studies in 16 countries, researchers at Yale University found that the countries with the highest rates of osteoporosis—including the United States, Sweden, and Finland—were those in which people consumed the most meat, milk, and other animal foods. This study also showed that African-Americans, who consume, on average, more than 1,000 mg of calcium per day, are nine times more likely to experience hip fractures than are South African blacks, whose daily calcium intake is only about 196 mg. Says McDougall, “On a nation-by-nation basis, people who consume the most calcium have the weakest bones and the highest rates of osteoporosis. … Only in thoseplaces where calcium and protein are eaten in relatively high quantities does a deficiency of bone calcium exist, due to an excess of animal protein.”
Harvard University’s landmark Nurses Health Study, which followed 78,000 women over a 12-year period, found that the women who consumed the most calcium from dairy foods broke more bones than those who rarely drank milk. Summarizing this study, the Lunar Osteoporosis Update (November 1997) explained: “This increased risk of hip fracture was associated with dairy calcium. … If this were any agent other than milk, which has been so aggressively marketed by dairy interests, it undoubtedly would be considered a major risk factor.”
A National Institutes of Health study at the University of California, published in the American Journal of Clinical Nutrition (2001), found that “women who ate most of their protein from animal sources had three times the rate of bone loss and 3.7 times the rate of hip fractures as women who ate most of their protein from vegetable sources.” Even though the researchers adjusted “for everything we could think of that might otherwise explain the relationship … it didn’t change the results.” The study’s conclusion: “n increase in vegetable protein intake and a decrease in animal protein intake may decrease bone loss and the risk of hip fracture.”
Another study published in the American Journal of Clinical Nutrition (2000) looked at all aspects of diet and bone health and found that high consumption of fruits and vegetables positively affected bone health and that dairy consumption did not. Such findings do not surprise nutritional researchers: The calcium absorption rate from milk is approximately 30 percent, while figures for broccoli, Brussels sprouts, mustard greens, turnip greens, kale, and some other green leafy vegetables range from 40 percent to 64 percent.
After reviewing studies on the link between protein intake and urinary calcium loss, dairy industry researcher Dr. Robert P. Heaney found that as consumption of protein increases, so does the amount of calcium lost in the urine (Journal of the American Dietetic Association, 1993): “This effect has been documented in several different study designs for more than 70 years,” he writes, adding, “The net effect is such that, if protein intake is doubled without changing intake of other nutrients, urinary calcium content increases by about 50 percent.”
Researchers from the University of Sydney and Westmead Hospital discovered that consumption of dairy foods, especially early in life, is associated with increased risk of hip fractures in old age (American Journal of Epidemiology, 1994).
In Pediatrics (2000), published by the American Academy of Pediatrics, Pennsylvania State University researchers showed that calcium intake, which ranged from 500 to 1,500 mg per day, had no lasting effect on the bone health of girls in their teens. “We (had) hypothesized that increased calcium intake would result in better adolescent bone gain. Needless to say, we were surprised to find our hypothesis refuted,” one researcher explained.
**** Finally, a review of all research conducted since 1985, published in the American Journal of Clinical Nutrition (2000), concluded: “If dairy food intakes confer bone health, one might expect this to have been apparent from the 57 outcomes, which included randomized, controlled trials and longitudinal cohort studies involving 645,000 person-years.” The researchers go on to lament that “there have been few carefully designed studies of the effects of dairy foods on bone health” and then to conclude that “the body of scientific evidence appears inadequate to support a recommendation for daily intake of dairy foods to promote bone health in the general U.S. population.”
http://www.milksucks.com/osteo.asp
