Aug. 3, 2000 -- Middle-aged women who choose to lose weight also lose a small amount of bone density in the process, which could leave them slightly more vulnerable to broken bones, a new study shows.
But this shouldn't be considered a green-light to overeat: Being overweight can lead to high blood pressure, heart disease, and other chronic problems, and researchers say their findings should not discourage women from continuing weight loss programs.
Instead, they say, doctors should monitor the bone density of their postmenopausal patients who are trying to lose weight, and should encourage them to build bone density through methods such as exercise and hormone replacement therapy.
"I would assume that people who need to lose weight might become more cautious, and more active about this issue when interacting with their doctors," study author Dinnie Chao, PhD, tells WebMD. She suggests that women "talk to their doctor and discuss risk factors for other diseases as a result of being overweight." Chao is with the Center for Health Services Research in Primary Care at the University of California, Davis, in Sacramento.
For the one-year study, published in the Journal of the American Geriatric Society, Chao and colleagues followed 67 overweight, postmenopausal women, some of whom were put on weight loss regimens. Their average age was 66, and their average weight when the study began was 178 pounds.
Researchers measured the bone mineral density -- which correlates with adequate calcium levels -- of the women's entire bodies, their lower spines, and their thigh bones. They found that the weight loss group had lost an average of nine pounds at six months and were down nearly eight pounds at the one-year mark. Weight loss was associated with a slight loss of bone strength, as measured by a decrease in total-body bone mineral density.
So what does this mean for the middle-aged woman who is trying to lose a little weight? "For these women, weight loss will probably have no effect on the skeleton," John J.B. Anderson, PhD, tells WebMD. "Physical activity is very important, and walking and upper-body strengthening are very good to maintain and improve bone density."
Anderson also suggests that women get enough dietary calcium, about 1,200 milligrams daily (to be decided by their doctors or nutritionists) and believes that, while it is controversial for other reasons, "estrogen is the best drug" for bone health. Anderson, a professor of nutrition at the University of North Carolina in Chapel Hill, was not involved in the study.
Concerns about bone mass should not keep women from losing weight, Rafael Bejarano-Narbona, MD, tells WebMD. Nevertheless, he believes that "every postmenopausal woman should have a bone-mineral density test done." The testing, he says, is usually covered by insurance. Bejarano-Narbona is medical director of the geriatric practice at Columbia Presbyterian Medical Center in New York.
"With an aging population, we should be aware of the consequences of osteoporosis and the need for treatment of this condition, as well as the importance of controlling high blood pressure," Bejarano-Narbona says.
Chao says that women, with the help of their doctors, should have a plan to improve their overall health. "Weigh the pros and cons of losing weight in order to reduce your risks for other diseases," she says. "And, if weight loss is chosen, incorporate ways to maintain or increase your bone density in your treatment plan."