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http://www.napa.ufl.edu/2003news/bonedensity.htm

GAINESVILLE, Fla. --- As the debate over the safety of hormone replacement therapy continues, University of Florida nurse researchers have shown in a small but promising study that a combination of vitamin supplements, exercise and weight training may provide postmenopausal women an alternate way to improve bone health and prevent osteoporosis.

In a UF study of postmenopausal women who were not taking hormone replacement therapy, those who participated in a regular exercise regimen that included weight training and took vitamin D and calcium showed significant improvements in bone density, strength and balance.

A growing body of evidence supports the benefits of exercise for the prevention of bone loss that commonly occurs with aging, but the latest findings are among the first to show exercise that includes resistance training can actually build bone-a result hormones have never achieved. Results from the preliminary study are described in the current issue of the journal Biological Research for Nursing.

“Vitamin D and calcium supplements can help slow down the loss of bone, and most hormone treatments can only stop future bone loss,” said James Jessup, the study’s principal investigator and an associate professor in UF’s College of Nursing who also is affiliated with UF’s Institute on Aging. “There is no drug out there that can cause the kind of improvement in bone density that was displayed in the research participants.”

Although the study was small, Jessup said the results are promising and likely will lead to expanded research efforts aimed at finding ways to improve bone health in postmenopausal women without the use of hormones.

UF researchers studied 20 healthy women ages 60 to 75 who lived in a community retirement facility. Half were randomly assigned to a group who exercised routinely and half to a control group who did not. Past scientific research has shown physical activity can improve balance, but to stimulate bone formation, resistance must be used in combination with exercise. Therefore, the exercisers wore weighted vests while doing cardiovascular exercise.

All the study’s participants maintained their usual eating habits and were supplied with and asked to take 1,000 milligrams of calcium citrate malate, the full U.S. recommended daily allowance for adult women, and 400 international units of vitamin D, twice the U.S. R.D.A. Past research has shown that supplements of calcium and vitamin D can reduce bone loss and the risk of fractures in older people.

In the women who exercised over a 32-week period, bone mineral density increased an average of 11 percent, as seen on X-ray imaging. In addition, their strength increased 26 percent, and their balance increased 27 percent. The women participated in supervised calisthenics, strength training, walking and stair climbing for 60 to 90 minutes three times a week. This included working with weight machines, and engaging in balance and agility training. The bone density of the women not participating in exercise actually decreased an average of 5 percent, and strength and balance did not change.