Widely Used Supplement Doesn't Stop Bone Loss
March 22, 2001 -- Many women in the U.S. and around the world are using the nutritional supplement ipriflavone, hoping it will prevent or limit the loss of bone that often occurs after menopause. Those have been misplaced hopes, apparently, according to a study in the latest Journal of the American Medical Association, which finds that ipriflavone has no more effect on bone density than a placebo does.
"Ipriflavone has been approved in Japan and many European countries, and has been used for a long time" co-author Claus Christiansen, MD, PhD, tells WebMD. "Unfortunately we found no beneficial effect at all." Christiansen is a professor at the University of Copenhagen and CEO of the Center for Clinical and Basic Research in Ballerup, Denmark.
Ipriflavone is a synthetic isoflavone derivative, widely sold as a nutritional supplement in the U.S. Natural isoflavones are found in soy products -- and to some extent in peas, beans, and other legumes.
Preliminary studies in animals, and some small studies in women, have suggested ipriflavones could limit bone loss in postmenopausal women. The current study, which was larger and lasted for three years, found no difference in bone loss or in biochemical indicators of bone metabolism between women who took ipriflavones and those who took an inactive placebo treatment.
Additionally, a significant percentage of women who took part in the study showed a decrease in certain white blood cells, although half of them had returned to normal within a year. White blood cells help fight infection.
"I always tell my patients that alternative therapies need to be held to the same scrutiny as standard pharmaceuticals, Stuart Weinerman, MD, tells WebMD. "Lots of patients have been taking ipriflavone based on very small preliminary studies. Now we have good data from a scientifically controlled, randomized, prospective study showing that it doesn't work." Weinerman is director of the metabolic bone disease program at North Shore University Hospital in Manhasset, N.Y.
"While the new study is very suggestive, its statistical power is not overwhelming," says Paul A. Gluck, MD. "This research does raise questions about the usefulness of ipriflavone but does not totally disprove it. They looked at women who had already experienced bone loss, and they might have seen different results if looked at a possible preventive effect in younger women."