Dietary Supplement Commonly Used To Help Prevent Osteoporosis May Also Be Protecting Women Against Heart Disease
Just when millions of women — and their doctors — are questioning the efficacy of hormone replacement therapy in reducing the risk of heart disease, a new study suggests that commonly used dietary supplements may actually be providing some of the protection they seek.
According to a report from New Zealand researchers in the April issue of the American Journal of Medicine, taking calcium citrate may protect postmenopausal women not only from bone fractures but also from heart disease. The findings of Dr. Ian Reid and colleagues from the Department of Medicine at the University of Auckland are from a one year supplementation study with 223 postmenopausal women who had not regularly used estrogens in the year prior to starting the study.
Dr. Reid told the Dietary Supplement Information Bureau: “Our study illuminates a possibly overlooked effect of calcium supplementation: improvement of blood cholesterol profiles. With many postmenopausal women already taking calcium supplements and living with a higher risk of heart disease, the public health benefits may extend beyond simply reducing bone fracture risk,” said Reid. “A supplement as inexpensive as calcium citrate, with multiple health protective effects, could have major public health implications.”
The women were all at least 55 years of age and had been postmenopausal for at least five years. The average age in the study group was 72.
Reid told the DSIB that women in the trial were consuming 910 mg of dietary calcium on average at the beginning of the study. They were then assigned to take 1,000 mg of calcium (as calcium citrate), or a placebo, as two 200 mg tablets before breakfast and then three 200 mg tablets in the evening. Blood cholesterol profiles were measured at the beginning of the study, and after 2, 6, and 12 months of supplementation.
“By the end of a year, the women supplementing with calcium citrate showed a significant 7% increase in HDL. This magnitude of increase parallels that seen with statin drugs, and is associated with a 20-30% reduction in cardiovascular events. LDL cholesterol dropped by 6 % in the same women. No appreciable changes appeared in the women receiving the placebo, for either type of cholesterol,” added Reid. “Our study is the longest and largest calcium-lipids clinical trial to date, leaving us with many questions. Is calcium citrate better than other forms? How would men or younger postmenopausal women respond? And, most importantly, does supplementation with calcium citrate reduce cardiovascular events and deaths?”
“These findings are indeed provocative,” said David Heber, M.D., director of the UCLA Center for Human Nutrition and a member of the DSIB Scientific Advisory Board. “Could women who are currently using calcium citrate to reduce the risk of osteoporosis-associated fractures unknowingly be reducing their risk of heart disease, too? While the women in this study started off with already high, cardioprotective amounts of HDL cholesterol in their blood, the findings of Dr. Reid and his colleagues could widen the scope of future calcium supplementation studies. We also need to address the genetic underpinnings of this study. We need to ask whether New Zealand women typify the response of North American, Asian, and European women, for example.”
The study was sponsored by the Health Research Council of New Zealand.