Help Your Bones, Hurt Your Heart

Taking calcium supplements to improve bone strength in middle-age could put women at higher risk of a heart attack, claim researchers.

Extra calcium could do more harm than good, even though broken bones account for thousands of deaths each year.

The researchers are calling for more studies to check the effect of high calcium intake on bone.

The latest study, published online in the British Medical Journal, involved 1,471 healthy postmenopausal women aged 55 and over with an average age of 74.

Participants were included if they were more than five years past menopause with a life expectancy of more than five years. Women already receiving treatment for osteoporosis or taking calcium supplements were excluded.

The participants were split into two groups, with one group given 1g daily of calcium supplements and the other a placebo.

The intake of calcium from all the women's diets was noted and both groups were followed up every six months for five years.

The study found heart attacks were more common in the calcium group, along with the occurrence of any of three vascular events: heart attack, stroke or sudden death.

Doctors checked the women's hospital records and death certificates to identify any heart attacks or vascular events that could have been unreported.

With these added events, heart attacks were still more common in the calcium group. Rates for heart attack, stroke or sudden death also increased.

Professor Ian Reid, lead researcher at the Faculty of Medical and Health Science at the University of Auckland, New Zealand, said healthy older women "randomly" taking extra calcium had increased rates of heart attack.

"This effect could outweigh any benefits on bone from calcium supplements," he said.

Pamela Mason, nutritionist and spokesman for the Health Supplements Information Service, said the study had several limitations, including a high drop-out rate. Only half of the group taking supplements and 40 percent on placebo group completed the study.

"Even if all the women had completed the study, it was a small group from which to measure the large number of cardiovascular endpoints," she added. Dr. Mason said the calcium intake in this study of women, averaging 800mg a day, was above the recommended UK rates of 700mg a day.

She said: "Previous studies have found benefits of calcium supplements in protecting against cardiovascular disease, reducing blood pressure and improving cholesterol.

"Given all these factors, it is too early to conclude that calcium supplementation has adverse effects on cardiovascular health.'"

Jenny Hope can be reached at j.hope@dailymail.co.uk.

Source: Daily Mail; London (UK). Provided by ProQuest Information and Learning. Powered by Yellowbrix.