Calcium Supplements May Raise Heart Attack Risk
Study Finds Calcium From Supplements Appears to Boost Heart Attack Risk; Supplement Industry Disagrees
WebMD News Archive
May 23, 2012 -- Calcium supplements should be taken ''with caution," Swiss and German researchers warn, as they may raise your risk of heart attack.
"The increase [in risk] is, I would say, moderate," says Sabine Rohrmann, PhD, assistant professor of chronic disease epidemiology at the University of Zurich.
Rohrmann and her team followed nearly 24,000 men and women for 11 years. Those who took calcium supplements had an 86% increased risk of heart attack compared to those who used no supplements.
However, the actual number of heart attacks during the follow-up period was small, with 354 recorded.
The researchers found a link, or association, between calcium supplements and heart attack, but the study cannot show cause and effect.
The dietary supplement industry takes issue with the findings. "The study is not consistent with the total body of science," says Taylor Wallace, PhD, senior director of scientific and regulatory affairs for the Council for Responsible Nutrition.
The study is published in the journal Heart.
Calcium Supplements & Heart Attack Risk: Context
Over the years, research on calcium and heart health has produced mixed findings.
Some previous research has suggested calcium from the diet may lower the risk of high blood pressure, obesity, type 2 diabetes, stroke, and heart disease. Other studies have not found these effects.
Two other recent analyses, published in 2010 and 2011, have triggered warnings that calcium supplements might boost the risk of heart attack.
Calcium & Heart Attack Risk: Swiss Findings
For the new study, the researchers asked the men and women to complete food surveys. They interviewed them to ask about vitamin or mineral supplements.
When the men and women entered the study beginning in 1994 through 1998, they were on average in their early 50s.
During the follow up, the researchers also recorded 260 strokes and 267 heart disease deaths.
The researchers found no link between total dietary calcium and stroke. They found no link between total dietary calcium and heart disease deaths.
They found that a higher intake of dietary calcium reduced the risk of heart attack.
They divided the participants into four groups. Those in the third group, with the next-to-highest intake of calcium from the diet, had a 31% reduced risk of heart attack compared to those who ate the least.
However, they found different results when looking at calcium supplements. Those who took calcium supplements had an 86% higher risk of heart attack compared to those who never took them.
The new findings are at odds with those of many other studies, says Wallace of the Council for Responsible Nutrition.
He also points out the relatively small number of heart attacks found in the study.
For calcium, he says, "We always recommend food first and then fill the gap with supplements," Wallace says. "The reality is, Americans don't get enough calcium."