BOSTON – Researchers at the Institute for Aging Research (IFAR) at Hebrew SeniorLife, an affiliate of Harvard Medical School (HMS), have published a study that shows no evidence of a link between calcium intake and coronary artery calcification, reassuring adults who take calcium supplements for bone health that the supplements do not appear to result in the development of calcification of blood vessels.
The paper, published today in the American Journal of Clinical Nutrition, found that study participants who had the highest calcium intake, from diet or supplements or both, had the same coronary artery calcification score as those who had the lowest calcium intake. The coronary artery calcification score represents the severity of calcified plaque clogging the arteries in the heart and is an independent predictor of heart attack.
"This study addresses a critical question about the association between calcium intake and a clinically measurable indicator of atherosclerosis in older adults," said Elizabeth (Lisa) Samelson, Ph.D., associate scientist at IFAR and an assistant professor at HMS and the lead author of the study. "There was no increased risk of calcified arteries with higher amounts of calcium intake from food or supplements."
Today's paper reported on an observational, prospective study using participants from the highly regarded Framingham Heart Study, the longest running medical study in history. The investigators examined 1,300 participants, both men and women with an average age of 60, who were asked about their diet and supplement use and then underwent CT scans of their coronary arteries four years later.
In recent years, reports have raised concern regarding a potential adverse effect of calcium supplements on risk of heart attack. However, the Institute of Medicine (IOM) concluded that evidence from clinical trials does not support an adverse effect of calcium intake on risk of cardiovascular disease. They recommended the following guidelines for calcium intake considered safe and effective for bone health: 1,200 mg per day of calcium for women over 50 and men over 70 and 1,000 mg per day for men between 50 and 70. The guidelines say supplementation can be used if the minimum requirements are not being met through diet.
Today's paper reassures people who take calcium at levels within the recommended guidelines for bone health that they can continue to do so safely, without worrying about the risk of calcifying their arteries, according to Samelson. However, "it is critically important that each individual discuss with a health care provider whether the recommendations are appropriate given his or her personal medical history."