Posted 19 October 2016
Calcium supplements could increase risk of heart disease, new study finds
By Andrea K. McDaniels October 17 2016
Calcium supplements that many women take to boost bone health increase their risk for heart disease, a new study has found.
The results show that calcium supplements make people more prone to plaque buildup in arteries, which contributes to the risk of a heart attack. The study, published in the Journal of the American Heart Association, is the latest salvo in a nearly decade-long debate about whether the supplements do more harm than good.
The researchers said their findings give patients reason to use caution when taking the supplements. It is better to get calcium from food such as dairy products, leafy green vegetables and fortified cereal and juices, they said.
When calcium plaque builds up in the arteries, it its blood flow, increasing heart-attack risk.
“We think the body metabolizes supplements and dietary calcium differently,” said Erin Michos of the Ciccarone Center for the Prevention of Heart Disease at the Johns Hopkins University medical school. “If you are worried about your bones, then get your calcium through food.” She said the study adds to growing evidence that calcium supplements are bad for the heart.
But the Council for Responsible Nutrition, which represents manufacturers of dietary supplements, said just as many studies show the opposite and pointed to evidence in the study that people who get a high dose of calcium from a mix of foods and supplements had the lowest risk of calcification in the coronary artery.
The study was prompted in large part because the scientists wanted to build on previous research by others that found calcium supplements never actually make it to a patient’s bones and instead accumulate in soft tissue and muscles, such as the heart.
The study used data from more than 6,000 people to look at the risk factors and characteristics of cardiovascular disease. Michos and fellow researchers focused on 2,742 participants who had CT scans taken at the study’s start and 10 years later. They found that supplement users were 22 percent more likely to develop heart disease over the decade.
The research did find that those who consumed the highest levels of calcium — from foods and supplements — were 27 percent less likely to develop heart disease.
“A lot of women are taking calcium supplements because they think it is good for their body,” Michos said. “We need to get the message out . . . that they need to take caution with the supplements they take into their bodies.”
Calcium Intake From Diet and Supplements and the Risk of Coronary Artery Calcification and its Progression Among Older Adults: 10‐Year Follow‐up of the Multi‐Ethnic Study of Atherosclerosis (MESA)
John J.B. Anderson, PhD1; Bridget Kruszka, MPH2; Joseph A.C. Delaney, PhD2; Ka He, MD, ScD3; Gregory L. Burke, MD, MSc4; Alvaro Alonso, MD, PhD5; Diane E. Bild, MD, MPH6; Matthew Budoff, MD7; Erin D. Michos, MD, MHS, FACC, FAHA ([email protected])*,8
Erin D. Michos, MD, MHS, FACC, FAHA, Division of Cardiology, Ciccarone Center for the Prevention of Heart Disease, Johns Hopkins University School of Medicine, Blalock 524‐B, 600 N Wolfe St, Baltimore, MD 21287. E‐mail: [email protected] Received May 31, 2016.
Accepted August 16, 2016.
© 2016 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.
Background Recent randomized data suggest that calcium supplements may be associated with increased risk of cardiovascular disease (CVD) events. Using a longitudinal cohort study, we assessed the association between calcium intake, from both foods and supplements, and atherosclerosis, as measured by coronary artery calcification (CAC).
Methods and Results We studied 5448 adults free of clinically diagnosed CVD (52% female; aged 45–84 years) from the Multi‐Ethnic Study of Atherosclerosis. Baseline total calcium intake was assessed from diet (using a food frequency questionnaire) and calcium supplements (by a medication inventory) and categorized into quintiles. Baseline CAC was measured by computed tomography, and CAC measurements were repeated in 2742 participants ≈10 years later. At baseline, mean calcium intakes across quintiles were 313.3, 540.3, 783.0, 1168.9, and 2157.4 mg/day. Women had higher calcium intakes than men. After adjustment for potential confounders, among 1567 participants without baseline CAC, the relative risk (RR) of developing incident CAC over 10 years, by quintile 1 to 5 of calcium intake, were 1 (reference), 0.95 (0.79–1.14), 1.02 (0.85–1.23), 0.86 (0.69–1.05), and 0.73 (0.57–0.93). After accounting for total calcium intake, calcium supplement use was associated with increased risk for incident CAC (RR=1.22 [1.07–1.39]). No relation was found between baseline calcium intake and 10‐year changes in log‐transformed CAC among those participants with baseline CAC >0.
Conclusions High total calcium intake was associated with a creased risk of incident atherosclerosis over long‐term follow‐up, particularly if achieved without supplement use. However, calcium supplement use may increase the risk for incident CAC.