Calcium supplements, many of which share the same ingredient as antacids, found to increase risk of heart disease
For years, researchers have been studying calcium supplements and their potential risk of heart disease and the science has pendulated between the nutritional supplement being risky and safe. Dietary calcium (or calcium obtained from foods such as dairy) has not been found to be harmful. Therefore most of the studies focus on calcium supplement tablets.
Many calcium supplements contain calcium carbonate, the same ingredient in over the counter antacids. Calcium carbonate works by neutralizing stomach acid. It is inexpensive and comes in tasty chew-able tablets. Many people who suffer from GERD (gastroesophageal reflux disease) take antacids regularly and due to their taste and low cost, many who don’t suffer from GERD will use antacids strictly for calcium supplementation. However the latest research may discourage us from doing so.
This week a new study revealed that calcium supplements could increase our risk of heart attack by 22%. How? Researchers from John Hopkins University reviewed 10 years of data from the Multi-Ethnic Study of Atherosclerosis and performed cardiac CT scans. In the patient group who took calcium supplements, the CT scans showed an increase in their coronary calcium scores. Coronary calcium is a marker for arteriosclerosis. The resulting plaques can narrow blood vessels that supply oxygen to the heart or break off causing a clot to form and again, preventing coronary blood flow. If either of these happen, a heart attack will occur.
So why would calcium supplements increase arteriosclerosis if dairy calcium does not? One theory I have is the chalkiness and powder of the supplement. As we know, calcium supplements could increase the risk of kidney stones, so possibly the powdery sediment settles along the blood vessels. Another theory could be something else in the tablet substrate that induces the placquing. One researcher suggested that maybe what is absorbed from a calcium supplement could be too big a dose all at once. When we consume dairy, our body slowly absorbs the calcium as it digests the food. So a bolus of calcium in pill or even liquid form may be “too quick, too much”.
The medical community is not ready to discourage calcium supplement use, as many individuals require calcium to prevent osteoporosis or to normalize low calcium blood levels. Likewise, many individuals find antacids to be extremely beneficial in curbing their heartburn. However, long term use may be of concern as this study points to some significant heart disease risk. May be worth discussing with your medical provider if you take these supplements or antacids regularly.
Daliah Wachs, MD, FAAFP is a nationally syndicated radio personality on GCN Network and Board Certified Family Physician