New research published in the British Journal of Medicine links calcium supplementation to an increased risk of heart attack in people over the age of 40. The study was led by Professor Ian Reid of the University of Auckland as a meta-analysis of 15 calcium trials conducted over the past 20 years.
Industry quickly found cause to take umbrage with the study, fearing its potential to undermine the potential benefits of calcium supplements to bone health. “The results from this meta-analysis do not undermine the value calcium supplements offer to those concerned with maintaining or increasing bone density, as years of research shows these products do,” said Andrew Shao, PhD, senior vice president of scientific and regulatory affairs at the Council for Responsible Nutrition (CRN).
The mainstream media is all over this story, with news coverage appearing at ABC, CBS, the Boston Globe and Business Week, just to name a few. Many of the medical professionals interviewed in these stories point toward an unfavorable risk/reward balance in light of the new study. According to these professionals, potential and minor improvements to bone health in reducing fractures and the effects of osteoporosis no longer seem worth the added risk to cardiovascular health.
CRN and the Natural Products Association (NPA) point toward flawed methodology in the meta-analysis, suggesting that old studies were recycled with a goal in mind, and many pertinent studies were ignored. “It’s unfortunate that these researchers are making sweeping judgments about the value of calcium supplements by only assessing a handful of handpicked studies,” said CRN’s Shao. Daniel Fabricant, PhD, vice president of global government and scientific affairs at NPA said in a statement: “There are thousands of studies on calcium, but the authors selected only eight to do this meta-analysis. None of the selected studies had cardiovascular outcomes as the primary end-points, and data on cardiovascular events were not gathered in a standardized manner, so it would appear much more of a predetermined outcome versus one of great scientific rigor.”
As to why calcium might increase risk of heart attack in consumers over the age of 40, we’re still in the realm of scientific hypothesis. Some evidence suggests that calcium supplements, as opposed to calcium intake from daily food sources, elevates levels of calcium in the bloodstream to such a degree that arteries harden. Others suggest that the meta-analysis is further flawed by its focus on calcium supplementation alone, when many consumers take calcium in combination with vitamin D.
Regardless, Professor Reid has signaled a clarion call for the supplement industry. In an interview with NutraIngredients.com, he said: “We have tended to focus on just the benefits of supplements without really looking at their safety. In the future I think we need to look at both the efficacy and the safety of supplements. People assume that these supplements are natural. A high calcium meal is natural, but taking highly concentrated calcium tablets is not, and does not have the same effects.”
NBJ Bottom Line
NBJ ranks calcium as the fourth most popular supplement in the United States. Sales reached $1.2 billion in 2009, nearly double 1999 sales of $681 million. In recent years, calcium has been tracking 3% annual growth. This compares to negative growth of 7% for vitamin E, itself the subject of a disparaging meta-analysis with widespread media coverage, as that supplement slowly attempts to gain traction from dramatic declines earlier in the decade.
Will calcium go the way of vitamin E? It’s a real possibility, given recent media attention, but far from a foregone conclusion as industry analysts and scientists begin to test the veracity of the meta-analysis. Also, look for more research from Professor Reid on the calcium/vitamin D front in the coming months. According to Reid, early evidence of meta-analysis on combined supplementation points to similar risky outcomes, so this might be a story that won’t go away for awhile.
Related NBJ links:
Has Vitamin E Turned the Corner?
U.S. Mineral Sales & Sales by Channel: 1996-2009 - Chart 12
Global Supplement & Nutrition Industry Report 2010