The study found that heme iron consumption increased the risk for coronary heart disease by 57 percent, while no association was found between non-heme iron, which is in plant and other non-meat sources, and coronary heart disease.

Hunnicutt said the link between iron intake, body iron stores and coronary heart disease has been debated for decades by researchers, with epidemiological studies providing inconsistent findings. The new IU research, a meta-analysis, examined 21 previously published studies and data involving 292,454 participants during an average 10.2 years of follow-up.

The body treats the two kinds of iron differently. It can better control absorption of iron from vegetable sources, including iron supplements, but not so with iron from meat sources.