Dietary iron and heart disease — what’s meat got to do with it?

The body, it turns out, doesn’t treat all dietary iron equally. A new study from the IU School of Public Health-Bloomington linked consumption of iron from meat with an increased risk of heart disease – a 57 percent increase.

steak

Heme iron is found in all meat sources but beef and pork contain higher concentrations than chicken or fish.

Researcher Jacob 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.

Hunnicutt said the body can better control absorption of iron from vegetable sources, including iron supplements, but not so with heme iron, which comes from meat sources.

“The observed positive association between heme iron and risk of CHD may be explained by the high bioavailability of heme iron and its role as the primary source of iron in iron-replete participants,” the researchers wrote in the journal article. “Heme iron is absorbed at a much greater rate in comparison to nonheme iron (37 percent vs. 5 percent). Once absorbed, it may contribute as a catalyst in the oxidation of LDLs, causing tissue-damaging inflammation, which is a potential risk factor for CHD.”

Iron stores in the body increase over time. The only way to reduce iron in the body is by bleeding, donating blood or menstruation. Some dietary choices, such as coffee and tea, also can inhibit iron absorption. The study was published in the Journal of Nutrition.

I wrote about this study in this news release.

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