Higher intake of heme iron, the type found in red meat and other animal products—as opposed to non-heme iron, found mostly in plant-based foods—was associated with a higher risk of developing type 2 diabetes (T2D) in a new study led by researchers at Harvard T.H. Chan School of Public Health.
While the link between heme iron and T2D has been reported previously, the study's findings more clearly establish and explain the link. "Compared to prior studies that relied solely on epidemiological data, we integrated multiple layers of information, including epidemiological data, conventional metabolic biomarkers, and cutting-edge metabolomics," said lead author Fenglei Wang, research associate in the Department of Nutrition. "This allowed us to achieve a more comprehensive understanding of the association between and T2D risk, as well as potential metabolic pathways underlying this association.
" The study is published in . The researchers assessed the link between iron and T2D using 36 years of dietary reports from 206,615 adults enrolled in the Nurses' Health Studies I and II and the Health Professionals Follow-up Study. They examined participants' intake of various forms of iron—total, , non-heme, dietary (from foods), and supplemental (from supplements)—and their T2D status, controlling for other health and lifestyle factors.
The researchers also analyzed the biological mechanisms underpinning heme iron's relationship to T2D among smaller subsets of the participants. The.