Iron is beneficial for health, but the source of iron can affect your diabetes risk, according to a study. Researchers found that heme iron, which is present in red meat and other animal products, could increase the risk of type 2 diabetes. In contrast, non-heme iron in plant-based food does not pose a similar risk.

The latest study conducted by researchers at Harvard T.H. Chan School of Public Health adds more evidence to previous studies that have identified diabetes risks associated with red meat.

The research evaluated 206,615 adults enrolled in the Nurses' Health Studies I and II and the Health Professionals Follow-up Study for their dietary details over 36 years. The iron intake of the participants including the total, heme, non-heme, dietary, and supplemental was noted along with their type 2 diabetes status. The results were published in Nature Metabolism.

"The study found a significant association between higher heme iron intake and T2D risk. Participants in the highest intake group had a 26% higher risk of developing T2D than those in the lowest intake group," the news release stated.

The results also showed that heme iron accounted for more than half of the type 2 diabetes risk associated with unprocessed red meat and also contributed moderately to the risk from various dietary patterns related to type 2 diabetes. However, there was no significant association between intakes of non-heme iron from diet or supplements with diabetes risk.

"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. This allowed us to achieve a more comprehensive understanding of the association between iron intake and T2D risk, as well as potential metabolic pathways underlying this association," said lead author Fenglei Wang, research associate in the Department of Nutrition.

The researchers also raised concern about the addition of heme to plant-based meat alternatives to enhance their meaty flavor and appearance. As these alternatives gain popularity, they suggest that further investigation into the health effects is needed.

"This study underscores the importance of healthy dietary choices in diabetes prevention. Reducing heme iron intake, particularly from red meat, and adopting a more plant-based diet can be effective strategies in lowering diabetes risk," said corresponding author Frank Hu, Fredrick J., Stare Professor of Nutrition and Epidemiology.

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