Higher intake of iron consumed in red meat, poultry and fish is associated with a higher risk for developing type 2 diabetes (T2D) – and new findings help to explain why.
Previous studies reported this link but those results stemmed mostly from survey responses. The new study used survey responses but also analyzed blood samples from patients to check for biomarkers that would more conclusively link the intake of the iron-containing substance heme present in meat to T2D risk factors.
Among 206,615 U.S. health professionals tracked for 36 years, those with the highest intake of so-called heme iron had a 26% higher risk of developing T2D than those with the lowest intake, researchers reported in Nature Metabolism.
In 37,544 of the participants, the researchers measured blood biomarkers associated with T2D, including those related to insulin levels, blood sugar, blood lipids, inflammation and iron metabolism. Higher heme iron intake was associated with higher levels of detrimental biomarkers and lower levels of beneficial ones such as HDL cholesterol, they found.
In 9,024 study participants, the researchers analyzed plasma levels of metabolites – small molecules resulting from bodily processes – and identified a dozen that may play a role in the link between heme iron intake and diabetes.
There was no significant association between intake of iron from plant-based sources and risk of T2D, according to the report.
“This study underscores the importance of healthy dietary choices in diabetes prevention,” Frank Hu of Harvard T.H. Chan School of Public Health in Boston, one of the study’s authors, said in a statement. “Reducing heme iron intake, particularly from red meat, and adopting a more plant-based diet can be effective strategies in lowering diabetes risk.”
The researchers said their findings raise concerns about the increasingly common practice of adding heme to plant-based meat alternatives to enhance their meaty flavor and appearance.
