Haem iron vs non-haem iron: Here’s why red meat may raise your diabetes risk

Haem iron, found in red meat and other animal products, has been linked to a 26 per cent increased risk of type 2 diabetes compared to non-haem iron found in plant-based foods, a new study has found.
While previous studies relied only on epidemiological data, in this study, researchers “integrated multiple layers of information, including conventional metabolic biomarkers, and cutting-edge metabolomics,” said lead author Fenglei Wang, a research associate at Harvard T.H. Chan School of Public Health, US.
Metabolomics is the study of small molecules within cells and tissues.
“This allowed us to achieve a more comprehensive understanding of the association between iron intake and type 2 diabetes risk, as well as potential metabolic pathways underlying this association,” Wang said. The study is published in the journal Nature Metabolism.
The researchers suggested that cutting down on red meat and adopting a plant-rich diet can help lower diabetes risk.
The findings also raised concerns about adding haem iron to increasingly popular plant-based meat alternatives to enhance their meaty flavour and appearance, they said.
For the study, the researchers used data from 36 years of dietary reports of over two lakh adults, close to 80 per cent of whom were women.
The participants were included from the Nurses’ Health Studies I and II, and the Health Professionals Follow-up Study, which looked at risk factors for major chronic diseases.
The researchers analysed the participants’ various forms of iron intake, including haem, non-haem and through supplements, and their type 2 diabetes status.
In a smaller group of over 37,000 participants, the team looked at the biological processes behind the link between haem iron and type 2 diabetes.
For this, data of the participants’ plasma metabolic biomarkers, including those related to insulin levels, blood sugar, lipids and inflammation, were analysed.
The researchers then looked at over 9,000 participants’ metabolomic profiles — plasma levels of small-molecule metabolites, which are substances derived from bodily processes such as breaking down food or chemicals.
“We found that among various types of iron intake, only a higher intake of haem iron was associated with a higher risk of type 2 diabetes,” the authors wrote.
They also found that haem iron accounted for more than half of the type 2 diabetes risk linked to unprocessed red meat and a moderate proportion of the risk for several T2D-related dietary patterns.
Further, “we observed that higher haem iron intake was associated with unfavourable profiles of plasma biomarkers in the domains of insulinaemia, lipids, inflammation, iron stores and metabolites correlated with type 2 diabetes,” they wrote.