People with the highest estimated intake of Neu5Gc, a sugar found mainly in red meat, had a 63% higher relative risk of developing type 2 diabetes, although researchers stress that the findings do not prove causation.
A French study presented at the European Association for the Study of Diabetes meeting in Milan has added a fresh clue to a long-standing question about why red meat is linked with type 2 diabetes. The research points to N-glycolylneuraminic acid, or Neu5Gc, a sugar that humans do not make themselves but can absorb from food, especially red meat, as a possible contributor to risk.
The analysis followed 89,953 adults in France’s NutriNet-Santé cohort for a median of 7.2 years. None had diabetes or cancer when the study began, and 966 participants went on to develop type 2 diabetes. After accounting for factors including age, sex, physical activity, diet quality, smoking and existing health conditions, people in the highest fifth of estimated Neu5Gc intake had a 63% higher risk than those in the lowest fifth. The researchers used three 24-hour food records and a database of measured Neu5Gc levels to estimate intake, so the figures reflect dietary estimates rather than direct blood measurements.
Even so, the numbers do not translate neatly into personal risk. The increase was a relative one, not a statement that most high consumers would become diabetic. The pattern also was not linear: the second-highest group showed a 41% higher risk, while the lower groups were not meaningfully different from the reference group. Men in the top intake group ate a median 97 grams of red meat a day, compared with 73 grams for women, although the study did not define a safe or harmful threshold.
The biological theory centres on the idea that Neu5Gc may be treated by the immune system as foreign. According to the research discussed in the article, most mammals make the molecule, but humans lost that ability through an ancient mutation. The compound can still enter the body through beef, lamb and, to a lesser extent, dairy, then become incorporated into tissues, where it may trigger antibodies and low-grade inflammation known as xenosialitis. Scientists have proposed that this process could interfere with insulin action and the pancreatic cells that produce insulin.
Earlier research has offered some support for that pathway. In 2003, scientists at the University of California, San Diego tested whether people absorb Neu5Gc by giving volunteers a pork-derived solution and found only small amounts were retained, with no immediate adverse effects. More recently, a 2020 study in BMC Medicine, using the same French cohort, linked higher Neu5Gc intake with higher anti-Neu5Gc antibody levels in 120 participants, although that work did not examine diabetes itself.
The picture becomes more complicated when dairy and cooking are considered. The French data found no diabetes link with Neu5Gc from dairy on its own, and the association seen for total Neu5Gc intake appeared to be driven mainly by red meat. Separate research published in BMC Medicine found the highest Neu5Gc concentrations in sheep and goat dairy, with lower levels in cow dairy and moderate levels in red and processed meat. An earlier paper in Proceedings of the National Academy of Sciences also reported that baking, boiling and frying did not significantly change Neu5Gc levels in the meat samples tested, suggesting cooking may not be a major factor in exposure.
Other scientists are now looking at whether gut microbes help release Neu5Gc from food in the first place. The National Institutes of Health has highlighted work showing that certain gut bacteria can free the compound from red meat, while a 2019 study in Nature Microbiology found that a Neu5Gc-rich diet altered the human gut microbiome, with Bacteroidales and Clostridiales among the groups most affected. Researchers have also identified bacterial enzymes that can release Neu5Gc from beef and pork sausage in laboratory conditions, although that remains an experimental finding with no proven effect on diabetes. Taken together, the evidence suggests a plausible mechanism, but not yet a settled answer.
Disclaimer: This content is for informational purposes only and is not intended to be a substitute for professional medical judgment, advice, diagnosis, or treatment.
