A large French study has singled out a specific sugar in beef, lamb and pork as a possible driver of type 2 diabetes.
Adults with the highest intake of the sugar, called Neu5Gc, had a 63 percent higher risk of developing the disease than those with the lowest intake.
The result comes from the NutriNet-Santé cohort and was presented this week at the 62nd annual meeting of the European Association for the Study of Diabetes in Milan.
Because it is an observational study and has not yet been peer-reviewed in full, the finding shows an association, not proof of cause.
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What Neu5Gc is, and why humans cannot make it
Neu5Gc is short for N-glycolylneuraminic acid, a sugar most mammals produce naturally. Humans do not.
An ancient mutation in a gene called CMAH means we lost that ability millions of years ago.
When we eat red meat, animal Neu5Gc is absorbed and slotted into human tissues, where the immune system treats it as foreign.
Earlier work has shown this can trigger chronic, low-grade inflammation, a process laid out in a study in PNAS that first proposed Neu5Gc as a mechanism linking red meat to disease.
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The sugar is concentrated in beef, lamb, pork, goat and game meats, with smaller amounts in dairy. Poultry, fish and plant foods contain little to none.
What the new French study found
The researchers followed 89,953 adults, average age 42, for a median of 7.2 years. During follow-up, 966 people developed type 2 diabetes.
Participants in the top fifth for meat-derived Neu5Gc intake had a 63 percent higher risk of type 2 diabetes than those in the bottom fifth.
Those in the second-highest group had a 41 percent higher risk. The link held after the team adjusted for age, sex, physical activity, overall diet quality, smoking and other health conditions.
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Body weight explained only part of the effect. Obesity accounted for roughly 13 percent of the association, meaning most of the increased risk remained after body mass index was taken into account. Neu5Gc from dairy showed no clear link to diabetes.
How this fits with earlier research
The link between red meat and type 2 diabetes is not new.
A 2021 meta-analysis in the International Journal of Environmental Research and Public Health pooled 15 cohort studies with 682,963 participants.
It found that each daily serving of processed red meat was tied to a 27 percent higher risk of type 2 diabetes, and each serving of unprocessed red meat to a 15 percent higher risk.
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Earlier work in the same French cohort, published in BMC Medicine in 2020, showed that people who ate more Neu5Gc had higher blood levels of antibodies against it, supporting the idea that the sugar provokes a lasting immune response.
What it means at the dinner table
The findings do not call for cutting red meat out entirely. They add weight to advice that has been building for years: eat less beef, lamb and pork, and lean more on poultry, fish, beans, lentils and other plant proteins.
Similar shifts have already been linked to better heart and gut health.
Type 2 diabetes is common in the United States. According to the CDC, 40.1 million Americans have diabetes and 115.2 million adults have prediabetes.
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Anyone worried about their own risk should talk with a doctor about screening, especially with a family history or extra weight around the middle.
The Neu5Gc findings are preliminary, and the authors caution that the results still need to be validated in other populations before firm recommendations can be built on them.
This article is made and published by Ida-Marie Palm Varbæk, who may have used AI in the preparation.