A Sugar in Red Meat Is Linked to a 63% Higher Type 2 Diabetes Risk

Keypoints:

• A French study followed 89,953 adults from the NutriNet-Santé cohort
• The highest intake of meat-derived Neu5Gc was linked to a 63% higher risk of type 2 diabetes
• The second-highest group had a 41% higher risk
• Neu5Gc from dairy was not associated with higher risk
• The findings are observational and preliminary, so they cannot prove cause

Researchers have linked a little-known sugar in red meat to type 2 diabetes. The sugar is N-glycolylneuraminic acid, known as Neu5Gc. Humans cannot make it, and the immune system treats it as foreign. The findings were presented at the annual meeting of the European Association for the Study of Diabetes in Milan.

The study drew on NutriNet-Santé, a long-running French cohort. It included 89,953 adults with an average age of 42. About 79% were women. None had type 2 diabetes or cancer at the start. Over a median follow-up of 7.2 years, 966 participants developed type 2 diabetes. The team estimated each person's Neu5Gc intake from their reported diet.

The results rise with intake. People in the highest fifth of meat-derived Neu5Gc intake had a 63% higher risk than the lowest fifth. The fourth fifth had a 41% higher risk. The pattern was not a straight line. Risk climbed steeply at the highest levels, which suggests a possible threshold. Results held after adjusting for age, sex, physical activity, diet and smoking.

The source mattered. Neu5Gc from dairy was not linked to higher risk. Total Neu5Gc from all foods showed a smaller 37% rise in the top group, mostly driven by meat. Lead author Leopold Fezeu of Université Sorbonne Paris Nord said the association may depend on the dietary source.

One biological idea is inflammation. Because the immune system sees Neu5Gc as foreign, it may trigger chronic low-grade inflammation. That could explain part of the known link between red meat and diabetes.

The limits are significant. The study is observational and has not been peer-reviewed. The association weakened and was no longer statistically significant once total red meat intake was included. That makes it hard to separate the sugar from other substances in meat. Fezeu also stresses that the figure is a relative risk. It does not mean 63% of heavy consumers will develop diabetes.