A sugar molecule found in red meat and some dairy, called Neu5Gc, is associated with a higher risk of type 2 diabetes in a large French study presented at a diabetes conference in Milan. The findings are preliminary, are not yet validated and could change in the final analysis. The lead researcher is Dr Leopold Fezeu, of a French university.
The study followed 89,953 adults in a long-running French nutrition cohort. Their mean age was 42, 79 per cent were women, and none had type 2 diabetes or cancer at the start. Each completed three 24-hour dietary records, from which Neu5Gc intake was estimated and ranked into five groups. Over a median follow-up of 7.2 years, 966 people developed type 2 diabetes.
What it found
The group with the highest Neu5Gc intake had a 63 per cent higher risk than the lowest group, a hazard ratio of 1.63 (95 per cent confidence interval 1.29 to 2.06), after adjustment for age, sex, physical activity, diet quality, smoking and existing conditions. That is a relative risk, not an absolute one. The second-highest group had 41 per cent higher risk, and the two middle groups showed no significant difference. The association weakened but stayed significant after body mass index was added, with obesity accounting for about 13 per cent of it. Median red meat intake in the top group was 97 grams a day for men and 73 grams for women, against 5 grams and none in the lowest groups. Neu5Gc from dairy showed no association, and across all sources the top group had a 37 per cent higher risk, driven mainly by red meat.
The researchers suspect the immune system treats Neu5Gc as foreign, producing antibodies and chronic inflammation, and Fezeu said the findings support inflammation as a specific mechanism linking red meat and type 2 diabetes. That mechanism is unconfirmed, and antibodies were not measured.
The limits
The study is observational and cannot show that Neu5Gc causes diabetes. Intake was estimated from food records and not measured directly, dietary changes during follow-up were not accounted for, and unmeasured lifestyle and social factors could have affected the results. When total red meat intake was also adjusted for, the Neu5Gc link was no longer statistically significant, though its direction stayed the same, so it cannot be separated from other components of red meat. Few cases occurred in each sex-specific group, making those estimates less precise.
