Participants in a large French observational study who consumed the highest levels of a sugar naturally found in red meat faced a 63% greater risk of developing type 2 diabetes, according to preliminary findings presented in Milan, Italy, Science Daily reported. The research focuses on N-glycolylneuraminic acid (Neu5Gc), a sugar abundant in beef and lamb that researchers suspect triggers prolonged immune activity and chronic inflammation.
Study tracks diabetes cases among adults
The investigation analyzed data from 89,953 adults enrolled in the NutriNet-Santé study, tracking health and nutrition outcomes over a median follow-up period of 7.2 years. During that timeframe, researchers recorded 966 new cases of type 2 diabetes among participants who had neither cancer nor diabetes at the start of the research. Participants averaged 42 years of age, and 79% were women.
Dietary records collected through three 24-hour periods allowed researchers to estimate Neu5Gc consumption using a validated food database. Participants were categorized into five groups based on their intake of meat-derived Neu5Gc. Individuals in the highest fifth of consumption showed a 63% increased risk of developing type 2 diabetes compared to those in the lowest group, while those in the second-highest group faced a 41% higher risk, Medical News Today noted.
“This is a relative risk: people in the top fifth of meat-derived Neu5Gc intake had a 63% higher risk than those in the bottom fifth, after accounting for many other factors,” lead author Dr. Leopold Fezeu from the Université Sorbonne Paris Nord in Bobigny, France, told Medical News Today. “It does not mean that 63% of high consumers will develop diabetes.”
Immune responses trigger chronic inflammation
Most mammals produce Neu5Gc naturally, but humans lost the ability to synthesize the molecule following an evolutionary mutation in the CMAH gene. Dietary intake allows the sugar to enter the human body and incorporate into tissues.
Prolonged immune responses against the sugar create chronic inflammation, which scientists suspect may interfere with insulin-producing cells or tissues that respond to insulin. However, obesity accounted for only about 13% of the observed relationship between the meat sugar and type 2 diabetes, indicating that inflammatory pathways operate independently of excess body weight.
The statistical association remained significant after researchers adjusted for established diabetes risk factors, including physical activity, smoking, overall diet, and existing health conditions. When body mass index was factored in, the association weakened slightly but remained statistically significant.
Dairy products show no diabetes risk
Although Neu5Gc is also present in dairy products, higher consumption of dairy-derived Neu5Gc showed no association with an increased risk of type 2 diabetes. Researchers attribute this difference to the smaller amounts of the sugar found in cow’s milk compared to red meats like beef and lamb.
Daily red meat consumption varied widely across the study groups. Men in the highest Neu5Gc intake group consumed a median of 97 grams of red meat daily, reaching 136 grams when processed meats were included. Women in the top group consumed a median of 73 grams of red meat daily, or 96 grams including processed meats. Conversely, men in the lowest intake group ate a median of just 5 grams of red meat per day, while women in that group consumed none.
When researchers additionally adjusted the statistical model for total red meat consumption, the direct link between Neu5Gc and diabetes weakened and lost statistical significance, though the direction of the association remained unchanged. This leaves open the question of whether the sugar acts independently or serves as a marker for other components of red meat.
Common Questions About the Study
Why does the human body react to Neu5Gc?
Humans lost the ability to produce the sugar naturally due to an ancient genetic mutation in the CMAH gene.
Does the study prove that red meat causes diabetes?
No, because the study is observational, it cannot establish cause and effect. Researchers note that unmeasured lifestyle factors and the reliance on estimated dietary records rather than direct biological measurements limit definitive conclusions.
Did dairy products show the same risk as red meat?
Higher consumption of Neu5Gc from dairy products was not associated with an increased risk of type 2 diabetes, likely because dairy items contain much smaller concentrations of the sugar than beef and lamb.
Next Steps in Neu5Gc Research
The research team plans to measure anti-Neu5Gc antibodies directly in large cohorts to test the xenosialitis mechanism in humans.