Scientists in France have found a possible reason why eating lots of red meat is linked to a higher risk of type 2 diabetes. In a new study, they looked at 89,953 adults and how much of a sugar called Neu5Gc they ate from foods like beef, lamb and pork. Neu5Gc is a molecule found in most animals, but humans cannot produce it in their bodies.

The reason this is important is that when humans eat red meat, Neu5Gc from the meat can enter human tissues. Because the body does not produce this sugar naturally, the immune system may see it as something foreign and start a small reaction against it. Scientists think this reaction could cause long-term inflammation, which may help explain why people who eat more red meat have a greater risk of type 2 diabetes.

The researchers found that people who ate the highest amounts of Neu5Gc from red meat had a 63% higher risk of getting type 2 diabetes than those who ate the least. The next step for scientists is to study blood samples, to see if people who eat more red meat also have stronger immune responses to Neu5Gc.