A positive correlation between the early introduction of dairy in infancy and the incidence of type 1 diabetes in genetically predisposed infants has been suggested by studies on rodents and humans, but are controversial.
On the other hand, an inverse relationship between the consumption of dairy foods and the development of metabolic syndrome and/or type 2 diabetes has been implied by epidemiological studies. Low-fat milk products appear to be consistently associated with a lower risk of type 2 diabetes. The role of high-fat milk products is less clear. Evidence suggests that cheese and fermented milk products may also have a beneficial effect.
Several dairy components, especially milk proteins, could play a role in the protective effect on glucose regulation by modulation of incretin hormones. Randomized controlled clinical studies and mechanistic studies are needed for more definitive answers.