Infant nutrition and development of type 1 diabetes

Previous studies have indicated that early exposure to complex foreign proteins, such as cow's milk proteins, increases the risk of type 1 diabetes in predisposed individuals.

"Therefore, In 2002, we embarked on a large-scale study on more than 2100 infants with a family member affected by type 1 diabetes and with genetic disease susceptibility to find an answer to the question whether delaying the exposure to complex foreign proteins will decrease the risk of diabetes", tells Professor Mikael Knip from the University of Helsinki, the leader of the TRIGR Study.

After breastfeeding the babies were either weaned to a special formula, where the cow's milk proteins were split into small peptides, or to a conventional infant formula with the regular cow's milk proteins.

The first study endpoint was positivity for at least two diabetes-associated autoantibodies by the age of six years.

The results show that there was no difference in the appearance of autoantibodies between the two study groups. However, the disease process resulting in clinical diabetes has clearly two phases, the first being the appearance of autoantibodies and the other the progression from autoantibody positivity to clinical disease.

Infant feeding and the risk of type 1 diabetes. Type 1 diabetes is generally considered to be a chronic, immune-mediated disease with a subclinical prodrome during which beta cell autoimmunity becomes overt disease at a variable rate in genetically susceptible individuals. Accumulated evidence supports a critical role of environmental factors in its development. Prospective birth cohort studies show that the first signs of beta cell autoimmunity may be initiated during the first year of life. This implies that risk factors for beta cell autoimmunity and type 1 diabetes must be operative in infancy. Early nutrition provides essential exogenous exposures in that period. This article discusses the role of factors related to infant nutrition in the development of beta cell autoimmunity and type 1 diabetes and the potential mechanistic pathways involved. So far, no specific dietary factor has been shown to be an unequivocal risk factor for beta cell autoimmunity or type 1 diabetes, and there are a number of contradictory observations with regard to the effect of various foods. This may reflect geographic and cultural differences in infant-feeding practices. Most studies suggest that the early introduction of complex foreign proteins may be a risk factor for beta cell autoimmunity, and a pilot intervention trial has implied that weaning to a highly hydrolyzed formula may decrease the risk of beta cell autoimmunity. Lack of vitamin D supplementation and accelerated growth might increase the risk of type 1 diabetes. Additional work, which includes the application of modern approaches such as metabolomics and epigenomics, is needed to discern the contribution of dietary factors in infancy to the diabetic disease process.