Early infant feeding and type 1 diabetes.

BACKGROUND: Infant feeding practices, particularly the type of milk feeding, have been associated with the development of type 1 diabetes. AIM OF THE STUDY: We studied the relationship between early infant feeding (during the first year of life) and diabetes in a large population-based cohort.
METHODS: In 1994-1995, 6,209 healthy full-term newborns participated in a study examining the effect of supplementary feeding, on development of allergy to cow's milk, in maternity hospitals. All supplements in the maternity hospitals were known. Mothers recorded the feeding of infants prospectively at home. In August 2006, from a nationwide diabetes registry, 45 children from our cohort were listed as having type 1 diabetes.
RESULTS: The distribution of cases was similar in the randomized feeding groups: 9/1,789 in the group that received adapted cow's milk-based formula; 12/1,737 in those who received extensively hydrolyzed formula; 16/1,859 in those who received banked human milk; and 8 among those 824 exclusively breast-fed in the hospital. When children who had received cow's milk-based formula in the maternity hospital were compared with those without such exposure, less number of children in the former group had diabetes by age 8 (P = 0.026), but by the end of the follow-up (11.5 years) the difference disappeared (P = 0.16). Length of breast-feeding and introduction of cereals and other solid foods were similar among those developing type 1 diabetes and those remaining healthy, while early regular daily feeding with cow's milk-based formula tended to associate with lower risk for type 1 diabetes (OR 0.66; 95% confidence interval 0.38-1.13; P = 0.08).
CONCLUSIONS: In an extended, secondary analysis of a population-based cohort, very early exposure to cow's milk is not a risk factor for type 1 diabetes; it may in fact diminish its appearance before age 8.