IDDM and milk consumption - A case-control study in Sao Paulo, Brazil

OBJECTIVE - To test the hypothesis that breast-feeding is a protective factor against IDDM and that early exposure to cow's milk is a risk factor for the disease. RESEARCH DESIGN AND METHODS - A case-control study was conducted in Sao Paulo, Brazil. A total of 346 diabetic children, aged <18 years, were identified in two institutions in the city of Sao Paulo. Duration of exclusive breast-feeding and age of introduction to cow's milk products in infant diet were compared with 346 sex-, age-, and neighborhood-matched control children. All comparisons between diabetic and control children were done using paired tests. RESULTS - Statistically significant differences were found for the duration of exclusive breast-feeding (P = 0.007) and for the age of introduction to cow's milk products (P = 0.047). Control children had a longer time of exclusive breast-feeding and had received cow's milk later in their diet than the case children. CONCLUSIONS - The results suggest that a shorter duration of exclusive breast-feeding is a risk factor for IDDM (odds ratio [OR] 2.13; 95% CI 1.28-3.55) and that the introduction to cow's milk products before age 8 days is a risk factor for the disease (OR 2.29; 95% CI 1.37-3.83).