IDDM and milk consumption. A case-control study in São 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 São Paulo, Brazil. A total of 346 diabetic children, aged < 18 years, were identified in two institutions in the city of São 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 1.8-3.55) and that the introduction to cow's milk products before age 8 days is a risk factor for the disease.