Longer breastfeeding is an independent protective factor against development of type 1 diabetes mellitus in childhood

Background Early weaning diet, early introduction of breast milk substitution and cow's milk have been shown to increase the risk of type 1 diabetes later in life. It is also shown that older maternal age, maternal education, preeclampsia, prematurity, neonatal illness and neonatal icterus caused by blood group incompatibility, infections and stress might be risk factors for type 1 diabetes. We aimed to determine whether early nutrition is an independent risk factor for diabetes despite other life events. Methods Data from 517 children (268 boys and 249 girls) in south-east of Sweden and 286 children (133 boys and 153 girls) in Lithuania in the age group of 0 to 15 years with newly diagnosed type 1 diabetes mellitus were included into analysis. Three age- and sex-matched healthy controls were randomly selected. Response rate in control families in Sweden was 72.9% and in Lithuania 94.8%. Information was collected via questionnaires. Results Exclusive breastfeeding longer than five months (odds ratio 0.54, 95% confidence interval 0.36-0.81) and total breastfeeding longer than 7 (0.56, 0.38-0.84) or 9 months (0.61, 0.38-0.08) among Swedish children 5 to 9 years old and later than the seventh month (0.24, 0.07-0.84) among all Swedish children is protective against diabetes when adjusted for all other above-listed risk factors. In Lithuania, exclusive breastfeeding longer than two months in the age group of 5 to 9 years is protective (0.58, 0.34-0.99) when adjusted for other factors. Conclusions Longer exclusive and total breastfeeding appears as an independent protective factor against type 1 diabetes. Copyright (C) 2004 John Wiley Sons, Ltd.