['Breast-feeding is the preferred method of infant nutrition. Its role in preventing childhood asthma is controversial.', 'Determine whether breastfeeding protects against the development of bronchial asthma in children.', 'A survey was answered by parents of children less than 18 years of age attending a Pediatric clinic at Cidra, Puerto Rico from July to December 2008.', "A group of 175 mothers were included in the study. The mean age was 28 years (range 14-50). The mean age of the children was 5 years. There was family history of asthma in 64% of the families. The prevalence of asthma in these children was 50%. Sixty-six percent of the mother's breastfed but only 27% did it exclusively. Children who were exclusively breastfed had a lower prevalence of asthma and milk protein allergy."] Does exclusive breastfeeding reduce asthma in a group of children from the Caguas municipality of Puerto Rico?