Influence of diet in infancy on asthma and atopy in young adults

Background The worldwide documented increase in allergic diseases including asthma remains unclear, but potential causes are changes in diet in infancy, particularly changes in breast-feeding and increased exposure to cows milk. Methods The Merthyr allergy prevention study (MAPS) was a randomised controlled trial to determine whether a cow9s milk restricted diet in early life decreases the likelihood of developing allergic diseases in a high risk, deprived population. Infants in intervention group had a cows9 milk free diet for the first 16 weeks of the child9s life. A soya milk preparation was supplied for those who did not wish to breast-feed. Infants in the control group had no restrictions on their cows9 milk intake. Questionnaire and clinical assessments for wheeze, atopy and asthma were completed at age 1, 7, 15 and 23 years. Results 487 infants were randomised, 238 to intervention and 249 to control. At age 23 years 77 subjects could not be traced, 361 were invited for assessment, 304 completed a questionnaire and 124 had clinical assessment. Wheeze at age 1 year was significantly less likely in those who were breast fed, but there were no significant associations at any other ages. Of those randomised to the intervention group (cows9 milk free diet), 41 (17.2%) were given cows9 milk before 16 weeks of life, and of those who were randomised to usual diet, 32 (13%) were given soya milk in the first 16 weeks of life. At age 23 years risk of atopy was significantly increased in the control group OR 2.66 (95%CI 1.25-5.67; p=0.008) and asthma OR 2.05 (95%CI 1.0-3.80; p=0.016). Conclusions In high risk infants, diet in infancy influences subsequent risk of atopy and asthma in young adulthood.