Abstract

Background There are ambiguous results regarding the role n-3 polyunsaturated fatty acids and fish might play in primary prevention of allergic diseases. The aim was to investigate the association between cod liver oil and fish consumption during pregnancy and in the first year of life and asthma and eczema at 2 years of age.

Methods From the Prevention of Allergy among Children in Trondheim study, a prospective birth cohort study in primary healthcare in Trondheim, Norway, 3086 children were followed prospectively from 1 year to approximately 2 years of age. The primary outcome variable was parental reported asthma and eczema at 2 years.

Results The mean age for introducing fish in the diet was 9.1 months. Excluding children with incident eczema before 1 year, a reduced risk of developing eczema was found if the child was eating fish once a week or more, adjusted OR (aOR) for any kind of fish 0.62 (95% CI 0.42 to 0.91 p=0.02), for oily fish aOR 0.21 (95% CI 0.05 to 0.86 p=0.03) and for lean fish aOR 0.67 (95% CI 0.41 to 1.08 p=0.10). The associations between maternal diet and eczema at 2 years and between the dietary factors and doctor-diagnosed asthma were all insignificant.

Conclusions Fish consumption in infancy was more important than maternal fish intake during pregnancy in preventing eczema in childhood. The intake of fish per se, not specifically n-3 polyunsaturated fatty acids, was most important in preventing eczema.