Can early intake of dietary omega-3 predict childhood externalizing behaviour?

Aim: To determine whether maternal and child intake of dietary omega-3 (n-3) fatty acids (FA), together with the presence or absence of breast-feeding, predicted psychiatric diagnosis of externalizing disorders in childhood. Methods: Data concerning childhood externalizing disorders were collected from 8242 children aged 7.9 years in a large British cohort. Intake of n-3 FA was measured for the study mother during pregnancy and for the child at 3 years. Duration of breast-feeding was examined to account for moderating effects. Adjustment was made for a variety of potential confounders. Results: Maternal intake of n-3 and breast-feeding predicted oppositional/conduct disorder and comorbid externalizing disorder before adjustment for confounding factors. However, there was no association between intake of n-3 by mother or child and any type of externalizing disorder once socio-demographic factors were taken into account. Conclusions: Any association between intake of n-3 and childhood externalizing disorders appears to be strongly confounded with socio-demographic factors. This is important to note given the current popularity of n-3 as a possible treatment for behaviour problems related to inattention and impulsivity. Care must be taken that studies investigating this relationship account fully for factors associated with both behaviour and diet.