EFFECT OF INCREASING BREAST-MILK DOCOSAHEXAENOIC ACID ON PLASMA AND ERYTHROCYTE PHOSPHOLIPID FATTY-ACIDS AND NEURAL INDEXES OF EXCLUSIVELY BREAST-FED INFANTS

Objectives: To determine the effect of increasing docosahexaenoic acid (DHA, 22:6 n-3) in breast milk on infant fatty acid profiles. A secon dary aim was to examine aspects of neural development. Design and Sett ing Double blind, placebo controlled study of infants recruited from p ostnatal wards at Flinders Medical Centre. Subjects: Fifty-two healthy term infants who were breast fed for at least 12 weeks and were from middle class families. Intervention: Breast milk with DHA concentratio ns that ranged from 0.1-1.7% of total fatty acids. This was achieved b y supplementation of the maternal diet for the first 12 weeks post par tum. Results: Breast milk DHA was related to infant plasma (r=0.89, P < 0.001) and erythrocyte (r=0.88, P(0.001) phospholipids in a saturabl e curvilinear manner so that breast milk DHA above 0.8% of total fatty acids resulted in little further increase in infant plasma or erythro cyte DHA levels. The rise in plasma and erythrocyte DHA was approximat ed by a fall in total n-6 polyunsaturated fatty acids. We could detect no relationship between visual evoked potential acuity (measured at 1 2 and 16 weeks) of infants by either the dietary grouping or the DHA s tatus of individuals. A stepwise multiple regression showed that infan t erythrocyte DHA at 12 weeks and home stimulation were the only indep endent factors associated with Bayley's MDI at 1 y (adjusted model r(2 ) = 0.18, P < 0.005); while at 2 y gender and social score of the spou se were the only significant predictors of Bayley's MDI (adjusted mode l r(2) = 0.22, P < 0.005). Conclusions: Increasing breast milk DHA lev els caused a dose dependent saturable increase in infant plasma and er ythrocyte phospholipid DHA. There were no long-term effects of infant DHA status on indices of neurodevelopment.