Research Update

Research updates summarize and critique current research. Where possible, critiques come from cited published articles or experts in the field.

Study Finds Improved Cognitive Development Among Preterm Infants with Supplementation of Docosahexaenoic and Arachidonic Acid

A study in Pediatrics found that supplementation with docosahexaenoic acid (DHA) and arachidonic acid (AA) for very low birthweight infants (VLBW) fed human milk was associated with improved cognitive development.  The study was a randomized, double-blind, placebo-controlled trial of 141 infants with very low birth weights (<1500 grams).  Roughly half of the infants received the supplementation of 32 mg of DHA and 31 mg of AA per 100 mL of human milk for an average of nine weeks; the supplementation began one week after birth and lasted until the infant was discharged from the hospital. Cognitive development was assessed at 6 months by using the Ages and Stages Questionnaire and event-related potentials (ERP’s), which can measure recognition memory. The authors found no difference in growth or adverse events between the two groups, but found significant improvement on the problem-solving score, significant lower response times after a standard image, and no difference in responses to novel images.  Higher levels of plasma fatty acids, including DHA and AA, were measured in the supplemented infants.

The strengths of the study include a randomized, double-blinded study design, the multidisciplinary approach, and the use of ERPs to assess cognitive development.  Limitations of the study include low statistical power for detecting differences and a high drop out rate; the authors estimated that at least 126 participants would be needed to detect significant differences between the groups; however, only 105 completed the six-month questionnaire.  A larger sample size is desirable.

The authors conclude that, “our present study is the first to show a beneficial effect on cognitive function of DHA and AA supplementation for VLBW infants fed human milk.”  This study, however, only assessed infant development at six months and the authors conclude that, “it remains to be seen whether this type of intervention may have long-term effects on cognitive function.”

* Henrisksen, C. Haugholt, K. Lindgren, M. et al.  Improved Cognitive Development Among Preterm Infants Attributable to early Supplementation of Human Milk With Docosahexaenoic Acid and Arachidonic Acid.  Pediatrics; 121; 1137-1145.