Long-chain polyunsaturated fatty acid supplementation in infants born at term.

BACKGROUND

This section is under preparation and will be included in the next issue.

OBJECTIVES

The n-3 and n-6 essential fatty acids alpha linolenic acid and linoleic acid are the precursors of the n-3 and n-6 longchain polyunsaturated fatty acids (LCPUFA). Controversy exists over whether LCPUFA are essential nutrients during infancy. The aim of this review is to assess whether supplementation of formula with LCPUFA is safe and of benefit to term infants.

SEARCH STRATEGY

Trials were identified by MEDLINE, checking reference lists of articles and conference proceedings, and by personal communication.

SELECTION CRITERIA

All randomised trials of formula supplemented with LCPUFA and with clinical endpoints were reviewed.

DATA COLLECTION AND ANALYSIS

Eight randomised studies were identified. One of these studies was excluded due to supplementation commencing after three weeks of age, and one is awaiting assessment. The remaining six trials were assessed to be of good quality.

MAIN RESULTS

Visual acuity was assessed by visual evoked potentials at 4 and 7-8 months in the studies of Makrides et al (1995 & 1996). The supplemented infants had an improved rate of visual maturation at both time points in the first study, but no difference was found between the groups at 4 months in the second study. Visual acuity was assessed by Teller acuity cards in the study of Carlson et al (1996), Clausen et al (1996) and Austed et al (1997). Supplementation had no consistent effect on visual acuity over the first year of life. General development was measured in five studies, all with small numbers. Two suggested a benefit of supplementation. One reported a benefit with supplementation at 4 months ( developmental quotient, DQ measured with the Brunet Lezine test, Agostini et al 1995), but when the groups were reassessed with the same test at 1 and 2 years, no differences were found in DQ (Agostini et al 1997). The other study reported a benefit with supplementation at 9 months (novelty preference measured by Fagan Infantest, Clausen et al 1996). The Adelaide studies showed no effect of supplementation on DQ at one year (Bayley Scales of Infant Development (BSID), Makrides et al 1995 &1996). The Portland study showed no effect of supplementation on development at one year (BSID) or at three years (Stanford Binet IQ test). The Portland study showed no effect of supplementation on language development at one year (McArthur Communicative Development Inventory, Janowsky et al 1995) or at three years (Peabody Picture Vocabulary Test, Scott et al 1997). Growth was measured in a small number of infants in the studies of Makrides et al (1995 & 1996) and Austed et al (1997). There was no suggestion that LCPUFA supplementation reduced the growth of term infants.

REVIEWER'S CONCLUSIONS: At present there is little evidence from randomised trials of LCPUFA supplementation to support the hypothesis that LCPUFA supplementation confers any benefit on visual or cognitive development. There are no data from the randomised trials presently available to indicate that LCPUFA supplements influence the growth of term infants.