Background: The n-3 and n-6 fatty acids linolenic acid and linoleic acid are precursors of the n-3 and n-6 long chain fatty acids (LCPUFA). Infant formula has historically only contained the precursor fatty acids. Over the last few years, some manufacturers have added LCPUFA to formulae and marketed them as providing an advantage for the development of term infants.
Objectives: To assess whether supplementation of formula with LCPUFA is safe and of benefit to term infants.
Search methods: We searched the Cochrane Central Register of Controlled Trials (The Cochrane Library, April, 2011), MEDLINE (1966 to April 2011), EMBASE (1980 to April 2011), CINAHL (December 1982 to April 2011) and abstracts of the Society for Pediatric Research (1980 to 2010). No language restrictions were applied.
Selection criteria: Randomised and quasi randomised trials comparing LCPUFA supplemented vs. non-supplemented formula milk and with clinical endpoints were reviewed.
Data collection and analysis: Methodological quality of studies was assessed using the guidelines of Cochrane neonatal review group. Data were sought regarding effects on visual acuity, neurodevelopmental outcomes and physical growth. When appropriate, meta-analysis was conducted to provide a pooled estimate of effect.
Main results: Twenty-five randomised studies were identified; fifteen were included (n = 1889) and ten excluded.Visual acuity was assessed by nine studies. Visual evoked potential was used in six studies, two used Teller cards and one used both. Four studies reported beneficial effects while the remaining five did not.Neurodevelopmental outcome was measured by eleven studies. Bayley scales of infant development (BSID) was used in nine studies; only two showed beneficial effects. Meta-analysis did not show significant benefits of supplementation. One study followed the infants up to nine years of age and did not find benefit of supplementation. One study reported better novelty preference measured by Fagan Infant test at nine months. Another study reported better problem solving at 10 months. One study used Brunet and Lezine test to assess the developmental quotient and did not find beneficial effects.Physical growth was measured by thirteen studies; none found beneficial or harmful effects of supplementation. Meta-analysis found that supplemented group may have marginally lower weight at one year of age.
Authors' conclusions: Majority of the RCTS have not shown beneficial effects of LCPUFA supplementation on the neurodevelopmental outcomes of term infants. The beneficial effects on visual acuity have not been consistently demonstrated. Routine supplementation of term infant milk formula with LCPUFA can not be recommended.