Karen Harris

Karen Harris is a professional writer and editor with more than two decades of experience in research-driven nonfiction writing. With a background in journalism and a Master's degree in English, she brings a meticulous approach to fact-finding, source evaluation, and clear communication of complex topics. Her work spans health, lifestyle, and consumer education, always with a focus on accuracy and readability.

Context

Long-chain polyunsaturated fatty acids (LCPUFA), including docosahexaenoic acid (DHA) and arachidonic acid (ARA), are structural components of the developing brain. Infant formula supplementation with LCPUFA has been proposed as a strategy to influence cognitive development.


This systematic review and meta-analysis evaluated randomized controlled trials comparing LCPUFA-supplemented versus unsupplemented infant formula on cognitive outcomes measured at ≥2.5 years of age.

Study Overview

Design: Systematic review and meta-analysis of randomized controlled trials (PRISMA-based; pre-registered protocols)


Population: 8 randomized trial cohorts (term and preterm infants); follow-up assessments between 3.3 and 16 years of age


Comparison:

  • Infant formula supplemented with LCPUFA (DHA alone or DHA + ARA, varying doses)

  • Unsupplemented infant formula

Primary Outcome: Standardized cognitive test scores (e.g., WPPSI, WASI, Stanford-Binet) at ≥2.5 years


Follow-up: Cognitive testing at ages ranging from 3.3 to 16 years


Funding: Original trials largely industry-funded; some follow-up analyses publicly funded


Evidence Certainty (GRADE): Overall low quality of evidence due to heterogeneity, attrition, and potential selective publication

Key Findings

  • No statistically significant difference in IQ scores between supplemented and unsupplemented groups in term-born children (pooled mean difference ≈ 0 points).

  • No statistically significant difference in IQ scores in preterm-born children.

  • Wide confidence and prediction intervals included the possibility of both benefit and harm.

  • Substantial statistical heterogeneity observed across studies.

  • Overall quality of evidence rated as low.

Limitations

  • High attrition rates across trials (median follow-up ≈ 53%).

  • Substantial heterogeneity (I² >70% in pooled analyses).

  • Evidence of potential selective publication of outcomes.

  • Variation in DHA/ARA doses, sources, and intervention durations.

  • Many original trials conducted in the 1990s–early 2000s.

Neutral Interpretation

The available evidence does not demonstrate a consistent long-term cognitive benefit of LCPUFA supplementation in infant formula, and the overall certainty of evidence remains low.

Full Citation

Verfuerden ML, Dib S, Jerrim J, Fewtrell M, Gilbert RE.
Effect of long-chain polyunsaturated fatty acids in infant formula on long-term cognitive function in childhood: A systematic review and meta-analysis of randomised controlled trials.
PLOS ONE. 2020.
PMID: 33152012
Available via PubMed: https://pubmed.ncbi.nlm.nih.gov/33152012/

Disclosure

This summary is based on a published systematic review and meta-analysis.
Conflict of interest statements are reported within the original publication.
This content is provided for informational purposes only and does not constitute medical advice.