The Effect of Long-Chain Omega-3 Polyunsaturated Fatty Acid Supplementation on Neuromuscular Function in Humans: A...

Neuromuscular function is central to strength, movement control, and fatigue resistance, with relevance for athletic performance and healthy ageing. Long-chain n-3 polyunsaturated fatty acid (LCn-3 PUFA) supplementation has been reported to improve muscle strength and physical function in the absence of muscle hypertrophy, suggesting modulation of neuromuscular function; however, the extent, consistency, and underlying mechanisms of these effects remain unclear.

The objective of this study was to systematically review the effects of LCn-3 PUFA supplementation on neuromuscular function across the lifespan in humans.

This systematic review with narrative synthesis was conducted in accordance with PRISMA 2020 guidelines. Literature searches were performed in PubMed, Web of Science, SPORTDiscus, and Scopus.

Eligibility criteria were defined using the participants, intervention, comparator, outcomes, and study design (PICOS) framework. Randomized and nonrandomized controlled trials in humans examining orally administered LCn-3 PUFA supplementation and neuromuscular outcomes were eligible for inclusion. Outcomes were classified as neural, muscular, or global indicators of neuromuscular function, and the findings synthesized in a narrative format.

Eleven studies were included. A range of neuromuscular outcomes were assessed across neural, muscular, and global domains, with substantial heterogeneity in the outcome measures, supplementation protocols, and study contexts. LCn-3 PUFA supplementation was associated with improvements in some neuromuscular outcomes; however, the findings were inconsistent, with numerous null and occasional context-specific adverse effects being reported. The limited evidence suggests that effects may be more likely following LCn-3 PUFA supplementation for around 2 weeks or longer, and that docosahexaenoic acid may play a role in neural outcomes, while interactions with structured exercise training remain unclear.

LCn-3 PUFA supplementation may influence aspects of neuromuscular function; however, the current evidence is limited and heterogeneous. Further well-controlled studies using standardized supplementation protocols and neuromuscular assessments are required in order to clarify potential mechanisms and identify populations most likely to benefit.