Regulation of inflammation by omega-3 and omega-6 fatty acids: a meta-analysis of randomized trials.
Level 1 - systematic review of randomized trials
Systematic review and meta-analysis of randomized controlled trials
PubMed 42163966 · doi:10.3389/fnut.2026.1799601
What was done
A systematic review and meta-analysis of six databases evaluated the anti-inflammatory effects of omega-3 and omega-6 polyunsaturated fatty acids (PUFAs). Nine randomized controlled trials (RCTs) with 504 participants were included. Outcomes were interleukin-6 (IL-6), C-reactive protein (CRP), interleukin-1 beta (IL-1β), and tumor necrosis factor-alpha (TNF-α), synthesized using fixed- or random-effects models. Subgroup analyses examined fatty acid type, population health status, and intervention duration.
What was found
Omega-3 and omega-6 supplementation showed no statistically significant effects overall on IL-6, CRP, or TNF-α (p > 0.05). IL-1β was significantly reduced in the intervention group (MD = -0.04, 95% CI: -0.07 to -0.01, p = 0.02), with a stronger effect in the omega-6 subgroup (MD = -0.05, p = 0.03). No significant differences in IL-6 or TNF-α were found between healthy participants and patients. Omega-3 did not change IL-6 in metabolic dysfunction-associated steatotic liver disease (MD = 0.00, p > 0.05), and short-term interventions (10–12 weeks) did not alter IL-6 for omega-6 or TNF-α for omega-3.
Why it matters
The findings challenge assumptions of broad anti-inflammatory efficacy for PUFA supplementation, demonstrating no overall impact on CRP, IL-6, or TNF-α and only a minor reduction in IL-1β.
Limits
The total sample size is small (9 RCTs, 504 participants), limiting statistical power. The abstract reports no details on PUFA dosage, specific baseline diets, or compliance, and intervention durations were relatively brief (10–12 weeks).
Cited by
- supports Controlled human feeding studies show that increasing dietary intake of omega-6 fatty acids does not increase systemic inflammation.