Across 4 studies, fish oil supplementation showed predominantly small beneficial effects on reducing triglyceride levels (3 of 4 studies beneficial), with one meta-analysis reporting a moderate effect (SMD -0.40). Most studies lasted 8–12 weeks and dosed 600–1000 mg EPA+DHA daily. Effects were observed in clinical populations with metabolic or inflammatory conditions such as MASLD, migraine, and prediabetes.
Caveats: Evidence base is small (4 studies). Effect sizes varied: a meta-analysis showed moderate effect, while individual RCTs reported small or neutral effects. One RCT in MDD patients found no significant benefit, suggesting the effect may be population-dependent. Dose and form were inconsistently reported, limiting dose specificity.
triglycerides [TG, pooled standard mean difference (SMD): -0.40 (95% CI: -0.58 to -0.21)]
Blood lipid indexes TC, LDL-C, and TG were reduced
The mean HbA1c rates and plasma triglyceride levels of krill-oil recipients were lower after the post-intervention. (No significant change reported for fish oil on these outcomes)
FO reduced serum triglycerides, hemoglobin A1c and increased HDL-cholesterol