To evaluate the beneficial and adverse effects of supplementation with omega-3 and omega-6 fatty acids in patients with migraine.

 A search was conducted in the Cochrane Central-Ovid, Scopus, Embase, and Web of Science databases updated in April 2024 for randomized controlled trials (RCTs) reporting the effects of omega-3 or omega-6 supplementation in patients aged 18 years and older with migraine. Primary outcomes included frequency and duration of migraine attacks, pain intensity, migraine impact, and/or adverse events. A random-effects model was used to obtain the mean difference (MD) with 95% confidence intervals (CI). The certainty of evidence was assessed using GRADE methodology.

Nine RCTs evaluating omega-3 supplementation were found. Two studies investigated intervention as a rich omega-3 diet and the others as omega-3 supplements (ranging doses: 1.5 to 6 grams/day). No RCT evaluating the effect of omega-6 supplementation was found. Omega-3 reduced the mean number of hours of headache/day (MD: -1.64 hours, 95% CI: -2.21 to -1.06), the mean number of headache days/month (MD: -2.11 days, 95% CI: -3.67 to -0.55), and the intensity of attacks (MD: -0.82 units, 95% CI: -1.54 to -0.10). Additionally, it improved the MIDAS scale (MD = -14.55 units; 95% CI: -21.76 to -7.35), however, it had no impact on HIT-6 score. There were no differences in adverse events in the intervention group compared to the control group. The certainty of evidence was low or very low for all outcomes due to high risk of bias of individual RCTs and high imprecision and inconsistency.

The effects of omega-6 supplementation may improve the intensity and frequency of migraine attacks and no severe adverse events. There is no evidence of the effects of omega-3 supplementation.