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Om39.0
Omega-3 Research
Probably helps
1,034 peer-reviewed studies
What the evidence says
Probably helps
Omega-3 helped in about half (18/27) of the studies that measured an effect — promising, but not unanimous.
Most evidence is from high-quality meta-analyses and randomised trials published 2015–2026 with a typical study size of 1,208 participants.
Based on 1,034 studies · 300 meta-analyses · 615 RCTs · 608,273 total participants
Confidence
High confidence
What the studies found
18helped7unclear2didn't help· 1007 more without graded effect data
By outcome
Heart & blood pressureImproved triglycerides and cardiovascular markers within 4-8 weeks · 4-8 weeks
Probably helps871 studies
Therapeutic & clinical
Likely helps156 studies
Women's healthMay help reduce menstrual discomfort and PMS symptoms · 1-3 cycles · Provides essential nutrients for healthy pregnancy · Ongoing · Anti-inflammatory support during menopausal transition · 4-8 weeks
Likely helps114 studies
Cognitive functionDHA is critical structural component of brain, supports memory · 8-12 weeks
Joint pain & arthritisReduced joint inflammation and stiffness within 4-8 weeks · 4-8 weeks
Mostly mechanism / observational10 studies
Safety profile
Limited support10 studies
Skin health
Mostly mechanism / observational9 studies
Bone health
Mostly mechanism / observational9 studies
Endurance & exercise performance
Mostly mechanism / observational8 studies
Longevity & aging
Mostly mechanism / observational7 studies
Fertility & reproductiveMay support reproductive health and fertility markers · 4-12 weeks
Mostly mechanism / observational5 studies
Focus & attentionImproved cognitive function · 4-12 weeks
Mostly mechanism / observational4 studies
Sleep & insomniaHigher omega-3 status associated with better sleep quality · 8-12 weeks
Mostly mechanism / observational4 studies
By the numbers
Pulled from 69 studies with measurable effects
Likely real effects
86%
across studies
People studied
608k
typical study: 1208 people
Strongest designs
915
300 pooled, 615 randomised
Showed benefit
67%
18/27 studies
How long studies ran
1–3 months
2
3+ months
6
Populations Studied
General population5
Cardiovascular patients4
Pregnant women3
Adults3
Active research area
723 studies in the last 5 years · Latest meta-analysis: 2026
201520202026
1muscle strength, endurance, and recoveryMeta-Analysisn=1,211 · large study2026
These findings reveal an outcome-specific efficacy pattern supporting targeted supplementation strategies aligned with primary training objectives in athletic populations.
Wang Z et al. · Nutrients (2026)
The analysis incorporated 35 trials enrolling 1211 participants.
Network consistency assessment revealed no significant disagreement between direct and indirect evidence across all outcomes.
These findings reveal an outcome-specific efficacy pattern supporting targeted supplementation strategies aligned with primary training objectives in athletic populations.
2Depressive disorder symptomsMeta-AnalysisCited 1×n=17,437 · very large study2025
This extensive systematic review and NMA of nutraceuticals for treating depressive disorders indicated a number of nutraceuticals that could offer benefits, either as adjuncts or monotherapies.
Cheng YC et al. · Psychological medicine (2025)
Adjunctive nutraceuticals consistently showed better efficacy than antidepressants (ADT) alone in outcomes including SMD, remission, and response.
This extensive systematic review and NMA of nutraceuticals for treating depressive disorders indicated a number of nutraceuticals that could offer benefits, either as adjuncts or monotherapies.
3Ankle-brachial indexMeta-AnalysisCited 2×n=1,830 · large study2024
The evidence is very uncertain about the effect of omega-3 fatty acids in people with intermittent claudication on quality of life, walking distance (pain-free or maximal), ankle-brachial index, and the incidence of revascularisation procedures or frequency of amputation in the lower limb.
Mohammady M et al. · The Cochrane database of systematic reviews (2024)
No clear effect
← WorseNo effectBetter →
Omega-3 compared with a control may have little to no effect on ankle-brachial index (MD -0.02, 95% CI -0.08 to 0.04; 3 studies, 168 participants; very low-certainty evidence).
The evidence is very uncertain about the effect of omega-3 fatty acids in people with intermittent claudication on quality of life, walking distance (pain-free or maximal), ankle-brachial index, and the incidence of revascularisation procedures or frequency of amputation in the lower limb.
The evidence suggests that omega-3 results in little to no difference in adverse events.
4Cognitive decline progressionMeta-AnalysisCited 13×n=2,766 · very large study2024
The CDR scale showed reduced progression of cognitive decline among patients with n-3-PUFA supplemental interventions, with no differences between different n-3-PUFA supplements.
Calderon Martinez E et al. · Neuropsychopharmacology reports (2024)
Noticeable benefit
← WorseNo effectBetter →
Most publications described positive cognitive outcomes from supplements (58%).
CDR scale showed reduced progression of cognitive decline (SMD = -0.4127, 95% CI: [-0.5926; -0.2327]), without subgroup differences between different dietary supplement interventions.
However, Souvenaid® showed a significant negative effect (SMD = -0.3593, 95% CI: -0.5834 to -0.1352) in ventricular volumes.
5Migraine prophylaxisMeta-AnalysisCited 15×n=6,616 · very large study2024
Migraine is a highly prevalent neurologic disorder with prevalence rates ranging from 9% to 18% worldwide.
Tseng PT et al. · Advances in nutrition (Bethesda, Md.) (2024)
No clear effect
← WorseNo effectBetter →
Migraine is a highly prevalent neurologic disorder with prevalence rates ranging from 9% to 18% worldwide.
Current pharmacologic prophylactic strategies for migraine have limited efficacy and acceptability, with relatively low response rates of 40% to 50% and limited safety profiles.
Forty RCTs were included (N = 6616; mean age = 35.0 y; 78.9% women).
6Anxiety symptomsMeta-AnalysisCited 7×n=2,189 · very large study2024
The present dose-response meta-analysis suggested evidence of very low certainty that supplementation with omega-3 fatty acids may significantly improve anxiety symptoms, with the greatest improvements at 2 g/d.
Bafkar N et al. · BMC psychiatry (2024)
Large benefit
← WorseNo effectBetter →
Each 1 gram per day supplementation with omega-3 fatty acids resulted in a moderate decrease in anxiety symptoms (SMD: -0.70, 95%CI: -1.17, -0.22; GRADE = low).
The non-linear dose-response analysis indicated the greatest improvement at 2 g/d (SMD: -0.93, 95%CI: -1.85, -0.01), and that supplementation in a dose lower than 2 g/d did not affect anxiety symptoms.
Omega-3 fatty acids did not increase adverse events (odds ratio: 1.20, 95%CI: 0.89, 1.61; GRADE = moderate).
7Preeclampsia riskMeta-AnalysisCited 2×n=8,004 · very large study2024
Based on the results of the present study, the consumption of omega-3 supplementation and fish oil significantly reduces the risk of developing preeclampsia.
Rajati M et al. · Clinical nutrition ESPEN (2024)
Based on the results of the present study, the consumption of omega-3 supplementation and fish oil significantly reduces the risk of developing preeclampsia.
8Cardiovascular outcomesMeta-AnalysisCited 7×n=40,991 · very large study2024
Our research reinforces that all patients, regardless of their cardiovascular health, may benefit from adding omega-3 fatty acids to their statin therapy.
Irfan A et al. · Current problems in cardiology (2024)
In contrast, our analysis found no statistically significant difference in the incidence of fatal and non-fatal stroke, coronary revascularization, and cardiovascular mortality.
Our research reinforces that all patients, regardless of their cardiovascular health, may benefit from adding omega-3 fatty acids to their statin therapy.
9Anxiety and depressionMeta-AnalysisCited 40×n=1,426 · large study2023
Only one study reported significant reduction in anxiety severity with 2.1 g/day EPA (85.6% of total EPA + DHA), therefore meta-analysis was not possible.
Kelaiditis CF et al. · Prostaglandins, leukotrienes, and essential fatty acids (2023)
Only one study reported significant reduction in anxiety severity with 2.1 g/day EPA (85.6% of total EPA + DHA), therefore meta-analysis was not possible.
These results support the therapeutic potential of EPA in depression at proportions ≥ 60% of total EPA + DHA and doses ≥ 1 g/day and < 2 g/day.
10Incident atrial fibrillationMeta-AnalysisCited 37×n=54,799 · very large study2023
In vivo levels of omega-3 fatty acids including EPA, DPA, DHA, and EPA+DHA were not associated with increased risk of incident AF.
Qian F et al. · Journal of the American College of Cardiology (2023)
No clear effect
← WorseNo effectBetter →
In multivariable analysis, EPA levels were not associated with incident AF, HR per interquintile range (ie, the difference between the 90th and 10th percentiles) was 1.00 (95% CI: 0.95-1.05).
HRs for higher levels of DPA, DHA, and EPA+DHA, were 0.89 (95% CI: 0.83-0.95), 0.90 (95% CI: 0.85-0.96), and 0.93 (95% CI: 0.87-0.99), respectively.
In vivo levels of omega-3 fatty acids including EPA, DPA, DHA, and EPA+DHA were not associated with increased risk of incident AF.
13Depressive symptomsSystematic ReviewCited 72×n=4,500 · very large study2021
Our primary analyses may suggest a small-to-modest, non-clinically beneficial effect of n-3PUFAs on depressive symptomology compared to placebo; however the estimate is imprecise, and we judged the certainty of the evidence on which this result is based to be low to very low.
Appleton KM et al. · Cochrane Database of Systematic Reviews (2021)
At present, we do not have sufficient high-certainty evidence to determine the effects of n-3PUFAs as a treatment for MDD.
Primary analyses may suggest a small-to-modest, non-clinically beneficial effect of n-3PUFAs on depressive symptomology compared to placebo.
More complete evidence is required for both the potential positive and negative effects of n-3PUFAs for MDD.
14Multiple sclerosis relapsing rate and inflammatory markersSystematic ReviewCited 85×n=5,554 · very large study2021
These roles were attributed to their beneficial effects on inflammatory markers, glutathione reductase, reducing the relapsing rate, and achieving balanced omega-6 to omega-3 ratios.Conclusion: Omega-3 and fish oils supplementations have beneficial effects on reducing the relapsing rate, inflammatory markers, and improving the quality of life for MS patients.
AlAmmar WA et al. · Nutritional neuroscience (2021)
The inclusions were studies performed on humans both male and female, aged 18 years at minimum, diagnosed with MS according to McDonald 2010 criteria.
Otherwise, all studies were excluded.Results: A total of 5554 studies were screened and seven were thoroughly focused on as they typically met the inclusion criteria.
These studies showed the beneficial roles of fish oil supplementation and omega-3 fatty acids in improving the quality of life of MS patients.
16Patient important outcomes after myocardial infarctionMeta-AnalysisCited 15×n=24,414 · very large study2019
For adult patients with AMI, omega 3 fatty-acids probably yield no benefit to patient important outcomes.
Popoff F et al. · BMC cardiovascular disorders (2019)
No clear effect
← WorseNo effectBetter →
Regarding adverse events, we are uncertain if Omega 3 fatty acids improve/reduce non severe adverse events (RR 1.39 95% CI 0.36 to 5.34; very low certainty).
There is probably little or no difference in the outcome suspension due to adverse events (RR 1.19 CI 95% 0.97 to 1.47; moderate certainty).
For adult patients with AMI, omega 3 fatty-acids probably yield no benefit to patient important outcomes.
17Depressed moodMeta-AnalysisCited 48×n=4,605 · very large study2018
In the well-being mental health group, the Hedges g was 0.12 (95% confidence interval, -0.05 to 0.29), which indicated no significant effect of n-3 PUFA supplementation on depressed mood compared w...
Bae JH et al. · Nutrition research (New York, N.Y.) (2018)
Huge benefit
← WorseNo effectBetter →
In the well-being mental health group, the Hedges g was 0.12 (95% confidence interval, -0.05 to 0.29), which indicated no significant effect of n-3 PUFA supplementation on depressed mood compared with placebo.
In the depressive group, the pooled Hedges g was -0.94 (95% CI, -1.37 to -0.50]) for the random-effects model, which indicated a large effect of n-3 PUFA supplementation on those with depressed mood compared with placebo.
Although this review shows that omega-3 fatty acids are effective in the treatment of elderly depressed patients, the benefits of omega-3 fatty acid supplementation were significant only in the elderly patients with mild to moderate depression.
18Cardiovascular events and coronary revascularizationMeta-AnalysisCited 24×n=144 · medium study2024
Omega-3 fatty acid supplementation reduced the risk of cardiovascular events and coronary revascularization, regardless of background statin use.
Dinu M et al. · European journal of preventive cardiology (2024)
Noticeable benefit
← WorseNo effectBetter →
Likely real
Lower risk was still observed in trials where most participants (≥60%) were on statin therapy.
Compared with DHA + EPA, EPA alone showed a further significant risk reduction of revascularizations (0.76, 95% CI 0.65-0.88; P = 0.0002; P-interaction = 0.005) and all outcomes except HF.
Omega-3 fatty acid supplementation reduced the risk of cardiovascular events and coronary revascularization, regardless of background statin use.
The find-ings highlight the heterogeneity in responses to omega-3 fatty acid supplementation and emphasize the need for cautious interpretation.
Fei L et al. · Asia Pacific journal of clinical nutrition (2024)
The meta-analysis revealed a neutral overall effect size of omega-3 fatty acid supplementation on proteinuria levels, assessed under both common and random effect models.
Despite the lack of statistically significant evidence supporting the efficacy of omega-3 fatty acids in reducing proteinuria, the variability in interventions and patient populations suggests potential individual responses.
The find-ings highlight the heterogeneity in responses to omega-3 fatty acid supplementation and emphasize the need for cautious interpretation.
20Meta-Analysis2026
Liu G, Wu C, Yang X, Liu Z, Zhu Y, Yang T · PeerJ (2026)