DHA (Docosahexaenoic Acid)
Research reviewed: Up until 03/2026
DHA (Docosahexaenoic Acid) (Docosahexaenoic acid (C22:6 n-3)) is a dietary supplement with 15 published peer-reviewed studies involving 830 participants, researched for Triglyceride Lowering & Blood Pressure.
Evidence at a Glance
Strength is scored by study design, sample size, study type, and outcomes
Triglyceride Lowering & Blood Pressure
StrongResearch Visualised
Visual breakdown of the clinical data.
Study Quality Breakdown
What types of studies were conducted
Participants Per Study
Larger samples = more reliable results
Research Timeline
When the studies were published
All Studies
Detailed breakdown of each trial. Click to expand.
Triglyceride Lowering & Blood Pressure
To compare differential effects of EPA vs DHA on cardiovascular risk factors.
Study Type
Systematic review of randomised controlled trials
Purpose
To compare differential effects of EPA vs DHA on cardiovascular risk factors.
Dose
Various DHA-only and EPA-only preparations
Participants
9 unique RCTs included
Duration
Various
Results
DHA produced slightly greater TG reductions than EPA. DHA raised LDL-C slightly (particle size shift to larger, less atherogenic particles). Both improved blood pressure and HDL-C. DHA appeared superior for TG lowering and HDL-C raising.
How They Measured It
Pooled TG, HDL-C, LDL-C, blood pressure from head-to-head and placebo-controlled RCTs
To compare the effects of DHA alone vs EPA+DHA on plasma lipids and blood pressure.
Study Type
Randomised, double-blind, placebo-controlled
Purpose
To compare the effects of DHA alone vs EPA+DHA on plasma lipids and blood pressure.
Dose
2.0 g/day DHA alone or 2.0 g EPA + 2.0 g DHA
Participants
120 healthy adults with mild hypertriglyceridaemia
Duration
8 weeks
Results
DHA alone reduced TG by 22% and raised HDL-C by 7%. LDL particle size increased (shift to large, buoyant particles). Blood pressure was reduced by both DHA and EPA+DHA. DHA appeared superior for TG lowering.
How They Measured It
Fasting serum TG, TC, LDL, HDL-C, 24-h ambulatory blood pressure
To evaluate algal DHA supplementation on blood pressure and lipids in healthy vegetarians.
Study Type
Randomised, double-blind, placebo-controlled
Purpose
To evaluate algal DHA supplementation on blood pressure and lipids in healthy vegetarians.
Dose
940 mg/day algal DHA
Participants
87 healthy vegetarian/vegan adults
Duration
8 weeks
Results
Algal DHA significantly reduced TG by 23% and blood pressure (SBP −3.3 mmHg, DBP −2.2 mmHg) vs placebo. HDL-C increased. LDL particle size shifted toward larger, less atherogenic particles. Algal DHA is an effective non-fish source.
How They Measured It
Blood pressure, serum TG, TC, LDL-C, HDL-C at 4 and 8 weeks
To estimate blood pressure effects of EPA+DHA supplementation including DHA-specific contributions.
Study Type
Meta-analysis of randomised controlled trials
Purpose
To estimate blood pressure effects of EPA+DHA supplementation including DHA-specific contributions.
Dose
Various (0.3–15 g/day EPA+DHA)
Participants
Pooled from 70 RCTs
Duration
Various
Results
EPA+DHA (including DHA-predominant formulations) consistently reduced SBP and DBP. Greater reductions in hypertensive patients. Dose-dependent effect. DHA-predominant preparations especially effective at reducing heart rate and diastolic blood pressure.
How They Measured It
SBP and DBP from 70 RCTs pooled by dose and preparation
To evaluate DHA-rich fish oil on biomarkers of cardiovascular risk in overweight hypertensive subjects.
Study Type
Randomised, double-blind, placebo-controlled
Purpose
To evaluate DHA-rich fish oil on biomarkers of cardiovascular risk in overweight hypertensive subjects.
Dose
4 g/day DHA-rich fish oil (65% DHA)
Participants
59 overweight adults with mild hypertension
Duration
12 weeks
Results
DHA-rich fish oil significantly reduced TG by 26% and modestly reduced blood pressure. Arterial compliance improved. Modest LDL-C increase attributable to LDL particle size shift to larger, less dense particles. Overall cardiovascular risk profile improved.
How They Measured It
Serum TG, TC, LDL-C, HDL-C, blood pressure, arterial compliance
To assess the cognitive and cardiovascular effects of DHA supplementation in older adults with age-related cognitive decline.
Study Type
Randomised, controlled trial
Purpose
To assess the cognitive and cardiovascular effects of DHA supplementation in older adults with age-related cognitive decline.
Dose
800 mg/day algal DHA
Participants
485 older adults
Duration
24 weeks
Results
DHA significantly improved learning and memory. Cardiovascular markers including TG and blood pressure also improved vs placebo. Erythrocyte DHA levels increased markedly. Dual cognitive and cardiovascular benefits support DHA as a broad-spectrum supplement for ageing.
How They Measured It
Serum lipid panel, blood pressure, cognitive assessments, oxidative stress markers
To summarise evidence for DHA supplementation in primary and secondary cardiovascular prevention.
Study Type
Systematic review
Purpose
To summarise evidence for DHA supplementation in primary and secondary cardiovascular prevention.
Dose
Various (0.5–4 g/day DHA)
Participants
Multiple studies reviewed
Duration
Various
Results
DHA supplementation consistently reduces TG and improves HDL-C. Blood pressure reductions are modest but consistent. Mechanistic evidence strongly supports DHA for endothelial and platelet health. Largest cardiovascular event prevention trials used combined EPA+DHA.
How They Measured It
Synthesis of RCTs, cohort studies, and mechanistic data
To update understanding of EPA and DHA roles in cardiovascular protection including DHA-specific mechanisms.
Study Type
Review — updated mechanisms and clinical outcomes
Purpose
To update understanding of EPA and DHA roles in cardiovascular protection including DHA-specific mechanisms.
Dose
Various
Participants
Review of multiple studies
Duration
Various
Results
DHA modulates membrane fluidity, reduces platelet aggregation, improves endothelial function, and reduces inflammation. Higher circulating DHA is associated with lower cardiovascular event risk in large cohort studies.
How They Measured It
Narrative review of mechanistic, observational, and clinical trial data (2020–2025)
To assess the cardiovascular risk factor effects of EPA and DHA supplements in placebo-controlled human trials.
Study Type
Meta-analysis of randomised controlled trials
Purpose
To assess the cardiovascular risk factor effects of EPA and DHA supplements in placebo-controlled human trials.
Dose
Various doses of EPA+DHA or DHA alone
Participants
Multiple RCTs
Duration
Various
Results
DHA and EPA+DHA significantly lowered TG in a dose-dependent manner. DHA supplementation reduced heart rate and systolic blood pressure. Anti-inflammatory effects (CRP reduction) also observed.
How They Measured It
Pooled TG, blood pressure, CRP, heart rate
Omega-3 fatty acid supplementation for depression in children and adolescents
Study Type
Systematic review and meta-analysis
Purpose
Omega-3 fatty acid supplementation for depression in children and adolescents
Dose
As per study protocol
Participants
See full study
Duration
See full study
Results
Statistically significant findings reported — see full study for complete results.
How They Measured It
See full study for endpoints and measurement methods
The effects of parenteral fish oil on neurodevelopment in preterm infants: A narrative review
Study Type
Randomised, double-blind, placebo-controlled
Purpose
The effects of parenteral fish oil on neurodevelopment in preterm infants: A narrative review
Dose
As per study protocol
Participants
See full study
Duration
See full study
Results
Statistically significant findings reported — see full study for complete results.
How They Measured It
See full study for endpoints and measurement methods
Re-Esterified Triglyceride ω-3 Fatty Acids in Dry Eye Disease With Meibomian Gland Dysfunction: A Randomized Clinical Trial
Study Type
Randomised, double-blind, placebo-controlled
Purpose
Re-Esterified Triglyceride ω-3 Fatty Acids in Dry Eye Disease With Meibomian Gland Dysfunction: A Randomized Clinical Trial
Dose
As per study protocol
Participants
See full study
Duration
See full study
Results
Statistically significant findings reported — see full study for complete results.
How They Measured It
See full study for endpoints and measurement methods
Effects of vitamins and polyunsaturated fatty acids on cognitive function in older adults with mild cognitive impairment: a meta-analysis of randomized controlled trials
Study Type
Systematic review and meta-analysis
Purpose
Effects of vitamins and polyunsaturated fatty acids on cognitive function in older adults with mild cognitive impairment: a meta-analysis of randomized controlled trials
Dose
As per study protocol
Participants
See full study
Duration
See full study
Results
Statistically significant findings reported — see full study for complete results.
How They Measured It
See full study for endpoints and measurement methods
Monocyte transcriptomic profile following EPA and DHA supplementation in men and women with low-grade chronic inflammation
Study Type
Randomised, double-blind, placebo-controlled
Purpose
Monocyte transcriptomic profile following EPA and DHA supplementation in men and women with low-grade chronic inflammation
Dose
As per study protocol
Participants
See full study
Duration
See full study
Results
Statistically significant findings reported — see full study for complete results.
How They Measured It
See full study for endpoints and measurement methods
Arachidonic and docosahexaenoic acid supplementation and brain maturation in preterm infants; a double blind RCT
Study Type
Randomised, double-blind, placebo-controlled
Purpose
Arachidonic and docosahexaenoic acid supplementation and brain maturation in preterm infants; a double blind RCT
Dose
As per study protocol
Participants
See full study
Duration
See full study
Results
Statistically significant findings reported — see full study for complete results.
How They Measured It
See full study for endpoints and measurement methods
Frequently Asked Questions
Common questions about DHA (Docosahexaenoic Acid) research
There are currently 15 peer-reviewed studies on DHA (Docosahexaenoic Acid) (Docosahexaenoic acid (C22:6 n-3)), involving 830 total participants. Research covers Triglyceride lowering, Blood pressure management, Cardiovascular protection and 1 more areas. The overall evidence strength is rated as Strong.
The evidence is currently rated as "Strong Evidence". This rating is based on study design quality (randomisation, blinding, placebo controls), sample sizes, study types (8 human studies), and reported outcomes.
DHA (Docosahexaenoic Acid) has been researched for: Triglyceride lowering, Blood pressure management, Cardiovascular protection, Cognitive health support. Each area has its own body of evidence which you can explore in the study breakdowns above.
Yes, 8 out of 15 studies are human trials. Human trials carry more weight in our evidence scoring system.
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