Flaxseed Oil
Research reviewed: Up until 03/2026
Flaxseed Oil (Linum usitatissimum seed oil (alpha-linolenic acid)) is a dietary supplement with 7 published peer-reviewed studies involving 1,450 participants, researched for Cardiovascular Health, Anti-inflammatory Effects, Dry Eye Syndrome and 1 more areas.
Evidence at a Glance
Strength is scored by study design, sample size, study type, and outcomes
Cardiovascular Health
ModerateAnti-inflammatory Effects
ModerateDry Eye Syndrome
ModerateBlood Pressure
ModerateResearch 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.
Cardiovascular Health
To evaluate flaxseed oil supplementation on lipid profiles and cardiovascular risk markers.
Study Type
Randomised, double-blind, placebo-controlled
Purpose
To evaluate flaxseed oil supplementation on lipid profiles and cardiovascular risk markers.
Dose
15 mL/day flaxseed oil (~7.5 g ALA)
Participants
147 adults with hyperlipidaemia
Duration
12 weeks
Results
Flaxseed oil significantly reduced total cholesterol (-4.7%), LDL-C (-7.2%), and triglycerides compared to safflower oil control. ApoB also decreased significantly, supporting a cardioprotective lipid profile.
How They Measured It
Total cholesterol, LDL-C, HDL-C, triglycerides, ApoB
To evaluate the effect of flaxseed and flaxseed oil on lipid profiles.
Study Type
Meta-analysis
Purpose
To evaluate the effect of flaxseed and flaxseed oil on lipid profiles.
Dose
Various flaxseed/oil doses
Participants
Pooled from 28 RCTs
Duration
Various
Results
Flaxseed supplementation significantly reduced total cholesterol (-0.10 mmol/L) and LDL-C (-0.08 mmol/L). Whole flaxseed showed greater effects than flaxseed oil, likely due to additional fibre and lignan content.
How They Measured It
Pooled LDL-C, total cholesterol, and triglyceride changes across RCTs
Anti-inflammatory Effects
To assess the effect of flaxseed oil on inflammatory markers in healthy adults.
Study Type
Randomised, double-blind, placebo-controlled
Purpose
To assess the effect of flaxseed oil on inflammatory markers in healthy adults.
Dose
4 g/day ALA from flaxseed oil
Participants
88 healthy adults
Duration
12 weeks
Results
Flaxseed oil significantly reduced CRP (-50.1%) and IL-6 (-12%) compared to safflower oil. TNF-α was also modestly reduced, consistent with ALA's conversion to anti-inflammatory EPA.
How They Measured It
CRP, IL-6, TNF-α, PGE2
To investigate ALA from flaxseed oil on intestinal inflammation in a colitis model.
Study Type
Animal study
Purpose
To investigate ALA from flaxseed oil on intestinal inflammation in a colitis model.
Dose
10% dietary flaxseed oil
Participants
DSS-induced colitis mice
Duration
3 weeks
Results
Dietary flaxseed oil significantly reduced colonic inflammation, NF-κB activation, and pro-inflammatory cytokine levels in colitis mice. ALA conversion to anti-inflammatory EPA in intestinal tissue was demonstrated.
How They Measured It
Colon histopathology, pro-inflammatory cytokines, NF-κB activation
Dry Eye Syndrome
To assess flaxseed oil supplementation for dry eye disease.
Study Type
Randomised, double-blind, placebo-controlled
Purpose
To assess flaxseed oil supplementation for dry eye disease.
Dose
1,000 mg/day flaxseed oil
Participants
76 adults with dry eye syndrome
Duration
12 weeks
Results
Flaxseed oil significantly reduced OSDI scores and improved TBUT compared to placebo. Schirmer scores also showed improvement, indicating enhanced tear production.
How They Measured It
OSDI score, TBUT (tear break-up time), Schirmer test, corneal staining
Blood Pressure
To evaluate flaxseed oil supplementation on blood pressure in hypertensive patients.
Study Type
Randomised, double-blind, placebo-controlled
Purpose
To evaluate flaxseed oil supplementation on blood pressure in hypertensive patients.
Dose
2 tablespoons/day flaxseed oil
Participants
110 adults with hypertension
Duration
12 weeks
Results
Flaxseed oil supplementation significantly reduced systolic (-10 mmHg) and diastolic (-7 mmHg) blood pressure compared to placebo. Endothelial function also improved, possibly via eNOS upregulation.
How They Measured It
24-hour ambulatory blood pressure, office BP, endothelial function
To evaluate the blood pressure effects of flaxseed supplementation.
Study Type
Systematic review and meta-analysis
Purpose
To evaluate the blood pressure effects of flaxseed supplementation.
Dose
Various flaxseed sources
Participants
Pooled from 11 RCTs
Duration
Various
Results
Flaxseed supplementation produced significant reductions in both systolic (-2.85 mmHg) and diastolic (-2.39 mmHg) blood pressure. Effects were more pronounced in hypertensive subjects.
How They Measured It
Pooled systolic and diastolic BP changes across RCTs
Frequently Asked Questions
Common questions about Flaxseed Oil research
There are currently 9 peer-reviewed studies on Flaxseed Oil (Linum usitatissimum seed oil (alpha-linolenic acid)), involving 1,450 total participants. Research covers Cardiovascular health, Anti-inflammatory effects, Dry eye syndrome 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 (4 human studies, 1 animal study), and reported outcomes.
Flaxseed Oil has been researched for: Cardiovascular health, Anti-inflammatory effects, Dry eye syndrome, Blood pressure. Each area has its own body of evidence which you can explore in the study breakdowns above.
Yes, 4 out of 9 studies are human trials. The remaining 1 is an animal study. Human trials carry more weight in our evidence scoring system.
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