Supplements · Diets
dietary flaxseed decreases blood pressure
In plain terms: Does eating ground flaxseed daily lower blood pressure?
Whole milled flaxseed produces a small-to-moderate real BP reduction, largest in hypertensives (the FLAX-PAD trial is a standout). But the effect is form- and endpoint-dependent — flaxseed-OIL trials are weaker and often null on diastolic BP — so overall it's a modest, not uniformly robust, dietary effect.
📅 Last reviewed: 2026-07-14 ⓘ
Evidence ladder
How far up the ladder this claim has climbed. A high consensus on a low rung means "consistent so far," not "proven in people."
Top evidence so far: All trials, pooled (Meta-analysis)
How the studies fall
The evidence (17)
| Source | Grade | Stance | Quality | Finding |
|---|---|---|---|---|
| Nie Y et al 2025 · study_type: meta-analysis | observational | supports | low | Human-centric evidence grading of 13 flaxseed oil trials rated the evidence body for blood pressure as grade B, concluding flaxseed oil intervention significantly decreases blood pressure (no pooled mmHg figure given); duration/dose not spe |
| Caligiuri 2016 · Hypertension | RCT | supports | moderate | In the same FLAX-PAD cohort, flaxseed reduced central aortic SBP/DBP by ~10/6 mmHg in baseline-hypertensive patients, mediated by changes in plasma oxylipins. |
| Musazadeh 2025 · Diabetes Metab Syndr | meta-analysis | mixed | low | GRADE-assessed meta-analysis in diabetic patients found flaxseed effects on BP modest and of limited certainty. |
| McNabb 2024 · Curr Hypertens Rev | meta-analysis | contradicts | moderate | Flaxseed and olive oil supplementation showed uncertain/limited BP effects in normo- to stage-1 hypertensive adults. |
| Yin 2023 · Adv Nutr | meta-analysis | mixed | moderate | ALA supplementation (mainly flaxseed) modestly lowered SBP and CRP but had no significant effect on DBP and raised LDL, with benefit concentrated at 3+ g/day for 12+ weeks. |
| Pan 2009 · Am J Clin Nutr | meta-analysis | mixed | moderate | Flaxseed interventions modestly improved blood lipids (context for CVD-risk claim) with effects varying by product type and sex. |
| Rodriguez-Leyva 2013 · Hypertension | RCT | supports | high | In PAD patients, 30g/day milled flaxseed for 6 months lowered SBP ~10 and DBP ~7 mmHg vs placebo, with a 15/7 mmHg reduction in those hypertensive at baseline. ↩ SUPERSEDED — pooled in the review above, counted once |
| Sala-Vila 2022 · Adv Nutr | observational | supports | low | Review reports ALA-rich foods including flaxseed reduce blood pressure and other CVD risk factors in trials and cohorts. |
| Fazeli Moghadam E et al 2024 · study_type: meta-analysis | meta-analysis | supports | moderate | Meta-analysis of 5 RCTs in hypertensive subjects found flaxseed supplementation significantly reduced systolic BP by 8.64 mmHg (95% CI -15.41 to -1.87) and diastolic BP by 4.87 mmHg (95% CI -8.37 to -1.37); duration not specified in abstrac |
| Kunutsor SK et al 2025 · study_type: meta-analysis | observational | supports | moderate | Narrative review synthesizing flaxseed cardiometabolic trials reports BP reductions of ~2-15 mmHg systolic and 1-7 mmHg diastolic, with optimal benefit at ≥30 g/day ground whole flaxseed for ≥12 weeks. |
| Jafarpour A et al 2026 · study_type: RCT | RCT | contradicts | moderate | 68 migraine patients took 20 g/d flaxseed powder vs roasted wheat powder for 8 weeks; blood pressure was a secondary outcome and changes were not significant between groups. |
| Toulabi 2022 · Explore | RCT | supports | moderate | In hypertensive patients, flaxseed supplementation significantly reduced blood pressure, BMI, and total cholesterol versus control. |
| Mahmudiono 2022 · Phytother Res | meta-analysis | mixed | moderate | Flaxseed oil reduced systolic but not diastolic BP in metabolic-syndrome patients across pooled RCTs. |
| Musazadeh V et al 2025 · study_type: meta-analysis | meta-analysis | supports | high | Meta-analysis of 18 RCTs (22 arms, 1,209 participants) found flaxseed supplementation reduced systolic BP by 4.30 mmHg (95% CI -6.64 to -1.96) and diastolic BP by 2.50 mmHg (95% CI -3.88 to -1.12); larger effects with 10-20 week duration, w |
| Khalesi 2015 · J Nutr | meta-analysis | supports | moderate | Pooled controlled trials found flaxseed consumption reduced blood pressure, with larger effects for whole-seed and longer interventions. |
| Li 2023 · Food and Function | meta-analysis | supports | high | Pooled analysis of 33 trials (2427 participants) found flaxseed supplementation significantly reduced SBP by ~3.2 mmHg, a real but smaller aggregate effect than the flagship single trial. |
| Hasan R et al 2025 · study_type: meta-analysis | meta-analysis | supports | moderate | Meta-analysis of 18 RCTs in patients with cardiovascular risk factors found flaxseed supplementation reduced systolic BP by 4.75 mmHg (95% CI -7.05 to -2.44) and diastolic BP by 3.09 mmHg (95% CI -4.37 to -1.81); high heterogeneity (I2>90%) |
Disagree, or know a study we missed?
We grade by evidence, not opinions. The way to weigh in is to point us to a study we haven't cited (check the evidence table above first), or to flag a problem with one we have. Every submission is reviewed; if it holds up, the grade updates and shows in Science Changes Its Mind.
Opens a short form. You'll sign in with Google so submissions are tied to a real account — we don't display your identity, and we only accept a link we can verify (PubMed, DOI, ClinicalTrials.gov).
Educational only, not medical advice. Grades and scores reflect published evidence weighted by study design and quality; see the methodology.