Flaxseed (linseed)
Whole-food source of α-linolenic acid, lignans, and viscous fibre, meta-analysis signal for blood pressure and LDL.
Why
Flaxseed (Linum usitatissimum) provides three potentially-relevant constituents: α-linolenic acid (the plant omega-3), lignans (the highest dietary source of secoisolariciresinol diglucoside), and soluble fibre. Meta-analyses of RCTs report systolic blood pressure reductions of 2–4 mmHg, modest LDL reductions, and improved glycaemic markers in type 2 diabetes. Ground flaxseed is more bioavailable than whole; oil delivers ALA but not lignans or fibre.
How it works
α-Linolenic acid is partially converted to EPA (~5–10% conversion), partial replication of fish-oil cardiovascular effects. Lignans modulate oestrogen metabolism and have mild SERM activity. Soluble fibre binds bile acids, modest LDL reduction.
Expected onset · BP effects over 6–12 weeks; lipid effects over 8–12 weeks
How to take
Dosage
30 g/day ground flaxseed (about 2 tablespoons), or 1 tablespoon flaxseed oil for ALA only. BP and lipid trials use 30–50 g/day.
Timing
With meals; mix into yogurt, porridge, smoothies. Refrigerate after grinding (rapid oxidation).
On the label
Ground flaxseed (or whole, ground at home) for full benefit. Cold-pressed oil for ALA. Flaxseed lignan concentrate (secoisolariciresinol) is a distinct supplement.
Ideal for
Adults with mild hypertension, mild dyslipidaemia, or seeking plant-source omega-3 (especially vegetarians/vegans).
Safety
Evidence
Ursoniu 2016 Clin Nutr meta-analysis (15 RCTs): flaxseed reduced systolic BP by 2.85 mmHg and diastolic by 2.39 mmHg, with effect larger (5–7 mmHg) in longer trials and in hypertensives. Pan 2009 Am J Clin Nutr meta-analysis (28 trials): whole flaxseed reduced LDL by 0.10 mmol/L on average; oil alone did not. Whole seed beats oil for lipid effect.
Where to get it
Shop Flaxseed (linseed) on AmazonSponsored · As an Amazon Associate, Healicus earns from qualifying purchases.