Antihypertensive Effect of Flaxseed: From Lab to Clinic

Joel M. Gore, MD

In a small, randomized trial, increased flaxseed consumption was associated with substantial reductions in blood pressure.

In animal studies, flaxseed has demonstrated antiatherogenic and anti-inflammatory properties and beneficial effects on vascular contractile function. To examine the effects of flaxseed ingestion on systolic and diastolic blood pressure (BP) in patients with peripheral arterial disease (PAD), investigators conducted a double-blind, placebo-controlled, randomized trial supported by several Canadian agricultural-industry initiatives. For 6 months, 110 PAD patients received various food products containing 30 g of milled flaxseed or placebo for daily consumption. Mean baseline BP was similar in both groups.

By 6 months, 13 patients from the flaxseed group and 11 from the placebo group had dropped out of the study. Body weight, waist circumference, and body mass index did not differ significantly between the two groups. At 1 month, plasma levels of the omega-3 fatty acid alpha-linolenic acid and enterolignans — used as biomarkers of dietary compliance — had doubled and increased tenfold, respectively, in the flaxseed group; these increases persisted through 6 months. At 6 months, systolic and diastolic BPs were lower in the flaxseed group than in the placebo group by 10 mm Hg and 7 mm Hg, respectively. Reductions in systolic and diastolic BP in the flaxseed group were greater in patients with baseline systolic BP ≥140 mm Hg than in the cohort as a whole (15/7 mm Hg vs. 7/5 mm Hg).

Citation(s):

Rodriguez-Leyva D et al. Potent antihypertensive action of dietary flaxseed in hypertensive patients. Hypertension 2013 Dec; 62:1081.