Key Findings:
The PADFlax trial found that 30 g/d of ground flaxseed reduced blood pressure in patients with peripheral arterial disease and uncontrolled hypertension by 15 mmHg (systolic) and 7 mmHg (diastolic) after 6 months. The effects appeared to be greater than the blood pressure lowering effects of the individual components of flaxseed (ALA, lignans and fiber) when tested in isolation. Reduction of 7 mm Hg in DBP and 10 mm Hg in SBP could translate into decreases of 46% and 29%, and 36% and 27% in the incidence of stroke and coronary heart disease, respectively. The research strongly recommends that flaxseed be part of the dietary regime for controlling hypertension.
ABSTRACT:
Flaxseed contains omega-3 fatty acids, lignans, and fiber that together may provide benefits to patients with cardiovascular disease. Animal work identified that patients with peripheral artery disease may particularly benefit from dietary supplementation with flaxseed. Hypertension is commonly associated with peripheral artery disease. The purpose of the study was to examine the effects of daily ingestion of flaxseed on systolic (SBP) and diastolic blood pressure (DBP) in peripheral artery disease patients. In this prospective, double-blinded, placebo-controlled, randomized trial, patients (110 in total) ingested a variety of foods that contained 30 g of milled flaxseed or placebo each day over 6 months. Plasma levels of the omega-3 fatty acid alpha-linolenic acid and enterolignans increased 2- to 50-fold in the flaxseed-fed group but did not increase significantly in the placebo group. Patient body weights were not significantly different between the 2 groups at any time. SBP was ≈ 10 mm Hg lower, and DBP was ≈ 7 mm Hg lower in the flaxseed group compared with placebo after 6 months. Patients who entered the trial with a SBP ≥ 140 mm Hg at baseline obtained a significant reduction of 15 mm Hg in SBP and 7 mm Hg in DBP from flaxseed ingestion. The antihypertensive effect was achieved selectively in hypertensive patients. Circulating alpha-linolenic acid levels correlated with SBP and DBP, and lignan levels correlated with changes in DBP. In summary, flaxseed induced one of the most potent antihypertensive effects achieved by a dietary intervention. (Authors Abstract)