Abstract-Flaxseed contains ω-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 ω-3 fatty acid α-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.

Dietary flaxseed has been shown to have potent antiatherogenic effects in rabbits. The purpose of the present study was to investigate the antiatherogenic capacity of flaxseed in an animal model that more closely represents the human atherosclerotic condition, the LDL receptor-deficient mouse (LDLrKO), and to identify the cellular mechanisms for these effects. LDLrKO mice were administered a regular diet (RG), a 10% flaxseed-supplemented diet (FX), or an atherogenic diet containing 2% cholesterol alone (CH) or supplemented with 10% flaxseed (CF), 5% flaxseed (CF5), 1% flaxseed (CF1), or 5% coconut oil (CS) for 24 wk. LDLrKO mice fed a cholesterol-supplemented diet exhibited a rise in plasma cholesterol without a change in triglycerides and an increase in atherosclerotic plaque formation. The CS mice exhibited elevated levels of plasma cholesterol, triglycerides, and saturated fatty acids and an increase in plaque development. Supplementation of the cholesterol-enriched diet with 10% (wt/wt) ground flaxseed lowered plasma cholesterol and saturated fatty acids, increased plasma ALA, and inhibited plaque formation in the aorta and aortic sinus compared with mice fed a diet supplemented with only dietary cholesterol. The expression of proliferating cell nuclear antigen (PCNA) and the inflammatory markers IL-6, mac-3, and VCAM-1 was increased in aortic tissue from CH and CS mice. This expression was significantly reduced or normalized when flaxseed was included in the diet. Our results demonstrate that dietary flaxseed can inhibit atherosclerosis in the LDLrKO mouse through a reduction of circulating cholesterol levels and, at a cellular level, via antiproliferative and anti-inflammatory actions.

From a consumer's perspective, ingesting 2 capsules of any of these oils in an attempt to achieve cardiovascular health benefits may not provide the desired or expected result over a 3 month period.

Abstract-In a randomized, double-blinded, controlled clinical trial, participants with peripheral arterial disease (75% hypertensive) consumed 30 g of milled flaxseed/d for 6 months. The flaxseed group exhibited significant reductions in systolic (−10 mm Hg) and diastolic (−7 mm Hg) blood pressure. Flaxseed contains the n3 fatty acid α-linolenic acid. Plasma α-linolenic acid increased with ingestion of flaxseed and was inversely associated with blood pressure. However, the antihypertensive mechanism was unclear. Oxylipins derived from polyunsaturated fatty acids regulate vascular tone. Therefore, the objective was to examine whether flaxseed consumption altered plasma oxylipins in a manner that influenced blood pressure. Plasma of FlaxPAD (Flaxseed for Peripheral Arterial Disease) participants underwent solid phase extraction and high-performance liquid chromatography-mass spectrometry/mass spectrometry analysis. The flaxseed group exhibited significant decreases in 8 plasma oxylipins versus control. Six of these (5,6-, 8,9-, 11,12-, 14,15-dihydroxyeicosatrienoic acid and 9,10-and 12,13-dihydroxyoctadecenoic acid) were products of soluble epoxide hydrolase, a pharmacological target for antihypertensive treatment. Patients exhibiting a decrease in total plasma soluble epoxide hydrolase-derived oxylipins, exhibited a significant decrease in systolic blood pressure (mean [ and infarction size 23 in animal models. The proposed relationship between epoxygenase-derived oxylipins and hypertension is depicted in Figure 1.95%To test the hypothesis that flaxseed decreased the levels of oxylipins associated with inflammation and vasoconstriction, the study objectives were 3-fold: (1) to characterize and quantify the plasma oxylipin profile of participants with PAD, (2) to compare changes in plasma oxylipin concentrations in the control and flaxseed groups, and (3) to determine the mechanism whereby any changes in oxylipins may have influenced blood pressure in the FlaxPAD Trial. Methods Participants and Food ProductsA randomized, double-blinded, parallel, controlled clinical trial was established to determine the cardiovascular effects of dietary flaxseed in patients with PAD.24 Seventy-five percent of the participants were diagnosed as hypertensive at baseline (blood pressure ≥140/90 mm Hg).2,24 Participants (n=110) consumed food products containing either 30 g of milled flaxseed (treatment) or a combination of mixed dietary oils, milled wheat, and bran (control) for 6 months. Further details of the food product composition, 25,26 participant enrollment, intervention allocation, clinical characteristics, and blood pressure outcomes have been previously published.2,24 The trial is available at http://www.clinicaltrials.gov/ct2/show/NCT00781950?term=grant+p ierce+flax&rank=1.All participants provided informed consent, and all procedures were performed according to institutional guidelines. The trial was approved by Health Canada and its Natural Health Product Directorate, the University of Manitoba Research Ethics Board,...