Posted on: Monday, January 20th 2014 at 6:30 pm
Written By: Sayer Ji, Founder
A promising new study published in the journal Hypertension titled, "Potent antihypertensive action of dietary flaxseed in hypertensive patients," reveals that dietary flaxseed may represent a powerful therapeutic intervention in patients with cardiovascular disease.
Canadian researchers at St. Boniface Hospital Research Centre, Winnipeg, conducted a human clinical trial in order to test whether flaxseed would produce measurable improvements in patients with peripheral artery disease (P.A.D), a condition in which atherosclerotic plaque builds up in the arteries that carry blood to the head, organs, and limbs.
The prospective, double-blinded, placebo-controlled, randomized trial, included 110 patients who ingested a variety of foods that contained 30 grams (approximately 4 tablespoons) of milled flaxseed or placebo each day over 6 months. The purpose of their study was to "examine the effects of daily ingestion of flaxseed on systolic (SBP) and diastolic blood pressure (DBP) in peripheral artery disease patients," as hypertension is commonly associated with P.A.D.
After six months, the results of the dietary intervention were impressive:
- Blood plasma levels of the omega-3 fatty acid α-linolenic acid and enterolignans increased 2- to 50-fold in the flaxseed-fed group versus the placebo group.
- Systolic blood pressure (SBP) was ≈ 10 mm Hg lower in the flaxseed group
- Diastolic blood pressure (DBP) was ≈ 7 mm Hg lower in the flaxseed group
According to the study, "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 researchers also found that circulating α-linolenic acid levels correlated with SBP and DBP, and lignan levels correlated with changes in DBP.
The final summary concluded: "[F]laxseed induced one of the most potent antihypertensive effects achieved by a dietary intervention."
Flaxseed's health benefits are as complex as the components of the remarkable seed itself. Each component, including its fiber, lignans and omega-3 fatty acids, possess unique health benefits. In fact, over the past decade, hundreds of studies have been performed on whole flaxseed and/or its parts, revealing their value in over 100 health conditions. Top on the list of clinically confirmed health benefits are its anti-breast cancer properties, but it also contains the following properties of value in cardiovascular conditions:
- Cholesterol Modulation: Flaxseed may reduce circulating total and LDL-cholesterol levels,[i] [ii] and prevent LDL cholesterol from oxidizing, which is what renders it atherogenic (heart-disease promoting).[iii]
- Increased Blood Flow: Flaxseed consumption improves flow-mediated dilation of the arteries (brachial) and reduces blood pressure.[iv]
- C-reactive Protein Reduction: Elevated C-reactive protein is often a marker for heart disease related inflammation and associated increased risk of cardiovascular events. A flaxseed-derived lignan supplement appears to reduce C-reactive protein in type 2 diabetics – a population a far greater risk for cardiovascular disease and associated events.[v]
- Plaque Reduction: Dietary flaxseed accelerates the regression of atherosclerotic plaques in the rabbit model.[vi] It is believed that secoisolariciresinol diglucoside (SDG), a phytoestrogen present in flax, is responsible for this anti-atherosclerotic effect.[vii]
Other ways in which flaxseeds confer cardioprotective effects is through their anti-inflammatory activity, largely due to the abundance of omega-3 fatty acids they contain, and their fiber, which improves the elimination of oxidized lipids, cholesterol, fat-soluble toxins and hormone metabolites through its bile-binding action.For more information on flaxseed's remarkable heart-friendly properties, read our recent article "Evidence That Flaxseed Is A Heart Disease Reversing Food."For additional research on clinically confirmed natural alternatives to blood pressure drugs, read "Garlic Compares Favorably To A Best-Selling Blood Pressure Drug."[i] An Pan, Danxia Yu, Wendy Demark-Wahnefried, Oscar H Franco, Xu Lin. Meta-analysis of the effects of flaxseed interventions on blood lipids. Am J Clin Nutr. 2009 Aug;90(2):288-97. Epub 2009 Jun 10. PMID: 19515737[ii] An Pan, Danxia Yu, Wendy Demark-Wahnefried, Oscar H Franco, Xu Lin. Meta-analysis of the effects of flaxseed interventions on blood lipids. Am J Clin Nutr. 2009 Aug;90(2):288-97. Epub 2009 Jun 10. PMID: 19515737[iii] Rogelio U Almario, Sidika E Karakas. Lignan content of the flaxseed influences its biological effects in healthy men and women. J Am Coll Nutr. 2013 Jun ;32(3):194-9. PMID: 23885993[iv] Sheila G West, Andrea Likos Krick, Laura Cousino Klein, Guixiang Zhao, Todd F Wojtowicz, Matthew McGuiness, Deborah M Bagshaw, Paul Wagner, Rachel M Ceballos, Bruce J Holub, Penny M Kris-Etherton. Effects of diets high in walnuts and flax oil on hemodynamic responses to stress and vascular endothelial function. J Am Coll Nutr. 2010 Dec ;29(6):595-603. PMID: 21677123[v] An Pan, Wendy Demark-Wahnefried, Xingwang Ye, Zhijie Yu, Huaixing Li, Qibin Qi, Jianqin Sun, Yanqiu Chen, Xiafei Chen, Yong Liu, Xu Lin. Effects of a flaxseed-derived lignan supplement on C-reactive protein, IL-6 and retinol-binding protein 4 in type 2 diabetic patients. Br J Nutr. 2009 Apr;101(8):1145-9. PMID: 18775100[vi] Andrew A Francis, Justin F Deniset, Jose A Austria, Renee K Lavallee, Graham G Maddaford, Thomas E Hedley, Elena Dibrov, Grant N Pierce. The Effects of Dietary Flaxseed on Atherosclerotic Plaque Regression. Am J Physiol Heart Circ Physiol. 2013 Apr 12. Epub 2013 Apr 12. PMID:23585134[vii] Kailash Prasad. Natural products in regression and slowing of progression of atherosclerosis. Curr Pharm Biotechnol. 2010 Dec;11(8):794-800. PMID: 20874684