At 41 percent unsaturated fat, 28 percent fiber and 20 percent protein, the diminutive flaxseed, provides a powerful nutritional package for the discerning health-conscious person. The health benefits of flaxseed have been broadly studied and and many of its purported health effects, including its ability to lower blood pressure, have substantiated.
Flaxseed vs. Walnuts
Supplementation with flaxseed lowers blood pressure and several other symptoms associated with metabolic syndrome -- a condition that increases risk for cardiovascular disease and diabetes, according to a study published in the November 2010 "Journal of Nutrition." Study participants ate diets supplemented with 30 g per day of flaxseed or 30 g per day of walnuts for 12 weeks. Metabolic syndrome decreased by 20 percent and 16 percent, respectively. Weight, waist circumference, blood sugar, cholesterol and blood pressure all decreased significantly in both the flaxseed and walnut groups. The researchers noted that lifestyle counseling also produced good results at decreasing the symptoms of metabolic syndrome, in the study.
Flaxseed Protein
A study published in the April 2010 "Journal of Agricultural and Food Chemistry" found considerable antioxidant and blood pressure-lowering properties of a protein extract of flaxseed. The flaxseed extract inhibited angiotensin-converting enzyme -- an enzyme involved in regulating blood pressure, showed free-radical scavenging activity and protected the essential fatty acid linoleic acid from oxidation. The researchers concluded good potential for flaxseed protein extract to be incorporated into foods to improve their nutritional value.
Safe But Ineffective
A short-term study found flaxseed safe but ineffective at lowering blood pressure or cholesterol. In the study, published in the March 2005 "Journal of Cardiovascular Pharmacology," volunteers aged 22 to 47 years ate three flaxseed muffins per day, totalling 32.7 g of flaxseed for four weeks. Blood pressures, heart rate, red and white blood cell counts were unaffected by the flaxseed supplemented diets. The researchers also noted that cholesterol levels were unchanged, however triglycerides increased. No adverse effects were observed on the liver or kidneys as a result of the flaxseed diet.
Metabolic Syndrome
Flaxseed lowers diastolic blood pressure and improves metabolic syndrome in men, says a study published in the April 2009 "Applied Physiology, Nutrition and Metabolism." Participants in the study took 543 mg per day of flax seed lignan -- compounds in flax seed that have estrogenic and antioxidant properties -- for six months while also engaging in an exercise program of walking. Significant reduction in diastolic blood pressure -- the bottom number of the blood pressure ratio -- was observed. The program of flax seed lignan and walking did not improve body mass or cholesterol levels compared to placebo and women in the study did not show reductions in metabolic syndrome parameters, note the researchers.
References
- "Journal of Nutrition"; Lifestyle counseling and supplementation with flaxseed or walnuts influence the management of metabolic syndrome. Wu H, et al.; 2010
- "Journal of Agricultural and Food Chemistry"; Antioxidant and angiotensin converting enzyme-inhibitory properties of a flaxseed protein-derived high Fischer ratio peptide mixture. Udenigwe CC, et al.; 2010
- "Journal of Cardiovascular Pharmacology and Therapeutics"; Effect of flaxseed consumption on blood pressure, serum lipids, hemopoietic system and liver and kidney enzymes in healthy humans. Stuglin C, et al.; 2005
- "Applied Physiology Nutrition and Metabolism"; A randomized controlled trial of the effects of flaxseed lignan complex on metabolic syndrome composite score and bone mineral in older adults. Cornish SM, et al.; 2009
