Flax: A Wealth Of ALA And LignansMarch 2014
Flaxseed’s abundance of the essential fatty acid alpha-linolenic acid (ALA) and fiber, combined with being the richest dietary source of antioxidant lignans in the human diet, translates into additional health benefits beyond those of other seeds.1 This unique nutritional profile offers unparalleled protection against metabolic syndrome, cardiovascular disease, and cancer.
The flax plant (Linum usitatissimum) belongs to the Linaceae family and has been coveted since the Stone Age for its versatility. In addition to its culinary use, flaxseed was believed to alleviate numerous health ailments such as constipation and respiratory infections. And flax fibers were processed to produce linen, a textile used to manufacture clothing, table coverings, and body armor for European countries and the United States beginning in the late 16th century. The three different flaxseed forms include whole, ground, and oil. Today, the major world producers of flaxseed are Canada, France, Russia, and Argentina.1
Guards Against Cardiovascular Disease
It is well understood that chronic inflammation is a significant contributor to the development of atherosclerosis. The plant-based omega-3 fatty acid ALA found in flaxseed has been shown to combat the process by decreasing the production of inflammatory cytokines. This was demonstrated in a 4-week human study where flaxseed oil use during food preparation inhibited the synthesis of tumor necrosis factor alpha (TNF alpha) and interleukin-1 beta by 30%.2
Multiple studies confirm the ability of flaxseed to lower blood pressure, especially in high-risk patients. Participants with peripheral artery disease ingesting 30 grams of flaxseed for 6 months significantly reduced their mean systolic blood pressure by 10 mmHg and diastolic blood pressure by 7 mmHg, compared to a placebo.3 And flaxseed oil supplementation for 12 weeks dropped both systolic and diastolic blood pressure by an average of 5 mmHg in dyslipidemic patients.4
Lowering total cholesterol and LDL cholesterol is another cardiovascular benefit of flaxseed consumption, according to a meta-analysis reported in the American Journal of Clinical Nutrition.5
Combats Insulin Resistance And Metabolic Syndrome
Insulin resistance, or the inability of the hormone insulin to increase glucose uptake and utilization in cells, is the driving force behind metabolic syndrome, a collection of health risk factors that include central obesity, high blood sugar, elevated triglycerides, low HDL cholesterol, and hypertension.6 It is estimated that around one-third of Americans have the condition, with the prevalence increasing with age and body mass index (BMI).7
Flaxseed shows great promise in reducing insulin resistance by modulating oxidative stress. In a human study involving overweight and obese glucose intolerant subjects, a diet supplemented with 40 grams of ground flaxseed daily for 12 weeks resulted in a 34.7% decrease in a measure of insulin resistance compared to baseline, thereby enhancing insulin sensitivity.8 This appears to result from favorable effects on oxidative stress as evidenced by a significant reduction in lipid peroxidation levels.8
To evaluate the efficacy of flaxseed supplementation in conjunction with a healthy lifestyle on managing metabolic syndrome, Chinese researchers conducted a randomized, controlled trial with 283 participants who met the criterion of three or more risk factors for the condition.9 Subjects were assigned to one of the following three groups for 12 weeks:
- Lifestyle counseling consisting of a low-fat diet, increased intake of fruits and vegetables, and limited alcohol;
- Lifestyle counseling plus 30 grams of flaxseed-enriched bread; or
- Lifestyle counseling plus 30 grams of walnuts.
Compared to baseline, 26.6% of subjects in the flaxseed group no longer met the criteria for metabolic syndrome at the end of the study, the highest of all groups. Equally noteworthy, central obesity was reversed in 19.2% of participants in the flaxseed group, compared to only 6.3 and 16% in the LC and walnut groups, respectively. This demonstrates the potential anti-obesity effects of flaxseed supplementation.9
Unlike most foods, flaxseed offers a multi-targeted approach to attacking cancer. Research has shown that flaxseed acts as a cancer-preventing agent through several modes of action including protecting against DNA damage,10 inhibiting angiogenesis (new blood vessel growth),11 reducing inflammation,12 and blocking cell proliferation.13
Epidemiological evidence reveals that higher intakes of flaxseed and flax bread cut the risk of breast cancer by 18 and 23%, respectively.14 Flaxseed consumption has been shown to increase levels of endostatin, a natural tumor angiogenesis inhibitor, in breast tissue comparable to the chemotherapy drug tamoxifen. This is an intriguing finding, since it suggests that flaxseed might provide some of the same benefits as tamoxifen without the potential side effects.15
In a study reported in the American Journal of Clinical Nutrition, postmenopausal women supplemented with 25 grams of flaxseed for 16 weeks saw a significant increase in the conversion of estrogen to 2-hydroxyestrone, a weak form of estrogen that decreases the risk for breast cancer.16 In patients with newly diagnosed breast cancer, the same dose of flaxseed enhanced apoptosis (programmed cell death) by 30.7%, whereas women taking a placebo showed no changes.17
Emerging evidence indicates that flaxseed might have a protective effect against prostate cancer. Researchers at the University of Texas discovered that 30 grams of flaxseed alone or as part of a low-fat diet significantly reduced tumor growth, compared to a low-fat diet or control in men with prostate cancer.13
Type II Diabetes Management
The primary target of nutritional therapy for type II diabetics is controlling blood sugar levels, since their chronic elevation is linked with numerous diabetic complications. In the laboratory, researchers discovered that lignans in flaxseed decrease the activity of alpha-amylase, an enzyme that breaks down starch into glucose.18 Patients incorporating 5 grams of flaxseed gum into their food daily for three months slashed blood sugar levels by 11.7%, from a mean average of 154 to 136 mg/dL.19
Type II diabetics are at increased risk for heart disease due to the typical presence of low HDL cholesterol and elevated triglycerides. This triglyceride/HDL ratio is an accurate predictor of cardiac events such as a heart attack.20 Diabetic participants treated with10 grams of flaxseed powder without any other dietary change experienced a decrease of 17.5% in triglycerides and an 11.9% increase in beneficial HDL cholesterol in just one month, thus improving their triglyceride/HDL ratio.21
One of the most common long-term complications of type II diabetes is diabetic nephropathy (kidney damage), a condition that precedes chronic kidney disease. Flaxseed supplementation was shown to be an effective strategy for reducing protein in the urine (proteinuria) and preserving renal function in an animal model of diabetic nephropathy.22 While these results are compelling, human studies are needed.
A wealth of scientific data demonstrates the remarkable impact of flaxseed supplementation against cardiovascular disease, metabolic syndrome, and cancer. Additionally, flaxseed shows great promise in managing type IIdiabetes and its complications. Opt for ground flaxseed over its whole counterpart since it is superior for digestion and absorption of nutrients.1
If you have any questions on the scientific content of this article, please call a Life Extension® Health Advisor at 1-866-864-3027.
- Available at: http://www.whfoods.com/ genpage.php?tname=foodspice&dbid=81. Accessed May 1, 2013.
- Caughey GE, Mantzioris E, Gibson RA, Cleland LG, James MJ. The effect on human tumor necrosis factor alpha and interleukin 1 beta production of diets enriched in n-3 fatty acids from vegetable oil or fish oil. Am J Clin Nutr. 1996;63(1):116-22.
- Available at: http://www.theheart.org/article/1470929.do. Accessed May 2, 2013.
- Paschos GK, Magkos F, Panagiotakos DB, Votteas V, Zampelas A. Dietary supplementation with flaxseed oil lowers blood pressure in dyslipidaemic patients. Eur J Clin Nutr. 2007 Oct;61(10):120-6.
- Pan A, Yu D, Demark-Wahnefried W, Franco OH, Lin X. Meta-analysis of the effects of flaxseed interventions on blood lipids. Am J Clin Nutr. 2009 Aug;90(2):288-97.
- Available at: http://www.racgp.org.au/afp/2013/august/the-metabolic-syndrome/. Accessed August 29, 2013.
- Mozumdar A, Liguori G. Persistent increase of prevalence of metabolic syndrome among U.S. adults: NHANES III TO NHANES 1999-2006. Diabetes Care. 2011 Jan;34(1):216-9.
- Rhee Y, Brunt A. Flaxseed supplementation improved insulin resistance in obese glucose intolerant people: a randomized crossover design. Nutr J. 2011 May;44(10): 1186-1201.
- Wu H, Pan A, Yu Z, et al. Lifestyle counseling and supplementation with flaxseed or walnuts influence the management of metabolic syndrome. J Nutr. 2010 Nov;140(11):1937-42.
- Hu C, Yuan YV, Kitts DD. Antioxidant activities of the flaxseed lignan secoisolariciresinol diglucoside, its aglycone secoisolariciresinol and the mammalian lignans enterodiol and enterolactone in vitro. Food Chem Toxicol. 2007 Nov;45(11):2219-27.
- Bergman Jungeström M, Thompson LU, Dabrosin C. Flaxseed and its lignans inhibit estradiol-induced growth, angiogenesis, and secretion of vascular endothelial growth factor in human breast cancer xenografts in vivo. Clin Cancer Res. 2007 Feb 1;13(3):1061-7.
- Kaithwas G, Mukherjee A, Chaurasia AK, Majumdar DK. Anti-inflammatory, analgesic and antipyretic activities of Linum usitatissimum L. (flaxseed/linseed) fixed oil. Indian J Exp Biol. 2011 Dec;49(12):932-8.
- Denmark-Wahnefried W, Polascik TJ, George SL, et al. Flaxseed supplementation (not dietary fat restriction) reduces prostate cancer proliferation rates in men presurgery. Cancer Epidemiol Biomarkers Prev.2008 Dec;17(12):3577-87.
- Lowcock EC, Cotterchio M, Boucher BA. Consumption of flaxseed, a rich source of lignans, is associated with reduced breast cancer risk. Cancer Causes Control. 2013 Apr;24(4):813-6.
- Aberg UWN, Saarinen N, Abrahamsson A, Nurmi T, Engblom S, Dabrosin C. Tamoxifen and flaxseed alter angiogenesis regulators in normal human breast tissue in vivo. PLoS One. 2011;6(9):e25720.
- Brooks JD, Ward WE, Lewis JE, et al. Supplementation with flaxseed alters estrogen metabolism in postmenopausal women to a greater extent than does supplementation with an equal amount of soy. Am J Clin Nutr. 2004 Feb;79(2):318-25.
- Thompson LU, Chen JM, Li T, Strasser-Weippi K, Goss PE. Dietary flaxseed alters tumor biological markers in postmenopausal breast cancer. Clin Cancer Res. 2005 May;11(10):3828-35.
- Hano C, Renouard S, Molinie R, Corbin C, Barakzoy E, Doussot J, Lamblin F, Laine E. Flaxseed (Linum usitatissimum L.) extract as well as (+)-secoisolariciresinol diglucoside and its mammalian derivatives are potent inhibitors of a-amylase activity. Bioorg Med Chem Lett. 2013 May;23(10):3007-12.
- Thakur G, Mitra A, Pal K, Rousseau D. Effect of flaxseed gum on reduction of blood glucose and cholesterol in type2 diabetic patients. Int J Food Sci Nutr. 2009;60:126-36.
- Gaziano JM, Hennekens CH, O’Donnell CJ, Breslow JL, Buring JE. Fasting triglycerides, high-density lipoprotein, and risk of myocardial infarcation. Circulation. 1997;96:2520-5.
- Mani UV, Mani I, Biswas M, Kumar SN. An open-label study on the effect of flax seed powder (Linum usitatissimum) supplementation in the management of diabetes mellitus. J Diet Suppl. 2011 Sept;8(3):257-65.
- Velasquez MT, Bhathena SJ, Ranich T, et al. Dietary flaxseed meal reduces proteinuria and ameliorates nephropathy in animal model of type II diabetes mellitus. Kidney Int. 2003;64:2100-7.
- Available at: http://nutritiondata.self.com/facts/nut-and-seed-products/3163/2. Accessed May 1, 2013.