Introduction
Flaxseed is the tiny seed that comes from the flax plant. It is high in healthy fat and fiber. Flaxseed has been used to ease symptoms of menopause, lower blood pressure, and promote weight loss. It can be eaten plain or used in cooking and baking. Flaxseed can also be taken as a pill or powder.
Dosages
25 to 30 grams once daily
What Research Shows
May Be Effective
- Breast cancer —may reduce the risk B1
- Benign prostatic hyperplasia —may improve lower urinary tract symptoms A1
- Diabetes —may improve glycemic control C1
- High blood pressure —may help lower blood pressure D1-D3
- Hyperlipidemia —likely to lower total cholesterol and triglycerides E1, E2
- Menopause —may reduce symptoms and improve quality of life G1, G2
- Premenstrual syndrome (PMS) —may ease breast pain H1
- Peripheral artery disease—may lower total and LDL (“bad”) cholesterol K1
Not Enough Data to Assess
Editorial process and description of evidence categories can be found at EBSCO NAT Editorial Process.
Editorial process and description of evidence categories can be found at EBSCO NAT Editorial Process.
Safety Notes
It is likely safe for most adults to take flaxseed in small doses for a short time, but intestinal fullness and allergic reactions are possible. L1-L4 Not enough studies have been done to say whether it is safe to use for a long period. It is also not known whether it is safe to take by women who are pregnant or breastfeeding.
Interactions
Talk to your doctor about any supplements or therapy you would like to use. Some can interfere with treatment or make conditions worse.
References
REFA Benign Prostatic Hyperplasia
REFA1 Zhang W, Wang X, et al. Effects of dietary flaxseed lignan extract on symptoms of benign prostatic hyperplasia. J Med Food. 2008 Jun;11(2):207-214.
REFB Breast Cancer
REFB1 Flower G, Fritz H, et al. Flax and Breast Cancer: A Systematic Review. Integr Cancer Ther. 2014 May;13(3):181-192.
REFC Diabetes
REFC1 Pan A, Sun J, et al. Effects of a flaxseed-derived lignan supplement in type 2 diabetic patients: a randomized, double-blind, cross-over trial. PLoS One. 2007 Nov 7;2(11):e1148.
REFD High Blood Pressure
REFD1 Rodriguez-Leyva D, Weighell W, et al. Potent antihypertensive action of dietary flaxseed in hypertensive patients. Hypertension. 2013;62(6):1081-1089.
REFD2 Khalesi S, Irwin C, et al. Flaxseed consumption may reduce blood pressure: a systematic review and meta-analysis of controlled trials. J Nutr. 2015 Apr;145(4):758-765.
REFD3 Ursoniu S, Sahebkar A, et al. Effects of flaxseed supplements on blood pressure: A systematic review and meta-analysis of controlled clinical trial. Clin Nutr. 2016 Jun;35(3):615-625.
REFE Hyperlipidemia
REFE1 Pan A, Yu D, et al. Meta-analysis of the effects of flaxseed interventions on blood lipids. AM J Clin Nutr. 2009;90(2):288-297.
REFE2 Torkan M, Entezari MH, et al. Effect of flaxseed on blood lipid level in hyperlipidemic patients. Rec Recent Clin Trials. 2015;10(1):61-67.
REFF Impaired Glucose Tolerance
REFF1 Demmers A, Korthout H, et al. Effects of medicinal food plants on impaired glucose tolerance: A systematic review of randomized controlled trials. Diabetes Res Clin Pract. 2017 Sep;131:91-106.
REFG Menopause
REFG1 Dew TP, Williamson G. Controlled flax interventions for the improvement of menopausal symptoms and postmenopausal bone health: a systematic review. Menopause. 2013 Nov;20(11):1207-1215.
REFG2 Cetisli NE, Saruhan A, et al. The effects of flaxseed on menopausal symptoms and quality of life. Holist Nurs Pract. 2015;29(3):151-157.
REFH Menstruation
REFH1 Mirghafourvand M,Mohammad-Alizadeh-Charandabi S, et al. Effects of Vitex agnus and Flaxseed on cyclic mastalgia: A randomized controlled trial. Complement Ther Med. 2016;24:90-95.
REFI Metabolic Syndrome
REFI1 van den Driessche JJ, Plat J, et al. Effects of superfoods on risk factors of metabolic syndrome: a systematic review of human intervention trials. Food Funct. 2018 Apr 25;9(4):1944-1966.
REFJ Obesity
REFJ1 Mohammadi-Sartang M, Mazloom Z, et al. The effect of flaxseed supplementation on body weight and body composition: a systematic review and meta-analysis of 45 randomized placebo-controlled trials. Obese Rev. 2017;18(9):1096-1107.
REFJ2 Mohammadi-Sartang M, Mazloom Z, et al. The effect of flaxseed supplementation on body weight and body composition: a systematic review and meta-analysis of 45 randomized placebo-controlled trials. Obes Rev. 2017 Sep;18(9):1096-1107.
REFK Peripheral Artery Disease
REFK1 Ede AL, Rodriguez-Leyva D, et al. Dietary flaxseed independently lowers circulating cholesterol and lowers it beyond the effects of cholesterol-lowering medications alone in patients with peripheral artery disease. J Nutr. 2015;145(4):749-757.
REFL Safety
REFL1 Alonso L, Marcos ML, et al. Anaphylaxis caused by linseed (flaxseed) intake. J Allergy Clin Immunol. 1996 Aug;98(2):469-470.
REFL2 Tsai HH, Lin HW, et al. Evaluation of documented drug interactions and contraindications associated with herbs and dietary supplements: a systematic literature review. Int J Clin Pract. 2012 Nov;66(11):1056-1078.
REFL3 Alvarez-Perea A, Alzate -Pérez D, et al. Anaphylaxis caused by flaxseed. J Investig Allergol Clin Immunol. 2013;23(6):446-447.
REFL4 Patel A, Bahna SL. Hypersensitivities to sesame and other common edible seeds. Allergy. 2016 Oct;71(10):1405-1413.