Dietary flaxseed lignan extract lowers plasma cholesterol and glucose concentrations in hypercholesterolaemic subjects

• Published in: British journal of nutrition Vol. 99; no. 6; pp. 1301 - 1309
• Main Authors: Zhang, Wei, Wang, Xiaobing, Liu, Yi, Tian, Haimei, Flickinger, Brent, Empie, Mark W., Sun, Sam Z.
• Format: Journal Article
• Language: English
• Published: Cambridge, UK Cambridge University Press 01.06.2008
• Subjects: administration & dosage; Adult; adults; Alanine Transaminase; Alanine Transaminase - blood; analysis; Biological and medical sciences; blood; blood glucose; Blood Glucose - analysis; Butylene Glycols; Butylene Glycols - administration & dosage; Cholesterol; Cholesterol - blood; Cholesterol, HDL; Cholesterol, HDL - blood; Cholesterol, LDL; Cholesterol, LDL - blood; Creatinine; Creatinine - blood; diet therapy; Dietary Fiber; Dietary Fiber - administration & dosage; dietary nutrient sources; dose response; Double-Blind Method; enterodiol; enterolactone; Feeding. Feeding behavior; Female; Flax; Flaxseed lignans; Fundamental and applied biological sciences. Psychology; gamma-Glutamyltransferase; gamma-Glutamyltransferase - blood; Genetic diversity; Glucose; Glucosides; Glucosides - administration & dosage; Humans; hypercholesterolemia; Hypercholesterolemia - blood; Hypercholesterolemia - diet therapy; lignans; Linear Models; linseed; Lipids; Male; Middle Aged; Nitrogen; Nitrogen - blood; Nutrition; nutritional intervention; plant estrogens; Plant Extracts; Plant Extracts - administration & dosage; Plasma; Secoisolariciresinol diglucoside; Studies; Triglycerides; Triglycerides - blood; Urea; Urea - blood; Vertebrates: anatomy and physiology, studies on body, several organs or systems; Secoisolariciresinol diglucoside; Glucose; Cholesterol; Flaxseed lignans; Human; Vertebrata; Mammalia; Lipids; Lignan; Extract; Concentration; Flaxseed lignans: Secoisolariciresinol diglucoside: Cholesterol: Glucose; Blood plasma
• ISSN: 0007-1145; 1475-2662; 1475-2662
• DOI: 10.1017/S0007114507871649

Lignans, derived from flaxseed, are phyto-oestrogens being increasingly studied for their health benefits. An 8-week, randomised, double-blind, placebo-controlled study was conducted in fifty-five hypercholesterolaemic subjects, using treatments of 0 (placebo), 300 or 600 mg/d of dietary secoisolariciresinol diglucoside (SDG) from flaxseed extract to determine the effect on plasma lipids and fasting glucose levels. Significant treatment effects were achieved (P < 0·05 to < 0·001) for the decrease of total cholesterol (TC), LDL-cholesterol (LDL-C) and glucose concentrations, as well as their percentage decrease from baseline. At weeks 6 and 8 in the 600 mg SDG group, the decreases of TC and LDL-C concentrations were in the range from 22·0 to 24·38 % respectively (all P < 0·005 compared with placebo). For the 300 mg SDG group, only significant differences from baseline were observed for decreases of TC and LDL-C. A substantial effect on lowering concentrations of fasting plasma glucose was also noted in the 600 mg SDG group at weeks 6 and 8, especially in the subjects with baseline glucose concentrations ≥ 5·83 mmol/l (lowered 25·56 and 24·96 %; P = 0·015 and P = 0·012 compared with placebo, respectively). Plasma concentrations of secoisolariciresinol (SECO), enterodiol (ED) and enterolactone were all significantly raised in the groups supplemented with flaxseed lignan. The observed cholesterol-lowering values were correlated with the concentrations of plasma SECO and ED (r 0·128–0·302; P < 0·05 to < 0·001). In conclusion, dietary flaxseed lignan extract decreased plasma cholesterol and glucose concentrations in a dose-dependent manner.