Effect of plant sterols and glucomannan on lipids in individuals with and without type II diabetes

Objective: The purpose of this study was to determine whether supplements of plant sterols and/or glucomannan improve lipid profile and cholesterol biosynthesis in mildly hypercholesterolemic type II diabetic and non-diabetic subjects and to compare the response of these two subject groups to the treatments. Design: A randomized, crossover study consisting of four phases of 21 days, with each phase separated by a 28-day washout. Setting: The Mary Emily Clinical Nutrition Research Unit of McGill University. Subjects: Eighteen non-diabetic individuals and 16 type II diabetic individuals aged 38 - 74 years. Interventions: Subjects were supplemented with plant sterols (1.8 g/day), glucomannan ( 10 g/day), a combination of glucomannan and plant sterols, and a placebo, provided in the form of bars. Results: Overall plasma cholesterol concentrations were lowered (P<0.05) after combination treatment (4.72 +/- 0.20 mmol/l) compared to control (5.47 +/- 0.18 mmol/l). Plasma low-density lipoprotein (LDL) cholesterol concentrations were decreased ( P<0.05) after glucomannan (3.16 +/- 0.14 mmol/l) and combination treatments (2.95 +/- 0.16 mmol/l) compared to control (3.60 +/- 0.16 mmol/l). The results of lipid profiles did not differ between subject groups. Overall plasma lathosterol concentrations, an index of cholesterol biosynthesis, were lowered (P<0.05) after the combination treatment compared to the plant sterol treatment. Conclusions: The results suggest that glucomannan and a combination of glucomannan and plant sterols substantially improves plasma LDL cholesterol concentrations.