Three-week psyllium-husk supplementation: effect on plasma cholesterol concentrations, fecal steroid excretion, and carbohydrate absorption in men.

This study was conducted to determine the effect of psyllium husk on plasma total and lipoprotein cholesterol in healthy human subjects and to elucidate possible hypocholesterolemic mechanisms. Seven males were given a nutritionally controlled diet based on their usual intake for x = 3 wk followed by 3 wk in which 21 g/d per person psyllium husk was added to the basal diet. After 10 d and after 3 wk of psyllium supplementation, total, low-density, and high-density cholesterol were reduced (p less than 0.002, p less than 0.01, and p less than 0.03, respectively). Fecal steroid excretion, determined from 5-d collections, was not affected by psyllium supplementation. Although psyllium tended to delay lipid absorption, plasma triglycerides, retinyl esters, glucose, insulin, and glucagon quantitated during meal tolerance tests given on the last day of each diet period were not different (p greater than 0.05). Thus the cholesterol-lowering mechanism of psyllium may not involve increased bile acid excretion or decreases in nutrient absorption.