title: Effects of psyllium hydrophilic mucilloid on LDL-cholesterol and bile acid synthesis in hypercholesterolemic men.
abstract: The goal of the current study was to determine the mechanism of the hypocholesterolemic effect of psyllium using a randomized, double-blind, crossover design. Twenty males (age 44 +/- 4 yr, weight 79 +/- 10 kg) with moderate hypercholesterolemia (total 265 +/- 17 mg/dl, low density lipoprotein (LDL) 184 +/- 15 mg/dl) were studied at baseline (B) and after randomization to receive a 40-day course of 15 g/day of either psyllium (Ps) or placebo (Pl) (cellulose). After a washout period (11 +/- 2 days), subjects were crossed over to the other fiber treatment for an additional 40 days and restudied. Intestinal cholesterol absorption, cholesterol synthesis in isolated peripheral blood mononuclear cells, bile acid kinetics, gallbladder motility, and intestinal transit were measured at each study period. Psyllium lowered LDL cholesterol (x:184 (B), 169 (Ps), and 179 (Pl) mg/dl; Ps vs. B,Pl: P less than 0.004, P less than 0.02), decreased relative cholesterol absorption (x:51 (B), 45 (Ps), and 49 (Pl) %; Ps vs. B,Pl: P less than 0.03, P less than 0.03), did not alter absolute cholesterol absorption, and increased the fractional turnover of both chenodeoxycholic acid (x:0.176 (B), 0.203 (Ps), and 0.170 (Pl) day-1; Ps vs. B,Pl: P less than 0.0001, P less than 0.01) and cholic acid (x:0.303 (B), 0.411 (Ps), and 0.301 (Pl) d-1; Ps vs. B, Pl: P less than 0.006, P less than 0.002). Bile acid synthesis increased in subjects whose LDL cholesterol was lowered by more than 10% (Ps vs. B: 1304 +/- 489 vs 992 +/- 307 mumol/day, P less than 0.006; Ps vs. PI: 1304 +/- 489 vs. 914 +/- 321 mumol/day, P less than 0.0002). We conclude that psyllium lowers LDL cholesterol primarily via stimulation of bile acid synthesis.
authors.affiliation: Section of Hepatology, University of Colorado School of Medicine, Denver 80262.
authors.forename: G T
authors.initials: GT
authors.lastname: Everson
authors.forename: B P
authors.initials: BP
authors.lastname: Daggy
authors.forename: C
authors.initials: C
authors.lastname: McKinley
authors.forename: J A
authors.initials: JA
authors.lastname: Story
mesh_terms: D000328:Adult; D001647:Bile Acids and Salts / Q000378:metabolism*; D001835:Body Weight; D002482:Cellulose / Q000494:pharmacology; D002784:Cholesterol / Q000378:metabolism; D008078:Cholesterol, LDL / Q000378:metabolism*; D003672:Defecation; D004032:Diet; D005704:Gallbladder / Q000187:drug effects / Q000502:physiology; D005772:Gastrointestinal Transit / Q000187:drug effects; D006801:Humans; D006937:Hypercholesterolemia / Q000378:metabolism* / Q000628:therapy; D008055:Lipids / Q000097:blood; D008297:Male; D008875:Middle Aged; D010349:Patient Compliance; D011620:Psyllium / Q000494:pharmacology*; D016032:Randomized Controlled Trials as Topic
chemical_list: D001647:Bile Acids and Salts; D008078:Cholesterol, LDL; D008055:Lipids; D011620:Psyllium; D002482:Cellulose; D002784:Cholesterol