Dietary sitostanol related to absorption, synthesis and serum level of cholesterol in different apolipoprotein E phenotypes.
Effects of small amounts of sitosterol, sitostanol and sitostanol esters (< 1 g/day of free sterols) dissolved in rapeseed oil (RSO) were studied on serum lipids and cholesterol metabolism in patients with primary hypercholesterolemia and different apolipoprotein E phenotypes on an RSO diet. One of the four groups was an RSO-fed control. Serum total and LDL cholesterol reductions were small in different plant sterol-fed groups, tended to be highest in the sitostanol ester group (-7%), but were significantly reduced by about 5% in the combined plant sterol groups. The reductions were -8% in the subjects with epsilon 4 allele and insignificant in those with apo E3/3 phenotype. Cholesterol precursor sterols in serum, markers of cholesterol synthesis, were increased only in the subjects with epsilon 4 allele. Cholesterol absorption was reduced by 7%, being 31% in the subjects with epsilon 4 allele, and fecal elimination of cholesterol was increased, a finding also indicating increased cholesterol synthesis. The changes in cholesterol absorption were related to those in fecal plant sterols (change in dietary intake) and serum total and LDL cholesterol (P = 0.04, 0.01 and 0.05, respectively). Thus, small amounts of dietary plant sterols (< 1 g/day), especially sitostanol esters dissolved in dietary fats, decrease serum total and LDL cholesterol by a proportional decrease in cholesterol absorption which, in turn, is associated with a compensatory increase in cholesterol synthesis. The effects are most consistent in subjects with epsilon 4 allele, but for effective hypocholesterolemic treatment dietary amount of sitostanol ester should exceed 1 g/day.
Miettinen
T A
TA
Second Department of Medicine, University of Helsinki, Finland.
Vanhanen
H
H
D000042:Absorption; D000328:Adult; D001057:Apolipoproteins E / Q000235:genetics*; D001937:Brassica; D002784:Cholesterol / Q000378:metabolism*; D008076:Cholesterol, HDL / Q000097:blood; D008078:Cholesterol, LDL / Q000097:blood; D004311:Double-Blind Method; D005229:Fatty Acids, Monounsaturated; D005260:Female; D006801:Humans; D006937:Hypercholesterolemia / Q000235:genetics / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D010641:Phenotype; D010938:Plant Oils / Q000008:administration & dosage; D000074262:Rapeseed Oil; D012855:Sitosterols / Q000008:administration & dosage / Q000494:pharmacology*; D014280:Triglycerides / Q000097:blood
D001057:Apolipoproteins E; D008076:Cholesterol, HDL; D008078:Cholesterol, LDL; D005229:Fatty Acids, Monounsaturated; D010938:Plant Oils; D000074262:Rapeseed Oil; D012855:Sitosterols; D014280:Triglycerides; C025473:gamma-sitosterol; D002784:Cholesterol; C021255:stigmastanol