Will recommended changes in fat and fibre intake affect cholesterol absorption and sterol excretion? An ileostomy study.
OBJECTIVE
To study cholesterol absorption and excretion in ileostomy subjects with different intakes of saturated fat and dietary fibre.


METHODS
Short-term experimental study, with four controlled diets in repeated measurements.


METHODS
Out-patients at metabolic-ward kitchen.


METHODS
Nine healthy volunteers with conventional ileostomy after colectomy because of ulcerative colitis.


METHODS
Four diet periods, each of 3 days duration: high saturated fat and low dietary fibre (STAND); reduced saturated fat (RESAT); high saturated fat and high fibre (FATFIB); and reduced saturated fat and high fibre (RESATFIB).


METHODS
Absorption of cholesterol, and ileal excretion of cholesterol, bile acids, fat and energy. Differences between diets evaluated with Friedman's two-way analysis of variance by rank sum with Bonferroni adjustment, and post hoc differences assessed by rank sum comparison.


RESULTS
RESAT and RESATFIB reduced fractional cholesterol absorption by 7% and 10%; RESATFIB and FATFIB increased net cholesterol excretion by 46% and 54% respectively. Further, RESATFIB increased net sterol excretion by 18%, all compared to STAND (P<0.05 for all). All three intervention diets contained more phytosterols than STAND (P<0.05), and the phytosterol content was inversely correlated to fractional cholesterol absorption (r=-0.77, P<0.01).


CONCLUSIONS
Current nutrition recommendations to reduce saturated fat and increase dietary fibre affect sterol excretion additively. The effect on cholesterol absorption might be partly explained by the content of dietary plant sterols.


BACKGROUND
Supported by grants from the Gothenburg Medical Society, grant numbers 94/086 and 99/082, and by the University of Gothenburg.
Ellegård
L
L
Department of Clinical Nutrition, University of Göteborg, Sahlgrenska University Hospital, S-413 45 Göteborg, Sweden. Lasse.Ellegard@sahlgrenska.se
Bosaeus
I
I
Andersson
H
H
D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D002791:Cholesterol, Dietary / Q000097:blood / Q000378:metabolism* / Q000493:pharmacokinetics; D004041:Dietary Fats / Q000008:administration & dosage / Q000494:pharmacology*; D004043:Dietary Fiber / Q000008:administration & dosage / Q000494:pharmacology*; D005260:Female; D006801:Humans; D007081:Ileostomy; D007408:Intestinal Absorption / Q000187:drug effects*; D008297:Male; D008875:Middle Aged; D013261:Sterols / Q000378:metabolism*
D002791:Cholesterol, Dietary; D004041:Dietary Fats; D004043:Dietary Fiber; D013261:Sterols