|Yokoyama, Wallace - Wally|
|Hong, Yun Jeong|
Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/8/2011
Publication Date: 10/26/2011
Citation: Yokoyama, W.H., Anderson, W.H., Albers, D.R., Hong, Y., Langhorst, M.L., Hung, S., Young, S.A. 2011. Dietary hydroxypropyl methylcellulose increases excretion of saturated and trans fats by hamsters fed fast food diets. Journal of Agricultural and Food Chemistry. 59(20):11249-11254. Interpretive Summary: Fast foods are generally high in calories, particularly fat calories, and also high in saturated fats. Saturated fats increase blood cholesterol. We found that hamsters fed diets containing either hamburgers and French fries, pizza, or pound cake had increased levels of plasma cholesterol. Plasma cholesterol and body weight was decreased when these fast food diets were supplemented with 5% of a viscous, soluble fiber (hydroxypropyl methylcellulose, HPMC). HPMC increased fat excretion in the feces and also increased saturated fat excretion.
Technical Abstract: The hypocholesterolemic and hypoglycemic effects of hydroxypropyl methylcellulose (HPMC), a semisynthetic nonfermentable soluble dietary fiber, are well established. However, effects of HPMC on dietary saturated fatty acids and trans fatty acids are largely unknown. This study investigated the effect of HPMC on digestion and absorption of fecal lipids in hamsters fed diets comprised of fast foods of the type typically consumed in Western diets. Male Golden Syrian hamsters were fed chow consisting of either freeze-dried ground pizza, pound cake, or hamburger and French fries supplemented with either HPMC or microcrystalline cellulose (control) for 3 weeks. We observed 1.9-5.8 fold greater excretion of saturated fatty acids (SAT; P < 0.05) and 2.7-7.5 fold greater excretion of trans fatty acids (TRAN; P < 0.05) with diets supplemented with HPMC compared to the control. Hamsters fed HPMC-supplemented diets gained significantly less body weight than the control group without a change in food intake. Significant decreases compared to controls in liver weights (18-36%) and the concentrations of both plasma and hepatic total cholesterol (24-61% and 21-59% respectively) were measured. We also observed significant increases compared to controls in fecal excretion of bile acids (2.6-3 fold; P < 0.05), sterols (1.1-1.5 fold; P < 0.05), and unsaturated fatty acids (UNSAT, 1.7-4.5 fold; P < 0.05). The animal body weight gain was inversely correlated with the excretion of fecal lipid concentrations of bile acids (r = -0.56; P < 0.005), sterols (r = -0.48; P < 0.005), SAT (r = -0.69; P < 0.005), UNSAT (r = -0.67; P < 0.005), and TRAN (r = -0.62; P < 0.005). These data highlight increased excretion of fecal SAT and TRAN by HPMC, which appear to reduce the amount of SAT and TRAN being absorbed by the hamster relative to the amount of UNSAT being absorbed from a high fat-containing food product.