Corn fiber oil lowers plasma cholesterol levels and increases cholesterol excretion greater than corn oil and similar to diets containing soy sterolsand soy stanols in hamsters

The aims of this study were to compare the cholesterol-lowering properties of corn fiber oil (CFO) to corn oil (CO), whether the addition of soy stano ls or soy sterols to CO at similar levels in CFO would increase CO's choles terol-lowering properties, and the mechanism(s) of action of these dietary ingredients. Fifty male Golden Syrian hamsters were divided into 5 groups o f 10 hamsters each, based on similar plasma total cholesterol (TC) levels. The first group of hamsters was fed a chow-based hypercholesterolemic diet containing either 5% coconut oil + 0.24% cholesterol (coconut oil), 5% CO, 5% CFO, 5% CO + 0.6% soy sterols (sterol), or 5% CO + 0.6% soy stanols (sta nol) in place of the coconut oil for 4 weeks. The stanol diet significantly inhibited the elevation of plasma TC compared to all other dietary treatme nts. Also, the CFO and sterol diets significantly inhibited the elevation o f plasma TC compared to the CO and coconut oil diets. The CFO, sterol, and stanol diets significantly inhibited the elevation of plasma non-high densi ty lipoprotein cholesterol compared to the CO and coconut oil diets. The st anol diet significantly inhibited the elevation of plasma high density lipo protein cholesterol (HDL-C) compared to all other dietary treatments. The s terol diet significantly inhibited the elevation of plasma HDL-C compared t o the CO and coconut oil diets, whereas the CFO diet significantly inhibite d the elevation of plasma HDL-C compared to the coconut oil diet only. No d ifferences were observed between the CFO and CO for plasma HDL-C. There wer e no differences observed between groups for plasma triglycerides. The CO a nd CFO diets had significantly less hepatic TC compared to the coconut oil, sterol, and stanol diets. The CO and CFO diets had significantly less hepa tic free cholesterol compared to the sterol and stanol diets but not compar ed to the coconut oil diet; whereas the coconut oil and sterol diets had si gnificantly less hepatic free cholesterol compared to the stanol diet. The CFO, sterol, and stanol diets excreted significantly more fecal cholesterol compared to the coconut oil and CO diets. In summary, CFO reduces plasma a nd hepatic cholesterol concentrations and increases fecal cholesterol excre tion greater than CO through some other mechanism(s) in addition to increas e dietary sterols and stanols-possibly oryzanols. (J. Nutr. Biochem. 11:443 -449, 2000) (C) Elsevier Science Inc. 2000. All rights reserved.