The effects of hard white and hard red winter wheats (whole flour, bran, straight-grade flour) and oatmeal on rat weight gains, serum and liver cholesterol levels, fecal fat, neutral sterols, and bile acids were compared. No differences in weight gains or feed efficiencies were noted for animals fed red versus white whole flours, brans or straight-grade flours. Only animals fed the white wheat bran diet gained less weight than the control animals. The bran diets were the least efficient feeds. By the end of week 8, animals fed red wheat diets tended to have lower serum cholesterol levels than those fed respective white wheat diets, but the difference was significant only in animals fed whole wheat flour. The wheat brans, whole red flour, red straight-grade flour, and oatmeal diets were hypocholestrolemic compared to the control diet. No significant differences occurred in liver cholesterol levels between groups fed respective hard white versus hard red wheat diets. Animals fed bran diets had significantly lower liver cholesterol concentrations than did those fed whole flour or straight-grade flour, but concentrations were similar to those of animals fed the oatmeal diet. Correlation analysis showed significant inverse relationships between total serum cholesterol and dietary fiber (especially soluble fiber), amount of fecal fat and neutral sterols excreted daily, dietary phenolics and phytic acid, and diet viscosity. The relationships were stronger for liver cholesterol. All of these factors may contribute to the hypocholestrolemic properties of grain diets. | |
