Lipidemic response of hamsters to rice bran, uncooked or processed white and brown rice, and processed corn starch

This study was undertaken to evaluate the lipidemic response of rice bran a nd the possible enhancement of its healthful properties by using raw or pro cessed white or brown rice in place of corn starch. All diets contained 10% total dietary fiber, 15% fat, and 0.5% cholesterol. Weanling male golden S yrian hamsters were fed cellulose control (CC), processed corn starch (PCS) , cellulose with processed brown rice (CPBR), rice bran (RB), RE with white rice (RBWR), RE with processed white rice (RBPWR), RE with brown rice (RBB R), and RE with processed brown rice (RBPBR) diets. After three weeks, the PCS diet significantly lowered total plasma cholesterol (TC) compared with the CC, CPBR, RBWR, and RBPBR diets. RE and RBBR diets significantly lowere d TC and LDL-C compared with CPBR diet. All the RE-containing and PCS diets significantly lowered liver cholesterol and liver lipid content. Processin g white rice increased TDF content 240% and insoluble dietary fiber (IDF) 3 60%, whereas soluble dietary fiber (SDF) decreased by 25%. Uncooked brown r ice contained 7 times as much TDF as uncooked white rice. Processing brown rice decreased its TDF, IDF and SDF contents by 12, 6, and 42%, respectivel y. The data suggest that a possible mechanism for cholesterol-lowering by r ice bran, with or without added raw or processed rice (white or brown), is by decreasing lipid digestibility and increasing neutral sterol excretion, whereas cholesterol-lowering by processed corn starch is mediated through o ther mechanisms.