This randomized, controlled trial of cholesterol lowering by an oat bran cereal containing beta glucan vs a corn cereal without soluble fiber in Hispanic Americans was conducted for 11 weeks. One-hundred fifty-two men and women, ages 30 to 70 years, with baseline low-density lipoprotein cholesterol (LDL-C) levels between 120 and 190 mg/dL and triglycerides <400 mg/dL were included. After eating a National Cholesterol Education Program Step 1 diet for 5 weeks, subjects were randomly assigned to the corn or the oat cereal for the next 6 weeks. The daily dose of beta glucan was 3 g. Consumption of oat cereal was associated with a reduction in plasma levels of both total cholesterol (-10.9+/-21.6 mg/dL; -4.5%) and LDL-C (-9.4+/-20.3 mg/dL; -5.3%). Consumption of corn cereal did not affect either total cholesterol (+1.2+/-18.3 mg/dL; 1.1%) or LDL-C (+1.2+/-17.5 mg/dL; 2.2%). Differences between the effects of the two cereals on total cholesterol and LDL-C were significant, P =.0003 and P =.0007, respectively.