Consumption of whole grain and legume powder reduces insulin demand, lipid peroxidation, and plasma homocysteine concentrations in patients with coronary artery disease: randomized controlled clinical trial

Abstract

Our objective was to evaluate whether isocaloric replacement of refined rice with whole grains and other plant products as a form of powder reduces coronary artery disease (CAD) risk factors, such as insulin demand and lipid peroxidation in CAD patients. Seventy-six male patients with CAD were randomly assigned to either a group ingesting a whole-grain meal daily or a control group for 16 weeks. In the whole-grain group, serum concentrations of glucose and insulin decreased by 24% and 14%, respectively, without altering body weight and energy intake, whereas daily intakes of fiber and vitamin E increased by 25% and 41%, respectively. Consumption of whole grains and legume powder in CAD patients without diabetes decreased fasting levels of glucose and insulin. The areas under the curve for insulin and glucose during the oral glucose tolerance test were also decreased. CAD patients with diabetes in the whole-grain group also showed reductions in fasting glucose and in the area under the curve for glucose. In the whole-grain group, plasma malondialdehyde and homocysteine and urinary 8-epi-prostaglandin F2α concentrations decreased by ≈28%. Also, lipid-corrected concentrations of α-carotene, retinol, tocopherols, and lycopene increased by 11% to 40%, and the percentage composition of n-6 fatty acids of serum phospholipid increased by 14% in the whole-grain group. The replacement of refined rice with whole grain and legume powder as a source of carbohydrate in a meal showed significant beneficial effects on glucose, insulin, and homocysteine concentrations and lipid peroxidation in CAD patients. These effects are likely to substantially reduce the risk factors for CAD and diabetes.