Actually, multiple mechanisms are probably involved in the protective effects of whole grains. Fiber decreases fat absorption and increases fat and cholesterol excretion thus lowering blood cholesterol levels. The side effect of a very high fiber diet is that fiber also decreased absorption of some minerals. Grains and glycemic response. Whole grains may reduce fasting glucose and insulin concentrations, which is especially important in diabetes.
Oligosaccharides are carbohydrate molecules in grains.
They may act like probiotics, increasing concentration of beneficial intestinal bacteria that improve digestion. Vitamin E has antioxidant activity and helps prevent and control cardiovascular disease and certain types of cancer. Phytate may be helpful in prevention of cancer by suppressing lipid peroxidation. Phytosterols reduce risk of cardiovascular disease and some types of cancer. Lignans are a type of phytoestrogen that may decrease a risk of hormone-related cancers.