Twenty-one mildly hypercholesterolemic men aged 30-59 y were provided with comparable barley and wheat foods for each of 4 wk in a crossover-designed experiment. The purpose ofthe study was to examine the influence oftwo sources of dietary fiber (nonstarch polysacchandes, NSP) on blood lipids and glucose concentrations. Barley contains /3-glucan as a source of soluble dietary fiber (DF) whereas wheat contains the largely insoluble cellulose and hemicellubose fiber. Total dietary fiber increased from a previous intake of2l-38 g/d during the period of study for the two groups. Consumption of barley relative to wheat foods was associated with a significant fall in both plasma total cholesterol (6%, P < 0.05) and in low-density-lipoprotein cholesterol (7%, P < 0.02) whereas triglyceride and glucose concentrations did not change significantly. It is concluded that barley dietary fiber is more effective than wheat dietary fiber at lowering blood cholesterol in hypercholesterolemic men