The high amount of soluble beta-glucans in oats may be responsible for beneficial effects on glucose tolerance and blood lipids. We studied 16 women and 7 men (aged 38-61y) with moderately high cholesterol concentrations who consumed normal diets to which oat extracts with either 1% or 10% soluble beta-glucans were added. Oat extracts comprised 10% of energy and were consumed in a 5-wk crossover design after a 1-wk equilibration period. At the end of the equilibration period and each 5-wk period, a carbohydrate tolerance test was conducted and responses to glucose, glucose plus oat extract containing 1% glucan, or glucose plus oat extract containing 10% glucan were determined. Glucose responses were reduced by both extracts in both men and women; however, in women, responses to the 10% extract were lowest. Insulin responses did not differ between men and women, but were lower after oat extracts. Glucagon responses were higher initially in men and were lowered after oat extracts in men but not in women. Modest amounts of oat extracts can be incorporated into normal diets with beneficial effects on glucose tolerance factors.