To determine whether increasing doses (amounts) of β-glucan present in an extruded breakfast cereal affect the glycemic and insulinemic responses in eight NIDDM subjects, compared with the same responses after a continental breakfast (bread, milk, cheese, ham).
Breakfast cereals were produced using various proportions of oat bran enriched in fiber, which contain an unusually high amount of a viscous polysaccharide, called β-glucan, and oat bran. The carbohydrate load was 35 g.
The maximum increases observed in plasma glucose after the breakfast cereal were 67% (P < 0.05), 42% (P < 0.001), and 38% (P < 0.001) with 4.0, 6.0, and 8.4 g β-glucan, respectively, compared with the continental breakfast. There was a linear inverse relationship between dose of β-glucan and plasma glucose peak or area under the glucose curve (R2 = 0.94, P < 0.05). Postprandial insulin increase was only 59–67% (P < 0.01) as high as the continental breakfast after all three levels of β-glucan.
The 50% decrease in glycemic response that was observed after the ingestion of 35 g carbohydrate is estimated to occur with ∼5 g β-glucan. This dose of β-glucan can easily be attained without the loss of taste by incorporating oat bran concentrate in products.