Insulin resistance, which can lead to type 2 diabetes, means that glucose is not processed properly and the pancreas compensates by producing more insulin, resulting in high levels of the hormone.
But a study published in this month's Diabetes Care (27:1281-1285)found that consumption of a high-fibre cereal reduced the rise in peak insulin compared with that seen after a low-fibre product.
Dr Thomas Wolever and colleagues from the University of Toronto, Canada, looked at the plasma glucose and insulin responses to two different cereals in 77 non-diabetic men. Thirty-five had normal fasting insulin levels while 42 had high levels, or hyperinsulinemia.
The subjects were studied on two occasions after 10- to 14-hour overnight fasts. The two test cereals contained the same amount of carbohydrate (25g) but different amounts of fibre.
The high fibre cereal had the same effect on blood glucose levels in all men, causing a lower rise than after the low-fibre cereal.
However, insulin peak rise was reduced by the high-fibre cereal only in hyperinsulinemic men but not in control subjects, report the researchers. This was not related to age, BMI, or waist circumference, they added.
Further studies are needed to investigate whether cereal could play a role in the ongoing management of insulin resistance.
Diabetes has already increased by one-third during the 1990s, due to the prevalence of obesity and an ageing population. There are currently more than 194 million people with diabetes worldwide but if nothing is done to slow the epidemic, the number will exceed 333 million by 2025, according to the International Diabetes Federation.