The findings go against the current trend to reduce carbohydrates in the diet, as advised by the Atkin's diet and similar regimes.
Metabolic syndrome strongly predicts both cardiovascular disease and type 2 diabetes. A recent study found that three out of every 10 children had three or more features of the metabolic syndrome: obesity around the belly, low levels of HDL cholesterol, high triglycerides and high blood pressure.
In the new study, researchers analysed data from 2,834 subjects at the fifth examination (1991-1995) of the Framingham Offspring Study. Metabolic syndrome was defined using the National Cholesterol Education Program criteria.
After adjustment for potential confounding variables, intakes of total dietary fiber, cereal fiber, fruit fiber, and wholegrains were inversely associated, whereas glycemic index and glycemic load were positively associated with insulin resistance.
The prevalence of the metabolic syndrome was significantly lower among those in the highest quintile of cereal fiber and wholegrain intakes compared to those in the lowest quintile, write the researchers in this month's Diabetes Care (27:538-546).
Conversely, the prevalence of the metabolic syndrome was significantly higher among individuals in the highest relative to the lowest quintile category of glycemic index.
Total carbohydrate, dietary fiber, fruit fiber, vegetable fiber, legume fiber, glycemic load, and refined grain intakes were not associated with prevalence of the metabolic syndrome.
"Given that both a high cereal fiber content and lower glycemic index are attributes of wholegrain foods, recommendation to increase wholegrain intake may reduce the risk of developing the metabolic syndrome," suggest the researchers.