Intake of Refined Carbohydrates and Whole Grain Foods in Relation to Risk of Type 2 Diabetes Mellitus and Coronary Heart Disease

Abstract

Recent survey data indicate that more than 50% of all adult Americans are overweight or obese. In parallel with this epidemic of weight gain in the general population, the incidence rate of type 2 diabetes mellitus (DM) is rapidly rising. Although their precise contributions are unclear, dietary factors are thought to affect body weight and the development of insulin resistance. Recent epidemiological data indicate that diets rich in high-fiber whole grains are associated with lower risk of coronary heart disease (CHD) and type 2 DM. These data are consistent with results from recent metabolic experiments, suggesting favorable lipid profiles and glycemic control associated with higher intake of whole grains, but not with refined grains. It seems prudent, therefore, to distinguish whole-grain rather than refined-grain cereal products for the prevention of chronic diseases.

• obesity
• type 2 diabetes mellitus
• coronary heart disease
• whole grains
• dietary carbohydrate
• dietary fat
• fiber
• dietary glycemic index

Key teaching points:

• The prevalence of obesity and type 2 DM is rising to epidemic proportions in the United States, although consumption of fats has decreased.

• Different types and amount of grains consumed may have different impacts on the occurrence of type 2 DM and CHD.

• Dietary glycemic load and insulin demand are functional concepts that should be applied in assessing the relative importance of refined carbohydrates and whole grain products in relation to type 2 DM and CHD risk.

• Replacing refined grains and potatoes with whole-grain and minimally processed grain products, along with increasing intake of fruits and vegetables, offers a simple strategy to lower dietary glycemic load and insulin demand that can ultimately reduce the risk of both type 2 DM and CHD.

Key teaching points:

• The prevalence of obesity and type 2 DM is rising to epidemic proportions in the United States, although consumption of fats has decreased.

• Different types and amount of grains consumed may have different impacts on the occurrence of type 2 DM and CHD.

• Dietary glycemic load and insulin demand are functional concepts that should be applied in assessing the relative importance of refined carbohydrates and whole grain products in relation to type 2 DM and CHD risk.

• Replacing refined grains and potatoes with whole-grain and minimally processed grain products, along with increasing intake of fruits and vegetables, offers a simple strategy to lower dietary glycemic load and insulin demand that can ultimately reduce the risk of both type 2 DM and CHD.

Notes

Presented in part at the 42nd Annual Meeting of the American College of Nutrition, Orlando, Florida, October 3–7, 2001.