When we talk about kids and sugar, the bottom line question often really is, “Does eating a lot of sugar truly cause diabetes?” Time after time, previous studies have found little relationship between total carbohydrate intake and diabetes risk. Using total carbohydrate intake, however, does not take into account the blood sugar effect or insulin demand of various forms of carbohydrates.

A study in The Journal of the American Medical Association looked at this issue. The report was part of a longitudinal study of diet and life style factors in relation to chronic diseases (the Nurses Health Study) that involved over 65,000 women, ages 40-65. All were free of cardiovascular disease, cancer, and diabetes at the beginning of the study. The subjects completed a detailed dietary questionnaire from which the scientists calculated the usual intake of dietary fiber, glycemic load, and the dietary glycemic index.

Glycemic index is a ranking of foods based on the glucose response and insulin demand they produce for the carbohydrate they contain. Insulin output produced may vary between foods that contain the same amount of carbohydrate. Other factors of the food influence the absorption of any given food, and not all types of carbohydrates produce the same insulin response. On a scale of 100, white bread has a glycemic index of 100, while broccoli is a 45.

The patients were followed for 6 years to chart the number who developed diabetes.

Of the 65,000 women, over 900 developed diabetes. The women eating foods with highest glycemic index (the carbohydrates that provoked the highest insulin demand) had the highest incidence of diabetes. High fiber whole grains reduced the chance of developing the disease. Cola beverages, white bread, white rice and potatoes were risk factors. Cold breakfast cereal and yogurt were associated with prevention.

The scientists concluded that diets with high refined carbohydrate and low fiber content lead to a chronic high demand for insulin and increased the occurrence of diabetes, independent of other dietary factors and currently known risk factors. Their final advice is that grains should be consumed in a minimally refined form to reduce diabetes.