Diabetes mellitus and dietary fiber of starchy foods

The rarity of diabetes mellitus in rural Africans and the increased incidence in urban Africans suggested that high-fiber, high-carbohydrate diets might protect against diabetes. Conversely it has been suggested that low-fiber starchy food is a diabetogenic factor in susceptible human phenotypes. Many years ago experimental studies demonstrated that carbohydrate tolerance was increased in healthy adults if they ate high-carbohydrate diets but was decreased if they ate high-fat diets. From 1940 in England and Wales, diabetes death rates reported only those who died directly from diabetes mellitus; all cardiovascular complication deaths were excluded. Standardized diabetes mellitus death rates in England and Wales fell from 1941 until 1954 to 1957 by 55% in men and 54% in women. These years coincided with the production of high-fiber National flour. These data suggested the dietary fiber hypothesis of the etiology of diabetes mellitus, namely that fiber-depleted starchy foods were diabetogenic and conversely that high-fiber starchy foods were protective. Recent experimental studies of diabetic hyperglycemic men have shown that high-fiber, high-carbohydrate diets cause remission of diabetes mellitus in many men who had been treated previously by oral agents of moderate doses of insulin, but not those who had previously received large amounts of insulin.