Hugh Trowell

DIABETES MELLITUS DEATH-RATES IN ENGLAND AND WALES 1920-70 AND FOOD SUPPLIES

Abstract Diabetes mellitus death-rates are reviewed in age and sex groups from 1920-22 until 1970. Although there was a change in cause assignment of diabetes deaths in 1940, standardised death-rates based on the comparative mortality indices (C.M.I.) bridge the break in the recorded death-rates. C.M.I. diabetes death-rates were almost stationary in both sexes 1933-38; they started falling in 1941 until 1954-57, by 54% in women, 55% in men. A comprehensive survey of food supplies pre-war up to 1966 permits an examination of all absorbed dietary factors that may have influenced the death-rates. This survey did not mention unabsorbed dietary factors in the National flour crude fibre 0·4-0·7 g. per 100 g. or white flour crude fibre 0·1 g. per 100 g. These figures are presented in order to complete the data. National flour was compulsory 1942 53, but optional during 1941 and again in 1954-56.

The development of the concept of dietary fiber in human nutrition.

Fundamental studies of the laxative action of wheat bran were undertaken in the United States in the early decades of the 20th century. Walker in South Africa extended these studies among African blacks and later suggested that cereal fiber protected them against certain metabolic disorders. Trowell in Uganda elaborated this concept with regard to the rarity of common noninfective diseases of the colon. Another stream of inquiry stemmed from the hypothesis of Cleave who postulated that the presence of refined sugar, and to a lesser extent white flour, caused many metabolic diseases, while the loss of fiber caused certain colonic disorders. Meanwhile Burkitt had collected massive evidence of the rarity of appendicitis and many venous disorders in rural Africa and parts of Asia. In 1972 Trowell proposed a new physiological definition of fiber in terms of the residue of plant foods that resisted digestion by alimentary enzymes of man. Southgate has proposed chemical methods to analyze the components of dietary fiber: cellulose, hemicellulose, and lignin.

Aspects of the epidemiology of diverticular disease and ischemic heart disease

Diverticular disease (DD) of the colon is common in populations where the intake of cereal fiber in the diet has been reduced dramatically for several decades. Also it has been shown that the addition of fiber in the form of wheat bran relieves the symptoms of the uncomplicated forms of the disease. Both diverticular and ischemic heart disease (IHD) have become major problems of the industrial nations of the Western world in this dentury. Consequently, it has been suggested that a deficiency of dietary fiber may play a part in the causation of IHD. The historical emergence and the geopraphical distribution of both DD and IHD are discussed and are shown to support this contention. New data regarding their prevalence in rural Africa and Asia have been obtained from over 170 hosptals, together with details of the radiological incidence of diverticulosis in India and South Africa. Admittedly the incidence of both diseases is known in very few countries with any degree of accuracy, but it is still crystal clear that DD and IHD appeared on the clinical scene together and that they are very closely associated geographically. Frequently they are found together in the same patient. This paper proposes that fiber deficiency may help to cause not only diverticulosis but also IHD.Diverticular disease (DD) of the colon is common in populations where the intake of cereal fiber in the diet has been reduced dramatically for several decades. Also it has been shown that the addition of fiber in the form of wheat bran relieves the symptoms of the uncomplicated forms of the disease. Both diverticular and ischemic heart disease (IHD) have become major problems of the industrial nations of the Western world in this dentury. Consequently, it has been suggested that a deficiency of dietary fiber may play a part in the causation of IHD. The historical emergence and the geopraphical distribution of both DD and IHD are discussed and are shown to support this contention. New data regarding their prevalence in rural Africa and Asia have been obtained from over 170 hosptals, together with details of the radiological incidence of diverticulosis in India and South Africa. Admittedly the incidence of both diseases is known in very few countries with any degree of accuracy, but it is still crystal clear that DD and IHD appeared on the clinical scene together and that they are very closely associated geographically. Frequently they are found together in the same patient. This paper proposes that fiber deficiency may help to cause not only diverticulosis but also IHD.

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.

Fiber-Depleted Starch Foods and NIDDM Diabetes

The hypothesis that fiber-depleted starch foods are the main factor producing NIDDM diabetes (henceforth called diabetes) started in my mind in 1929 soon after I joined the Kenya Medical Service. It continued on and off in my mind until it culminated in two articles published in 1987, some 59 years later.