B. F. Walker

Appendicitis, fibre intake and bowel behaviour in ethnic groups in South Africa

Information on appendicectomy-prevalence was secured on 15,317 16-20-year-old South African pupils and students—Negroes, Coloureds (Eurafricans), Indians and Caucasians. Data were also obtained on crude fibre-intake, frequency of defaecation, and transit-time of digesta. Among students, 18-20 years, appendicectomy was very uncommon in rural Negroes (0·5%) and periurban Negroes (0·9%), slightly more common in urban Negroes (1·4%), but very common in Caucasians (16·5%); prevalences in Coloured and Indian groups were low (1·7 and 2·9%). Rural Negroes had a far larger fibre-intake, greater frequency of defaecation, and much shorter transit-time; yet, in the four ethnic groups in urban areas, despite wide differences in appendicectomy-prevalence, data on these variables were similar. Differences in other aspects of the bowel milieu intérieur must therefore be sought. Corresponding studies were made on 1325 Caucasian pupils in Homes; their diet is less sophisticated (in respect of fibre, sugar and fat-intakes) than that of the general population. Pupils had slightly greater defaecation-frequency, lesser transit-time, and an appendicectomy-incidence only 23% of that of an appropriate control-group. The conclusion is reached that the causes of appendicitis are wholly environmental.

Nutrition, diet, physical activity, smoking, and longevity: from primitive hunter-gatherer to present passive consumer--how far can we go?

In millennia past, and until recently, among hunter-gatherers and like populations, in all populations, in measure, down through the ages, the securing of sufficient food was lifes primary purpose. Virtually all people were physically very active during early life and later in their everyday occupations. In contrast, nowadays, in Western populations, with relative abundance of food, the way of life is mainly one of enjoyment of meals, of work, and of leisure time, in a context of as few as one child per family, and with long survival times of about 75 to 80 y, due in large part to much reduced child mortality and the effective treatments of disorders and diseases. As to changes in food consumption, compared with the erratic and often monotonous fares of the past, both far and not so distant, everyday diets have changed tremendously in variety, nutritional value, and palatability such that, inter alia, overeating is almost inevitable. Compounding the latter, sedentariness is the rule, in contrast to the previously very high level of everyday physical activity in the masses of populations. In consequence, one speculation is that, by 2230, all Americans will be obese. Although the living of much longer lives is highly gratifying, understandably, all wish to have longer healthy life expectancy, i.e. to suffer as little as possible before death. However, with regard to the present-day passive consumer, although the practical recommendations for leading still healthier lives, dietarily and non-dietarily, are well known, very few are interested, and still fewer practice them. Nevertheless, for the few who, with determination, are eager to improve their lifestyles, there could be highly profitable lengthening of years of healthy life expectancy by eating less, eating more plant foods, being much more physically active, and restricting non-dietary risk factors (smoking, alcohol consumption).

Metacarpal bone dimensions in young and aged South African Bantu consuming a diet low in calcium

Groups of South African Bantu boys and girls of 14 years, compared with local Caucasian children, have lower cortical thickness, cortical score, and crosssection and volume scores for second metacarpal. Yet, when these parameters on groups of aged Bantu men and women, 70-79 years, are compared with published values on corresponding Caucasians, there are no significant differences. Further, aged Bantu have lower prevalences of hip fracture and severe collapse of vertebral bodies. Since a low calcium intake, and in aged Bantu women numerous pregnancies and long lactations, are compatible with satisfactory bone data, it is questioned whether the present insistence on a high calcium intake is justified.

Cardio-thoracic ratio in Negroes in Southern Africa

Negro groups in West, Central and Southern Africa, also in Jamaica, have mean cardio-thoracic ratios significantly greater than those in corresponding age-sex groups of Caucasians. To throw more light on the situation, studies on young and elderly Negroes have been made in certain groups in Southern Africa, also on local Caucasian groups. Only slight differences in ratio were found between local Negro groups, and Caucasian groups in South Africa, also in Wales and Tecumseh (U.S.A.). Yet ratios in Negro males from Malawi and Mozambique, resident in South Africa, were significantly greater than values in local Negroes. High ratios are not therefore invariable for Negroes. The difference observed relates to heart, not thoracic diameter. Since the phenomenon, which concerns heart position, is apparent in the young, almost certainly it is of ethnic origin. Investigations on cardiomegaly in African populations must take this factor into reckoning. Its presence or absence locally may readily be assessed by determining ratios in relatively small numbers of young people of both sexes.