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Biomedical subjects

B F Walker

Publications and source records attributed to B F Walker.

At least 109 records · Page 6Linked to original sources
PubMed1984

Glycaemic index of South African foods determined in rural blacks--a population at low risk of diabetes.

Published values on glycaemic indices of foods are based on studies made on subjects in diabetes-prone populations. Values have therefore been determined in South African black rural adolescents--a population at very low risk to the disease. While the profile of responses evoked by common foodstuffs on blood glucose levels was similar in blacks to that reported for white subjects, mean levels in blacks were 1 mmol/l or more lower. The glycaemic indices of legumes, particularly that of gram dal, were much lower than those for cereal products, vegetables and fruit.

Adolescent↗
PubMed1983

Acceptability trials of maize meal fortified with niacin, riboflavin and folic acid.

In Western countries two common and successful measures employed to combat nutritional deficiencies and deficiency diseases are: (i) enrichment of refined cereal products with nutrients lost during milling; and (ii) fortification of common foodstuffs with nutrients the intake of which in the general population is regarded as inadequate. In South Africa in 1978 a committee appointed by the Medical Research Council urged that because of the nutritional situation, particularly among the Black population and more especially relating to pellagra, niacin, riboflavin and folic acid should be added to the staple maize meal. Accordingly, investigations have been undertaken to assess the ability of Blacks to discriminate between fortified and non-fortified maize meals. Studies on groups of adolescents and adults revealed that this ability is not significant, indicating that no problem should be encountered as regards the general acceptability of the fortified product. These findings are in agreement with acceptance by the public overseas of enriched bread and 'corn' products where the latter have been introduced. There is therefore no reason why the milling industry should delay the fortification of all maize meal produced for human consumption.

Adolescent↗
PubMed1983

Dental caries in South African rural black women who had large families and long lactations.

A general recommendation for good bone and teeth formation is that a high intake of calcium is essential. Some consider that pregnancy and lactation, with associated calcium depletion, could aggravate caries development. South African black mothers in rural areas have habitually low calcium intakes, and usually several pregnancies and long periods of lactation. To learn whether high parity is detrimental to caries scores, investigations were made on a selected total of 521 black mothers, 250 aged 35-44 years, and 271 aged 45-54 years. Each group was sub-divided into those with small families (1-3 children) or large families (5 + children). The numbers involved were 122 and 133 mothers, and 128 and 138 mothers, respectively. Studies revealed: black mothers had very much lower mean caries scores than values reported for white mothers, who are accustomed, inter alia, to high calcium intakes, have few children, and often no or short lactation periods; black mothers of large compared with small families did not have significantly higher mean caries scores; and upper and lower thirds of black mothers respecting calcium intake, and sugar intake, did not have significantly different mean caries scores. Hence, in the context studied, it would seem that high parity has no obvious effect on caries scores.

Adult↗
PubMed1982

Knowledge of nutrition among housewives in three South African ethnic groups.

Studies on housewives and other groups in Western populations have revealed: (i) a generally high level of claimed or "perceived' knowledge of nutrition; (ii) a much lower level of accurate knowledge; and (iii) an often unsatisfactory application of correct knowledge. Since little is known of knowledge of nutrition in South African populations. White, Indian and Coloured housewives were questioned by use of a questionnaire similar to that used overseas. While the local populations had a fair knowledge of the identity of most nutritional components, their knowledge about good sources of these components and of foods commendable for body building, energy, and slimming, or of those which promote fattening, was only moderately satisfactory. Misconceptions were similar to those reported elsewhere. Factors having a bearing on inadequate or incorrect information are discussed, as is the extent to which this may affect health and disease patterns in Third World and Western populations. Factors detrimental to progress are differences of opinion among nutrition experts and insufficient knowledge on the health/ill-health patterns of those who are knowledgeable of nutrition compared with those who are less knowledgeable.

Black or African American↗
PubMed1982

Defaecation frequencies in Black, Indian, Coloured and White populations - what do they signify?

Using questionnaires covering a 7-day period, frequencies of defaecation were determined in a total of 2937 Black, Indian. Coloured and White subjects aged from 10 years upwards. It transpired that the overall frequency in rural Blacks was roughly twice that of Whites. Among rural Blacks defaecation frequencies of 5-7 per week were recorded in 16%, and from 1-3 per day in 80%. The corresponding figures among urban Blacks were 25% and 71%, among Indians 58% and 34%, among Coloureds 46% and 39%, and among Whites 59% and 29%. The wide differential in frequencies between Blacks and Whites is consistent with the wide differential prevailing in proneness to noninfective bowel diseases. On the other hand, Indians and Coloureds had defaecation frequencies little different on average from those of Whites, yet the former two populations are far less prone to bowel diseases. Hence caution must be exercised in correlating defaecation frequency with proneness to bowel diseases. Since bowel behaviour includes numerous aspects, defaecation frequency should not be regarded in isolation.

Adolescent↗
PubMed1982

Serum high density lipoprotein cholesterol levels in African schoolchildren living near or very far from school.

In African populations, coronary heart disease (CHD) is rare, Serum high density lipoprotein (HDL) cholesterol levels, negatively associated with CHD, understandably are significantly higher in African children and adults, compared with their White Counterparts. On enquiring into the role of physical activity, observations at 3 rural African schools showed that children of 10-12 years, who regularly walked long distances attending school (average about 10 km daily) had only slightly (although significantly) elevated mean HDL cholesterol levels, compared with groups who lived near by. It is considered that the diet of pupils (inter alia, having low fat and high fibre contents), associated with the high level of activity which prevails generally, share responsibility for their high HDL cholesterol levels.

Africa↗
PubMed1982

Serum lipids in long-lactating African mothers habituated to a low-fat intake.

African women, accustomed to a low fat intake, have relatively low blood lipid levels, and are virtually free from coronary heart disease. Among lactating mothers, the amount of fat voided daily in their breast milk is of the same order as that ingested in their habitual diet. However, investigations showed that long-lactating mothers, compared with appropriate control groups, did not exhibit significant hypolipidaemia.

Adolescent↗
PubMed1982

Sugar intake and weight and height of pupils of 16 years in South Africa ethnic groups.

In South African ethnic groups--Blacks. Indians, European-African-Malay, and whites--measurements were made on a total of 2037 pupils, aged 16 yr, of sugar intake, weight, and height. In the various subgroups there was no clear-cut trend for high sugar-consuming pupils (upper thirds), compared with low sugar-consuming pupils (lower thirds), to have greater mean weights and heights. presumably, high consumers of sugar eat less of nonsugar foods, and vice versa. In approximate gradings for habitual physical activity, a slight trend was apparent for those in upper thirds to have higher mean sugar intakes.

Adolescent↗
PubMed1982

Breakfast habits of adolescents in for South African populations.

Breakfast habits by using questionnaires, were established in a total of 4717 South African pupils of 16 to 18 yr. In the groups of rural and urban Black, Indian, European-African-Malay, and white pupils studied, respective proportions who had no solid breakfast (both sexes combined) were approximately 21, 19, 13, 13, and 14%. Proportions who had only porridge or bread (or toast) plus drink were 77, 73, 61, 71, and 56%. Such breakfast provided ranges of means of 223 to 345 kcal, 9 to 14 g protein, 7 to 18 g fat, 51 to 185 mg calcium, and 3.2 to 5.1 mg iron. Proportions who had a cooked breakfast (including egg, meat, fish), eaten with or without a cereal food, were 1, 4, 17, 8, and 29%. Such meals contributed means of 495 to 704 kcal, 11 to 26 g protein, 24 to 39 g fat, 110 to 225 mg calcium, and 3.9 to 5.5 mg iron. In the South African groups studied, the issue of breakfast or no breakfast had no clear-cut bearing on weight, height, class position, or frequency of absence from school. The degree by which, in a given community, nutrition in general and breakfast in particular, regulates health and/or academic performance, needs proper research in prospective studies.

Adolescent↗
PubMed1982

Contrasting patterns of caries profile and dental treatment in pupils of 16-18 years in South African ethnic groups.

Investigations on caries profile and state of teeth treatment were made on 3752 high school pupils of 16-18 years, namely, rural and urban Black, Indian, Colored (Eur-African-Malay) and White pupils. Rural Blacks had a low mean DMFT of about 2, and a caries-free prevalence of 52%. Of the few with affected teeth, 10% were extracted, none filled, and 90% decayed; i.e. restorative dental attention was virtually nil. Among English and Afrikaans pupils attending Government Schools, mean DMFT was about 10, and caries-free prevalence negligible. Of affected teeth, 13% were extracted, 59% filled and 28% decayed. The situations regarding the urban Black, Indian and Colored groups were intermediate. The Jewish pupils, well-circumstanced and attending private school, had a mean DMFT of 6.5, moreover 6% were caries-free. Of affected teeth, 1% had been extracted; 93% were filled, and only 6% remained decayed. Since it transpired that the diets of the three White subgroups, cariogenically, were much the same, the advantageous position of the Jewish pupils was judged to be due primarily to their excellent oral hygiene motivation, particularly their demonstrably regular visits to dentists.

Adolescent↗
PubMed1982

Appendicectomy prevalences in South African adolescents.

From questioning 16,939 South African pupils of 16-18 years, in 56 high schools, mean prevalences of appendicectomies in representative segments of ethnic groups were found to be: rural Blacks 0.6%; urban Blacks 0.7%; Indians, 2.9%; Coloureds (Eur-African-Malay), 1.7%; Whites, 10.5%. Percentages in the sexes were similar. Only those of Indian and Coloured pupils appear to be increasing. Blacks and Whites, respectively, have high and low intakes of fibre-containing foods, which are negatively correlated with appendicectomy prevalences. However, although intakes of fibre-containing foods are slightly higher in Indians and Coloureds than in Whites, the former's appendicectomy prevalences are lower than would be dietarily expected.

Adolescent↗
PubMed1981

Dental caries in South African black and white high school pupils in relation to sugar intake and snack habits.

DMFT scores, total sugar intakes and snacks habits were determined in 1918 South African Black pupils (923 rural, 995 urban) and 724 White pupils (English and Afrikaans speaking) aged 16-18 years inclusive. Mean DMFT scores of school groups of Black pupils (both sexes) ranged from 0.9 and 2.0 in rural areas, to 4.2-6.7 in urban areas (where data were far higher than such obtained 7 years ago), and were 9.2 and 10.2 for White pupils. Corresponding mean daily sugar intake were - rural Blacks, 69 g and 97 g, urban Blacks 118-141 g, respectively (all slightly higher than previously); and Whites 102 g and 123 g. Mean DMFT scores of girls were higher than those of boys; yet while mean sugar intakes of Blacks girls and boys were somewhat similar, White girls' intakes were much lower than those of White boys. In the ethnic-sex groups studied, mean DMFT scores for pupils in upper, compared with lower, third of sugar intake, were higher in nine of the 14 sub-groups. Mean DMFT scores in upper, compared with lower, third of exposure to snack practices were higher in 11 of the 14 groups. However, most of the differences were slight. In further research, more intensive enquiries should be pursued on roles of ethnic and familial factors, as well as on roles of inter-acting dietary components additional to sugar and sugar-containing foods.

Adolescent↗
PubMed1981

Tonsillectomy prevalences in South African schoolchildren.

Tonsillectomy prevalences, using questionnaires, were determined on series of school pupils (total number 10,271), aged 16-18 years, in four South African ethnic groups. Prevalence were, approximately: rural Blacks 2%, urban Blacks 3%, Indians 8%, Coloureds (Eur-African-Malay) 9% and Whites 44%. The inter-ethnic profile of differences is similar to the inter-ethnic profiles of other differences (e.g. in appendicectomy prevalences).

Adolescent↗
PubMed1980

Blood pressures of South African Black adolescents aged 16 to 17 years.

In South Africa, in urban but not rural areas, hypertension is far more common in Black than in White adults. To throw light on this adverse situation, blood pressures are being determined in various segments of Black populations, in the present instance on series of school pupils aged 16 to 17 years, in rural and urban areas. Mean data lay within the ranges of means published for Black children in the USA and for White children in the USA and elsewhere. Neither level of salt nor of sugar intake appeared influential; the same applied to obesity. Evidently, the noxious factors which promote the excessively high frequencies of hypertension in urban Black adults are not yet in operation in young adolescents.

Adolescent↗