Gastric cancer. Some aspects of epidemiology, risk factors, treatment and survival

Gastric cancer mortality has fallen sharply in many Western populations, yet world-wide it probably remains the single commonest cancer. A diet rich in salted or smoked food and low in vitamin C contributes to its pathogenesis, while the environmental type of atrophic gastritis and intestinal metaplasia are consistently associated and may represent precursors of malignant change. Better food preservation may have a protective effect. Since patients with gastric cancer usually present with incurable disease and survive for only a few months, only those likely to live long enough to benefit from surgery should be operated upon. In the small proportion of patients who have curable disease, extended lymph node dissection increases morbidity and has not convincingly been shown to prolong survival. The palliation offered by surgery, and particularly that achieved by chemotherapy and radiation, deserves further study. Screening for gastric carcinoma seems unlikely to decrease mortality.

Serum cholesterol, lipoproteins, and plasma coagulation factors in South Africa blacks on a high-egg but low-fat intake

Twenty-five rural South African black males who worked on an egg farm an average of 4.1 yr had a mean habitual cholesterol intake of 1240 mg/d with fat supplying only 20% of total energy. Although total serum cholesterol was slightly although significantly higher and serum triglycerides significantly lower than those for a control group, no disturbance was evoked in the distribution of cholesterol between HDL, LDL, and VLDL fractions. Coagulation factors were within the normal range, but the high egg consumer group had significantly higher plasma fibrinogen and factor IX levels with a shorter mean prothrombin and partial thromboplastin time, possibly indicative of a slight hypercoagulable state. Apparently rural blacks can handle a very high cholesterol intake without meaningful disturbance in serum lipid homeostasis.

The relationship between the intake frequency and the total consumption of sucrose among four South African ethnic groups

Frequency of intake of sucrose and its total consumption have been implicated as major causative factors in the pathogenesis of dental caries. In the absence of contrary information, it seems that the figure of five sugar exposures per day is a prudent one for the practitioner to recommend to young patients.

Cancer prevention, detection and survival--how hopeful is the outlook?

Recent overall appraisals of cancer occurrence, detection, treatment and survival have noted: rising incidences; relatively steady mortality rates; and disappointingly small improvements in survival time (the magnitudes of which are controversial). In this review attempts have been made to answer questions on countermeasures--principally, what could be done, and what is likely to be done. It is concluded, broadly, that in Western populations the only ameliorative changes likely are reductions in frequency and intensity of cigarette smoking, and improvements in early detection of certain cancers by screening procedures. Accordingly, the outlook is very unpromising. Claims of halving cancer mortality by the year 2000 would seem to be hyperbole. As to developing populations, frequencies of certain cancers (oesophageal, liver and cervix) are likely to fall, but they will be replaced by increases in cancers characteristic of Western populations. Yet rises in incidence of diet-related cancers (breast, colorectal, and possibly prostate) may be retarded by slow rises in socio-economic state.

Appendectomy in South African inter-ethnic school pupils

In 1984-1985, prevalences of appendectomy in inter-ethnic series of South African school pupils of 16-18 yr were: rural blacks, 0.5%; urban blacks, 1.0%; Indians, 2.6%; coloreds (Eur-African-Malay), 2.2%; Afrikaans whites, 13.4%; and English whites, 9.9%. Corresponding respective annual incidences per 1000 pupils of 10-19 yr were: 0.3, 0.6, 1.9, 1.7, 9.8, and 7.8. Thus, appendectomy is rare or infrequent in all except the white populations. Peak occurrence was postpubertal. There was no consistent sex bias. Dietarily, mean daily fiber intake was relatively low in all groups, 17.9-26.1 g. While the percentage of energy from fat intake was low in blacks, 16.3-22.3%, it was much higher in the other populations, 32.7-39.5%. Clearly, factors other than diet are involved in regulating frequency of appendectomy. While mortality is negligible and morbidity slight, elucidation of causation and prevention of the disease is desirable since subsequently appendectomy patients are at greater than average risk to certain cancers.

Effects of graded sucrose additions on taste preference, acceptability, glycemic index, and insulin response to butter beans

Dried beans, because of their high-fiber content and low-glycemic index, are especially suitable for diabetic diets. Most South African bean recipes contain sucrose, and since a restriction of artificial sweeteners seems desirable, replacing sucrose would be impractical. Hence, we examined the effects of 10, 20, and 30% sucrose additions to cooked dried butter beans on taste preference and acceptability in 29 diabetic patients and 11 control subjects. The effect of sucrose additions on glycemic index and insulin response to butter beans was determined in control subjects. Both diabetic and control subjects preferred beans with sucrose additions (p less than 0.005). Additions of sucrose up to 20% of total carbohydrate had no adverse effects on glycemic index or insulin response of butter beans (p less than 0.05), which indicates that addition of moderate amounts of sucrose to a low glycemic index food may improve palatability without impairing the favorable effect on blood glucose and insulin response.

Dietary fibre and mineral metabolism

Current dietary recommendations urge, inter alia, an increased consumption of fibre-containing foods. Some experimental studies made on various animals and man indicate that the associated increases in intakes of fibre and phytic acid may prejudice mineral status respecting calcium, magnesium, iron and zinc. An examination has been made of the experimental evidence, also of the epidemiological evidence on numerous types of populations, past and present, developing and developed. It has been concluded that diets high in fibre, characteristically do not have meaningful ill effects on well-being or unequivocally enhance morbidity. In particular populations in certain regions where deleterious effects have been reported it is judged that local factors, not wholly understood, are in operation. In assessing the extent of the benefit to be derived from the dietary changes urged, results must be viewed holistically and not in isolation. It is believed that the beneficial effects respecting reduced pronenesses to various degenerative diseases are likely to far outweigh the possible adverse effects of reduced bioavailability of mineral nutrients.

Dietary fibre, minerals and vitamins

In Western populations a century ago diets consumed by the masses included a large amount of little refined cereal products. Intakes of vegetables (other than potatoes) and fruit, also foodstuffs of animal origin, tended to be low. Since then the situation changed conversely. There is now a third stage of change--authorities are urging reversion toward greater reliance on foods of plant origin, with increased intakes of less refined cereal products, legumes and vegetables and fruit. In developing countries, the first two stages are represented by rural traditional and urban partially Westernized diets. This paper provides details of intakes of diets generally, especially of dietary fibre, mineral salts and vitamins during the stages referred to, in both First and Third World populations, and discusses their bearing on the occurrences of nutrition-related diseases.

Characteristics and occurrence of appendicitis in the black population in Johannesburg, South Africa

In black patients seen at Baragwanath Hospital, Johannesburg, appendicitis occurs most frequently in the 10-19-year-old age group. There is a pronounced male bias. Parasitic ova in the appendix are very seldom observed (3.6%). Fecaliths, present in 20% of diseased appendices, are noted far less frequently than are reported for white patients (50%-75%). There are about two cases of appendicitis per 1,000 admissions of adults annually, a low frequency consistent with the tenfold differential of appendectomies reported to prevail in urban black and white adolescents. The progressively changing diet of urban blacks, currently low in fat and in dietary fiber, has not yet become associated with a marked increase in the occurrence of the disease (nor of most other noninfective bowel diseases).