EMERGENCE OF DIVERTICULAR DISEASE IN THE URBAN SOUTH AFRICAN BLACK

Transcription

1 GASTROENTEROWGY 72: , 1977 Copyright 1977 by The Williams & Wilkins Co. Vol. 72, No.2 Printed in U.s A. EMERGENCE OF DIVERTICULAR DISEASE IN THE URBAN SOUTH AFRICAN BLACK I. SEGAL, M.B.B.CH., M.R.C.P., A. SOLOMON, M.B.B.CH., D.MED., D.M.R. (D), M.MED. (RAD.D.), AND J. A. HUNT, M.B.B.CH., F.R.C.S. Baragwanath Hospital and the University o f the Witwatersrand, Johannesburg, South Africa A low residue, fiber-deficient diet has been postulated as the cause of diverticular disease-the commonest affiiction of the colon in the Western nations. This condition is virtually unknown in Mricans (blacks) who live south of the Sahara, and who have not changed their traditional high residue diet. This paper presents 16 Africans with diverticular disease. A disturbing feature is that 5 of the patients are young, being in their fourth decade, and only 4 are over the age of60. Their dietary history confirms the hypothesis as to the etiology, and also shows that the urbanization of the South African black has been accompanied by the emergence of diverticular disease, a condition hitherto virtually nonexistent in this population. During the past 70 years, in Western populations diverticular disease has reached alarming proportions in adults, being the commonest affiiction of the colon. 1 Although the exact incidence is unknown, it has been stated to affect one-third of people over 40 and twothirds over 80 years of age. 1,2 Painter and Burkitt 2 have postulated that the reason is that the environment of the colon has been changed, and that diverticula are attributable primarily to changes in the diet. The major dietary change suggested is the refining of flour and other cereals, and hence the depletion of cereal fiber in the diet. The situation is further aggravated by the increased consumption of refined sugar at the expense of unrefined foodstuffs. It is well known that diverticular disease is very rare in people who have not changed their traditional diet over the centuries, and the condition is virtually unknown in African blacks who live south of the Sahara. 2 With the present rapid growth of urbanization and industrialization in South Africa, and with the concomitant changes in eating habits, diverticular disease might be expected to show a major increase in incidence. Accordingly, it is important to describe dietary changes that have taken place in those who were previously exempt from the d i s e a ~. Baragwafiath Hospital, Johannesburg, serves a large urban African black population of at least one million people. It is only in the last few decades that these people have migrated from a rural environment to urban industrialized centers. Many of their children, born Received March 15, Accepted July 22, Address r equests for reprints to: Dr. I Segal, University of Wi twatersrand, Department of Medicine, Baragwanath Hospital, P.O. Bertsham, 2013, Johannesburg, South Africa. The authors wish to thank Dr. A. R. P. Walker, Professor L. Schamroth, Professor H. H. Lawson, and Professor A. Bleksley for their assistance in the preparation of this paper. They further wish to thank Dr. G. Cohen for access to his radiological records. 215 and reared in the city, are now growing to maturity. This situation provides an ideal opportunity for the study of the effects of urbanization on disease patterns. This paper presents an analysis ofthe first 16 patients with diverticular disease seen at this hospital. Materials and Methods Twelve patients with diverticular disease were seen during Four patients seen during the first 2 months of 1975 are also included in this survey. Patients were questioned as to their age, habitat, occupation, educational status, background, and dietary habits. Results Sex distribution. There were 10 males and 6 females. Age. Ages ranged from 31 to 71 years, 5 of the patients being in the fourth decade. The mean age was 48.9 years. Habitat. The patients had all resided in Johannesburg for over 20 years. Occupation and level of sophistication. The men were engaged in sedentary occupations, and the women were domestic servants. All were urbanized people and reflect a more sophisticated phase of development-educationally and socially - than does the relatively unsophisticated rural African. Background. With one exception, the patients' parents were not poor, and any form of food was freely available from childhood onward. Dietary habits. The diets regularly consumed had the same pattern - a very high refined carbohydrate intake, with a low fiber content. Refined sugar, in one form or another, was consumed in large amounts and in a variety of less usual ways. Some substituted "starch water" (warm water with sugar added) for their tea, and one had sandwiches of white bread with a liberal sprinkling of sugar. Condensed milk (high in sugar content) was often used instead of milk. All patients consumed soft

2 216 SEGAL ETAL. Vol. 72, No.2 TABLE 1. Diverticular disease in the urban African black" Patient Age Sex Isolated Diffuse Size y r Colonic site Sigmoid Descending Transverse Ascending colon colon colon colon 1. E. J. 35 M + Large W. G. 54 M + Small + 3. E. M. 60 F + Small M. T. 30 F + Small + 5. H. N. 64 M + Large J. M. 35 F + Small D. M. 46 M + Large J. W. 57 M + Large G. M. 38 M + Large D. M. 31 M + Small J. M. 69 F + Large M. T. 45 F + Small E. K. 47 M + Mixed - mainly small 14. S. P. 43 M + Small S. M. 58 M + Large H. S. 71 F + Large a Isolated - usually no more than three per region; small-usually smaller than 5 mm; large - greater than 5 mm. Cecum drinks (mineral waters high in sugar content), jam, and cakes. The consumption of white bread was the rule. One-half did not eat maize meal-the staple food of the black - and the remainder ate only refined white maize meal. Fruit was rarely eaten and vegetables were taken once a week. Meat was eaten daily. Fish and eggs were eaten more than once a week. Most had been eating this refined food-low fiber diet since childhood. The fathers of two owned grocery shops, and the patients consumed large quantities of sweets (candy) and confectionery. One patient was a commercial traveler, who regularly ate Westernized food, and the father of another was a chef at a hotel and cooked similar food at home. Another patient had been a domestic chef for 27 years and ate food similar to that which he cooked. The domestic servants ate the diet of the households in which they worked - a refined foodlow fiber diet. Clinical Presentation Six patients presented with rectal bleeding and 4 presented with hemorrhoids. Two had abdominal pain, and 2 had an abdominal mass. Two patients had iron deficiency anemia. Without exception, all volunteered a long history of severe constipation. Because of its previous rarity, diverticular disease was not suspected in any of the patients when they presented to the hospital. Radiology Barium enema studies revealed that 6 patients had isolated diverticula, i.e., no more than three per region. The remaining 10 showed diffuse diverticula, the type usually seen in Western countries. The anatomical sites of the diverticula were as follows: 14 in descending colon, 10 in the transverse colon, 8 in the sigmoid region, 7 in the ascending colon, and 3 in the cecum. One-half of the patients had large diverticula, i.e., over 5 mm, and 7 had diverticula under 5 mm. One patient showed a mixed picture, primarily with small diverticula. Discussion The tradional diet of the rural South African black 3 is based on maize, supplemented in some areas with "kaffir corn" (Sorghum vulgare), millet, and wheat products. Other foods include dried peas, beans, ground nuts, pumpkin, melons, and other vegetables, fruits, and wild greens (mfino, morogo). The consumption of fermented cereal products varies regionally. Meat and milk are consumed irregularly, and increasing amounts of sugar, tea, and condensed milk are now being consumed. In the towns, most urban blacks consume a diet that is partially westernized. Maize meal porridge still remains the staple diet, but the consumption of sugar and sugar products (jam, condensed milk, soft drinks) has increased considerably. Meat, milk fat, and tinned foods are consumed to a greater extent by urban blacks than by their rural counterparts. Generally, therefore, the diet is adequate in calories and gross protein, low in animal protein and fat, and high in carbohydrate and crude fiber.3 Among blacks in urban areas, there is an increasing proportion, usually in the higher income group or among those who are domestic servants, who eat a diet that in almost all respects is similar to that consumed by Western populations, i.e., a low residue, fiber-deficient diet, from which the plant fiber has been removed, with refined cereal products and a high sugar intake. It is particularly among this segment of the population that diverticular disease might be expected to appear. In 1958, Keeley4 reviewed adult admissions to this hospital for the years 1954 to 1956 and found no cases of diverticular disease. At the same time Higginson and Simson 5 found diverticula in only 1 of 2367 necropsies, of whom 789 were over 45 years of age. In the 3-year period

3 February 1977 DIVERTICULAR DISEASE IN SOUTH AFRICAN BLACKS 217 FIG. 1. Patient J. W. -diffuse, large, multiple diverticula of colon. before 1971, Solomon, as quoted by Painter and Burkitt,6 reported that at Baragwanath Hospital, which serves solely the black population, diverticula were observed in only 6 of 1000 consecutive barium enemas. Levy, as quoted by Trowell et al./ in recording 13 years of radiological hospital experience in Johannesburg among blacks, reported no cases of diverticula whatsoever. This is in sharp contrast to the South Mrican white; in a series of 221 barium enemas carried out on a sample white population of Johannesburg, 20.8% revealed diverticula (table 2). Furthermore, Kloppers, as quoted by Trowell et al., 7 states that onethird of middle-aged whites in South Mrica have diverticular disease, and Kaye et al. s showed an incidence of 14.8% in a white Johannesburg hospital population. Much more recently, Bremner and Ackerman 9 examined a series {)f necropsy findings which extended over a period of 13 years, and concluded that the South Mrican black develops diverticular disease extremely seldom. The hypothesis of the etiology postulated by Painter and Burkitt is confirmed by the dietary history of these patients. They are the forerunners of a population group who have almost fully given lip their traditional foods and changed from a high to a low residue diet. Because all suffered from severe constipation, this confirms the association of constipation and diverticular disease, first pointed out by Gross in Will diverticular disease occur in a younger age group in the South African black? Five of 16 patients were in their 30's and only 4 were over the age of 60. Although the series is too small to draw definite conclusions, we believe that this high proportion may be significant. The age-adjusted prevalence figures in the hospital population (table 3) show that there is a marked disparity in the prevalence of diverticula in the older age group; e.g., in the 61- to 70-year-old age group the figure is 0.77 per 1000 hospital patients for the blacks, as against per 1000 hospital patients for whites. The age profile of patients with diverticular disease is seen to follow the pattern of the age distribution of patients in the hospital population (table 3). The largest number of black hospital patients are under the age of 50, as are the patients with diverticular disease. In contradistinction, the majority of white patients with diverticular disease are over the age of 50. Noteworthy was the association of hemorrhoids with diverticular disease in 4 of 16 patients (25%). Painter"

4 218 SEGAL ET AL. Vol. 72, No.2 FIG. 2. Patient S. M. - diffuse, large, multiple diverticula of colon, sparing transverse colon. TABLE 2. Comparison of incidence and age distribution of diverticular disease in black and white populations of J ohannesburg Diverticular Age distribution Diverticular Age distribution Age group disease in of Johannesburg disease in of Johannesburg blacks black population whites white population yr % % TABLE 4. Comparison of age distribution and number of barium enemas performed in black and white groups Age group Black group White group yr % % TABLE 3. Comparison of incidence, age distribution, and age-adjusted prevalence in black and white hospital populations of Johannesburg.. Age distri-. Ag!ad-.. Age distri- Age-adjusted DlVertlc- bution of Juste p,:ev- D l v e r t bution ~ c - of prevalence in Age ular dis- black hos- alence In ular dis- white hos- white hosgroup ease in pital popu- b.lack hos- e a In ~ pital popu- r.ital popublacks lahon e t popu- ~ l whites lation ation/looo atlon/l000 y r % % ILl LlO reported the association in 18.57%. This series also shows a relative rarity of diverticula in the sigmoid colon, which is the site of election for this abnormality in most Westernized countries. The reason for this is unknown, but it may be related to the longer colon that is present in blacks. 11 Teubes 13 showed that the diameter of the pelvic colon in blacks varied from 10.1 to 16.5 em, whereas the diameter in whites is given as 4 cm.14 Therefore, the above factors could lead to a more even distribution of pressure along the colon, and also to less efficient segmentation in the sigmoid colon. During 1974, 440 barium enemas were carried out in this hospital (table 4), and 12 illustrated diverticula. This constitutes 2.7% of all barium enemas undertaken in Hence, although diverticular disease is still uncommon, it certainly occurs more frequently than before. Undoubtedly, Painter and Burkitt's prediction 2 that diverticular disease will become more common in sub-saharal Africa is correct. The urbanization of the South African black has thus been accompanied by the emergence of diverticular disease, a condition hitherto virtually nonexistent in this population. Addendum In 1975, 250 barium enemas were performed at Barag-

5 February 1977 DIVERTICULAR DISEASE IN SOUTH AFRICAN BLACKS 219 wanath Hospital. Twelve patients were found to have diverticular disease, giving an incidence of 4.8%. REFERENCES 1. Shulman AG: High bulk diet for diverticular diflease of the colon. West J Med 120: , Painter NS, Burkitt DP: Diverticular disease of the colon: a deficiency disease of Western civilization. Br Med J 2: , Walker ARP: Nutritional, biochemical and other studies on South African populations. S Afr Med J 40: , Keeley, KJ: Alimentary disease in the Bantu: a review. Med Proc 4: , Higginson J, Simson I: Schweiz Z Allg Pathol Bakteriol 21: , Painter NS, Burkitt, DP: Diverticular disease of the colon, a 20th century problem. Clin Gastroenterol 4:3-21, Trowell H, Painter NS, Burkitt D: Aspects of the epidemiology of diverticular disease Ischaemic heart disease. Am J Dig Dis 19: , Kaye J, Solomon A, Lazar SJ: Further experience with Dulcolax in barium enema examinations. Med Proc 12: , Bremner CG, Ackerman LV: Polyps and carcinoma of the large bowel in the South Mrican Bantu. Cancer 26: , Gross S: Elements of Pathological Anatomy. Philadelphia, Blanchard and Lea, 1845, p Painter NS: The high fibre diet in the treatment of diverticular disease of the colon. Postgrad Med J 50: , Lewis, JH: The Biology ofthe Negro. Chicago, The University of Chicago Press, Teubes MN: Volvulus of the sigmoid colon in relation to the anatomy of the pelvic colon. S Afr Med J 37: , Report of the Task Group on Reference Man. International Commission on Radiological Protection. Publication 23. Oxford, Pergamon Press, 1975