January 1, 1931
The Masai have a relatively very high intake of protein, fat and calcium, while the Kikuyu have a high intake of carbohydrate and a low one of calcium.
Studies of nutrition. -- The physique and health of two African tribes
by J. B. Orr and J. L. Gilks
- IV.-SUMMARY OF RESULTS. Preliminary observations and a review of existing information suggested that disease is more prevalent amongst native races than is generally supposed, and indicated that the incidence of certain diseases might be correlated with diet. A survey of two tribes, the Masai and Akikuyu, showed that the diet of the former consisted to a large extent of milk, meat and raw blood, and that of the latter mainly of cereals, roots and fruits, the bulk of the diet being cereals. The outstanding points of difference in chemical composition of the two diets were that the Masai have a relatively very high intake of protein, fat and calcium, while the Kikuyu have a high intake of carbohydrate and a low one of calcium. Differences were found in the dietary customs between men and women in both tribes, the diets of the females approaching in each case to the mean between the diets of the males. Physical measurements showed that the full-grown Masai male is on an average, 5 inches taller and 23 lb. heavier than the full- grown male Kikuyu, and his muscular strength, as determined by the dynamometer, is 50 per cent. greater. Marked differences were found in the incidence of disease in the two tribes, bony deformities, dental caries and anaemia, pulmonary conditions and tropical ulcer being much more prevalent amongst the Akikuyu. On the other hand, intestinal stasis and rheumatoid arthritis were more common amongst the Masai. Analyses showed that routine Hospital and Prison diets are markedly deficient in calcium, the average daily intake being only about 0.3 gm. Ca, as compared with the assessed requirement of about 1 gm. Examination of the blood of Kikuyu and other natives on a similar dietary showed that the concentration of calcium was lower than the European standard, the average of 90 cases, prisoners and farm labourers (not pathological) being 9.4 mg. per 100 c.c. serum, as compared with 10-0 to 10.5 mg. in Europeans at home, and 11.4 mg. in 13 Europeans in Kenya. The range of variation in blood calcium was wide, from 7.3 mg. to 11.2 mg., the highest figure being below the mean for Europeans in Kenya. -
It would be an interesting study to correlate diet and stature in different countries, to ascertain whether any correlation exists between the quality of the diet and mean adult stature. There are differences in the incidence of disease in the two tribes, and one of the tribes, the Akikuyu, show abnormalities in the composition of the blood. The diet of this tribe is very rich in carbohydrate, relatively rich in phosphorus, but deficient in calcium. Experimental data have been brought forward to lend support to the suggestion that deficiencies in the diet, abnormal composition of the blood and reduced susceptibility to certain diseases which have been noted in this tribe, may be correlated. The possibility that diet may influence the susceptibility to certain infectious diseases raises one of the most important problems in nutritional research. With regard to the bearing of the results of the investigation on conditions in Kenya, we are probably justified in concluding that the diet commonly in use amongst the Akikuyu and other tribes of similar customs is badly balanced, being too rich in carbohydrate and deficient in calcium. It is probably deficient also in other substances required as constructive material for growth, and in certain of the vitamins. On the other hand, the Masai, with a diet at the opposite extreme, possibly have too little vegetable food rich in carbohydrate and cellulose. Improvement might be brought about by increasing the use of green vegetables by both tribes, and of milk by the Akikuyu. The problem is therefore one which concerns not only medical and public health, but also agricultural authorities. A general improvement of agriculture and animal husbandry amongst the Akikuyu will almost certainly be accompanied by an improvement in the health and working capacity of the natives themselves. This problem is not confined to Kenya. It appears to exist in many different areas in our tropical dependencies. It may be judged from the introductory statements in the early part of this report that the loss of health and efficiency attributable to deficient diet is, therefore, of considerable economic importance.