Tins report, prepared jointly by the Director of the Rowett Research Institute and the Director of Medical Services in Kenya and issued by the Medical Research Council, is of considerable interest and value ; but, as its authors warn us, too much must not be read into it, nor must final or dogmatic conclusions be drawn from it. It is an analysis of the findings of two investigators, specially qualified and highly experi- "enced, who, backed by financial assistance provided by the Empire Marketing Board, engaged in a detailed and careful enquiry into the dietetic habits and into the stature, vigour and susceptibility to disease of two adjacent tribes in the Kenya Colony. The diet of one of these tribes, the Masai, consists very largely of milk, meat and raw blood ; whilst that of the other tribe, the Akikuyu, is mainly composed of cereals, supplemented by roots and fruits. The dietary of the Masai thus includes a high proportion of proteins, fats and calcium ; whilst that of the Akikuyu is over-rich in carbohydrates, and relatively deficient in proteins, fat and lime. Some thousands of members—men, women and children—of each of these tribes were carefully examined and measured, the physical measurements being taken only of healthy individuals, whilst the incidence of disease was studied both in hospital and in the field. In the comparison, the vegetarian tribe came out badly ; the average full-grown Masai male being five inches taller and twenty-three pounds heavier than his neighbour. Moreover, his physical strength
as measured by the dynamometer was found to be 50 per cent. greater. Except for a higher liability to rheumatoid arthritis and to intestinal troubles, the Masai are much less
subject than the Akikuyu to nearly all diseases. Lung affections, for instance, which are responsible for nearly 50 per cent. of all the native deaths in hospital, are far more common among the cereal-eaters than among the carnivores.
It would be rash, however, at once to jump to the con- clusion that all these differences can be attributed to the relative virtues and failings of a meat and of a vegetarian dietary. The two tribes, though geographically propinquent, are racially distinct ; and it is quite possible that a reversal of their dietaries would not lead to a complete reversal of the statistics. What does seem to be clear is that a restricted meat diet is more likely to be furnished with the elements-- mineral and other—essential to human well-being than is a restricted vegetarian one.
Recent experiments in this country have, indeed, demon- strated the very important part played in physical develop- ment and in susceptibility to disease by those vitamins which are more particularly associated with milk and other animal fats. The deficiencies of calcium in the cereal dietary could, of course, be remedied without resorting to animal foods ; and it was noticed by the investigators that the women of the Akikuyu, who are accustomed extensively to supplement the ordinary cereal dietary of the tribe with abundance of green leaves, are more generally vigorous and far less subject to disease than are the males. The matter is one for further investigation ; and there is certainly no need for the most broad-minded vegetarian to give up his creed as outworn and discredited on the strength of these findings. But, at the same time, the findings should be seriously contemplated and given full weight. After making all allowances for possible racial differences, it is clearly established that diet is a very important factor both in determining stature and in promoting immunity from disease.
But another fact of no less importance emerges from these investigations. There is still a widespread belief that, in spite of physical dangers, the life of the primitive native essentially a healthier, because a more " natural," one than that of civilized peoples. But, when we read that the infantile death-rate in the native reserves amounts to between 400 and 500 per 1,000, half of these deaths being due t" pneumonia ; and that, of 16,000 men of one district of the reserve who were called up during 1917 for enrolment in the Carrier Corps, 10,000 were immediately rejected on medical grounds (a further 17 per cent. being rejected tb physically unfit after the first march) ; whilst, among 14,000 medically passed men, employed on the Uasin Gishu railway in 1923, the death-rate was 85 per 1,000 (the admissions to hospital during the year being over 5,000), the legend of the
healthy savage is hard to maintain. HARRY ROBERTS.