[Water consumption in Saharan nomads. A remarkably reduced and constant consumption]

The writer has carried out two studies of the Western Sahara (Missions UNESCO-Institut Scientifique Cherifien 1961 and 1964) bearing upon the consumption of water by the Saharan nomads. In spite of their environment, the consumption appeared to be remarkably low and constant. Very strict dietary practices, the salinity of the water, and special behavioural customs seemed to be the basis of this strict economy of fluid intake. Genetic factors could also, of course, be partly responsible. The dietary practices are characterised essentially: 1) by a regime which in general contains the minimum of protein: milk foods, cereals, and sugars, and 2) by the habitual exclusion of salt in the preparation of meals; the sodium necessary for water/sodium balance deriving solely from the salinity of the water. Water with little or average salt content (total 2-3 g/l) seems to meet the normal needs of the body - there is no need for the salt pill - and, moreover, to quench the thirst more effectively than pure water (Paque, 1964) - presumably by making good the deficit (cf. Stricker, 1970). On the other hand, saltier water (total 4-8g/; Na 1 g/l or more) appears to pose more complex physiological problems for which the prime solution is to apply the Saharan rule, i.e. that no supplementary salt should be added to the diet (Paque, 1963). In desert life there are thus certain rules which must be obeyed. As for the matter of behavioural customs influencing water balance, they consist in the main of habitually limiting the frequency of water intake (often just twice daily, sometime only once daily) together with a careful choice of clothing and the wearing of the veil. Finally, genetic factor could result in a more efficiently controlled loss of water (and of salt?) VIA THE SKIN.