Milk tolerance and the malnourished African.

Adult (primary) lactose malabsorption is practically universal in Africans of Bantu and San ('Bushmen') stock. Recent environmental changes, especially in rural areas, have exacerbated rates of malnutrition in hospital patients belonging to these groups. In order to assess the advisability of using milk as a nutritional supplement for such patients, the tolerance and absorption of 350 ml boluses of whole milk (containing 17 g lactose) was measured in 110 malnourished hospitalized patients in Namibia and South Africa belonging to Bantu (ie, Zulus, Hereros, and Kavangos) and San (ie, Bushmen) populations and compared with 22 healthy Westernized controls. Mild symptoms of intolerance were noted in about 10 per cent of Bantus and 20 per cent of Bushmen in comparison to 33 per cent of lactose-malabsorbing controls consuming Westernized diets and reported rates of 48 and 80 per cent in American population studies. The average increase in breath hydrogen excretion of 20 parts per million was also lower than the value of 34 parts per million in controls. Fasting breath methane concentrations were high in between 60-84 per cent of the groups of patients, but the level was not significantly affected by milk ingestion. Despite the combination of hypolactasia and malnutrition, 350 ml drinks of milk were well tolerated by African patients. Thus, milk should form an appropriate nutritional supplement for Africans hospitalized in rural areas.