Nomadic tribe has message for us

Press, 28 February 1981, Page 10

Nomadic tribe has message for us

Goodput

One of the outstanding graduates in medicine from Otago University, who is now working in the United States, is Professor John Murray, of the Department of Medicine, University of Minnesota, in Minneapolis. He became famous in academic circles in the United States when he took sabbatical leave and drove with his wife, son, and daughter in two landrovers across the Sahara. . Unlike most Saharan travellers, their journey had a definite purpose. They took medical gear, power supply, centrifuges, and other equipment to carry out a several months survey on nomadic tribesmen living in the central Sahara, near Lake Chad.

A recent issue of the prestigious “American Journal of Clinical Nutrition” reveals that this unique New Zealand family of researchers came back with a new and exciting story. It leads off a series ,on “International Nutrition.”

John Murray and his family decided to compare the nutritional and disease conditions of two halves of a single tribal group.

One half of the nomadic Turkana living near the shore of Lake Rudolph drank only milk as a

source of protein. This was the traditional lifestyle which may have been followed for thousands of years. The other half of the same genetic and tribal group lived in the region of Ferguson’s Gulf on Lake Rudolph, and persistenly ate more than 150 grams of fish each day. - This fish is apparently quite plentiful, in spite of the fact that Lake Rudolph is an ancient lake in the Rift Valley fed largely by the Omo River which brings down silt from the Ethopian highlands.

There is no outlet, and trace minerals may accumulate in the lake. In view of the very isolated nature of the study site — obviously no new experience for the resourceful Murrays — an amazingly wide range of observations were made on 230 milk drinkers, who were an average age of 31.3 years. The “fish eaters” were 231 in number, with an average age of 32 years, and the average heights and weights were not different from the milk drinkers.

The only real difference in the diet was that the milk drinkers ate slightly more fat and less carbohydrate and protein.

The calorie content, or total energy supply, of the diet was the same ini both groups. To the surprise of the research workers the fisheating, and thus higherprotein eating, Turkana had greater rates of disease.

They bad higher rates of malaria, diarrhoea, and a disorder called brucella. More of them also had an enlarged liver or spleen, and an unusual skin condition called, molluscum Contagiosium. Of even greater surprise was the fact that the more healthy, milk-drinking Turkanas had lower amounts of circulating red cells and iron in their blood.

They also had less amoebae, which are a type of intestinal parasite. It could have been .reasonably expected that lower -protein intake, lower circulating iron levels in the blood, and fewer defensive white cells of the body would have led to more disease, and not less in the milk drinkers.

The . only explanation which seems to fit the facts is ■ that the ,fish-eat-> ing- group has developed these habits over recent generations, and has not yet had time to adapt to eating more protein. Before the last few hun-