Hearing loss and coronary heart disease

Hearing tests were carried out in 1961, 1962, and 1963 among members of the isolated Mabaan tribe which for centuries has lived in virtual silence in the jungle of southeast Sudan. At all frequencies (500 to 24,000 cps) and all ages, their hearing is far superior to any previously recorded. Equally interesting are measurements of their systolic and diastolic blood pressures which are comparable at 15 and 75 years of age; coronary heart disease is unknown. The tribe's main food is millet, some fish, nuts, wild dates, and little meat. Members of the tribe are muscular and well postured at all ages, physically active, never obese, do not smoke, age slowly and are agile in their seventies and eighties. The mean cholesterol level is 160 mg/ 100 ml. Occasionally a tribal member moves to the city of Khartoum, and subsequently develops hypertension and coronary heart disease. In the United States,