The association between dietary fats and heart disease (see above) seemed a strange subject for an ear and hearing specialist to be discussing. But Manhattan Ear Surgeon Samuel Rosen believes that the loss of hearing acuity in men and the incidence of heart attacks may have something in common. And he offered some fascinating evidence at the A.M.A. convention last week to support the idea.
Dr. Rosen got on the trail among the Mabaan, a primitive tribe in a remote part of the southeast Sudan who eat practically no meat or saturated fat and have low cholesterol and blood-pressure levels even in their 70s. They are a quiet people, but that alone did not explain why their hearing is amazingly sharp, especially for frequencies as high as 12,000 cycles per second—about the upper limit for an adult Western man. Equally significant, said Dr. Rosen, the Mabaan have no pronounced hearing loss at 4,000 c.p.s., which is particularly associated with loss of elasticity throughout the body, including small bone joints in the inner ear.
To test his hypothesis, Dr. Rosen later studied men in two mental hospitals in Finland, where the intake of hard dairy fats and the incidence of heart disease are about the world's highest. Finnish doctors put the men in one hospital on a low-fat diet. After five years, their cholesterol levels and their heartdisease death rate dropped, as expected. In addition, low-fat men in the 50-to-59 age range had more acute hearing than men aged 40 to 49 in the nondiet, high-fat hospital.
Dr. Rosen maintains that loss of hearing with aging results largely from clogging and hardening of the minute arteries nourishing the ear. If so, it may be possible to detect future victims of heart disease early in life by a simple, though sensitive, hearing test. Finns aged 10 to 29, on high-fat diets, suffer hearing loss earlier than young Yugoslavs or Cretans, on low-fat diets. To find out whether the pattern holds for the U.S., Dr. Rosen is studying New York City schoolchildren and their parents. If a simple hearing test does indeed give early warning of heart disease, he said, the time to put Americans on a lowfat, anti-cholesterol diet may be during childhood.