Culture and Coronaries

American men have one of the highest heart-disease rates in the world; 378 out of every 100,000 die as a result of coronary attacks each year. Japanese men have one of the world's lowest heart-disease rates; coronaries yearly claim only 92 out of every 100,000 of the country's males. Most medical researchers have long been convinced that the difference is dietary: the traditional fish-and-rice diet of the Japanese is much lower in fat content than the meat, dairy and fried-food menu favored by Americans. But a new study by researchers from the University of California at Berkeley seems to show that the difference is largely cultural, not culinary. The findings indict stress, American-style, as a major cause of coronaries.

The Berkeley team, headed by Dr. Michael Marmot, conducted a ten-year study of some 4,000 Japanese men living in the San Francisco area, investigating their background and lifestyle as well as their diet, cholesterol levels, smoking habits and other factors usually associated with heart disease. When the data were finally analyzed, it became apparent that the Japanese who cling to their traditional lifestyles, which defuse tension by emphasizing acceptance of the individual's place in both family and society, fare well. Even those who indulge in high-fat diets suffer fewer coronaries than their American counterparts. But those who adopt the aggressive, competitive and impatient traits of most Americans increasingly succumb to the strain. The study found that Japanese who made a moderate transition to Western ways suffered 2 1/2 times as many heart attacks as those who continued to live like their forebears. Those who plunged most fully into the stress of American life were five times as likely to have coronaries as those who maintained Japanese ways.

Even in their highly industrialized homeland, the researchers note, Japanese have considerable protection against stress. They live in closely knit groups and compete as a group, rather than as individuals. But once they enter the U.S., many become subject to the same stresses as Americans. "Most Americans move away from their support group during their lives, move from one place to another, drop old friends and take up with a new set of people," explains Marmot. "That's a very un-Japanese thing to do."

Critics of the Berkeley study are likely to insist that diet still cannot be discounted as a cause of coronaries. But researchers like Drs. Meyer Friedman and Ray Rosenman, cardiologists from San Francisco's Mount Zion Hospital and Medical Center, find that the study's conclusions support the theory espoused by their book, Type A Behavior and Your Heart (TIME, April 15, 1974). The San Francisco doctors have long insisted that the American way of life is hard on the heart. The Berkeley study suggests that they are right.

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