As a people, the Japanese fascinate students of epidemiology because they are such an apparent paradox: they have the lowest rates of heart disease in the world despite the fact that smoking, one of the strongest risk factors, is virtually universal among Japanese men.
Japan’s longevity statistics confound all our expectations about what it takes to live a long and healthy life. The country produces the world’s largest number of centenarians; currently a reported 40,000 Japanese people have reached their hundredth birthday, many of them smokers.
Epidemiologists find transplanted societies particularly instructive, as they afford an opportunity to examine just how a particular community fares when confronted with profound social, cultural and dietary upheavals. Len Syme and Reuel Stallones, two professors of epidemiology at the School of Public Health at Berkeley, wished to study just this issue by examining heart disease risk plus dietary factors and any social changes in a pool of 12,000 men, divided among those who remained in Japan and two groups that had emigrated to Hawaii or Northern California.
Stallones was interested in whether the Japanese had low rates of heart disease in their home country because of their low-fat diet, and whether the rate went up when they adopted a typical burger-and-fries American diet. But Syme was fascinated by the social factor: whether moving countries and cultures was so destabilizing that it caused heart disease.
The results confounded both their expectations. The rate of heart disease among Japanese men immigrating to California was five times greater than the rate among those who stayed in Japan, and the rate among those who moved to Hawaii was midway between the two.
This signalled that immigration didn’t automatically cause heart disease. The results appeared to be completely independent of any of the usual supposed risk factors for heart disease, such as smoking, high blood pressure, diet or cholesterol counts; in fact, the Japanese population studied contained the highest number of smokers and the lowest levels of heart disease.
Amazingly their results also appeared to be independent of any dietary changes. Whatever the Japanese ate—whether tofu and sushi or a Big Mac and fries—had no bearing on their propensity to heart disease.
Although changes in dietary habits made no difference in terms of heart disease, the kind of society the transplants created for themselves did. The most traditional group of Japanese Americans had a heart-attack rate as low as their fellow Japanese back home, while those who had adopted the Western go-ahead lifestyle increased their heart-attack incidence by three to five times. These differences could not be accounted for by any of the usual risk factors like diet.
Those with social networks and social support were protected against heart disease regardless of whether they smoked or suffered from high blood pressure. Social mobility—moving outside your own cluster and no longer belonging—made you ill.
Leonard Syme was so intrigued by such findings that he travelled to Japan and interviewed scores of Japanese to find the X-factor that accounted for this impregnable good health among the Japanese.
What he discovered, as his interviewees repeated in interview after interview, was that Americans were lonely.
The Japanese, particularly in southern Japan, maintain tight-knit social groups that are mutually supportive, even in business. Until Japan’s severe economic recession in the 1990s, joining a firm as an employee was not unlike marrying into a family—a relationship for life.
Syme then enlisted a graduate student of his, Lisa Berkman, to examine the importance of social networks and social support as protection against heart disease. Berkman assembled the health statistics of most of the inhabitants in Alameda County by combing through nine years’ worth of California’s Human Population Laboratory statistics. Eventually she was able to show that those who felt lonely and socially isolated were two to three times more likely to die of heart disease or other causes than those who felt connected to others.
These results were independent of risk factors such as high cholesterol, high blood pressure, smoking and family history.
Berkman was fascinated to learn that our biological responses to stress, the ‘fight-or-flight’ mechanism produced by our autonomic nervous and endocrine systems, are subdued when a companion is present or we believe that support will be present, or even when we just think about having support.
Syme has concluded that the quality of the connection to a person’s immediate geographical cluster is one of the most potent predictors of health and illness. Even in the face of devastating adversity, a cohesive group connection, or Bond, can be protective against virtually any risk factor—be it migration, dislocation, poverty, poor diet, even alcoholism.
The need to move beyond the boundaries of ourselves as individuals and to Bond with a group is so primordial and necessary to humans that it remains the key determinant of whether we remain healthy or get ill, even whether we live or die. It is more vital to us than any diet or exercise programme; it protects us against the worst toxins and the greatest adversity; it is the best drug in the world—even better than diet and exercise.
The Bond we make with a group is the most fundamental need we have because it generates our most authentic state of being: the sense of belonging, of being part of something bigger.
Adapted from my new version of The Bond: The Power of Connection (Hay House, £12.99), which features a large new section of practices to strengthen Bonds with your family, work colleagues, neighbourhood and larger community.