Earlier this month, a study in the Journal of the American Medical Association compared the health of a group of men in the United States with that of a very similar group of men in England. The researchers found a striking difference in the quality of health of the two populations—the Americans were sicker and died younger than their British counterparts. The results are anxiety-provoking because they can't easily be accounted for—and because one of the study's authors, Dr. Michael Marmot of University College, London, is a giant in the field.
Marmot's new study compared two populations, one in England and one in the United States, totaling about 8,000 in all, with many similar characteristics. All were male, non-Latino whites between the ages of 55 and 64. The researchers curbed diversity in this way in order to weed out extraneous factors. But in each group, the men ranged widely in terms of income and educational attainment. Thus, though the study primarily compared the health consequences of living in the United States or living in England, the researchers also looked at the degree to which socioeconomic status contributed to the health differences they found.
Marmot and his co-authors—James Banks, Zoe Oldfield, and James P. Smith—asked the research subjects to self-report rates of diabetes, high blood pressure, heart disease, lung disease, stroke, and cancer. The researchers found that American men were far sicker with these chronic diseases than British men similar in age, ethnicity, and socioeconomic status. When these two groups were compared, the American men were worse off with respect to every disease the study included. Often, the differences were striking: 12.5 percent of the American men reported that they were diabetic, compared to 6.1 percent of the British men; the men in the United States were 1.25 times as likely to report high blood pressure, more than 1.5 times as likely to report heart disease, and 1.7 times as likely to report cancer.
Could the difference have been one of interpretation—do American and British men respectively exaggerate or underplay illness? To rule out this possible weakness of self-reporting, Marmot's team considered studies that examined lab test results, so they could objectively corroborate the reports of the patients in their own study. The team found that, in general, for both groups the level of self-reported illness and the laboratory findings closely matched. (For instance, in England, self-reporting of diabetes was 8 percent higher than diabetes confirmed by laboratory testing, while in the United States, the self-reported rate was 11 percent higher.) So, both self-reporting and lab results suggest the same thing: British men appear to be significantly less likely to suffer from chronic disease than similar Americans.
There are many ways in which these results are not at all what one would expect. For instance, the United States spends a great deal more on health care than England does—2.4 times as much per capita. And other differences like the terrible state of British dentistry also ought to weigh in Americans' favor. It's long been suspected that dental and oral infections play a role in promoting heart disease and possibly stroke. Tooth loss can lead to poor nutrition and social isolation among the elderly, which increase the risk for illness and early death.
So, how do we account for the apparent better health of Englishmen? This study shows that the answer doesn't relate to race or ethnicity. The researchers also showed that neither smoking (Brits and Americans smoke in about equal numbers) nor overeating (Americans do this more than Brits) nor heavy drinking (here the Brits have the edge) could account for the difference. So what, then?
Perhaps the answer comes from Marmot's previous research. As a social epidemiologist, Marmot's life's work has been seeking to understand the social determinants of health—for example, the extent to which poverty and inequality in the provision of health services leads to poor health and lower life expectancy. (Answer: a lot. For example, just under one in three children living in Sierra Leone will die before age 5, compared with three in 1,000 children in Iceland. The difference is a hundredfold.) Marmot's greatest contribution is probably the "social gradient"—the notion that in any culture the rates of illness and mortality are strongly affected by one's socioeconomic status. At any given age, the higher you are on the social totem pole, the lower your likelihood of illness and the longer you are likely to live. This prediction—that higher socioeconomic status means better health and longer life—is equally true in cultures of plenitude and cultures of material deprivation.
In 1967, Marmot began the first of his two Whitehall studies— epidemiological research involving a total of about 28,000 British civil servants. Again, the group was selected to weed out diversity: The subjects were all male in one of the two studies, virtually all white, and none had physically demanding or dangerous jobs. But they ranged in employment grade from messengers and doorkeepers to the highest-level administrators. Marmot and his team examined the relationship between their employment levels and their rate of death from heart disease (in the first Whitehall study) and from other kinds of chronic illness (in the second study). The team found that men in the lowest civil-service grade—doorkeepers, for example—were three times more likely to die of heart trouble than, for example, administrators in the highest grade. About a third of the difference in death rate could be attributed to differences in risk: Lower-status workers were more likely to be obese, smoke, and spend less leisure time on physical activity. But other factors were clearly at work.
The factor that Marmot found played the greatest role was the lack of control that people in lower status occupations felt over their jobs. This factor was an important predictor for risk of heart disease and depression. It was most acute when employees faced situations of high stress but had little autonomy in dealing with them. Women who felt they had little control over their lives at home also had an increased risk of depression and of heart disease. The factors that correlated with good health were a sense of being happy much of the time or of working in a situation where the supervisor was perceived as acting in a fair or just manner. High levels of both appeared to protect against heart disease.
Marmot's work counters the strong bias among physicians and public health planners to understand the roots of illness and mortality in straightforward biological and mechanical ways. The professionals often want to blame dirty water, lack of calories, smoking, overeating, and poor access to modern diagnostic and treatment methods. No doubt all these problems contribute to illness and early death. But social factors also directly affect health, and not just through the obvious pathway from poverty to limited access to food or clean water or good medical care. Among British white-collar workers, good health and high status are intimately related, even in a health-care system that gives everyone access to good medical care. The same relationship holds true in America and in most of the rest of the world.
We don't know yet precisely how a sense of low status or lack of control activates the biological mechanisms that cause heart trouble or other chronic disease, but there is clearly some powerful interplay. The critical point may simply be that unrelieved stress and anxiety are intrinsically bad for your health. Which forces us to ask the question: Is life more stressful in the United States than it is in England? Perhaps Marmot's next study will venture an answer.