Why Do Chinese Outlive Indians? : THE HEALTH OF NATIONS The True Causes of Sickness and Well-Being<i> by Leonard A. Sagan (Basic Books: $19.95; 216 pp.)</i>

The French propose a jesting New Year’s Eve toast: “It’s better to be rich and in good health than poor and ill.” Leonard Sagan, a physician and epidemiologist, would agree, and he’d add that--if you want to celebrate many New Years--it’s better still to be upper class, educated, blessed with loving family and friends, and stressed--but only enough to keep life challenging.

Sagan, who believes that the subjective, complex state we call “health” can best be measured by life expectancy, seeks to explain why life expectancy increases and why it may stop doing so. Thus his daunting, self-imposed task is to trace changes in this indicator throughout the entire world, in rich nations and poor--a tall order for a short book, despite a staggering array of references.

His conclusions are unlikely to endear him to development planners, nutritionists, assorted health professionals or his own colleagues. Against received wisdom, he offers evidence that sanitation, improved diets and better medical care have less influence on survival than other factors associated with “modern” societies, defined as those based on science and technology, increased productivity, individualism, gender equality, the nuclear family, urbanization and, above all, education.

Why has life expectancy in the United States, which spends more per capita on health than any other country except Sweden, dropped behind that of 18 countries including Greece, Spain and Italy? Because, says Sagan, American health habits are worsening in spite of the fitness craze, and at the same time the psychosocial climate is deteriorating. The incidence of mental illness is appallingly high (17-23% of the U.S. population displays some psychiatric disorder at any given time), while illiteracy, divorce, teen-age pregnancy, child abuse and homelessness mount inexorably.

All these social scourges shorten average life spans, and they are unfailingly found in higher proportions among the poor. So are alcoholism, obesity and smoking. Incredibly, “social class is a good predictor of auto accident death rates” (the lower the class the more fatalities), and upper-class cancer patients survive longer than lower-class patients, even when the latter are diagnosed at the same stage and receive identical treatment.

Worse still, Sagan asserts, the U.S. medical system may relieve symptoms, but it does not lengthen life and frequently impairs it. At least half the antibiotics prescribed are harmful and predispose to infection, “far too much (intrusive) diagnostic testing is done,” and unnecessary, life-threatening surgery is commonplace. No one can prove conclusively whether “cancer treatment prolongs life, shortens life or has no effect at all,” nor is there “persuasive evidence that hospital-based treatment (of cardiovascular ailments) is superior to home-based treatment as measured by survival.”

One can only applaud Sagan’s efforts to throttle sacred cows and to push the reigning medical paradigm away from high-tech magic bullets and costly, dehumanizing efforts to stretch out the lives of the terminally ill, toward a health system that could encompass the “obvious human problems of neglect, brutality, loneliness and ignorance.”

Serious flaws, however, mar this compassionate, provocative and scholarly book. Sagan ignores some of the biggest life-expectancy stories of the century. Is it because they carry a political message? In 1960, the average life span for both sexes was 43 years in India, 41 in China. By 1985, according to World Bank figures, the average life expectancy in India was 57 years for men, 56 for women; in China, however, it was 68 years for men but 70 for women! Clearly, political choices favoring greater social equality must have contributed something to China’s vastly superior performance.

Strong support for the argument that literacy heavily influences survival could have been provided by Nicaragua, where the Sandinistas have reduced illiteracy from 57% to 12%, while insuring a basic diet and primary health care for nearly everyone. In response, the infant mortality rate plummeted by more than 30% between 1979 and 1983, but Sagan doesn’t tell us so. He does note the good record of the Indian state of Kerala, where female literacy is 64% and infant mortality the lowest in the country, but he fails to say that Kerala was for many years administered by a progressive leftist government. Nor does he ever invoke the present U.S. Administration’s indifference, indeed hostility, to the poor when explaining why America now trails poorer countries in life expectancy.

One further fears that elites may find Sagan’s downgrading of the role of nutrition and sanitation a heaven-sent justification for their view that the poor don’t really need better diets or clean water since these haven’t much to do with life spans anyway.

The battle over the “small but healthy” hypothesis currently raging among nutritionists is not academic nit-picking but reflects a political struggle for resources. If people who are by all normal standards underfed can nonetheless “adapt” to malnutrition and survive, the food problem virtually disappears, statistically speaking, and with it the need for governments and the rich to concern themselves with the chronic hunger of their poorer compatriots.

Readers of “The Health of Nations” will learn much that is valuable and fascinating but should be prepared to supply a framework of their own political questions--and answers.