A hundred years ago, immigrants were treated as vectors of decline and mental illness. The biggest role of the U.S. Public Health Service when it was created in 1902 was to quarantine and examine newcomers for signs of physical and moral degeneracy. Over the past few decades, however, research has established that foreign-born inhabitants of the United States live longer and healthier lives than native-born Americans, even though they have far less access to health care. Whether Asian, white, Hispanic, or black, immigrants can expect to live four years longer on average than native-born whites, while suffering fewer chronic illnesses, including neuroses.
But according to the most recent data on immigrant health, these health advantages decline over time. The longer they live in the United States, the sicker immigrants get, especially if they are people of color. According to a new study by the Centers for Disease Control comparing the health of immigrants and native populations, white European immigrants report improved health after living five or more years in the United States, but most other immigrants—blacks and in particular Hispanics—have the opposite experience. No one knows exactly why, and the causes are clearly multiple. But the most important factor may be the biological difficulty of tolerating the abundance of America life.
For example, black immigrants are half as likely as black Americans to be fat or have heart disease—and only a third as many smoke, regardless of socioeconomic status and age. Similarly, even the poorest, doctorless Hispanics entering the United States are healthier than Hispanics born here. Sixteen percent of Hispanic immigrants who've been here fewer than five years are obese, compared to 22 percent of Hispanics living in the United States for five years or longer. The rates of hypertension and cardiovascular disease also dramatically increase among Hispanic immigrants of long standing, as do complaints of stress and mental instability. And Hawaiian studies have shown that breast and colon cancer and heart disease rates rise the longer Japanese and Korean immigrants live in the United States.
In sum, whatever it is about American life that makes African-Americans and native-born Latinos sicker, on average, than your average white person—recent studies show higher rates of obesity, diabetes, and hypertension—eventually drags down new arrivals as well. Acculturation to American life signifies regression to the health mean of one's ethnic group.
Reaching for explanations, scientists have suggested that immigrants are a self-selected bunch—immigration officials play some role in selecting out the sickly—who must be especially hardy to make a difficult transition to a new land. Also, while they come from countries where infectious disease shortens lives, people from Third World countries have the advantage of belonging to cultures where peoplestay married longer; live in larger households with more family members; use fewer drugs, cigarettes, and alcohol; and eat less fat. These are all healthy behaviors. Over time here, however, these immigrants become more like Americans—hardworking single and divorced McDonalds eaters. In their home countries, immigrant women tend to smoke, drink, and divorce less than they do here; with sexual equality, apparently, come some bad habits. The discrimination and related stress that blacks and Hispanics contend with in the United States is also part of the mix of explanations for their deteriorating health.
The decline in health that follows immigration isn't a problem here only. In Canada, a country less conflicted over race and immigration (with a population that is 20 percent overseas-born, compared to 12 percent of the U.S. population), the same trends hold true. White immigrants to Canada largely maintain their health over time, but blacks get sicker. (The number of Hispanic immigrants to Canada is relatively small.) The adoption of bad diet and exercise patterns explains some of this difference. But minorities in Canada do not lack access to health care the way they often do in the United States.
Thus, genes are probably the best explanation for much of the marked deterioration of the health of immigrants as they move from the Third World to the First World. While driving to work and eating lots of saturated * fats is bad for all humans, it seems to take a special toll on people from warm climates. Genetic studies have shown that many Latinos, blacks, and south Asians have a greater inherited predisposition for diabetes and hypertension. The presumption is that people living in traditionally poorer areas of the world evolved more of a "thrifty genotype," allowing them to survive on a starvation diet. But they're exposed to a variety of metabolic problems once they start consuming Western carbohydrate portions. The obesity epidemic hits former Third Worlders hardest.
Still, what's clear from the CDC study, and other data on the health of immigrants, is that most of the things that make immigrants sicker the longer they stay here are caused by things they can avoid. Even if the consequences of such behaviors may be worse, in general, for people of color, thecontrast between the health of new arrivals and longtime immigrants underlines the value of truisms about the importance of exercise and moderation in smoke, drink, and munchies.
Immigration to North America isn't a total wash, healthwise. At least new arrivals reap the benefits of our high rate of vaccination and cervical exams. Asians in particular show lasting health gains. Here and in Europe, routine pap smears have reduced cervical cancer rates dramatically over the past 30 years. But the practice hasn't caught on as fast in Asia, and cervical cancer rates there are far higher. Women in Vietnam, for example, suffer the disease five times as often as white Americans. And liver cancer is more common throughout Asia because of infections from hepatitis B, which infants are vaccinated against in the United States.
If only there were a vaccine against eating Krispy Kremes.