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The Best Science Writing Online 2012
Showcasing more than fifty of the most provocative, original, and significant online essays from 2011, The Best Science Writing Online 2012 will change the way...
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For decades scholars and public health officials have known that people with greater income or formal education tend to live longer and enjoy better health than their counterparts who have less money or schooling. The trend holds true wherever researchers look—in poor countries or rich ones, in Europe, Asia or the Americas—but two notable exceptions stand out.
One is known as the healthy immigrant effect. Looked at as a group, immigrants to countries as diverse as the U.S., Australia, Germany and Canada live longer than their new native-born neighbors. Yet immigrants also tend to be less well educated and are often more likely to live in poverty in those countries.
The other exception is called the Hispanic paradox and is particular to the U.S. In study after study, people of Hispanic descent (typically of Spanish, Mexican, Cuban, Puerto Rican, or Central or South American origin) seem to live longer than non-Hispanic whites, who on average happen to be richer and better educated. In 2006, for example, life expectancy at birth in the U.S. was 2.5 years higher for Hispanics than for non-Hispanic whites. The paradox is real; data errors, such as small sample size or the underreporting of Hispanic ethnicity on death certificates, cannot explain it. Yet the cause of the paradox has long been a mystery.
Recently I took a closer look at both the healthy immigrant effect and the Hispanic paradox with Andrew Fenelon, a graduate student at the University of Pennsylvania. Fenelon studies sociology and, like me, demography—a relatively small field that I often describe as the ecology of human populations. Just like ecologists, demographers are interested in the fertility, mortality and migration patterns of certain species; in our case, that species is humans. Samuel Preston, one of the world’s leading demographers (and Fenelon’s Ph.D. adviser), had a hunch about what might cause the U.S. Hispanics’ longevity advantage in particular, and Fenelon and I had some ideas about how to test that hunch and to see if it applied as well to the immigrant advantage.
Today Fenelon and I believe we can largely explain both anomalies. If our research is correct, then it largely stems from just one factor—a factor that was hiding in plain sight all along.
Unraveling a Mystery
Scholars have come up with many hypotheses to explain the general immigrant advantage, and most of these ideas simultaneously attempt to account for the more specific Hispanic paradox as well. They link the two phenomena because many Hispanics in the U.S. are immigrants: according to the latest census data, two out of five Hispanics living in the U.S. were not born there.
Among the most popular explanations for the immigrant advantage is that such individuals might be unusually resilient, both mentally and physically. They must, after all, need energy and motivation to leave their homes and build a new life on foreign soil, the thinking goes. At the very least they are not likely to be on their deathbeds when they move. Perhaps, therefore, immigrants are simply healthier than the average person when they arrive in the U.S. Alternatively, maybe immigrants who get sick leave the U.S. and return home for care, which would then leave the population of remaining immigrants unusually healthy.
In addition to a putative immigrant advantage, proposed explanations for the Hispanic paradox generally emphasize culture and lifestyle. Hispanics in the U.S. could have stronger family ties that may help steer them through periods of ill health and stress. Another possibility: Hispanics might eat more nutritious foods. Or their work and leisure activities might be more physically demanding, which promotes physical fitness. All these notions are plausible. Yet to date, no studies have been convincingly able to link such behaviors to the Hispanic lifespan advantage.
One lifestyle factor, however, correlates with elevated death rates in almost every mortality study of any population in the world: smoking.
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22 Comments
Add CommentExcellent perspective but flawed interpretation.
Reply | Report Abuse | Link to thisIt is flawed to extrapolate lung cancer deaths to other smoking related deaths because the chance of a smoker dying from smoking depends on many factors, some of which may be very different between immigrants and natives.
Even if a lower smoking related death rate really explains the immigrants' longevity, it may not be solely caused by less smoking. It is quite possible that immigrants who are smokers are less likely to die from smoking than natives who smoke the same amount. I wonder if the author has compared the lung cancer rates of immigrants and natives who smoke the same amount.
Let me propose an explanation for the immigrant advantage - stress. It is well established that wealth is correlated with longevity, but it is not absolute wealth but comparative wealth that matters. It is because being happy or stressed depends very much on how one compares oneself with others around. Immigrants may be less well off from a demographer's point of view, but they FEEL very well off when they compare themselves with people they are connected - fellow immigrants and people still living in their homelands.
The same psychological factor can also explain the difference in smoking habits - people and animals are more prone to addiction when they are stressed.
I expect the immigrant advantage will still be very significant even when smoking is banned.
Another explanation for the immigrant advantage is immigrants' successful second generation. It is well documented that the children of immigrants are more successful in their pursuit of studies and careers. Thus during the later stage of their lives, the immigrants afford to lead richer lifestyles than their own wealth suggests, thanks to support from their richer children who also tend to have stronger ties with their parents.
Reply | Report Abuse | Link to thisThe headline of this article mentions "two populations" but does not state what the second population is. From what I have read the Japanese people in this country (and also in their homeland) have the best mortality statistics. This suggests that a combination of life style and genetics are paramount for a healthy life, not money spent on health care.
Reply | Report Abuse | Link to thisIt also implies that excessive spending on medical care will not improve significantly the quality of life if there is no accompanying significant change in life style.
Immigrants avoid doctors because the don't trust them. They likely were not vaccinated when they were born. That means they were mentally damaged and their immune system was not damaged.
Reply | Report Abuse | Link to thisSomething to check. Just a guess
What do you mean by mentally damaged?
Reply | Report Abuse | Link to thisi should have said ....not mentally damaged
Reply | Report Abuse | Link to thisSeems pretty reasonable analysis and makes sense. Smoking is quite bad for long-term health. If a certain population smokes alot more than another, then the smoking population won't live as long.
Reply | Report Abuse | Link to thisThe key seems to be stress, with large variations on how well particular individual's bodies handle or don't handle stress. Various things like lifestyle, eating habits and family/friends support all help to lower stress. Stuff like smoking raises stress on the body (various amounts based on the individuals personalized reactions to smoke+contaminants).
Laura, you have too many extrapolations and asumptions to reach a valid conclusion. If you over dose on anything, it can kill. I see nothing on the well documented health benifits of low dose nicotene. I was a commercial floorcovering installer for 40 years. The apprentices had an 85%drop out rate and about the same for the young journymen. The one who made it to retirement were much healthier than average as are our children. Immigrants would follow the same selection. Ask your self why the Food and Drug Administration has not followed their mandate with Tobacco and where did all the TV commercials go all of a sudden? Does someone need to go to jail for biasing your education for fun and profit?
Reply | Report Abuse | Link to thisIt isn't as simple as that. No ethnic group outlives the Japanese who are among the heaviest smokers on the plant. Last time I looked Japan ranked #1 or #2 in cigarette consumption per capita. In Europe, the Greeks excel in life expectancy but they also rank at or near the top in cigarette consumption.
Reply | Report Abuse | Link to thisPersonally I think anyone who smokes is a damn fool. Yet the link between smoking and lung cancer isn't nearly as clear cut as it's made out to be.
As an ex-patriot I have found that people that move to a new country tend to be healthier, both physically and mentally, than the general population and therefore live longer. People that are sick or depressed don't pick up and move to a new country.
Reply | Report Abuse | Link to thisI think people from poorer countries where people die of diseases that are routinely cured in Canada and the US, Have undergone genetic changes making them healthier than us. I also think the reason why blacks are superior athletes is because they were picked in Africa as good specimens, survived the boat trip and the tough life as slaves and impoverished people. The survivors have got to be tougher than the average person.
Reply | Report Abuse | Link to thisWayne Jones
Ottawa
You have proven my husband's comments over the last 30 years - that having taking statistics, he came away with the conclusion that Statistics can be used to prove any per-conceived concept. Having lived my life in an area originally settled by the Spanish in the 1500's, I can absolutely tell you that the locals tend to die before the age of 30. Which makes me wonder from where your demographics originate. Consulting with a denizen of a local barrio, we came up with an alternate scenario: that Hispanics and recent immigrants tend to take those jobs which are labor-intensive. And that if you look at the origins of humanity, humans are designed to 'work' - designed to be physical in their daily activities. Ergo - sitting behind a desk is counter-productive to longevity. Could this be an alternate result of these statistical data?
Reply | Report Abuse | Link to thisThis article proves what my husband has told me for 30 years. Having studied Statistics, he has always said that statistics could be used to prove any preconceived concept.
Reply | Report Abuse | Link to thisLooking at this premise in another way, from the viewpoint of having lived 6 decades in the part of the country settled by the Conquistadors: in reality, young Hispanic males partake of risk-taking lifestyles, and are often dead by the age of 20. Or they join gangs - and gang members Always smoke as a sign of being 'macho'. It looks like your data have been taken from some flawed source.
So, let's look at your premise another way. Homo sapiens were designed to be active daily, millions of years ago. Take that premise to current times - and what do Hispanic populations have in common with immigrant populations? They tend to take on the labor-intensive jobs that lazy Americans will not perform. Jobs which, ultimately, keep them healthy throughout their lives. Could that be they reason they live longer?
Really, "white men can't jump". There are genetic advantages to being Black which come down to a deeper heel bone around which the tendons wrap enabling more ability to 'jump'. Political correctness be damned - there are physical differences that need to be recognized - if my child were missing, please let me know that a skeleton found does or does not match my ethnic heritage!
Reply | Report Abuse | Link to thisThank you. This article proves what I've heard for 35 years from someone who studied Statistics in college. That statistics can be used to 'prove' any pre-conceived thesis.
Reply | Report Abuse | Link to thisHow about this one: new immigrants and the Hispanic population tend to take on labor-intensive jobs, and the human body was designed to work daily. Which means that desk jobs are not healthy. Having lived in the Southwest all my life, I can tell you that young Hispanics ALL smoke, and large numbers of them are dead by the age of 25. Most join gangs. So I would also question your data collection.
Thank you! Your article proves what my husband has said for 35 years - that Statistics can be used to prove any pre-conceived concept. Having lived all my life in the Southwest, among descendants of the Spanish Conquistadors, I would like to point out that young Hispanic males ALL smoke. How about this concept: Hispanics and Immigrants tend to take the manual-labor jobs in this country. Those jobs Gringos won't stoop to taking. And - surprise! - Homo sapiens were designed to work - not to sit at a desk job. Ergo, physical labor equals a healthy life style. Just a thought.
Reply | Report Abuse | Link to this"Immigrants avoid doctors because the don't trust them."
Reply | Report Abuse | Link to thisIt is called "The Hispanic Paradox" (not the "immigrant paradox"). Hispanics have been in the US since about 200 years before the Mayflower was built. YOU are the immigrant.
BTW: Immigrants do not trust *politicians*, but they trust doctors.
"Immigrants avoid doctors because the don't trust them."
Reply | Report Abuse | Link to thisIt is called "The Hispanic Paradox" (not the "immigrant paradox"). Hispanics have been in the US since about 200 years before the Mayflower was built. YOU are the immigrant.
BTW: Immigrants do not trust *politicians*, but they trust doctors.
This is what the doctor says:
Reply | Report Abuse | Link to this"Let me give my opinion now on why Hispanics have better health in the USA than non-Hispanic whites. It has to do with the support they give one another and their strong family lives that counter the adverse effects of the gap and their poverty. Much has been written about this so-called Hispanic Paradox. I came to understand the reasons by reflecting on Hispanic patients I see in the ER. I never see a single Hispanic patient. There is always a group of people huddled together. I have to go and figure out who the patient is, for everyone comes to offer support. By contrast, I'm much more likely to see a white person lying there writhing in pain alone. So we can conclude that it is the nature of psychosocial relationships, the support people have and give in a society, that is more responsible for their health as communities, than any other factor. "
"The headline of this article mentions "two populations" but does not state what the second population is."
Reply | Report Abuse | Link to thisYes, it does:
(1) Immigrants
(2) Hispanics
In this day and age, it is easy to confuse the two groups, but they are different. :-)
(I happen to be both)
This article is VERY related:
Reply | Report Abuse | Link to thishttp://www.washingtonpost.com/wp-dyn/content/article/2006/04/10/AR2006041001385.html
http://tinyurl.com/l9opd
"Yet the link between smoking and lung cancer isn't nearly as clear cut as it's made out to be."
Reply | Report Abuse | Link to thisThe link in one direction is almost perfect: If you get lung cancer, you are a smoker. A remote exception is people who work with and breath asbestos all day (who are zero these days). Some people can smoke all they want and don't get cancer, like some people who eat lots of salt and don't get high blood pressure.