Immigrant health paradox update

I wrote a few years ago about the surprisingly low infant mortality rates among immigrants, especially Mexican immigrants, given their relative socioeconomic status. As poor as they other, in other words, we would expect higher infant mortality rates than they have. This has been called the epidemiological paradox. Here is an update, which includes some text from the previous post.

In almost every race/ethnic group, immigrants are healthier.* Here’s the pattern for infant mortality, now updated with 2010 infant mortality rates from federal vital statistics records (click to enlarge).


For Latinos in particular, their health is surprisingly good given their economic conditions. Robert Hummer and colleagues, in a 2007 article, offered a succinct description:

…the relatively low levels of education, income, and health insurance coverage among Hispanics compared with non-Hispanic whites is thought to place the former at higher risk for negative health outcomes. However, it is well documented that some Hispanic groups exhibit similar observed death rates compared with the non-Hispanic white population and much lower death rates than the non-Hispanic black population, whom they closely resemble with respect to socioeconomic characteristics. The greatest enigma is exhibited by the Mexican-origin population of the United States. This Hispanic subgroup is characterized by low educational attainment; low health insurance coverage rates; mortality rates similar to non-Hispanic whites; and much more favorable mortality rates than those of non-Hispanic blacks across most of the life course.

In a 2013 revisiting of the paradox, Daniel Powers confirms the basic pattern, but adds an important wrinkle for Mexican mothers: the foreign-born advantage disappears for older mothers. Thus, children born to older Mexican immigrants have similar risks as those who mothers are born in the U.S. He concludes, in part:

Given the association between infant survival and maternal health, differential infant survival within the Mexican-origin population suggests that longer exposure to social conditions in the U.S. undermines the health of mothers who, in general, seem to have more favorable health endowments than their non-Hispanic white counterparts as evidenced by the relatively lower rates of infant mortality at younger ages.

Immigrants are often healthier than the average people in the countries they came from, which explains some of the paradox. However, our ability to accurately assess the relative health of immigrants versus the populations they left behind is limited by available data. Further, in the case of Mexico, the situation is complicated by cyclical movements of immigration and emigration. In a recent paper, Georgiana Bostean reviews this problem, and compares the health of immigrants, non-migrants, and return migrants to Mexico. And — It’s complicated. She concludes:

…there is no simple explanation for Latinos’ perplexing health outcomes, such as simply that healthier people migrate. Rather, migrants are positively selected in some health aspects, negatively selected in others, and in yet other health outcomes, there is no selection effect. In sum, selective migration plays a role in explaining some of U.S. Latinos’ health outcomes, but is not the only explanation and does not account for the Paradox.

These articles are a good place to start on this topic: lots of references to fill in the background and previous research on this paradox, which goes back at least to the 1980s. This is a fascinating and important research area, dealing with such questions as health behaviorintergenerational change, thorny puzzles about different immigrant groups, child development and lots more.

*Because Puerto Rico is part of the U.S. (albeit not a free part), people born in Puerto Rico who move to the states are not immigrants, just migrants. In the figure I used the terms “US Born” and “Foreign born,” but this is just shorthand, and not strictly accurate for Puerto Ricans.

14 thoughts on “Immigrant health paradox update

    1. Yes, thanks. The CDC table breaks down the groups under headings for 50 states + DC versus elsewhere. To put them in categories that mirror the others I simplified to US v. foreign born. Will add a note!


    1. I don’t know. But I imagine it has at least partly to do with the lower barriers to movement for them. (So there may be less selection of healthier people coming to the mainland and less healthy people going back.)


  1. The paradox of better “First Generation Immigrant” health has been extensively studied in medical literature and reported in hundreds of publications; I provide a few reasons first, and then list the publications (you need to look outside sociology, in MedLine, for example):

    (BTW, infant mortality is not a sufficient indicator; the better indicators are life expectancy at various ages, 5, 35, and 65).

    1. Self selectivity: People who chose to be immigrants are younger, healthier and fitter. More precisely, the fittest, emigrate.

    2. People who were born in foreign countries have more exposure to pathogens, both, water-borne and air-borne. This allows the body’s defense mechanisms to work to develop a n in-built defense. Anti-biotics and vaccines actually work to reduce the natural defense.

    A well known example is India (or China); the water and air has a much larger loading of pathogen which cause diarrhea, typhoid and cholera; mosquitoes cause dengue, typhoid. However, the local population has, developed, both genetic and time-developed defences once they live past 5. Similarly, the issue of chickenpox, air-borne breathing illnesses, etc.

    In contrast, children born to immigrants do not receive the immune system benefits of being raised and surviving through age 5 in a tropical country, and have lower immune resistance, and lower life expectancy at age 35 and 65 than the parents and native populations.

    3. The immigrant population is slow to adapt the high cholesterol processed food diet of richer countries, primarily because of a lack of money and culture (they cook their own food from purchased vegetables, fruit and meat); however, very subsequent generation picks up more of the dietary habits and picks up the risk of strokes, cancer, etc. Issues like AIDs, obesity, smoking-induced, etc are less see [3].

    There is an exception to the Latino rule; Hispanics in Mexico and Puerto Rico have higher life expectancy at 45 and 65 than US born Hispanics, although, foreign born Hispanic at US have better life expectancy than Hispanics at Home. A paradox is that foreign-born Hispanics seek medical help much less than US-born or even Hispanics at home. The immigrant paradox is closed tied to another finding “Higher volume of medical care does not improve health care outcomes”.

    General references to immigrant health

    “Immigrant Health—Selectivity and Acculturation
    Guillermina Jasso, New York University
    Douglas S. Massey.Princeton University
    Mark R. Rosenzweig, Harvard University
    James P. Smith, Rand.

    In contrast, Samuel Preston a UPENN sociologist, attributed lower immigrant mortality rates to lower smoking, obesity, AIDS and homelessness.


    [2] Is the High Level of Obesity in the United States Related to Its Low Life Expectancy?
    Samuel H. Preston, University of PennsylvaniaFollow
    Andrew Stokes, University of Pennsylvania


    [3] Anatomy of a Municipal Triumph: New York City’s Upsurge in Life Expectancy
    Samuel H. Preston and Irma T. Elo
    March 2014,
    Population and Development Review, a Journal of the Population Council


  2. Randolph Nesse and George C. Williams’ “Why we get sick: the new science of Darwinian medicine (1994)”


    Principles of evolutionary medicine (2009), an Oxford University Press textbook by Peter Gluckman, Mark Hanson and Alan Beedle

    explain the “punctured equilibriums” in evolutionary medicine and health


  3. See Chapter 8 and 9 of Principles of evolutionary medicine (2009) on evolutionary perspectives; this probably is the closest to truth, and shows that sociology, economics, matter less than Evolution and Genes.


    1. I promise this i my last reply!

      March Hochberg (nstitut des Sciences de l’Evolution, CNRS, Université Montpellier 2, France) has studied the impact of parasites, pathogens carried in the body as a source of disease resistance in new environments.


  4. >>Anti-biotics and vaccines actually work to reduce the natural defense.

    Uhh, I’m sorry, there’s absolutely no basis for this. Antibiotics work on bacterial infections (they have no effect on human cells), and vaccines actually bolster your immune response to a pathogen.


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