The Hispanic Paradox in Epidemiology

It’s no question that life expectancy in many countries, including the United States is highly correlated with socio-economic status. Dozens of studies have reached to this conclusion, stating that socioeconomic status is one of the strongest predictors of early death and illness around the globe. This is fairly intuitive—lower income means lower quality health insurance (or none at all), less access to healthy, fresh foods, safe living areas, health education… I could go on.

However, there’s one outlier that leaves epidemiologists puzzled, and that’s Hispanics. Non-white Latinx people have consistently been documented with higher life expectancies than whites in the United States, with an even bigger difference within foreign-born Latinx people. Mortality rates at 65 years and above are estimated to be a shocking 10 to 15% lower amongst Hispanics than whites. This comes as a surprise because, according to the US Census Bureau, Hispanics are more likely to live in poverty in the US than whites, and are less likely to have any health insurance in their preretirement years. This, of course, raises the question of why. Epidemiologists have been studying this phenomenon for decades and have contributed plenty of theories.

One of the most prominent is the salmon hypothesis, which reasons that, like a salmon who returns to its birth place before its death, Hispanics of poorer health tend to return to their home country before death. This could be for several reasons. First, this could be because the journey of migration to the United States is arduous and dangerous, only the strongest and healthiest actually make it over the border, while the weaker and sicker either don’t survive the trek or decided to head back home.  Additionally, it’s possible that aging Hispanic immigrants in the US often choose to return to their home countries after retirement, meaning their eventual death will not count in US data. Lastly, data has shown that the return of Hispanics to their home countries is often precipitated by poor health, resulting in the same skewed statistics. However, research conducted on this phenomenon is limited in scope and accuracy. However, this doesn’t apply for certain ethnic groups, such as Cubans, as Cuba is not a country that is easily returned to due to political and geographic circumstances, meaning a sick Cuban immigrant in the United States is likely to remain in the United States until their death, and yet they still have lower morality rates than whites in the United States. However, it could still hold that only the healthiest Cuban-born people enter the States in the first place.

In contrast, some epidemiologists believe that Hispanics are genetically dispositioned to be healthier than whites. For example, “relative to non-Latino Whites, Latinos have a health advantage for cardiovascular disease, cancer from all causes, and cancer of the lung, colon, breast, and prostate,” according to the American Journal of Public Health. Additionally, they tend to have healthier habits: both Hispanic men and women are less likely to drink alcohol than whites, and Hispanic women are less likely to smoke cigarettes than white women. However, possibly due to their lower socioeconomic status, Hispanic women’s preventive health strategies are not on par, as they are “less likely to have ever had a Pap test, clinical breast examination, or mammogram than non-Latina whites.” Additionally, Latinx don’t have a mortality advantage over whites throughout all diseases, as they’re more likely to die from “diabetes, liver disease, homicide (amongst male Latinos), cervical cancer, and AIDS.” Lastly, Hispanic infants are more likely to be born with a low birth weight (a strong indicator of health later in life) than most other races.

Another theory may be even harder to quantify than the salmon bias: strong cultural ties and family connection. Latinx families traditionally emphasize closeness, sharing and loyalty, and this tradition tends to be maintained even when a Latinx family migrates to the United States. The idea of family traverses beyond the nuclear family, as cousins, aunts, uncles, grandparents and beyond are included in the tight-knit unit. Studies have found that closer family relations have led to the family’s more effective response to disease and disability within the family, suggesting that closeness could actually create real health effects. While it might seem far-fetched, connecting with others has been shown in scientific research to “relieve harmful levels of stress, which can adversely affect coronary arteries, gut function, insulin regulation, and the immune system,” according to Harvard Medical School. Although difficult to prove, it’s a possibility that Latinx culture’s emphasis on the family network might overtake the negative effects of lower socioeconomic effects on health and life expectancy.

Of course, of these three theories, we can’t be certain what exactly is the cause behind the Hispanic Paradox. Reasoning from all three might be sprinkled throughout, as well. Either way, the Hispanic Paradox raises interesting and thought-provoking questions about the socioeconomic and racial determinants of health and immigration in the United States and worldwide.

Sources:

https://www.sciencedaily.com/releases/2017/01/170131190102.htm

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2546603/

https://ajph.aphapublications.org/doi/pdf/10.2105/AJPH.89.10.1543

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3064884/

https://www.health.harvard.edu/healthbeat/strengthen-relationships-for-longer-healthier-life

https://journals.sagepub.com/doi/pdf/10.1177/027112149201200307

http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.183.6912&rep=rep1&type=pdf