Oh, to Live the Hispanic Paradox
You eat too much, you lack the money to eat healthy, you should die, right?
Posted Jul 14, 2014
In spite of lower socioeconomic status (SES) and higher rates for diabetes mellitus and obesity, several studies have shown equal or lower mortality rates for Hispanics in the United States when compared to non-Hispanic whites. Interestingly, the majority of current literature suggests that, in general, lower SES is correlated with worse health outcomes as well as greater mortality. And therefore, this unexpected mortality finding as regards Hispanics has been termed the “Hispanic paradox”.
After all, you eat too much, you lack the money to eat healthy, you should die earlier, correct?
Why are Hispanics throwing predictions of life span out the window?
There have been several proposed hypotheses to describe these findings. Most notably, the “salmon bias hypothesis,” cultural influences, and, of course, genetic variation, are theories that have been put forth. The salmon bias hypothesis assumes that foreign-born Hispanics return to their country at the end of life; and because we lack access to death records in those countries, their deaths are not recorded in this country, and thus these individuals appear to have lower mortality.
The sociocultural characteristics of the Hispanic population have been shown to play a role in alleviating negative effects of low SES, such as worse health outcomes. Recently, genetic factors have been shown to perhaps play a role in the Hispanic paradox in a type of lung disease that has some heritable components. An interesting article in this month’s issue of “Arthritis Care & Research” explores how the Hispanic paradox affects patients suffering from the chronic painful illness, rheumatoid arthritis.
The researchers who published their findings studied over 700 rheumatoid arthritis patients, comparing the differences in rheumatoid arthritis severity and comorbidity between Hispanic and non-Hispanic white ethnic groups. They noted that the baseline swollen and tender joint counts were higher in Hispanics when compared to non-Hispanic whites. Social support networks were compared, and it was found that non-Hispanic whites had greater positive interaction support, in addition to greater access to emotional and informational support. Over time, Hispanics had more tender and deformed joints, and more pathological x-ray changes.
Despite the lower SES for Hispanics in this study, despite the worse rheumatoid arthritis manifestations, non-Hispanic whites tended to die earlier compared to the Hispanic members of this cohort. The authors of this study did not have data to support the salmon bias hypothesis. And they were not able to demonstrate that the Hispanic survival advantage was due to differences in social support. While the study was not designed to survey various genetic markers, it is still possible that there are genetic protective factors at work here.
So, the Hispanic paradox continues to impress, this time when one examines the severe and chronic disease rheumatoid arthritis: After adjusting for age and sex, mortality in Hispanics was not increased—this despite lower SES and more severe rheumatoid arthritis.
We are, however, still left with a puzzle, as opposed to an explanation of the paradox. Perhaps the answer, when found, will render us all a little healthier.