An African-American or Mexican-American senior living in a community where many neighbors share their background is less likely to have cancer or heart disease than their counterpart in a more mixed neighborhood.
Results of the new study by Kimberly Alvarez, a PhD student at Columbia University's Mailman School of Public Health, and Becca Levy, PhD, associate professor of Epidemiology and Psychology at the Yale School of Public Health, appear in the December issue of the American Journal of Public Health and online.
Counter to prevailing notions, researchers found that "living in the barrio or ethnically dense communities isn't always bad for your health," says Alvarez. "For older minority adults, it's actually the reverse: living in an ethnically dense neighborhood is beneficial when it comes to heart disease and cancer," adding that these are the two most common chronic conditions and causes of death among minority older adults.
The researchers used survey data to look at health outcomes of 2,367 Mexican-American and 2,790 African-Americans over age 65 living in communities with high percentages of African-Americans (New Haven, Conn. and north-central North Carolina) and Mexican-Americans (Arizona, California, Colorado, New Mexico, and Texas). Among African-Americans, those living in a county with an ethnic density of 50% or more (that is, where half or more of the population shared the same background) were 46% less likely to report doctor-diagnosed heart disease and 77% less likely to report cancer than those who lived in an ethnic density of less than 25%. Mexican Americans living in a county with an ethnic density of 50% or more were 33% and 62% less likely to report heart disease and cancer, respectively, than those who lived in an ethnic density of less than 25%. Ethnic density was significantly more protective for heart disease in African-Americans than Mexican-Americans; the association between ethnic density and cancer was equally strong for both groups.
Cultural factors could help to explain the phenomenon. "Communities with high ethnic density may be more likely to share values like respect for elders and have close-knit family structures," says Dr. Levy. Earlier studies showed high levels of social support within communities of Hispanic immigrants. "These networks may facilitate better health behaviors and, in turn, better health outcomes," adds Alvarez. "For example, information about free health clinics may be more freely exchanged in these communities."
Past studies showed a health benefit of ethnic density for Hispanics, but the reverse for African-Americans; these results were in keeping with what is known as the Hispanic Paradox: that even with similar levels of socioeconomic status, Hispanics have comparable, or in some cases better, health outcomes than White Americans. Adding a wrinkle to this rule, Alvarez and Dr. Levy are the first to find a positive effect for ethnic-density among African-Americans. The difference, Alvarez explains, may owe to the fact that past studies have looked at African-American children and young adults rather than seniors and measured ethnic density in relation to whites rather than within subsets of other minority populations.
"Having this information is important given the rapidly growing population of older adult minorities," says Alvarez.
Support for the study was provided by grants from the National Institute on Aging (R01AG032284), the National Heart, Lung, and Blood Institute (R01HL089314), and the Patrick and Catherine Wildon Donaghue Medical Research Foundation (to Dr. Levy).