U.S.-Born Blacks More Susceptible to Developing Asthma Than Those Born in Other Nations, Study of Dorchester, Mass., Finds
Blacks born in the U.S. are nearly three times more likely than blacks born outside of the U.S. to have asthma, according to a study published in the November issue of the Journal of Asthma, Boston Globe reports. The study, led by Tufts University researcher Doug Brugge, was conducted in response to a request from parents in Dorchester, Mass., who were concerned about a high number of asthma cases in their community, according to the Globe.
For the study, in 2005 and 2006, the research group -- including 20 parents of children with asthma and Harvard medical students -- surveyed Dorchester community residents. The analysis included information on 290 adults and 157 children. Researchers found that 30% of U.S.-born blacks had been diagnosed with asthma, compared with 11% of blacks who were born in another country. A previous study by Brugge found similar findings among foreign-born Asians and Hispanics.
According to the Globe, foreign-born blacks could have fewer asthma cases because of more sunlight exposure during childhood and less time spent inside, "where mold, cockroach droppings and other [asthma] triggers dwell." In addition, the disparity could be because "natives of other nations, especially those in the developing world, may encounter more infections growing up [and thus] their immune systems often ignore threats such as dust mites and mold." The same exposure among those with less immunity can cause allergic reactions that lead to asthma, the Globe reports.
George O'Connor, director of the Adult Asthma Program at Boston Medical Center, said, "There may be a price to be paid for growing up in a more sterile, hygienic environment with fewer infections as a child," such as the U.S., and "the price to be paid is that your immune system may develop more along the lines of promoting allergic responses."
Researchers noted that the findings represent a snapshot of a single neighborhood but reflect "an emerging recognition that scientists should stop regarding racial and ethnic groups as monoliths," according to the Globe (Smith, Boston Globe, 12/1).
The study is available online.