by FREDRICK KUNKLE
Ara Sparkman with her belongings on a Milwaukee street. “Eviction has become typical in the lives of poor black women,” a sociologist said. PHOTO/Sally Ryan/The New York Times
A new group of studies into racial disparities among people with Alzheimer’s disease suggests that social conditions, including the stress of poverty and racism, substantially raise the risks of dementia for African Americans.
In four separate studies, researchers found that conditions that affect blacks disproportionately compared with other groups — such as poor living conditions and stressful events such as the loss of a sibling, the divorce of one’s parents or chronic unemployment — have severe consequences for brain health later on.
One study by University of Wisconsin researchers found that stress literally takes years off a person’s life in terms of brain function — an average of four years for African Americans, compared with 1½ years for whites.
Another Wisconsin study showed that living in a disadvantaged neighborhood is associated with later decline in cognitive function and even the biomarkers linked to Alzheimer’s disease, which is the most common form of dementia.
In the other two studies, researchers with Kaiser Permanente and the University of California at San Francisco found a higher degree of dementia risk for people born in states with high rates of infant mortality. Researchers at Kaiser Permanente and the University of California at Irvine found that racial disparities in the incidence of dementia that were previously found among people who are 65 years and older also appear in the very oldest demographic, people who are 90 or older.
These lifelong effects of stress and disadvantage could be direct, perhaps in line with previous research showing that sustained stress can physically alter the brain. Or the impact could be the result of cascading effects, such as when a powerfully disruptive event affects a person’s early schooling and limits achievement later on.
“No one’s looking at the same kind of things, but the research all dovetails really well,” said Megan Zuelsdorff, an epidemiologist with the University of Wisconsin School of Medicine and Public Health. “It is the social environment that’s contributing to disparities.”
She and other researchers said the overall thrust of the studies’ findings — which were presented Sunday in London at the Alzheimer’s Association’s annual conference — not only offers additional evidence of racial inequities in people’s risk of dementia but suggests the need for more urgent interventions directed at those communities.
“Not one of these things is good news — except that they are modifiable,” Zuelsdorff said.
Over the years, researchers have theorized that blacks are more susceptible to Alzheimer’s owing to genetics and higher rates of obesity, diabetes, hypertension and cardiovascular disease.
Washington Post for more