New studies looking at how social conditions may affect risk of dementia found that living in stressful circumstances hits one group hardest: African Americans. According to NPR, four studies presented at an international conference in London Sunday all presented evidence linking poverty, disadvantage, and stressful life events to cognitive issues among aging African Americans. African Americans are twice as likely to develop dementia as white Americans, which researchers previously attributed to genetics and conditions such as obesity, diabetes, and cardiovascular disease, reports the Washington Post. But studies looking at both white and African-American people with those conditions still showed racial disparities, indicating there was something missing from the puzzle. Epidemiologist Rachel Whitmer began looking at how social conditions might come into play.
"We're starting to understand how early life stress and early life deprivation can increase your risk of a number of health outcomes in late life,” she says. “And the latest thing is understanding how and why that might affect the brain." Her team’s research—one of the studies presented Sunday—took a look at people born in states with high infant mortality rates (a red flag of social problems like poverty). African Americans were 40% more likely to develop dementia in these states, while other groups’ risk wasn’t linked to place of birth. A separate study found that enduring stressful events such as unemployment, divorce, or losing a child added around a year and a half to brain aging in white participants. For African-Americans, who were found 60% more likely to experience stressful events, the brain aged four years with each instance. Per NPR, now researchers are tasked with finding out how such events change the brain.