Living in a racially segregated neighborhood can be bad for the blood pressure (BP) if you are a black adult, according to Northwestern University researchers. They found that simply moving away from that neighborhood is enough to reduce systolic blood pressure 1 to 5 points.
In the study, which was partly funded by the NIH, the researchers examined BP readings for 2,280 black adults who participated in the Coronary Artery Risk Development in Young Adults (CARDIA) study. The participants were initially screened in 1985 and 1986 then reexamined several times over the next 25 years. The Northwestern study is the first to look at the longitudinal effects of segregation on BP compare the effect within the same individuals. Previous research had looked at single points in time.
The researchers categorized neighborhood segregation as high, medium, or low, using a scale that compareed the percentage of black residents in a neighborhood to the surrounding area. When neighborhoods were more segregated, the participants had small but statistically significant increases in systolic BP. Less segregation equaled a “notable” drop in BP.
Participants who lived in a highly segregated neighborhood and moved to a less segregated one saw the most significant improvements. Those who moved temporarily saw a 1 mm Hg drop. A permanent move equaled 3 to 5 mm Hg. That’s a “powerful effect,” said lead author Kiarri Kershaw, assistant professor of preventive medicine at Northwestern. Just 1 mm Hg lower at the population level, she notes, could mean “meaningful” reductions in heart attacks, strokes, and heart failure. The associations persisted even after the researchers accounted for marital status, body mass index, smoking history, physical activity, and socioeconomic status of the community.
The changes in blood pressure were not related to poverty or household income. Kershaw says less stress, achieved by reducing exposure to violence and improving opportunities for socioeconomic mobility, is “likely a key factor.” Other factors that could help include improving access to health-promoting resources, such as full-service grocery stores, recreation centers, and health care clinics.