By 2050, 75 percent of Alzheimer’s disease and related dementia cases will occur in low- and middle-income regions, such as rural South Africa. What role do social and economic exposures play in whether or not people develop dementia in old age?
A project by Indiana University and partner universities will determine how socioeconomic exposures in mid-to-later-life affect memory decline and Alzheimer’s disease and related dementia risk. The project is funded through a $2 million National Institutes of Health grant.
"As the world’s population ages, Alzheimer’s disease and dementia are on the rise," said Molly Rosenberg, assistant professor at the IU School of Public Health-Bloomington and lead investigator on the study. "We know that people’s economic situations likely contribute to their risks for Alzheimer’s disease, but very little research is actually conducted in low-income areas. This study in rural South Africa helps fill this gap by answering questions about how income expansions at different key points in the lifespan might protect against cognitive aging and dementia in older ages."
Rosenberg said there is a critical gap in our understanding of how low-income settings and socioeconomic status can best be targeted by interventions to prevent or delay the onset of Alzheimer’s disease and dementia. Researchers are studying a cohort of older adults in rural, low-income South Africa and collecting cognitive data on them as they age.
The study is unique because researchers are able to link back to over three decades of socioeconomic data, such as whether the recipients were part of social protection programs (government programs equivalent to welfare, social security, etc.) in earlier life, to see what sort of influence those earlier life exposures have on cognitive aging outcomes.
"Specifically, we will be able to look at whether mid-life food security, employment, or household assets influence dementia risk by linking our cohort of older adults back to these census data that have been collected in the study site since 1992," Rosenberg said. "We will recreate what their socioeconomic conditions were when they were younger and see the associations with dementia."
The data will help determine the impact of cumulative exposure to disadvantageous socioeconomic conditions on Alzheimer's disease and dementia and how such exposure affects both men and women. The researchers' goal is to inform gender-equitable socioeconomic status interventions to prevent or delay Alzheimer’s disease and dementia in low-income settings.
"This work will help prevention strategies not only in sub-Saharan Africa, where there is currently little data outside of this study, but also for guiding interventions in Alzheimer’s disease and related dementias prevention programs globally," Rosenberg said.
Coady Wing and Janet Jock at the IU O’Neill School, Rishika Chakraborty at the IU School of Public Health-Bloomington, and researchers from the University of Michigan, Harvard, UNC, and the University of the Witwatersrand (Johannesburg) are also partners in the study.
