In the U.S. an estimated 32 million adults are considered illiterate, according to the United States Department of Education. Among people considered illiterate, researchers found that they may be at an increased risk of dementia, based on a study published online in Neurology.
The objective of the study, researchers stated, was to “investigate whether illiteracy was associated with greater risk of prevalent and incident dementia and more rapid cognitive decline among older adults with low education.”
To begin the study, researchers analyzed 983 adult participants from a longitudinal community aging study; 746 of which were literate and 237 illiterate. The participants were of Caribbean-descent, resided in northern Manhattan, New York, and only took part in four years of education, according to researchers.
The participants underwent medical exams and cognitive tests every 18 months to two years. “Neuropsychological measures of memory, language, and visuospatial abilities were administered at baseline and at follow-ups,” researchers stated.
“At each visit, functional, cognitive, and medical data were reviewed and a dementia diagnosis was made using standard criteria. Logistic regression and Cox proportional hazards models evaluated the association of literacy with prevalent and incident dementia, respectively, while latent growth curve models evaluated the effect of literacy on cognitive trajectories, adjusting for relevant demographic and medical covariates.”
Based on the findings, researchers found that illiteracy was linked to a higher chance of developing dementia.
The study’s co-authors concluded: “We found that illiteracy was independently associated with higher risk of prevalent and incident dementia, but not with a more rapid rate of cognitive decline.”
“The independent effect of illiteracy on dementia risk may be through a lower range of cognitive function, which is closer to diagnostic thresholds for dementia than the range of literate participants.”