Education Levels Tied to Risk for Alzheimer Disease in Older Adults

Adults aged 65 or older with lower levels of education and no college degree have higher levels of declining large-scale functional brain network organization, leaving them at greater risk for developing Alzheimer disease, according to new research published in Nature Aging.

Differences in education are linked to health disparities due to socioeconomic factors such as health habits and access to resources. Researchers aimed to determine if there is a relationship between the attainment of education in an individual to longitudinal changes in the brain system segregation as an adult, as well as if changes in brain network organization can predict clinical decline in older adults.  

“Efforts to link an individual’s education and environment to their brain changes, including both brain structure and measures of brain pathology have yielded mixed results,” wrote Micaela Y. Chan, PhD, Center for Vital Longevity and School of Behavioral and Brain Sciences, University of Texas at Dallas, Dallas, TX, USA, and co-researchers.

“Establishing a link between educational attainment and specific brain changes during older age is not only an important step toward understanding environmental determinants of brain diseasebut could also catalyze discovery and incorporation of new brain health ‘biomarkers.’”

Dr Chan et al collected diverse participant cohort data from the Charles F. and Joanne Knight Alzheimer Disease Research Center at Washington University in St Louis of longitudinal magnetic resonance imaging (MRI) sessions and clinical visits from a total of 417 participants. The final data sample included 265 participants aged 45 to 86, who had 2 or more resting-state scan sessions that met the inclusion criteria.

Participants self-reported their levels of education between 6 and 22 years. Participants with 16 or more years of formal education were defined as college plus; participants with fewer than 16 years of formal education were defined as below college.

Patients categorized as college plus were associated with higher occupation-based socioeconomic index in addition to living in higher income areas and having a higher median household income.

“Changes in brain system segregation were examined as a function of participants’ educational attainment and age, with follow-up analyses examining whether this relationship was independent of other health indicators that have established and hypothesized associations with education and brain function,” wrote Dr Chan et al. Variables such as cardiovascular health and history of traumatic brain injury were the same in both groups.

Overall, researchers found older age and lower brain system segregation were associated, and college degrees and higher levels of brain system segregation were associated.

There were significant interactions within the findings between education, time, and age at baseline which showed that older adults in the below college group showed declining brain system segregation over time. This was not evident in participants with college degrees.

“Older adults who never completed a college degree exhibit greater declines in resting-state brain system segregation, a measure of large-scale network organization and function,” Dr Chan et al. wrote. “These observations demonstrate that changing functional network organization is an important preclinical warning signal of cognitive impairment that is not captured by measures of brain structure or pathology.”

“These results demonstrate that the trajectory of an individual’s brain network organization varies in relation to their educational attainment and, more broadly, is a unique indicator of individual brain health during older age,” Dr Chan et al. concluded.

Future studies should further evaluate the time course of brain network changes relative to clinical decline as well as identify environmental factors impacting the relationship between an individual’s educational attainment and changes in their brain network organization.

Chan, M.Y., Han, L., Carreno, C.A. et al. Long-term prognosis and educational determinants of brain network decline in older adult individuals. Nat Aging 1, 1053–1067 (2021). https://doi.org/10.1038/s43587-021-00125-4

MDLinx. 2021. Researchers identify new biomarker of Alzheimer's disease. [online]  [Accessed 7 December 2021].