An image of a brain white matter change in a patient with Alzheimer's disease. Credit: Shutterstock

There are more than 5 million Americans living with Alzheimer's disease, and 50 million with other dementias, according to figures from the Alzheimer's Association. Research into these diseases and how to prevent them is key as more and more Americans live longer, raising their risk for developing cognitive impairment.

In a new study, University of Nebraska–Lincoln sociologist Marc A. Garcia explored how can benefit cognitive health in later life, and whether there are differences in its benefits among minorities.

Garcia and his co-authors found that among adults is associated with better cognitive function regardless of race and ethnicity, however whites are still living a greater percentage of their lives in good cognitive health, compared to their Black and Hispanic counterparts. This suggests structural racism is playing a role, Garcia said.

"Despite similar levels of educational attainment, racial/ethnic and nativity disparities in cognition persist, indicative of long-standing and deeply-rooted inequalities in educational attainment and quality of education," he said.

Garcia and his co-authors used data from the Health and Retirement Study and the National Health Interview Survey to parse the cognitive health and dementia life expectancies for older white, Black, U.S.-born and foreign-born Hispanic adults with varying educational attainment, from less than to some college or more.

They found that individuals with high school and some college or more can expect to spend significantly more years cognitively healthy than those with no high school degree. At age 50, men with some college or more can expect to spend 9.4 to 12.3 years more cognitively healthy than their counterparts with less than a high school degree.

However, when looking specifically at Black and Latino adults, the cognitive health expectancies are less promising. Cognitive health disparities were greatest between white and Black adults. For example, with less than a , Black men can expect to spend 6.1 years less cognitively healthy than their white counterparts.

Additionally, the research showed older Latinos show a lot of variation in cognitive health outcomes.

"Whether you were born in the U.S. or not is as important as educational attainment for life expectancies," Garcia, assistant professor of sociology, said.

Garcia, who has previously published research documenting racial and ethnic disparities in cognitively healthy life expectancies, said he was still surprised at the magnitude of disparities found in this study.

"This came as a surprise because education is thought to be this 'great equalizer,'" Garcia said. "Our findings indicate that this is not the case, as there are also large racial/ethnic and nativity differences in the benefits adults may reap from educational attainment."

Researchers have hypothesized that greater educational attainment plays a role in future cognitive function in two ways. First, it contributes to a "cognitive reserve," which may help adults maintain normal levels of cognitive function longer. Secondly, higher education also lowers the risk factors for poor cognitive function.

"Higher educational attainment in young adulthood can lead to higher occupational status, better health care access, and better opportunities to engage in mentally and physically stimulating activities, which can be beneficial for later in life," Garcia said, explaining the hypothesis behind his research.

Garcia is continuing this line of research, and said scientists should continue to monitor and document population-level socioeconomic and health characteristics contributing to Alzheimer's and related dementia.

"Alzheimer's disease is a major public health concern in the U.S. and is expected to be highest among racial and , who are projected to experience the highest rates of population growth over the coming decades," Garcia said. "Thus, there are major implications for Black and Latino families and communities who lack the resources to confront the growing crisis."

Garcia said the research can be used to guide and implement data-driven changes in allocating care resources that promote healthy cognitive aging among minority and immigrant groups.

"This includes the need to address the inequity in both educational attainment and quality of education resulting from structural racism," he said.

More information: Marc A Garcia et al. Educational Benefits and Cognitive Health Life Expectancies: Racial/Ethnic, Nativity, and Gender Disparities, The Gerontologist (2020). DOI: 10.1093/geront/gnaa112