By Will Boggs MD

(Reuters Health) – Higher education may build a stronger foundation for overall brain function, but starting from this higher level of function doesn’t influence how fast cognition declines in old age, researchers report.

Previous studies have linked higher education to greater cognitive reserve, the mind’s ability to optimize its performance, which might delay or at least buffer the onset of noticeable changes in cognitive function with age.

But there is conflicting evidence on whether education level also influences how fast thinking skills deteriorate once they start to go, the study team notes in Neurology. Based on nearly 3,000 older individuals followed over time, the new research suggests that it does not.

“Education is not a strong determinant of how cognition ages,” lead author Robert Wilson from Rush University Medical Center’s Alzheimer’s Disease Center in Chicago told Reuters Health by email.

Wilson’s team used data from 2,899 men and women participating in two long-term U.S. studies to evaluate the contribution of education to cognitive reserve and how steeply it declines with aging. At the beginning of the study, participants’ average age was just shy of 78. On average, members of the group had more than 16 years of education.

All were free of dementia when they enrolled, and participants took annual cognitive tests for an average of eight years. Brain autopsies were performed on those who died during the study period.

Researchers found that younger age and higher level of education at baseline were associated with a higher level of overall cognition at the start of the study period. And women had higher baseline cognitive functioning levels than men did.

During the years after baseline assessments, however, education was not linked to slower rates of cognitive decline or with a later start of cognitive decline associated with emerging dementia. If anything, the rapid decline in cognitive function toward the end of life seemed to begin earlier among individuals with higher levels of education.

The likelihood of finding evidence of strokes on autopsy studies of the brain appeared to be lower in individuals with higher levels of education, but higher education did not prevent the more rapid cognitive decline associated with strokes or dementia.

“Level of education is related to the level of cognitive function at the beginning of old age but not to changes in cognition thereafter,” Wilson said. “Better understanding of factors contributing to cognitive reserve may suggest novel strategies for maintenance of cognitive function in old age.”

“Most surprising is the modest effect of education in this study,” said Dr. Isabel Pavao Martins from the University of Lisbon in Portugal, who was not involved in the study. “But this may be due to the overall high level of education in the population sample. If you study larger educational variations, the results may be different,” she said by email.

“Higher education is a protective factor anyway, since those subjects perform better all along their path,” Pavao noted. “More investigation is necessary comparing subjects with different educational backgrounds.”

SOURCE: Neurology, online February 6, 2019.