Education does not protect older people from losing their memory, researchers from the University of Southern California (USC) have argued.
Contrary to previous studies, which have suggested a link between high levels of education and better cognitive performance, USC's research found 70-year-olds with higher education levels experienced the greatest drop in performance.
The authors suggest the findings, published in Research on Aging, meant older people may no longer be able to compensate for age-related memory loss by using their schooling.
Study director Eileen Crimmins of the USC Leonard Davis School of Gerontology said the study offered insight into the way we learn and unlearn, but recommended people should not stop their education based on the results.
"We are starting to find evidence of how the brain works over the entire lifecycle," she said.
"This study clarifies that while cognitive performance in old age is related to early life education, not all aspects of cognitive performance relate to education in the same way."
Lead author Dawn Alley added: "Even though we find in this research that those with higher education do better on mental status tests that look for dementia-like symptoms, education does not protect against more normal, age-related declines, like those seen on memory tests."
Previous studies have suggested that memory loss is the first sign that an older person's cognitive abilities are declining and they are developing dementia.