Some studies have suggested that a higher level of education may correlate with lower incidence of dementia, which has been interpreted as suggesting education could increase a “cognitive reserve” that buffers against the disease. A new study published in the journal Neurology, however, found that level of education did not correlate with onset or progression of dementia.
In all participants, higher levels of education correlated with a higher level of global cognition at the start of the study but did not correlate with rate of cognitive decline. In participants who developed dementia, the rate of cognitive decline accelerated at a mean of 1.8 years before dementia was diagnosed and this also did not correlate with level of education. In the deceased, the onset of cognitive decline correlated with having more education, not less, again with no correlation to the rate of cognitive decline.
“This finding that education apparently contributes little to cognitive reserve is surprising given that education affects cognitive growth and changes in brain structure,” said study author Robert S. Wilson, PhD, of Rush University Medical Center in Chicago, “but these results did not show a relationship between a higher level of education and a slower rate of decline of thinking and memory skills, or a later onset of the accelerated decline that happens as dementia starts.”
For the study, researchers analyzed information from the Religious Orders Study, which involves older Catholic clergy members across the US, and the Rush Memory and Aging Project, which evaluates older people from the Chicago metropolitan area. Participants in both studies have annual examinations and give permission for a brain autopsy upon death.
The 2,899 participants had a median age of 78 at the start of the study and an average of 16.3 years of education. Participants were followed for 8 years. A total of 696 participants developed dementia during the study and 405 of these individuals died during the study and had a brain autopsy. Of those who did not develop dementia, 347 died during the study and had brain autopsy. Participants level of education was classified as 1 of 3 tiers, including fewer than 12 years, 13 to 16 years, and 17 or more years.