Although previous research has shown that having a higher level of education can protect the brain against dementia, new evidence published in the Neurology showed that education was not associated with the onset or decline of accelerated decline in the elderly who developed dementia.
These results indicated that the contribution of education to "cognitive reserve" may be limited to its link with the level of cognitive function prior to old age, according to the researchers.
"The level of education is widely used as an indicator of cognitive reserve.This higher level of education is associated with a lower risk of dementia and supports this idea" Robert S. Wilson, PhD, of Rush University Medical Center, and colleagues wrote. "However, prospective studies suggest that this association is primarily attributable to the association of education with a level of cognitive function rather than rate of cognitive change."
To determine the role of education in the cognitive reserve, researchers analyzed data on older adults from two longitudinal cohort-pathology studies that had annual cognitive tests (n = 2,899) and subgroups that developed dementia accident, died and underwent neuropathological examination.
Investigators also quantified 10 neurodegenerative and cerebrovascular diseases of those who underwent neuropathological examinations. The participants were grouped into three education level groups: 12 years or less, 13 to 16 years and 17 or more years.
The average duration of the studies among the participants was 16.3.
Although the instruction was associated with the initial level of global cognition in all participants, it was not associated with the linear rate of cognitive change (estimate = -0.0004; P = .44), based on the results. These results remained after Wilson and colleagues repeated the analysis by comparing the lower education group with each of the other education groups.
In the participants who developed dementia, the researchers found that the rate of global cognitive decline accelerated an average of 1.8 years before the diagnosis; however, education was linked to the onset of dementia or accelerated decline.
In those who died, the analysis revealed that the rate of global cognitive decline accelerated an average of 3.4 years before death; however, the highest level of education was linked to the accelerated decline and was not linked to the rate of acceleration.
"The strengths of this analysis include that it was based on multiple participants who were observed for a longer period of time than previous analyzes," Wilson said in a press release. "It is possible that the contribution of education to cognitive reserve depends on other factors, such as life experiences or biological factors, but these results do not show a relationship between a higher level of education and a slower rate of decline in skills of thought and memory or a later onset of the accelerated decline that occurs when dementia begins. "
Furthermore, education was not linked to global cognitive change not attributable to neuropathological burden, nor did education reduce the connection between the higher neuropathologic burden and the more rapid cognitive decline, the study revealed.
"This finding that education apparently contributes little to the cognitive reserve is surprising given that education affects cognitive growth and changes in brain structure," Wilson said. "But formal education generally ends decades before old age begins, so late activities involving thinking and memory skills … can also play a role in cognitive reserve and may be more important than remote experiences like the school". – by Savannah Demko
Revelation: Wilson's reports grant NIH's support. Please consult the study for all relevant financial information of all other authors.