Large, 14-year study finds no effect, contradicting previous research
MONDAY, Feb. 2 (HealthDay News) -- Education does not slow the rate of cognitive decline among the elderly, new research shows.
The finding contradicts several earlier studies that suggested more education lowered the risk for Alzheimer's disease and dementia.
"Your rate of cognitive decline really doesn't depend on the number of years of schooling you've had," said study author Robert S. Wilson, a professor of neuropsychology at Rush Alzheimer's Disease Center at Rush University Medical Center in Chicago.
However, more education "does give you the advantage of having a higher level of cognitive functioning in old age. You have to decline for somewhat longer to reach the effect where you're no longer able to be independent and engage in self-care," he noted.
The Rush researchers said their study differs in several ways from the earlier research that found an education connection: It followed a large population (6,500 people) over a longer period of time (up to 14 years) and, most importantly, measured their changes in cognition at three-year intervals, Wilson explained. The research that measured changes in cognition at only two points in time was limited, he suggested. "Assessment of cognition at three or more points in time permits separation of initial level of cognition from the rate of change," the study authors wrote.
The researchers added that there have been other studies using three or more testing points, but the results have been inconsistent because of the confusing effects of other variables. Wilson and his team found the variables related to age, sex, race and five chronic diseases (heart disease, hypertension, stroke, diabetes and cancer) connected with aging had no effect on the results.
The findings were expected to be published in the Feb. 3 issue of Neurology.
The methods that the Rush researchers used to measure cognitive changes over time may also be a model for how people should be monitored for cognitive changes, said Dr. Michael Ehlers, a professor of neurobiology at Duke University's Howard Hughes Medical Institute.
"I think we are really on the verge of major new therapies that are going to change the landscape of dementias, and this has come about as a result of the investment that has been made in basic neuroscience. It's almost certainly going to pay off in a big way," Ehlers said.
Because the Rush study shows that higher levels of education do not reduce the rate of cognitive decline, brain exercises later in life might not be helpful, Ehlers added. "It makes me leery of doing more crossword puzzles and reading the New York Times at 75 years old," he explained.
But if more education means it takes someone longer to decline to the point where they are debilitated, that does have an important impact on the tremendous costs connected with caring for people with Alzheimer's disease and dementia, he explained.
"It's almost as if you have to pay up front or pay later. Either you invest in education or you invest in nursing home care," Ehlers said.
For more on Alzheimer's, go to the Alzheimer's Association.
SOURCES: Michael Ehlers M.D., Ph.D., professor, neurobiology, and investigator, Howard Hughes Medical Institute, Duke University, Durham, N.C.; Robert S. Wilson, Ph.D., professor, neuropsychology, Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago; Feb. 3, 2009, Neurology
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