WEDNESDAY, Feb. 15, 2006 (HealthDay News) -- Research suggests that people with higher educational levels may be able to delay the onset of Alzheimer's disease.
However, if and when symptoms do appear, cognitive decline appears to happen faster in better-educated compared to less-educated people, new research suggests.
The news does not necessarily portend disaster, however.
"It doesn't change anything from what we already know," said Maria Carrillo, director of medical and scientific affairs for the Alzheimer's Association. "There have been reports of that and reports saying the opposite. The jury continues to be out. This is just another paper that throws more weight on this possibility without discounting the other."
The study, which appears in the March issue of the Journal of Neurology, Neurosurgery and Psychiatry, involved 312 New Yorkers aged 65 and older who had already been diagnosed with Alzheimer's disease. The participants were followed for more than five years, undergoing repeated neurological assessments during that time to determine brain function.
Overall, the participants' cognitive performance declined by 9 percent per year. But each additional year of education resulted in an additional 0.3 percent annual deterioration.
The decline was most evident in speed-of-thought processes (a 0.6 percent drop per year) and memory (0.5 percent), the researchers said.
What would account for these seemingly paradoxical findings?
The study authors point to the "cognitive reserve" theory, which tries to explain why some people with Alzheimer's are able to delay clinical manifestations of the disease.
"The theory behind previous research is that people with higher education have a higher brain or cognitive reserve, maybe a larger number of brain cells or more efficient brain systems or networks," said lead author Dr. Nikolaos Scarmeas, assistant professor of neurology at Columbia University Medical Center in New York City. "These people with higher education have more redundancy or reserve so they can cope if part of the brain is destroyed."
After symptoms of the disease appear, however, the opposite happens. "They go downhill faster," Scarmeas said. "We think it's because they have delayed the onset so long that a lot of the brain changes have accumulated and when they reach the point of clinical manifestation, they can't compensate any more and they sort of crash."
Carrillo added: "When that reserve is out, when they reach a critical point where the brain cannot sustain function, [so] the decline is observed to be faster."
The findings may help physicians by giving them more information on the future course of the disease, based on education, Scarmeas said.
A next step might be to see if there is any difference in life expectancy between more- and less-educated Alzheimer's patients, said Dr. Vincent Marchello, vice president of medical affairs at Metropolitan Jewish Health System and assistant professor of clinical medicine at Mount Sinai School of Medicine, both in New York City.
While this study gives no insight into the biology behind the manifestations, "it sort of stirs interest into explaining and investigating further the association between education and Alzheimer's disease with biological studies," Scarmeas said.
Said Carrillo: "Researchers would find it most interesting because it gives you clues as to how exactly brains with different educational backgrounds deal with the burden of Alzheimer's."
The positive side of the finding is that keeping your brain active may help delay the outward signs of Alzheimer's.
"By staying mentally active, you can delay the onset of Alzheimer's by a few years," Carrillo said. "Promoting mental agility can be protective."
More information
The Alzheimer's Association's Maintain Your Brain program has more on keeping your brain healthy.
