Diet of Mental Stimulation Might Reduce Alzheimer's Risk
Lifetime of reading, games lowered levels of brain plaques, researchers
Monday, January 23, 2012 from National Library of Medicine, National
Institutes of Health
Jan. 23, 2012 (HealthDay News) -- People who engage in activities such as
reading and playing games throughout their lives may be lowering levels of a
protein in their brains that is linked to Alzheimer's disease, a new study
Although whether the buildup of the protein, beta amyloid, causes
Alzheimer's disease is debatable, it is a hallmark of the condition, the
"Staying cognitively active over the lifetime may reduce the risk of
Alzheimer's by preventing the accumulation of Alzheimer's-related
pathology," said study author Susan Landau, a research scientist at the
Helen Wills Neuroscience Institute at the University of California,
"Some of the literature has hypothesized this finding, but this is the first
study to report that lifetime cognitive activity is directly linked to
amyloid deposition in the brain," she said. "We think that cognitive
activity is probably one of a variety of lifestyle practices --
occupational, recreational and social activities -- that may be important."
The report was published in the Jan. 23 online edition of the Archives of
In the United States, more than 5 million people have Alzheimer's disease,
and it is now the sixth-leading killer in the country, according to the
researchers. No cure exists for the neurodegenerative condition, but a draft
of the first-ever National Alzheimer's Plan released last week laid out
plans by the federal government to have effective treatment by 2025.
For the study, Landau's team used a special imaging technique called
positron emission tomography, which is able to see beta amyloid plaque in
the brain, plus neuropsychological tests to see what effect cognitive
stimulation might have on Alzheimer's risk.
The tests were done on 65 healthy people, average age of about 76. In
addition, they tested 10 patients with Alzheimer's disease whose average was
nearly 75 and 11 young people who were an average of about 25 years old.
"We interviewed them about their lifetime participation in cognitively
stimulating activities," said lead researcher Dr. William Jagust, a
professor of neuroscience also at the Helen Wills Neuroscience Institute.
The researchers found that people who engaged in brain-stimulating
activities, particularly when they were young and middle-aged, had the least
amount of beta amyloid.
Those older adults who reported the most activity had amyloid levels similar
to those young individuals, while those who engaged in the least such
activities had amyloid levels similar to the Alzheimer's patients.
"This study suggests that not only does it reduce your risk of Alzheimer's
disease, but it may affect the pathological process itself," Jagust said.
Why this kind of mind stimulation reduces the amount of beta amyloid isn't
known, he added.
"The environment may affect the amount of amyloid that's deposited," he
said. "This kind of lifetime cognitive activity may make people's brains
more efficient. And if your brain is functioning better, it's possible that
would result in producing less of this amyloid," he explained.
"Cognitive activity seems to have powerful effects on the brain," Jagust
said. "Lifestyle can have a profound effect on the basic biology of
The size of the effect isn't known nor is the size of the reduction in risk
for Alzheimer's disease, he noted.
Greg M. Cole, associate director of the Alzheimer's Disease Research Center
at the University of California, Los Angeles, said that "a number of studies
have suggested that increased education or cognitive activity associates
with reduced risk for Alzheimer's."
"So if you have more wits to begin with, you can afford to lose more before
you become impaired," he said.
However, this new study reports something different, namely that higher
cognitive activity in young and middle-aged adults is associated with lower
levels of Alzheimer's pathology, Cole said.
"There may be a plausible theory for this because increased brain use
increases fitness and reduces the amount of brain activity required to
execute a task, and production of the beta amyloid toxin is associated with
brain activity. This is an interesting new finding that may have serious
implications," he said.
Another expert, Dr. Sam Gandy, the Mount Sinai Professor of Alzheimer's
Disease Research at Mount Sinai Hospital in New York City, added that "this
new study jibes well with other existing epidemiological studies in which
social engagement has been linked to successful cognitive aging on purely
"There is also a link between physical activity and reduced risk for
Alzheimer's, and one would guess that physical exercise might well delay
onset of Alzheimer's if exercise were begun years before cognitive decline
developed, but this is yet to be established," Gandy said.
SOURCES: William Jagust, M.D., professor, neuroscience, Helen Wills
Neuroscience Institute, University of California, Berkeley; Susan M. Landau,
Ph.D., research scientist, Helen Wills Neuroscience Institute, University of
California, Berkeley; Sam Gandy, M.D., Ph.D., Mount Sinai Professor of
Alzheimer's Disease Research, Mount Sinai Hospital, New York City; Greg M.
Cole, Ph.D., neuroscientist, Greater Los Angeles VA Healthcare System,
associate director, Alzheimer's Disease Research Center, University of
California, Los Angeles; Jan. 23, 2012, Archives of Neurology, online