The findings of a new study suggest that the protective effects of an
active cognitive lifestyle arise through multiple biological pathways.
For some time researchers have been aware of a link between what we do
with our brains and the long term risk for dementia. In general, those
who are more mentally active or maintain an active cognitive lifestyle
throughout their lives are at lower risk.
"The ideas of a 'brain reserve' or 'cognitive reserve' have been
suggested to explain this, but were basically a black box. This research
throws some light on what may be happening at the biological level,"
said Associate Professor Michael J. Valenzuela, a brain aging expert at
the Brain and Mind Research Institute, University of Sydney, Australia,
who led this new study.
Researchers used data from the Cognitive Function and Ageing Study, a
large population-based study in the United Kingdom that has been
following over 13,000 elderly individuals prospectively since 1991.
At the time of this study, 329 brains had been donated and were
available for analysis. Brains were compared based on the individual's
dementia status at death (yes or no) and cognitive lifestyle score, or
CLS (low, middle, or high).
The three CLS groups did not differ among multiple Alzheimer's
disease (AD) neuropathology measures, including plaques, neurofibrillary
tangles, and atrophy. This means that cognitive lifestyle seems to have
no effect on the brain changes typically seen in those with Alzheimer's
disease.
However, an active cognitive lifestyle in men was associated with
less cerebrovascular disease, in particular disease of the brain's
microscopic blood vessels. An active cognitive lifestyle in women was
associated with greater brain weight. In both men and women, high CLS
was associated with greater neuronal density and cortical thickness in
the frontal lobe.
"These findings suggest that increased engagement in stimulating
activities are part of a lifestyle that is, overall, more healthy,"
commented Dr. John Krystal, Editor of Biological Psychiatry. "Rather
than specifically protecting the health of activated circuits, it seems
that a more active lifestyle has general effects on brain health
reflected in greater neuronal density and preservation of the blood
supply to the brain."
"Overall, our research suggests that multiple complex brain changes
may be responsible for the 'use it or lose it' effect," Valenzuela
added.
With a globally aging society and the risk of dementia increasing
significantly with age, dementia-prevention strategies are of rising
importance. Understanding the mechanisms of cognitive enhancement
through research such as this can help support and inform the
development of effective strategies to enrich cognitive lifestyle and
potentially reduce dementia risk.
http://www.sciencedaily.com/releases/2012/04/120425094358.htm