Mild Alzheimer's disease patients with higher physical
fitness had larger brains compared to mild Alzheimer's
patients with lower physical fitness, according to a
study published in the July 15, 2008, issue of Neurology®,
the medical journal of the American Academy of Neurology.
For the study, 121 people age 60 and older underwent
fitness tests using a treadmill as well as brain scans
to measure the white matter, gray matter and total volume
of their brains. Of the group, 57 were in the early
stages of Alzheimer's disease while the rest of the
group did not have dementia.
"People with early Alzheimer's disease who were less
physically fit had four times more brain shrinkage when
compared to normal older adults than those who were
more physically fit, suggesting less brain shrinkage
related to the Alzheimer's disease process in those
with higher fitness levels," said study author Jeffrey
M. Burns, MD, of the University of Kansas School of
Medicine in Kansas City and member of the American Academy
The results remained the same regardless of age, gender,
severity of dementia, physical activity and frailty.
There was no relationship between higher fitness levels
and brain changes in the group of people without dementia.
"People with early Alzheimer's disease may be able
to preserve their brain function for a longer period
of time by exercising regularly and potentially reducing
the amount of brain volume lost. Evidence shows decreasing
brain volume is tied to poorer cognitive performance,
so preserving more brain volume may translate into better
cognitive performance," Burns said.
"This is one of the first studies to explore the relationship
between cardiorespiratory fitness and Alzheimer's disease,"
Burns says people should be cautious when interpreting
the study results because scientists only observed the
standard measure of fitness at one point in time.