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Physical
Fitness Keeps Older Minds Sharp: Report Saturday,
April 5
By Charnicia E. Huggins NEW YORK (Reuters Health) - Staying
physically fit is not only good for your body, it also seems to help keep your
mind in good shape, new study findings show.
Researchers found that adults who were most fit at the start of a six-year study
maintained their mental sharpness over time and did better in tests of their
mental function conducted years later than did their less physically fit peers. "Physical activity appears to be
good for the brain as well as the body," study author Dr. Deborah E. Barnes
of the VA Medical Center in San Francisco, California, told Reuters Health. "Older adults with higher levels
of cardiorespiratory fitness experience a slower rate of cognitive decline over
time," she added. Cardiorespiratory fitness describes the
heart's and lungs' efficiency in processing oxygen, Barnes explained.
"People who are not very fit have difficulty processing oxygen when they
exercise -- that is why they get 'winded' or have difficulty breathing,"
she said. Previous studies have shown that adults
with low levels of physical fitness are likely to experience more mental decline
over time than their more active peers, but those studies relied on the
participants own self-reports of activity, the researchers note. Other studies that have detected an
association between cardiorespiratory fitness and better mental function have
been poorly designed or did not include many older individuals. In the current study, the researchers
again used cardiorespiratory fitness -- determined by the adults' performance
during a standard treadmill-based exercise test -- because it is largely
determined by habitual physical activity, and may therefore give more accurate
information than adults' self-reports of physical activity, they note. The participants' mental function was
evaluated with a test that measured their ability to register and recall words,
follow instructions and their orientation to time and place. At the start of the study, which
included 349 adults aged 55 and older, none of the participants had any symptoms
of cardiovascular disease, physical disability, or mental impairment. Adults who were the most fit at the
start of the study exhibited the least amount of mental decline, Barnes and her
colleagues report in the Journal of the American Geriatrics Society. For
example, their scores on the mental state examination at follow-up were similar
to their scores at the start of the study. Their least physically fit peers, in
contrast, scored lower on the mental state exam by follow-up, and performed
lower on other tests of their mental function, such as remembering fewer words
during the word recall test than their peers. Several explanations exist for why
fitness may be associated with better mental function in older adults, the
researchers note. Cardiorespiratory fitness may reduce a
person's risk of cardiovascular disease, high blood pressure, diabetes and other
conditions known to be associated with poor mental function in older adults,
they speculate. Or, cardiorespiratory fitness may be directly associated with
blood flow in the brain, reductions in which have been linked to lower mental
function in both Alzheimer's disease patients and normal older adults. In a related editorial, Dr. Eleanor M.
Simonsick of the National Institute on Aging and Johns Hopkins University School
of Medicine in Baltimore, Maryland, writes that the study "represents a
shift in the right direction for studies examining physical activity, fitness
and cognitive function." She cautions, however, that the
long-term association between fitness and mental function does not necessarily
mean that differences in physical fitness are the cause of the differences in
mental function. More study is needed, Simonsick concludes. In the meantime, Barnes advised that
"older adults who are already active should keep exercising," and
those who are inactive "should consider beginning an exercise program,
ideally in consultation with a physician." Grants from the National Institute on
Aging and an award from the National Institute of Mental Health funded the
research. SOURCE: Journal of the American
Geriatrics Society 2003;51 |