WEDNESDAY, June 30 (HealthDay News) -- If you want to help your
young daughter avoid dementia much later on in life, a new study
suggests it might be a good idea to send her outside to play.
Canadian researchers believe they've found a link between
exercise in adolescence and fewer cases of senility in a woman's
The study doesn't definitively prove that exercise lowers the
risk of dementia. And the research is only based on the
recollections of older women, some with signs of dementia, about
Still, the findings suggest that "early life physical activity
is important to late-life health and in particular in preventing
late-life cognitive impairment. The sooner you start being
physically active, the better it is," said study author Laura E.
Middleton, a researcher at the Sunnybrook Health Sciences Center in
Scientists have been trying to document a link between exercise
and dementia in later life in the hopes of understanding how
physical activity affects the brain. The new study was designed to
examine how exercise in youth may affect women in their later
The researchers asked more than 9,300 women in the United States
about their exercise habits before the age of 18, at 30, at 50 and
in late life. All were over 65, and their average age was 72.
The findings appear in the June 30 issue of the
Journal of the American Geriatrics Society.
About 15 percent to 30 percent of the women reported being
inactive during each period of their lives. Exercise occurring
before the age of 18 seemed to be most influential: Close to 17
percent of those who didn't report being active then had symptoms
of dementia, while just 8.5 percent of the others did.
The researchers adjusted their statistics so they wouldn't be
thrown off by factors such as weight and age. After they did that,
those who thought they exercised as kids were still 30 percent less
likely to show signs of dementia.
The researchers don't know if exercise in childhood directly
leads to less dementia since other factors could be at play, such
as diet. And exercising as kids -- playing outdoors, for example --
may set a pattern for physical activity later in life, Middleton
If there is a cause-and-effect link between early exercise and
less mental decline, she said it may have something to do with the
brain's ability to change and develop new circuitry. It's also
possible that exercise leads to less clogging of blood vessels in
the brain, she said.
It's not clear whether men might benefit in the same way. The
study only looked at women, Middleton said, and previous research
has suggested that women benefit more from exercise than men.
Greg Cole, a brain researcher who's familiar with the findings,
said scientists are interested in the benefits of exercise when it
comes to brain decline, but they're focusing on studying the
elderly at risk instead of looking backward at childhood.
Cole said the study's reliance on the memory of the elderly
"makes one wonder" about its reliability. But childhood habits
could presumably lead to lifelong habits that might contribute to
the benefits of adult exercise seen in other studies, said Cole, a
professor of medicine and neurology at the University of California
at Los Angeles.
Kidshealth.org has details on
children and exercise.