Walking may significantly decrease risk for dementia in older men
Older men (71-93 years) who walked the least
had nearly twice the risk for dementia compared with peers who walked
the most in a comparison study on walking and development of dementia,
according to an article in the September 22nd issue of the Journal
of the American Medical Association.
Although previous evidence had suggested that physical activity
may be related to clinical expression of dementia, there was no
evidence whether low-intensity activity such as walking was associated
with lower risk for expression of the disease.
Robert D. Abbott, Ph.D., of the University of Virginia School of
Medicine, Charlottesville, Va., and colleagues examined the association
between walking and future risk of dementia in older men.
The current study included 2,257 physically capable men aged 71
to 93 years in the Honolulu-Asia Aging Study. Distance walked per
day was assessed from 1991 to 1993. Follow-up for incident dementia
was based on neurological assessment at two repeat examinations
(1994-1996 and 1997-1999).
The researchers found that after adjusting for age, men who walked
the least (less than 0.25 mile/day) experienced a 1.8-fold excess
risk of dementia compared with those who walked more than 2 miles/day.
Men who walked 0.25 to 1 mile/day experienced a 71 percent increased
risk of dementia compared with men who walked the most (more than
2 miles/day). These associations persisted after accounting for
other factors, including the possibility that limited amounts of
walking could be the result of a decline in physical function due
to preclinical dementia.
“There are no clear explanations for the relation between walking
and dementia,” the authors wrote. “Although associations were independent
of other study characteristics that were determined at the time
when walking was assessed, it may be that men who walk frequently
are more resistant to risk factor changes or transitions into adverse
risk factor states. Although changes in risk factor status in the
course of follow-up were not considered in the current study (nor
were such data always available), it would be important to determine
if men who walk regularly are less prone to development of intervening
conditions that have a closer link with dementia.”
“Although complex, this study and past evidence suggest that walking
and active lifestyles in general are associated with a reduced risk
of dementia,” the researchers concluded.
In a separate article in the same issue, researchers found that
regular physical activity including walking was associated with
better performance on cognitive function tests and less decline
over time among older women (age 70 years or older) who were participating
in the long-term Nurses’ Health Study.
The authors wrote “… the apparent cognitive benefits of greater
physical activity were similar in extent to being about three years
younger in age and were associated with a twenty percent lower risk
of cognitive impairment. The association was not restricted to women
engaging in vigorous activities …”
“In summary, in our study, as well as in other epidemiologic investigations,
higher levels of physical activity, including walking, are associated
with better cognitive function and less cognitive decline.”
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