Late-Life Cognitive Decline Slowed in Elderly Women by Minimal Exercise
Two studies support growing evidence that habitual physical activity slows age-related changes in cognition and risk of
dementia
July 19, 2011 Senior citizen women see their late-life cognitive decline slow down as they engage in regular minimal
exercise. Two studies published as Online First by by Archives of Internal Medicine, one of the JAMA/Archives journals, clearly point
to new hope in a method of slowing age-related mental decline. In one study, the women had vascular or coronary risks.
Previous research has suggested that physical activity is associated with reduced rates of cognitive impairment in older
adults. However, much of this research has apparently been conducted among individuals who are generally in good health.
Those with chronic systolic heart failure have
been historically considered too frail to exercise - see link to video
in caption about founder - March 25, 2011
We can let
ourselves dream about creating a new drug for humans one that could
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Further, many of these studies rely on self-reports of physical activity, which are not always accurate; and focus on
moderate or vigorous exercise, instead of low-intensity physical activity. The two articles being presented today seek to fill in these gaps
in the research.
Women with vascular or coronary risks
In one article, Marie-Noλl Vercambre, Ph.D., from the Foundation of Public Health, Mutuelle Generale de l'Education
Nationale, Paris, and colleagues examined data from the Women's Antioxidant Cardiovascular Study, which included women who had either
prevalent vascular disease or three or more coronary risk factors.
The researchers determined patients' physical activity levels at baseline (1995 to 1996) and every two years thereafter.
Between 1998 and 2000, they conducted telephone interviews with a total of 2809 women 65 years or older. The calls included tests of
cognition, memory and category fluency, and followed up the tests three more times over the succeeding 5.4 years.
The researchers analyzed data to correlate cognitive score changes with total physical activity and energy expenditure
from walking.
As participants' energy expenditure increased, the rate of cognitive decline decreased. The amount of exercise equivalent
to a brisk, 30-minute walk every day was associated with lower risk of cognitive impairment.
Second study looks at women with average age of 74+
In another study, researchers utilized data from the Health, Aging, and Body Composition study, an ongoing prospective
cohort study. The researchers measured participants' total energy expenditure by using doubly labeled water, a technique that provides
evidence of how much water a person loses and thus serves as an objective measure of metabolic activity.
Laura E. Middleton, Ph.D., from the Heart and Stroke Foundation Centre for Stroke Recovery, Sunnybrook Research
Institute, Toronto, and colleagues calculated participants' activity energy expenditure (AEE), defined as 90 percent of total energy
expenditure minus resting metabolic rate.
The 197 participants, with an average age of 74.8 years, had no mobility or cognitive problems when the research began in
1998 to 1999. At that time, researchers assessed participants' cognitive function, and followed up two to five years later with the Modified
Mini-Mental State Examination (MMMSE).
The authors adjusted the data for baseline MMMSE scores, demographics, fat-free mass, sleep duration, self-reported
health and diabetes mellitus. When these variables were accounted for, participants who had the highest AEE scores tended to have lower odds
of incident cognitive impairment. The authors also noticed a significant dose response between AEE and incidence of cognitive impairment.
The authors of both articles suggest that there is more to be learned about the relationship between physical activity
and cognitive function.
"Various biologic mechanisms may explain the positive relation between physical activity and cognitive health," write
Vercambre and colleagues. Middleton and co-authors state,
"The mechanisms by which physical activity is related to late-life cognition are likely to be multifactorial."
Both groups of researchers note that studies such as theirs point toward some possible answers. As Vercambre and
co-authors comment, "If confirmed in future studies, physical activity recommendations could yield substantial public health benefits given
the growing number of older persons with vascular conditions and their high risk of cognitive impairment."
And Middleton and colleagues conclude, "We are optimistic that even low-intensity activity of daily living may be
protective against incident cognitive impairment."
Commentary: Brains and Aging
These studies serve to "buttress growing evidence that habitual physical activity and fitness are associated with
age-related changes in cognition and risk of dementia," says an editorial in the journal by Eric B. Larson, M.D., M.P.H., from Group Health
Research Institute, Seattle.
The key finding of the Vercambre and colleagues study, he writes, "is that older women with high levels of vascular risk
constitute a major risk group and that vascular risk is linked to cognitive decline."
Of the work published by Middleton and colleagues, Larson observes, "The fact that the study used a validated measurement
of energy expenditure, not just self-report, makes the results of further importance."
Such research, he states, is increasingly needed as the population ages and the health care field attempts to cope with
higher rates of cognitive decline.
In this context, Larson suggests that articles such as the ones presented here "highlight a gradual but steady change in
current thinking about risk factors for late-life dementias." Vascular risk factors such as limited physical activity may be modifiable and
represent a way to reduce the incidence of cognitive impairment among older adults. Physical activity, growing scientific evidence suggests,
could be one such avenue.
"I believe that these findings can inform practice and the advice that we give our aging patients," comments Larson.
"We can tell them that ongoing maintenance of physical activity is definitely worthwhile and likely of increasing benefit
as they advance into old age." In addition, Larson stresses the need for research into "programs that promote ongoing physical activity,
especially in late life."
Dr. Larson is supported by a grant from the National Institute on Aging.
The articles were released on July 19 to coincide with the International Conference on Alzheimer's Disease in Paris and
will be included in the July 25 print edition.
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