Aerobic exercise slows cognitive decline in Alzheimer’s disease
Cardiovascular exercise training may help slow the decline in brain
function seen in Alzheimer’s patients, a new review of past research suggests.
Researchers assessed data from 19 studies conducted between 2002 and 2015 that
examined the effects of exercise on cognitive ability in 1,145 people at risk of or
diagnosed with Alzheimer’s disease. Nearly 90 percent were randomized controlled
trials, which are the most reliable type of study.
Most participants were female (71%); the average age was 77. Just over half of the
study subjects participated either in an aerobic exercise program, or an aerobic
program plus a resistance training intervention. The rest of the study participants
received only usual care.
Aerobic exercises include brisk walking, jogging, swimming, cycling and other
activities that boost the heart rate and strengthen the heart and lungs.
On average, participants exercised 3.5 days per week at moderate intensity, with each
session lasting 30 to 60 minutes. While the programs tested in some of the studies
were as short as 8 weeks, others lasted more than 6 months.
Results indicated that exercise - specifically, cardiovascular exercise - had a strong
favorable impact, researchers reported in the Journal of the American Geriatrics
“We found a statistically significant increase in cognitive function that favored the
groups receiving the exercise interventions compared to the non-exercise control
groups,” lead study author Gregory Panza, from the University of Connecticut in
Storrs, told Reuters Health by email.
For example, he said, among people with similar cognitive test scores at the start, “an
individual in the exercise group would score higher on the cognitive function tests
than 69% of patients in the non-exercise control group” by the end of the study.
Cognitive function was most commonly assessed using the Mini-Mental State Exam
(MMSE), but other validated tools also were used. The tools evaluate things like
problem solving and processing speed, motor ability, multi-tasking and recollection of
events as well as object recognition and ability to plan, all of which serve as proxies
for mental sharpness.
The positive effect of exercise wasn’t the only thing researchers discovered.
“True, we found that brain function improved,” coauthor Linda Pescatello, also from
the University of Connecticut, said in a phone interview. “But in the group that did
not receive exercise, there was actually a deterioration. This deterioration was
unanticipated and really accentuates the importance of our findings.”
Adding resistance training to aerobic exercise did not appear to make a difference,
This study is the first to suggest that aerobic exercise may be more effective than
other types of exercise when the goal is to preserve the cognitive health of older adults
at risk of or with Alzheimer’s disease, Panza said.
“Exercise can change the brain chemistry. It can change neurotransmitters associated
with depression, anxiety and stress as well as brain chemicals associated with
learning,” said Carol Ewing Garber, Director of the Applied Physiology Lab at
Columbia University, Teachers College, in New York City, who wasn’t involved in
the study. “These changes can result in improved mood, resilience to stress and
improve functions of the brain such as processing speed, attention, short term memory
and cognitive flexibility among other things.”
“To date, evidence supports aerobic exercise as the preferred modality for
(Alzheimer’s disease), but more studies are needed to confirm this,” Pescatello said.
“This is a relatively new area of research, and there really just isn’t enough data
available to make a clear determination.”
SOURCE:bit.ly/2CmXVdj Journal of the American Geriatrics Society, online
January 24, 2018.
Written by Mary Gillis originally published in Reuters Health.