Want to reduce your risk of dementia in older age? Move as much as you can.
We've all heard about techniques to get us more physically active — take the stairs, park the car a bit further from your destination, get up and march in place for a minute or two when standing or sitting at a desk.
Now a study finds even simple housework like cooking or cleaning may make a difference in brain health in our 70s and 80s.
"Exercise is an inexpensive way to improve health and our study shows it may have a protective effect on the brain," says Dr. Aron S. Buchman with Rush University Medical Center in Chicago, who led the study.
Previous research found just 45 minutes of walking three days a week actually increased brain volume among individuals 65 and older.
The new study, published Wednesday in the online issue of Neurology, is unique because Buchman was able to analyze the actual brains of study participants. The findings are a "great thank you" to the participants who agreed to donate their brains for research after death, he says.
The study looked at 454 older adults who were 70 or older when the research began. Of those adults, 191 had behavioral signs of dementia and 263 did not. All were given thinking and memory tests every year for 20 years.
In the last years of research before death, each participant wore an activity monitor called an accelerometer, similar to a Fitbit, which measured physical activity around the clock — everything from small movements such as walking around the house to more vigorous movements like exercise routines. Researchers collected and evaluated 10 days of movement data for each participant and calculated an average daily activity score.
The findings show that higher levels of daily movement were linked to better thinking and memory skills, as measured by the yearly cognitive tests. And when Buchman analyzed brain tissue under a microscope, this finding turned out to be the case even for individuals with at least three signs of Alzheimer's disease, such as amyloid plaques and neurofibrillary tangles. Even though these individuals might have been diagnosed with Alzheimer's, 30 percent of them had "normal" cognition at death, says Buchman.
Why one person shows signs of dementia and another, who has similar degenerative changes in the brain, does not, is a mystery. But Buchman says the new findings suggest that physical activity may be protective, even amidst developing Alzheimer's. It sort of masks the symptoms, he says, and is an "empowering finding" suggesting you can have some control over your brain health even if you don't have control over developing Alzheimer's.
"It's almost as if the physical activity was helping the brain to bypass the physical damage," says Dr. Tim Church, a preventive medicine specialist with Pennington Biomedical Research Center at Louisiana State University who was not involved in the research. "It appears that physical activity was critical to creating a reserve that protects against those physical damages."
And, while intense activity and exercise is highly beneficial, even light activity can make a difference, says Buchman. "As long as you have some activity and you're moving, whether you're chopping onions, typing, sweeping the floor or even running," you can reduce your risk of cognitive decline.
The findings are impressive, says research scientist Carl Cotman, director of the Institute for Brain Aging and Dementia at the University of California, Irvine, showing that physical activity may "offset the ill effects of brain degeneration." He adds that lifestyle interventions such as an increase in physical activity and movement can be powerful even in the presence of disease. Cotman was not involved in the research.
But exactly how the protective effect may work is unclear. Buchman says the current findings are a "great start" but he hopes to look more closely at participant's brains to measure different proteins and try to identify which ones might link physical activity to better cognition.
There are some caveats to the study. The findings do not show clear cause and effect. Study participants with dementia had significantly lower indications of movement compared to those without dementia. It may be possible that as people lose memory and thinking skills, they also reduce their physical activity.
And the study did not have data on how active participants were over the course of their lives. It could be that older adults who moved more were also lifelong exercisers so it's not known if physical activity in early life may have played a role.
While previous research suggests that people may be able to beat back dementia with exercise, Buchman acknowledges that "more studies are needed to determine if moving more is truly beneficial to the brain."
MARY LOUISE KELLY, HOST:
New research finds that older adults who routinely move either with daily exercise or just simple physical activity like housework may protect their brains against age-related damage. NPR's Patti Neighmond reports on the study published online in the journal of the American Academy of Neurology.
PATTI NEIGHMOND, BYLINE: Researchers wanted to know how movement of any type affected the brain of older adults who were 70 or older when the study began. They were given yearly tests of cognitive ability. Neurologist Aron Buchman with Rush University Medical Center in Chicago headed the study. For 10 days straight, participants wore Fitbit-like activity monitors which measured everything they did during the day.
ARON BUCHMAN: Whether you're chopping onions or whether you're typing or whether you're sweeping or whether you're running, the activity counts are going to be measured.
NEIGHMOND: Now, what makes this study unique - all participants agreed to donate their brains for research after their death. This meant Buchman was able to analyze brain tissue under the microscope and compare individuals who moved the most to those who didn't move much at all.
BUCHMAN: Higher levels of total daily activity was associated with a lower risk of developing dementia and was associated with a slower rate of cognitive decline.
NEIGHMOND: And what's most surprising, says Buchman - more physical activity meant lower cognitive decline even for people who, on autopsy, had numerous degenerative changes in the brain, things like amyloid plaques, tangles and vascular abnormalities. The take-home message, he says, is empowering.
BUCHMAN: If you lead a more active lifestyle with physical activity, you're going to maintain your cognition even though you're accumulating degenerative changes in your brain.
NEIGHMOND: The keyword here is movement. Anything an older person can do to increase activity is a good thing.
BUCHMAN: It doesn't have to be going to the gym. Even somebody who's limited and housebound who gets up and moves in the house or goes up and down stairs in the house has the potential to benefit.
NEIGHMOND: The findings are positive news, says preventive medicine physician Tim Church with the Pennington Biomedical Research Center.
TIM CHURCH: And what was fascinating was the physical activity seemed to protect against these different lesions or areas of the brain that were damaged.
NEIGHMOND: Creating something of a brain reserve or resilience.
CHURCH: Despite the damage, the physical activity is still allowing the brain to function properly.
NEIGHMOND: It's not clear exactly how physical activity might protect against age-related changes in the brain. Neurologist Buchman hopes to do more research with the donated brains and figure out which proteins or other mechanisms might link increased physical activity to better cognition. For now, though, the message might sound familiar. Get up. Get going, and move around as much as you can. Patti Neighmond, NPR News. Transcript provided by NPR, Copyright NPR.