If you want to pump up your brain and cut your Alzheimer’s risk, get moving.
That’s one of the takeaway lessons from recent research that compares exercise rates and gray matter in aging brains.
The study suggests that those who keep active―whether they walk, swim, garden, dance, golf, play tennis, hike or do aerobics―may significantly decrease their risk of Alzheimer’s disease.
“Activity is fantastic,” said Maegan Hatfield-Eldred, PhD, a clinical neuropsychologist with Spectrum Health Medical Group.
While there has been much research linking exercise to brain health, the recent study makes an even stronger case for the role of exercise in reducing dementia risk because it tracks changes over decades, said Dr. Hatfield-Eldred.
Researchers at the University of California, Los Angeles, and the University of Pittsburgh examined surveys completed by nearly 900 participants in a 30-year Cardiovascular Health Study. The participants, age 78 on average, also had MRI scans to measure gray matter in brain structures involved in memory.
Those in the top 25 percent for physical activity had larger brain volumes in the frontal, temporal and parietal lobes, including the hippocampus. They also had a 50 percent reduction in their risk of Alzheimer’s, the researchers reported.
The findings provide plenty of encouragement to get active, said Dr. Hatfield-Eldred. It shows that even those who live sedentary lives in middle age can still benefit by boosting activity levels later in life.
Even people with mild cognitive impairment show benefits from exercise.
“It’s still not likely to be a magic cure,” Dr. Hatfield-Eldred cautioned.
Research has not shown exercise can reverse the cellular changes involved in Alzheimer’s. But those with higher volume of gray matter may have greater reserves. If they get Alzheimer’s, they may be able to go longer without symptoms becoming apparent.
“If we can delay onset of dementia and slow it down, that will make a huge difference in people’s quality of life,” she said.
Uncertainty exists about how exercise could increase brain volume, Dr. Hatfield-Eldred added. It may work by boosting cardiovascular health, which in turn can decrease Alzheimer’s disease risk.
“The heart pumps blood to the brain. That’s where the brain gets nutrients and energy,” she said. “It requires a healthy heart to have a healthy brain.”
But scientists don’t yet know if exercise causes brain benefits beyond those linked to heart health.
One step at a time
The study also doesn’t show how much exercise is enough―and where the benefits level out.
Working with patients, she advises finding ways to boost activity levels that work with their lifestyle. Not everyone can start jogging 30 minutes a day. Some people have medical issues that affect the types of exercise they can do. They may begin with a 15-minute walk or a chair exercise program.
“With any kind of behavioral change, people are much more successful if they go about it in incremental changes rather than trying to drastically overhaul everything at once,” she said.
The study, funded by the National Institute of Aging, was published in the Journal of Alzheimer’s Disease.