New research suggests that even a simple exercise routine may only help older Americans with mild memory problems.
Doctors have long recommended physical activity to keep a healthy brain in shape. But the government-funded study marks the longest test of whether exercise makes a difference when memory begins to slip — research conducted amid a pandemic that added isolation to the list of risks to participants’ brain health.
Researchers recruited about 300 sedentary older adults with hard-to-detect memory changes called mild cognitive impairment, or MCI — a condition that is sometimes, but not always, a precursor to Alzheimer’s. Half were assigned to aerobic exercises and the rest to stretching-and-balancing movements that only increased heart rate modestly.
Another key component: Participants in both groups were showered with attention by trainers who worked with them at YMCAs around the country—and when COVID-19 shut down gyms, they helped them move at home via video calls.
After a year, cognitive testing generally showed that neither group had gotten worse, said lead researcher Laura Baker, a neuroscientist at the Wake Forest School of Medicine. Brain scans also did not show the shrinkage that accompanies worsening memory problems, she said.
In comparison, similar MCI patients in another long-term study of brain health – but without exercise – experienced significant cognitive decline over the course of a year.
These early findings are surprising, and the National Institute on Aging cautioned that tracking non-exercisers in the same study would have provided better evidence.
But the results suggest that “this is possible for everyone” — not just seniors who are healthy enough to sweat hard, said Baker, who presented the data Tuesday at the Alzheimer’s Association International Conference. “Exercise must be part of the prevention strategies” for vulnerable elderly people.
Previous research has found that regular physical activity of some kind can reduce harmful inflammation and increase blood flow to the brain, said Maria Carrillo, head of the Alzheimer’s Association.
But the new study is especially exciting because the pandemic hit halfway, leaving already vulnerable seniors socially isolated — something long known to increase people’s risk of memory problems, Carrillo said.
It is a frustrating time for dementia research. Doctors are hesitant to prescribe a high-priced new drug called Aduhelm that was supposed to be the first to slow the progression of Alzheimer’s – but it is not yet clear whether it really helps patients. Researchers reported last month that another drug that works in the same way — by targeting amyloid plaques that are a hallmark of Alzheimer’s — failed in a key trial.
While amyloid clearly plays a role, it’s important that drugmakers increasingly target many other factors that can lead to dementia, Carrillo said, because effective treatment or prevention will likely require a combination of tailored strategies.
One example of a new approach: Sometimes in dementia, the brain has trouble processing blood sugar and fat for the energy it needs, John Didsbury of T3D Therapeutics told the Alzheimer’s meeting. His company is testing a pill aimed at boosting metabolism, with results expected next year.
In the meantime, there is a growing need to determine whether steps people can take today — such as exercise — can offer at least some protection.
How much and what kind of exercise? In Baker’s study, seniors had to move for 30 to 45 minutes four times a week, whether it was at a vigorous turn on the treadmill or the stretching exercises. It’s a big ask for anyone who is sedentary, but Baker said MCI’s effects on the brain make it even harder for people to plan and stick to the new activity.
Hence the social stimulation — which she credited with each participant completing over 100 hours of training. Baker suspects that the sheer volume may explain why even the simple stretch produced an apparent benefit. The participants were to train without formal support for another six months, data Baker has not yet analyzed.
“We wouldn’t have done the exercise on our own,” said retired agricultural scientist Doug Maxwell of Verona, Wis., who joined the study with his wife.
The duo, both 81, were both assigned to the stretch classes. They felt so good afterward that when the study ended, they bought electric bikes in hopes of even more activity — efforts Maxwell acknowledged are hard to keep up.
Next up: Baker is leading an even larger study of older adults to see if adding exercise to other non-harmful steps like a heart-healthy diet, brain games and social stimulation together can reduce the risk of dementia.
The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institute’s Department of Science Education. AP is solely responsible for all content.