Even simple exercise can help with brain aging

New research suggests that even a simple exercise routine can help older Americans with mild memory problems.

Doctors have long advised physical activity to help maintain a healthy brain. But the government-sponsored study marks the biggest test yet 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.

The researchers recruited about 300 sedentary seniors with subtle 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 exercise and the rest to stretching and balance movements that only modestly increased their heart rate.

Another key ingredient: Participants in both groups were cared for by trainers who worked with them at YMCAs around the country — and when COVID-19 closed gyms, helped them continue commuting at home via video calls.

After a year, cognitive tests showed neither group had worsened, said lead researcher Laura Baker, a neuroscientist at Wake Forest School of Medicine. Nor did brain scans show the shrinkage that accompanies worsening memory problems, he said.

By comparison, similar MCI patients in another long-term brain health study — but without exercise — experienced significant cognitive decline over a year.

These early findings are surprising, and the National Institute on Aging cautioned that following non-exercising people in the same study would provide better proof.

But the results suggest that “this is doable for everyone” — not just for seniors healthy enough to sweat hard, said Baker, who presented the data Tuesday at the Alzheimer’s Association International Conference. “Exercise should be part of prevention strategies” for at-risk seniors.

Previous research has found that regular physical activity of any kind can reduce harmful inflammation and increase blood flow to the brain, said Alzheimer’s Association chief scientific officer Maria Carrillo.

But the new study is particularly interesting because the pandemic is halfway through, leaving already vulnerable seniors socially isolated — something known to increase people’s risk for memory problems, Carrillo said.

It’s a frustrating time for dementia research. Doctors are hesitant to prescribe a high-priced new drug called Aduhelm, which is supposed to be the first to slow the progression of Alzheimer’s disease — but it’s not yet clear whether it actually helps patients. Researchers last month reported that another drug that works similarly — targeting amyloid plaques that are a hallmark of Alzheimer’s — failed in a key study.

While amyloid clearly plays a role, it’s important that drugmakers increasingly target the many other factors that can lead to dementia, Carrillo said, because effective treatment or prevention will likely require a combination of tailored strategies.

An example of a new approach: Sometimes in dementia, the brain has trouble processing blood sugar and fats for the energy it needs, John Didsbury of T3D Therapeutics said at the Alzheimer’s meeting. His company is testing a pill aimed at revving up that metabolism, with results expected next year.

Meanwhile, there is a growing urgency to sort out whether steps people could take today – such as exercise – could offer at least some protection.

How much and what kind of exercise? In Baker’s study, older adults were required to move for 30 to 45 minutes four times a week, whether it was a brisk turn on the treadmill or stretching exercises. That’s a big question for anyone who leads a sedentary life, but Baker said the effects of MCI on the brain make it even harder for people to plan and stick with new activity.

Hence the social stimulation – which he said led each participant to complete over 100 hours of exercise in a year. Baker suspects the sheer volume may explain why even simple stretching provided an apparent benefit.

“We wouldn’t do the exercise alone,” said retired agricultural researcher Doug Maxwell of Verona, Wis., who participated in the study with his wife.

The duo, both 81, were both placed in the stretching sections. They felt so good afterward that when the study ended, they bought electric bikes in hopes of getting even more active — efforts Maxwell admitted are hard to keep up with.

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 Section is supported by the Howard Hughes Medical Institute Science Education Division. AP is solely responsible for all content.

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