Exercise May Help Prevent, Even Slow, Alzheimer’s Disease

There is no cure yet and no vaccine.

But new methods for staving off dementia and Alzheimer’s are continuing to emerge.

Exercise has been identified as one way in which the disease might be delayed or lessened.

And, while its effectiveness hasn’t yet been proven, the evidence is beginning to accumulate.

The latest comes from a study that found patients with a rare inherited, early-onset form of the disease who exercised for at least 2.5 hours a week had better cognitive performance and fewer signs of Alzheimer’s than those who didn’t.

That study, published Tuesday, suggests that the benefits from exercise seen in Alzheimer’s patients might hold for even those who are at the highest risk of developing the disease.

That supports suggestions from past studies that exercise has beneficial effects, including slowing the rate of cognitive decline in healthy people as well as those at risk of dementia and those who already have it.

Some studies have even found exercise may be tied to a reduced risk of developing Alzheimer’s.

But a lot of questions remain unsettled, including whether there may be other factors — better diet, more social lifestyle, etc. — that people who exercise more might have and which might be bigger reasons for the benefits.

“We do see a separation between those who exercise and those who don’t, but a lot of the studies are observational so far,” Laura D. Baker, PhD, a geriatric medicine professor at the Wake Forest School of Medicine in North Carolina who has studied the relationship between exercise and cognitive impairment, told Healthline.

“It begs the question, is there something else going on or is it exercise itself?”

Baker, who wasn’t involved in the latest study, said she’s conducting clinical trials to try to look into questions like that.

For now, she said the scientific consensus that has been emerging points to aerobic exercise as the most effective type of physical activity and that it makes the most difference for those who are already at higher risk due to factors such as aging, cognitive impairment, and genetics.

But more studies might change that picture.

“It’s not to say that exercise doesn’t help those who are younger. It’s just that we don’t have tools right now to know whether it’s helping,” Baker said.

She added that other types of exercise may have benefits, too. But the mechanisms of aerobic exercise — in which heart rate and breathing is elevated for an extended period — seem to line up with benefits.

Why exercise is effective

Why exercise appears to work may have to do with the benefits of exercise to cardiovascular health.

“There’s some evidence to suggest that healthy blood pressure and good cardiovascular health are really beneficial to the brain,” Rebecca Edelmayer, PhD, director of scientific engagement at the Alzheimer’s Association, told Healthline.

She said that may have to do with decreasing the decline in performance of small blood vessels to the brain and increasing how effectively oxygen is pumped through the body.

Baker noted that exercise could fight dementia by increasing the number of synapse connections, improving cell walls to allow for better exchange of nutrients, and improving vascular health.

“So, basically cleaning out the pipes so the blood can get to the tissue that it’s supposed to supply,” she said.

What the study revealed

In the new study, the participants all had the early-onset genetic mutation.

Their physical activity was classified as either low or high level based on whether they got at least 150 minutes of exercise per week or not.

Those with high levels of physical activity were diagnosed with milder dementia 15 years later than those with lower levels. Typically, those with that mutation get Alzheimer’s between age 30 and 60.

That 150-minutes figure may not be a magic number, but it does likely take sustained exercising to see effects, Baker said.

She said the current consensus so far is about 30 to 40 minutes three to four times a week.

How to reduce the risk

There’s enough evidence that the Alzheimer’s Association has named exercise as one of the top lifestyle habits to adopt to reduce risk of dementia.

It also recommends eating a diet high in fruits and vegetables, getting enough sleep, staying social, and challenging your brain through learning or puzzles.

The organization is conducting a large two-year study to look at which lifestyle factors are most beneficial.

The great thing about these sorts of actions, Baker said, is all the side effects are positive.

Even if more exercise doesn’t slow cognitive decline, the only risk you’re running is getting all the other many benefits that come from exercising regularly.

“A lot of times the field just wants to find a magic pill, but (studies like the one published Tuesday) keep the conversation moving, keep us considering the value of non-pharmacological interventions, which are so often pushed aside because they’re hard.” she said.