Cognitive Decline Isn’t Always a Sign of Alzheimer’s Disease: How Exercise Can Help

A mother kisses the forehead of her daughter
Experts say forgetfulness isn’t always a sign of dementia. Halfpoint Images/Getty Images
  • It’s estimated that nearly 6 million people in the United States have Alzheimer’s disease.
  • Researchers note that forgetfulness in older adults is not always a sign of dementia.
  • They add that exercise and daily movement can help ward off or ease cognitive decline.
  • Researchers do point out not to ignore symptoms of cognitive decline. Rather, contact a medical professional for a series of tests.

If you’re of a certain age and have taken to searching “symptoms of dementia” when things slip your mind, two recent studies show potential good news.

One study finds that impaired cognition can be part of the range of normal aging and is not always an early sign of Alzheimer’s disease.

The second study finds that we may all have access to a “medicine” to help ward it off: exercise.

Both studies move the world closer to something that experts say has been long missing: a more detailed understanding of how brain health works.

“Think about all the things we know about the workings of the heart,” Kaitlin Casaletto, PhD, a neuropsychologist and assistant professor at the UCSF Memory and Aging Center, told Healthline. “Now we’re getting that kind of input for the brain.”

Her team’s study looked at how physical activity in later life relates to brain health.

Researchers looked at the brain health of more than 400 participants in the Memory and Aging Project at Rush University in Chicago, including information from those who have died and donated their brains to science.

Casaletto and her team found that activity, even in the oldest participants, helped the brain build “protective behaviors,” something long suspected but not proven before.

“Our work is the first that uses human data to show that synaptic protein regulation is related to physical activity and may drive the beneficial cognitive outcomes we see,” she said.

And while “synaptic protein regulation” — which is the function of cells, neurons, and receptor cells communicating — may sound complicated, spurring it in the body and brain is not.

Exercise of all kinds helps it work well.

“Physical activity — a readily available tool — may help boost this synaptic functioning,” Casaletto said.

What it means for you

While more research is needed, Casaletto said her observational study indicates a positive link between exercise and cognitive health is getting clearer.

“The golden question is how much activity is (a good choice) and what passes for enough?” she said. “We don’t exactly know yet.”

But there is much they do know.

“We know the more movement we have, the better,” Casaletto said.

And while researchers are hoping to refine suggested activity goals, she said that about 150 minutes of movement a week seems to be a good start.

She suggests all people, particularly those getting older, get out and move, be it walking a dog, biking to a friend’s house, or just moving in whatever way they prefer.

“If we could bottle that mechanism,” she said, “it could be a main treatment for cognitive decline.”

There is more her team hopes to learn. That includes whether the impact varies between people’s sex and race, and whether it varies at different ages.

They hope to use devices such as the Fitbit in future studies to drill down to those details.

Forgetful? It might not be a sign

Another study, published Jan. 10, found that some memory loss may not be — as experts previously believed — a steppingstone to cognitive disease.

The study, led by Ece Kocagoncu, PhD, Prof. James Rowe, and their colleagues at the Cambridge Centre for Frontotemporal Dementia and Related Disorders at the University of Cambridge in England, looked at cognitive frailty and what, if anything, it hints at in the future.

Cognitive frailty, Kocagoncu explained to Healthline, is a subgroup of population defined by reduced cognitive performance on tests in the absence of any subjective memory complaints or a clinical diagnosis of mild cognitive impairment or dementia.

In other words, Kocagoncu said, “These individuals feel perfectly fine, but on the cognitive tests they perform worse than what is considered a good performance for their age. Instead, they perform similarly to patients with mild cognitive impairment.”

“Some researchers argue that cognitive frailty is a precursor to Alzheimer’s disease, and that if we follow these individuals over many years, they will eventually develop Alzheimer’s,” she said.

Their study, Kocagoncu said, shows that these people represent a branch of normal cognitive aging, and that not every low cognitive score means dementia. 

“Just because someone doesn’t get a high score on a cognitive test doesn’t mean that they are doomed to get Alzheimer’s,” she said. “The picture is much more positive than that.”

That could mean, she said, that some testing done to find hints of cognitive disease may not be enough on its own. 

“Tests often used in the clinic to help diagnose dementia (such as the Mini-Mental State Examination, MMSE), are unlikely to give an accurate picture of our cognitive health when used alone,” she said.

What symptoms can mean

That does not mean you should ignore symptoms.

If you feel that your memory is not the same as before, definitely go see a neurologist, Kocagoncu said. Just ask them to perform more than those tests.

“What we are saying is that these tests are useful when used in conjunction with biomarker tests for Alzheimer’s,” she said. 

Her study also found that cognitive underperformance might be a result of an accumulation of psychosocial, lifestyle, and medical risk factors rather than disease.

“Factors such as malnutrition, social isolation (living alone, not seeing or talking to friends or family often), stress, depression, having a sedentary lifestyle, hearing/vision impairment, cardiovascular disease, chronic inflammation, and lower education levels are known to contribute to worsening of cognitive function,” Kocagoncu said.

Conversely, she said, education may help ward off cognitive decline.

It’s important to emphasize, she said, that cognitive frailty due to risk factors is different from cognitive impairment in Alzheimer’s disease. 

“The latter case is progressive, whereas the former might be partly reversible by taking some positive actions with our lifestyle and habits,” Kocagoncu said.

Even at an advanced age, adding movement and educational opportunities may help ward off decline.

In other words, said Casaletto, it looks like we have the ability to better our brain health long term in our daily lives.

“It gives me hope,” she said. “It leads me to believe I should be doing more of these protective behaviors.”

You May Also Like