Study: Keeping Your Brain Active May Delay Alzheimer’s by 5 years

There is a new study that has been published within Neurology. Titled “Cognitive Activity and Onset Age of Incident Alzheimer Disease Dementia”, it was published on July 14, 2021. Basically, it is suggesting this. If you keep your brain active in old age then you can delay Alzheimer’s dementia by as much as 5 years. The essence of it is the old fitness saying – use it or lose it.

Is this really true?

Let’s take a brief look.

What exactly did the research team do?

They looked at 1,978 people with an average age of 80 who did not have dementia at the start of the study. They then followed them for roughly seven years. On an annual basis they were all given examinations that included cognitive tests.

457 of them were eventually diagnosed with dementia.

The hypothesis they were testing was that a higher level of cognitive activity would predict an older age of dementia onset in Alzheimer’s disease (AD) dementia. That is exactly what they found …

Those with the highest levels of activity, on average, developed dementia at age 94
Those with the lowest cognitive activity, on average, developed dementia at age 89

That’s where the 5 year difference comes from.

What is “cognitive activity”, what did they measure?

Basically they rated their subjects in seven activities on a five-point scale. For example, they asked them questions such as these:

“During the past year, how often did you read books?”
“During the past year, how often did you play games like checkers, board games, cards or puzzles?”

In other words, “cognitive activity” does not imply mental gymnastics, but instead were people who actively engaged and did not just sit in front of the TV and vegetate.

What if it was the dementia that caused the low cognitive activity?

It’s a very valid criticism. They anticipated it, so they did strive to test this as well. To address this they looked at the brains of 695 people who died during the study. What they found was that there no association between how active they were cognitively and markers of Alzheimer’s disease and related disorders in their brains.

Summary

Once you reach very old age, markers such as amyloid and tau protein deposits buildup up happens. If however you keep active and engaged, then this study would appear to suggest that you can delay the onset of Alzheimer’s by as much as five years. It might not appear to be much, but those extra five years can make a huge difference, not just for the individual, but also for all those around them.

But …

Like any such study, caution is wholly appropriate. There are distinct limits here …

They only studied a group of mainly white educated people, so it would be tricky to apply their conclusion to the wider population.

Comments by the Study Author

Via the press release …

“The good news is that it’s never too late to start doing the kinds of inexpensive, accessible activities we looked at in our study, Our findings suggest it may be beneficial to start doing these things, even in your 80s, to delay the onset of Alzheimer’s dementia.”
“Our study shows that people who engage in more cognitively stimulating activities may be delaying the age at which they develop dementia, It is important to note, after we accounted for late life level of cognitive activity, neither education nor early life cognitive activity were associated with the age at which a person developed Alzheimer’s dementia. Our research suggests that the link between cognitive activity and the age at which a person developed dementia is mainly driven by the activities you do later in life.”
study author Robert S. Wilson, PhD, of Rush University Medical Center in Chicago