Can Cognitive Exercise Speed Up Dementia?

New research suggests that seniors who did mentally stimulating activities such as crossword puzzles postponed the loss of thinking skills, but had an accelerated rate of decline once dementia set in later in life. Neuropsychologist Robert S. Wilson explains the finding.

IRA FLATOW, host:

Up next, your aging brain. We've heard for a while, you know, all those things about how mental exercises like crossword puzzles or reading or listening to the radio could help you ward off the dementia that comes with old age - give your brain some exercise. Well, new research out this week in the journal Neurology says that some cognitive exercise might actually speed up dementia later when you get older.

Joining me now to take more about this somewhat puzzling finding and what it means for us aging crossword-puzzle lovers, like myself, is my guest Robert Wilson. Robert S. Wilson is professor of neurological science and behavioral science at Rush University Medical Center in Chicago. Welcome to SCIENCE FRIDAY.

Dr. ROBERT S. WILSON (Neurological Science and Psychology Professor, Rush University Medical Center): Hi, Ira. Thanks for having me on.

FLATOW: This is sort of surprising to us.

Dr. WILSON: It is a counterintuitive finding, though it's long been anticipated in the field.

FLATOW: Tell us exactly what - to clarify what it is, tell us exactly what you have found.

Dr. WILSON: Well, a number of studies, including ours, have found that people who have a cognitively-active lifestyle are less likely to develop dementia and Alzheimer's disease and experience cognitive decline.

FLATOW: Right.

Dr. WILSON: Our study asks: What happens to people who develop Alzheimer's disease despite having been cognitively active? And we found that they actually decline more rapidly than do people who are less cognitively active before the disease onset.

FLATOW: Mm-hmm. So when you are diagnosed then with Alzheimer's, you decline more rapidly to catch up with those other people? Would that be phrasing it correctly?

Dr. WILSON: Yes, I think what we really think - we certainly don't think that cognitive activity is bad for you in any way, shape or form.

FLATOW: Mm-hmm.

Dr. WILSON: We think what's really happening is that you're, in effect, buying extra time in a cognitively healthy state and paying for it with less time in a cognitively disabled or demented state. See, what's going on is we think cognitive activity does not affect the underlying accumulation of the pathology in the brain, but rather helps stable off the effect of that pathology until it reaches some threshold after which lifestyle really no longer matters. At that point, the person who had a cognitively active lifestyle actually has accumulated more pathology than a person with a less active lifestyle. And so, we think they decline faster from that point.

FLATOW: Are you saying then that the cognitive active lifestyle, the crossword puzzles and brain exercises, actually hurts your brain in a certain way but we don't notice it until we crossover, until that threshold of actually being diagnosed with some sort of brain disorder?

Dr. WILSON: No, no. We don't think it hurts your brain at all.

FLATOW: Mm-hmm.

Dr. WILSON: We think it helps stave off the initial symptoms from the buildup of this pathology. But if you were destined to get the disease anyway and the pathology is continuing to build up, at some point your defenses are no longer effective. And at that point, because of how effective they've been before that point, you've got a lot more pathology than the person next to you who's got just as much cognitive impairment but they didn't have that tool to fight off the pathology so they actually have less at that point than do you. So, really, it's just delaying the effect of that pathology.

FLATOW: Mm-hmm.

Dr. WILSON: It's not, in any way, worsening your course. You end up, we think, at the same place as someone who is less cognitively active. But in doing so, you spend less of your lifespan in a cognitively disabled state. And that, I think, is something that virtually anyone would say is a benefit.

FLATOW: Do you have any idea what the mechanism going on here is that it delays it and then causes that rush to the end?

Dr. WILSON: Well, we don't know exactly. But we do know from - there have been longitudinal studies with neuroimaging and intensive training program. So there's a famous study of German medical students who have to cram for exams over a three-month period. And during that period, it's documented that the size of the hippocampus, which is important for memory, and part of the neocortex, which is important for thinking, got larger. There are similar studies for jugglers and with parts of the brain devoted to sensory motor coordination, so short-term, intensive training programs can change the structure and function of your brain. Our brains are activity-dependent, so what kind of brain you have depends a lot on what you ask it to do.

FLATOW: Mm-hmm. And...

Dr. WILSON: And...

FLATOW: Go ahead. I'm sorry.

Dr. WILSON: And the state and health of your brain, when you enter old age, is absolutely critical because these pathologies of old age are nearly ubiquitous. If you die in your 80's and we do a brain autopsy on you, at least two-thirds of the individuals will have sufficient Alzheimer's disease pathology to warrant a diagnosis, though many fewer would have shown the clinical symptoms. Over a third will probably have one or more strokes. About 20 percent will have another pathology called Lewy body pathology, which is also associated with dementia. So it's very rare to find a brain that is free from this pathology. Yet, there are huge individual differences in how well we can fight off that pathology and maintain our cognitive health in old age. And that's what a lot of these lifestyle studies are really aimed at, is trying to really get the most mileage out of the brain that you enter old age with.

FLATOW: So the take-home message here is don't give up those brain exercises?

Dr. WILSON: Absolutely don't give them up. And - but it's important that they be done on a fairly frequent basis and persistent over time.

FLATOW: And what exercises would they include?

Dr. WILSON: Well, our study isn't terribly informative on that. We ask about things that practically any old person would have access to. We think that the most important kinds of behaviors probably have to do with reading and need to be practiced, again, on a very regular basis.

FLATOW: Mm-hmm. I noticed that you had listening to the radio in there.

Dr. WILSON: Yes. Listening to...

FLATOW: It's important to us.

(Soundbite of laughter)

Dr. WILSON: Listening to the radio and watching television for older people is one of the few windows to the outside world. And though we joke a lot about what's on radio or TV, there's certainly a lot of high quality content. I'm not going to say where that might be, but...

(Soundbite of laughter)

FLATOW: Let me get a call from Al(ph) in Oregon. Hi, Al.

AL (Caller): Hello. Good afternoon. Thank you for taking my call. I want to ask your expert there about the specifics of cognitive activity in my own profession. I'm a stage actor, specifically a Shakespearean stage actor. And I've worked with a number of individuals, 70 years old and better, who were just as vibrant and mentally acute as one could hope to be at their age. And I was wondering if continuous memorization, character study, really getting into a text such as a Shakespearean actor has to do, if that can help stage off cognitive dementia such as you describe.

Dr. WILSON: That's a really excellent question. There's a husband and wife team by the name of Noice, N-O-I-C-E, who have been doing research for about the last 10 or 15 years on this various actual question. And they've done some intervention studies and found that teaching older people how to act, giving them theater classes if you will, increases their memory and cognitive function substantially compared to control groups who were taught, you know, fine art history or something of this sort.

FLATOW: Mm-hmm.

Dr. WILSON: So it does appear that there's something about acting that is very beneficial to the brain. We don't know exactly what it is.

FLATOW: Well, we hope to have you back on when you know.

Dr. WILSON: Okay.

(Soundbite of laughter)

FLATOW: And we do hope you'll find out. Thank you for taking time to be with us today, and have a good weekend.

Dr. WILSON: Okay. Thank you so much for having me.

FLATOW: You're welcome. Robert S. Wilson is a professor of neurological science and behavioral science at Rush University Medical Center in Chicago. I'm Ira Flatow. This is SCIENCE FRIDAY from NPR.

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