Dr.Aaron Carroll: The idea that brain training might lower the risk of dementia has been a popular topic for a long time, but the evidence has been sorely lacking. A recent publication of clinical trial data has the media claiming that the evidence is now in the room with us.

Are they right? Does dominate in your friends in Wordle and the Mini crossword have a significant downstream effect on dementia? That's the topic of this week's Healthcare Triage.

Much like physical exercise, your brain gets better at doing puzzles, memory games, or other brain training exercise the more that you do them. Following the use it or lose it logic. Researchers have posed the question of whether flexing those brain muscles.

Yes, we know the brain isn't really a muscle, but we're trying out metaphors here Anyway, whether that can stave off neurological diseases like Alzheimer's. Unfortunately, the data on that haven't been promising, But results from the advanced cognitive training for independent and vital elderly or the active trial. Have some people taking a second glance, particularly because the trial was large, randomized and controlled.

Everything we love about a good trial. So to the research, Participants were assigned to one of three types of training memory, reasoning, or speed of processing, or to a control group with no training. They completed a short intervention about ten training sessions over several weeks, with some participants receiving additional booster sessions around 1 to 3 years later.

The researchers then tracked dementia related diagnoses over a 20 year follow up period. at first glance, the results look impressive. People trained in reasoning got better at, well, reasoning. The people trained in speed got better at processing visual information quickly.

And here's where all the excitement comes in. This group also had lower rates of dementia over time. Cue the headlines.

A short, simple brain training intervention might reduce your risk of dementia decades later. We hate to spoil the fun, but health care triage is going to health care triage. We've read the paper.

And while we never missed the chance to applaud a good old fashioned randomized controlled trial, we've got to address the elephant in the room. The first elephant is just timing. The idea that completing these brain training tasks over a period of weeks would have a significant effect on a complex brain disease around two decades later is just implausible.

And while the group receiving speed training tasks saw those lower rates of diagnoses, there was no significant effect for the groups receiving memory or reasoning training. That is an oddly specific effect. And that brings us to the second elephant significance.

The paper does indeed report that the participants who received the short duration of speed processing and training were significantly less likely to be diagnosed with dementia later on. Statistically significant, tells us that a result is unlikely to be due to chance. That's an important step.

But the next important consideration is whether the difference is clinically significant. Clinical significance asks a different question. Is the effect actually meaningful in real life?

And when you look closely at the active trial data, you start to see why this distinction matters. In the control group that received no brain training exercises, the number of people ever diagnosed with dementia was 239, or about 48.7% of the group. Compare that to the speed group, where the paper is claiming a significant reduction in diagnoses.

In this group, the number of individuals ever diagnosed with dementia was 223, or about 43.5% of the group. The difference was reported to be statistically significant, but we're talking about a roughly five percentage point gap, which doesn't translate as well to clinical significance. To further drive the point, let's take a look at the other brain training groups in the memory group.

The number of people ever diagnosed with dementia was 231, or about 44.8%. Those numbers for the reasoning group were 223. About 44.4%.

Those percentages aren't much higher than the 43.5% of the reasoning group, but they were not determined to be statistically significant. So one brain training exercise reduces the group risk of dementia diagnosis to 43.5%, while other trainings reduce the risk to just over 44%. But only the first training had a significant effect.

That's a lot to put on that approximately one percentage point. So in a nutshell, the effect of brain training was statistically detectable, but likely not dramatic in a practical sense. Many people in the control and other training groups did just as well over the long run.

The recent media coverage isn't technically wrong, but it gives the impression that brain training is a powerful tool for preventing dementia when the evidence just doesn't support that. Is it a waste of time to brain train? Probably not.

Keeping our cognitive skills sharp can hardly be a bad thing. And evidence does suggest that it can help us to maintain daily tasks as we age, and a little competition over vocabulary or math games can be an important social connection. I do it every day, but as far as solving the complex problem of dementia, we'll keep looking to the research.

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Make it bigger and better. We'd especially like to thank our research associates Joshua Crowe, Edward Liljeholm and Christopher Learn, and of course, our Surgeon Admiral Sam.