It’s clear that a cure for Alzheimer’s disease, which affects around 5.4 million Americans, is still a long way off.
But new findings suggest we may be getting closer to knowing how to prevent the devastating neurodegenerative disease.
On Sunday, results from a promising 10-year trial involving nearly 3,000 older adults were announced at the Alzheimer's Association International Conference in Toronto. The trial found that a specific type of computerized brain training game that tests mental quickness decreased the onset of dementia by 48 percent compared with controls.
These results have not been published in an academic journal, and should be considered preliminary until they are. But they do lend hope: If Alzheimer’s can’t be cured, maybe it can be prevented, or at least its worst symptoms can be postponed.
Why fast thinking may be protective against Alzheimer’s
The big idea behind the new research is that speed-processing training builds what’s know as cognitive reserve.
In Alzheimer’s, a type of dementia, the brain physically becomes degraded by malicious plaques and proteins. Eventually, symptoms like memory loss, difficulty moving, and loss of reasoning set in.
Scientists believe that structural damage to the brain can precede cognitive changes by 10 years. And so there may be a window of opportunity in those 10 years to strengthen a person’s established neural connections to stave off the onset of the disease.
The researchers working in this area are aiming to find a constellation of activities that bolster the mind as it degrades. They call this reinforcing process building “cognitive reserves.” The research this far suggests having a stimulating job, a good diet, good exercise, and strong social ties are keys to increasing these reserves.
And now it appears a specific type of computerized brain training may help as well.
The study results presented at the Alzheimer’s conference found evidence for one type of brain training — a very specific task that targets speed of mental processing. In other studies, speed of processing training has been shown to help older Americans pay better attention on the road.
In this type of training, participants are quickly shown cartoon images of objects on a screen. They are then asked questions about what they saw and where. As the training progresses, the task grows harder, with more objects persisting for a shorter time onscreen.
Here’s an example of the task as presented at the Alzheimer’s conference.
Here’s another example. This one is a bit harder.
What gives this unpublished evidence some weight is the strength of the study design. The data was pulled from ACTIVE trial, an NIH-funded longitudinal study to better understand how to prevent the onset of dementia. The study began in 1998 and recruited 2,800 older Americans (average age 74) in six cities. All participants were healthy at the beginning of the study.
Participants were sorted into four groups. One control group that received no brain training at all. The three experimental groups trained with a memory-based brain training game, a strategy-based game, or the visual processing game I mentioned above.
The participants received a total of 10 hours of training in the first five weeks of the trial. Around half of each experimental group got additional training after 11 months and 35 months.
Ten years on, only the speed training group showed a decreased risk for dementia. Around 14 percent of the control group developed symptoms of dementia after 10 years. Eight percent of those who received the most amount of speed training did. That’s around a 50 percent reduction in risk for dementia. What’s more, the researchers found a dose-response curve, meaning those who received more training in booster sessions were more protected than those who received less.
(Note: A company called Posit Science now owns the commercial rights to this speed task. The company did not own it at the beginning of the ACTIVE study. It had no involvement in the funding, design, or analysis of the data, according to Jerri Edwards, a professor at the University of South Florida and lead author of the study. And none of the authors of the study have a stated conflict of interest, though Edwards says she worked as a consultant for Posit Science in 2008.)
No other type of training showed these improvements. And these differences only appeared after the five-year mark of the study.
It’s important to note that these results are not a validation of brain training as an industry, but just of this one specific task. As Vox has reported, brain training doesn’t work for increasing IQ. And scientists have serious reservations about commercial brain training companies.
In fact, this study also showed that the two other types of brain training exercises did not have any effect all all.
“There are lots of different cognitive training techniques, there are lots of different products, and the effects of any of the cognitive training exercises are very specific,” Edwards tells me.
In the past, scientists have been very skeptical of brain training games
This is the first data to suggest computerized brain training can help protect against dementia. And in recent years, many scientists have been skeptical of the entire field of brain training.
In 2014, a group of 70 scientists signed a consensus statement, harshly criticizing computerized games: "To date, there is little evidence that playing brain games improves underlying broad cognitive abilities, or that it enables one to better navigate a complex realm of everyday life," they wrote. “No studies have demonstrated that playing brain games cures or prevents Alzheimer’s disease or other forms of dementia.”
In January, the Federal Trade Commission called out Lumos Labs, the maker of Lumosity, for deceptive marketing. The FTC claimed Lumos "preyed on consumers’ fears about age-related cognitive decline, suggesting their games could stave off memory loss, dementia, and even Alzheimer’s disease," as a statement from the administration’s Bureau of Consumer Protection explained.
But according to Glenn Smith, the chair of the department of clinical and health psychology at the University of Florida, the new data could become the first evidence that one type of brain training game could be effective.
“FTC chastised Lumosity for making claims about dementia they hadn’t proven, because nobody had that kind of data. But here, potentially is that kind of data,” Smith said. (He was not involved in the study but was briefed on the data.)
There are still good reasons for skepticism
Though this new data is surprising and exciting, it still needs to be vetted by the academic community. Peer review isn’t a panacea, but it’s at least an additional layer of scrutiny (which is especially needed when there’s a corporate interest that stands to make some money from marketing these results.)
Smith, the researcher who was not involved with the study, is optimistic.
“I suspect they probably will be [published] pretty quickly,” he says. “They’ve collected and analyzed data in the right ways for years and years and years.”
Even then, these findings ought to be replicated in a separate effort. And there are a few other points that will need to be clarified in future research.
1) No one really knows why speed-processing training works
It’s thought that “cognitive reserves” — a function of how sharp we keep our minds through work and social stimulation — save our cognition even as the brain becomes afflicted with the plaques that causes Alzheimer’s. One of the sources of these cognitive reserves may be mental quickness. Others may be social stimulation or analytical thinking.
“The whole problem [of dementia-related memory failures] is in the efficiency in encoding the information in the first place, more than the ability to retrieve it later,” Smith says. “That’s why processing speed matters to our learning and memory.”
But that’s just a theory. Scientists have yet to nail down what exact changes speed-processing training causes in the brain.
“One of the ideas would be is if you’re continuing to use your brain in a certain way, you’re actually benefiting the communication between brain cells, in a way that’s beneficial long term,” Maria Carrillo, the chief science officer at the Alzheimer’s Association, said recently.
2) The study showed a significant effect for people who completed just 11 hours of training. How could such a small dose of training have such a large impact on the brain?
This isn’t entirely known.
“That’s why a lot of folks have skepticism, because the dosing seems so limited,” Smith says. “I hope we’re about to transition from a place where we start to wonder if there’s any benefit to this kind of activity to one where we’re asking ‘how much of it, over what period of time, to optimize your outcomes.’”
The New Yorker asked this same question to Susanne Jaeggi, a cognitive aging researcher at the University of California and one of the scientists who signed the consensus statement. “If you stop doing it after ten or even fourteen sessions, how on earth can you continue to have these effects ten years later?” she told the New Yorker.
According to STAT, the long-lasting nature of the effect could be a result of what’s known as the “bootstrapping effect”:
Maybe people who received speed-of-processing training “did something different over the years,” said Laurie Ryan, who oversees Alzheimer’s research at the National Institute on Aging. “Maybe they changed their lifestyle in some way,” with the training giving them a little cognitive boost that they parlayed into more reading, more travel, more social engagement, and more of other activities that boost “cognitive reserve,” the brain’s cushion against dementia.
Or it could be a fluke. Even well-designed studies can find false positives. More research will have to be done to determine if this level of training can replicate to show lasting changes in new samples.
Also, the five-year results of the ACTIVE training showed no difference in dementia for those who got the training. Why did differences only emerge between five and 10 years? These are all open questions that should be analyzed.
3) Research presented at conferences can change
Hilda Bastian, a writer on the PLOS blog network, points out that data presented at conferences often looks different when it comes out in a publication:
Details that come out about trials later are often quite different to what was presented at conferences. A study of cardiology articles post-conferences from 1999-2002 found around 40% had discrepancies, and a sports medicine study found 63% had at least 1 major issue.
(Bastian also worries that this new data is a reanalysis of a study that was not explicitly set up to study dementia rates at 10 years. Increasingly, scientists prefer researchers preregister all their analyses in advance. This ensures researchers can’t cherry-pick methods later on.)
The big picture: Researchers want Alzheimer’s prevention to start early
Overall, these results — and the larger research on cognitive reserves — present an opportunity: that there may be time to reinforce the brain before the worst symptoms of Alzheimer’s set in. This is especially important in an aging population. Numbers of Americans with dementia and Alzheimer’s are sure to increase in the coming years.
“We’re going to need to detect the changes in individuals at the earliest time,” the Alzheimer’s Association’s Carrillo says. “If we can detect those changes, and then begin to intervene with lifestyle changes, or medications, that’s the ultimate goal: We want stop the progression of the disease before your loved ones lose their memories.”