“The best thing about getting old,” the late John McCain liked to joke, “is you get to hide your own Easter eggs.” Wouldn’t it be great if our brains didn’t decline? If our memories didn’t get worse, and we didn’t get a bit slower at thinking? Even if we don’t end up with dementia, most of us will experience some cognitive decline.
Researchers at Massachusetts General Hospital are looking into one fascinating aspect of this: So-called “superagers,” who seem to have the amazing trick of aging much more slowly than everyone else, especially when it comes to short-term memory. Turns out they really exist. And their brains really are different. The problem? We still don’t know why. I spoke to Dr. Yuta Katsumi, a cognitive neuroscientist at MGH and part of the team looking into superagers. When I asked him why superagers have avoided memory decline, he laughed. It’s one of the questions he’s asked most often. “My answer always is, ‘We don’t know,’” he said. It’s going to take a lot more research before they really find out, he said. Katsumi and his fellow researchers have just published a new paper on their research. Bottom line? Superagers exist, and their brains look and act differently to others. Massachusetts General Hospital studied 40 older individuals with an average age of 67. They set them some computer-based tasks involving perception and memory. They were shown, in total, over 200 face-word combinations on a computer screen. They had to work out which ones they’d seen before, and whether the pairings had been changed. It’s known as the California Verbal Learning Test, and it’s widely used in cognitive studies. While they were taking the test, their brains were scanned using functional MRI, or fMRI, to track activity. Meanwhile, the team at MGH also put a bunch of people in their 20s through the same test. Some 17 of the 40 older adults, or about 40%, proved to be what scientists are now calling “superagers.” They performed much better on the test than the others. Their performance was similar to that of the subjects in their 20s. And the researchers could see this on the fMRI scans. The superagers had brain activity that was indistinguishable from the brain activity of the subjects in their 20s. The difference, Katsumi says, lies in the visual cortex, an area of the brain associated with seeing and remembering. “The visual cortex of superagers is able to process the images more efficiently, and that is associated with better memory,” he says. And the visual cortex is one of the regions of the brain that most typically shows functional decline as we age, he says. In other words, the superagers seem to be keeping the brains of their youth. They are avoiding the cognitive decline seen in others. The latest study is part of a continuing research project into brain health that has already been running for 10 years. It’s these types of studies that are slowly chipping away at the vast coalface of ignorance about the brain. We know so little—which is one reason over half the population experiences cognitive decline, and 6 million already have Alzheimer’s. [https://www.cdc.gov/aging/aginginfo/alzheimers.htm] That number is going up rapidly as the population ages. “The number of people living with the disease doubles every five years beyond age 65,” says the CDC. Katsumi warns that even the latest findings only get us so far. “Our evidence is correlational at best,” he says. “We don’t know what causes people to have better brain structure and better memory… We don’t know how to make people superagers.” As for all the various products and strategies that supposedly help keep your brain healthy and slow, or avoid, cognitive decline? He says the evidence is pretty thin for most of them. That includes computer-based “brain training” applications, though he says they are backed by big marketing campaigns. “I don’t think the conclusion [that they work] is that solid,” he says. Playing a lot of Sudoku could end up making you really good at Sudoku, he says, but that doesn’t mean you’ll keep your other mental faculties sharp. The two things that we know help? Aerobic exercise, and changing your diet to include things like omega-3 fats. Just walking for 30 minutes a day, three times a week, is enough to help lower your risk of cognitive decline, Katsumi says. Meanwhile, the research goes on. It may not be enough to save current generations of adults from decline and eventual dementia, but who knows? Maybe we’ll get there in time for today’s children—or their children.