Aging often goes hand-in-hand with declining memory, but some lucky older adults, sometimes called “super agers,” seem to keep their memory sharp as ever. Scientists — and the rest of us — can’t wait to find out just how that’s possible.
“We desperately need to understand how some older adults are able to function very well into their seventh, eighth, and ninth decades,” Bradford Dickerson, an associate professor of neurology at Harvard Medical School, said in a recent press release. “This could provide important clues about how to prevent the decline in memory and thinking that accompanies aging in most of us.”
In a study published Wednesday in The Journal of Neuroscience, Dickerson and his colleagues at Massachusetts General Hospital took a look at the brains of several older adults with remarkable memory performance.
They found that certain areas of their brains, particularly those involved in learning and memory, were similar in size to those of young people.
“We were surprised to learn that the super agers had brains with areas important for memory that did not show the typical shrinkage seen in most older adults,” Dickerson told The Huffington Post in an email. “Some of these areas were not just in between the size of young and typical older adults but were actually the same size of young adults in their 20s.”
When a region of the brain gets smaller, it means that it may have fewer brain cells, and fewer connections among the cells. For some people, the damage is a result of mini-strokes or is linked to brain diseases like Alzheimer’s. For other people, medical conditions such as heart disease and diabetes can affect the functioning of the brain. Or it may simply be the usual age-related wear and tear, similar to what happens to bones, muscles and skin.
Dickerson and his colleagues examined 17 super agers in their 60s and 70s. The participants were given a memory test that involved memorizing a list of 16 words and repeating it 20 minutes later.
Most older adults will remember between eight and 10 of these words after a delay, Dickerson said. But young adults will remember 13 or more words. Super agers also remember 13 or more words ― sometimes as many as all 16.
Brain scans comparing super agers with typical older adults and young adults revealed that some brain areas remained youthful and thick in super agers.
Specifically, these areas belonged to two networks: the default mode network, which is involved in learning and remembering, and the salience network, involved in identifying important information that needs attention.
Moreover, the area at the intersection of the salience and default mode networks was thicker in super agers than in typical older people.
“We believe that effective communication between these networks is very important for healthy cognitive aging,” said Alexandra Touroutoglou, a co-author of the study.
But what makes these brains stay young?
“We don’t know,” Dickerson said. “That is the next question.” It may be that these people start life with bigger brains and better memory abilities, and are just taking longer than their peers to show the effects of aging. Or it may be that the answer lies in their genetics or lifestyle.
In a study recently presented at the International Conference on Memory in Budapest, researchers examined 62 super agers and found that their brains shrink at a much slower rate than the brains of other people.
But if there’s a habit all super agers have in common, researchers haven’t found it yet.
“They don’t all have pristine diets or exercise regimens ― some of them drink, and some have been smoking for many years,” Emily Rogalski of Northwestern University told New Scientist. “They don’t all have a high IQ, and they aren’t all doctors and lawyers. Their health history is very variable, but cognitively, they’re doing much better than their peers.”