July 17, 2024 – The changes can begin in middle age, but they’re not usually noticeable until decades later. By age 60 and beyond, the changes can pick up speed and may become obvious.
“As we get older, our brain actually starts to shrink and lose mass,” said Marc Milstein, PhD, a Los Angeles brain health researcher. The start of that shrinkage, as well as the path it takes, can vary, said Milstein, who wrote The Age-Proof Brain.
“Starting at 40, our overall brain volume can start shrinking about 5% every 10 years,” he said. “Our brain has connections where our memories are stored, and as we age, we lose some of these connections. That can make it challenging to remember and to learn new information.”
As scary as that may sound, “We can slow down this process,” Milstein said.
Those who have apparently slowed down the process the most are called “super agers” and are the focus of intense research. But plenty of other people, beyond their 70th birthday, boast that they wow their friends often with their spectacular memories and other mental skills.
‘Typical’ Brain Changes Over Time
With age, the hippocampus– critical for making new memories and accessing old ones – loses volume. When learning new information, Milstein likens the hippocampus to a “waiting room” of the brain. “It’s one of the first places information goes.”
And the brain has to decide: Is this information worth transferring on to longer-term memory? As we get older, our brain’s ability to not be distracted can have a negative impact on our ability to transfer this information, Milstein said. That’s why multitasking when we get older can make it more challenging to learn new information, he said. The prefrontal cortex – important for managing emotions and stress – also shrinks.
These structural changes and shrinkage vary from person to person, said David B. Reuben, MD, a professor of medicine and chief of geriatrics at the UCLA David Geffen School of Medicine. “How much it contributes to decline is variable.”
By your late 70s and into the 80s, the speed of processing information can slow, he said. He likens it to a computer that needs an update. “Before you update your computer, you get the same answers, but they’re slower,” he said.
Deficits in retrieval, or what Reuben calls “tip of the tongue” syndrome, can happen, too, and they’re normal. “You know you know it, but you can’t get the word or words out.” Then, sometime later, it may pop into your head, so you relax and figure your memory is OK.
With age, mixing up a name can happen, just as it can earlier in life, said Joe Verghese, MD, a cognitive neurologist and chief of the Division of Cognitive & Motor Aging at Montefiore Medical Center in the Bronx, NY.
If it’s an isolated incident, it’s not a red flag, he said. It’s more apt to happen in a stressful situation. But it can happen to anyone. “It’s like an older mother calling her first son by her second son’s name,” said Verghese, who admitted he once called his son by his dog’s name.
The reduction in brain volume can lead to noticeable changes in thinking skills, Verghese said. But, he said, it’s important to point out that in normal aging, “the degree of shrinkage doesn’t always correlate to how you perform cognitively, or in day-to-day life.” In other words, your brain could have noticeable shrinkage but you are still getting through the day mostly fine.
If brain imaging such as an MRI is repeated over time, the shrinkage would probably be noticeable as the years go on, comparing one scan to another, Verghese said. But in clinical practice, he said, he doesn’t do serial MRIs to assess shrinkage; rather, he goes by how people are doing clinically, by assessing if they are walking, talking, and thinking normally.
He is an expert in the link between gait and dementia, finding that changes in how you walk can be used to predict mild issues with mental skills as well as dementia.
“How you walk is an important indicator of health, of how well you are doing cognitively as well as physically,” Verghese said.
That’s because walking involves processes from the brain to the nerve endings in the feet. When walking gets stiff, it could signal a number of issues – from arthritis and the need for more movement to possible Parkinson’s or other conditions. A stiff gait isn’t normal, he said. “You should be able to walk freely. If you are not doing so, there is a reason for it,” although it might not be treatable.
Enter the Exceptions
Despite brain shrinkage, some people continue to impress friends with their memory skills later in life.
Sylvia Schmidt, 89, is a longtime member of a book club where most members are at least a decade younger. But she was the only one who realized they had already read a book the leader once selected. Others argued with her at first, said Schmidt, who lives in a retirement community in Fullerton, CA. But the leader looked up the book (As a Driven Leaf) and proved her right, and now they all know better. “They all remark I have a phenomenal memory,” Schmidt said proudly.
She recently had a detailed political discussion with another resident who at first insisted her details about an incident, complete with dates, were incorrect. When his girlfriend looked up the details, finding Schmidt’s version accurate, he changed his mind.
Perry Solomon, 79, of Santa Monica, CA, is a consultant to small and medium-size businesses. Recently, he was talking about travel hassles with his wife and could still describe, in detail, an incident that happened more than 40 years ago during a family trip.
“It was about how our passports were stolen as our daughters were sitting on our suitcases but got sidetracked [by a thief] on a sidewalk in Manhattan while we were checking out of the hotel,” Solomon said.
He’s also on the advisory board of several companies and said he often hears from colleagues: “How the hell did you remember that?”
Reuben has a patient he sees in his geriatric practice who’s still working, at age 98. “His memory is better than mine,” Reuben said. Another patient, 90-plus, is still teaching at the university level, memory intact.
Enter the Super Ager Exceptions
These “super agers” include Edith Smith, who, at 110, is the oldest of more than 100 people taking part in the Northwestern University SuperAging Program. Similar programs, also funded by the National Institutes of Health, are in operation at other sites in the U.S.
“There are many different definitions of successful cognitive aging,” said Tamar Gefen, PhD, an assistant professor of psychiatry and behavioral sciences at the Northwestern University Feinberg School of Medicine in Chicago, who directs the program there. For the Northwestern program, “a super ager is an individual over age 80 whose memory function is at the level of a 50-year-old or even better,” she said, as determined by testing.
Gefen is often asked for a profile of a typical super ager. She doesn’t have one. “We have super agers who smoke. We have super agers who drink a six-pack [although not every day]. We have super agers who are depressed. Some have 8 years of education; others have 20 years. We have super agers who are Holocaust survivors, who have been to hell and back.”
Genetics plays a role, of course, she said. But that’s not all.
“A couple of factors we have noticed by observation is that super agers seem to be more social, more extroverted [than usual],” Gefen said. But, she acknowledged, that could be because of sample bias, with the more extroverted people more likely to enter studies.
That’s not to say that the suggestions on the standard list of good health habits for the brain – exercise, manage cardiovascular health, follow a good diet – aren’t important, Gefen said. She cited a list, published in The Lancet in 2020, of 12 potentially modifiable risk factors for dementia (such as hearing impairment, high blood pressure, depression, and low social contact). Yet, she said, some of her super agers may have addressed perhaps three of those factors and ignored the other nine.
Research: What Protects the Brain?
Researchers are focused on how to protect brain health with age. Among the findings:
Stay social: In a study of nearly 9,000 people ages 65 and older in Japan, all without dementia, the total brain volume in the group with the lowest frequency of social contact was lower in the hippocampus and other regions, compared with that in the group with the highest frequency of social contact. Depression seemed to partly explain the link, the researchers said.
Exercise: Even moderate walking, such as taking fewer than 4,000 steps a day, has been linked with increased brain volume and potential brain protective effects, a study of more than 10,000 people found. Social dancing can improve cognition, reduce Alzheimer’s risk, and be an effective alternative to traditional exercise, Verghese and his colleagues found. In the study, they assigned 25 older adults either to treadmill exercise or social dancing for 6 months.
Seek new information: “Think about learning new information,” Milstein said. Try something fun that’s outside your comfort zone. “Take a new course. Find something new to you. You are driving the brain to make new connections.”
