Following last week’s presidential debate between the 78- and 81-year-old candidates – and the impression among some that President Joe Biden look at “old and fragile,” with at least a public call For cognitive tests, much of America has age in the brain.
But what do Does age really affect the brain? Fortune I consulted aging experts to get a clearer idea.
The incredible shrinkage of the cortex
“THE the brain undergoes many changes associated with aging, and one of them is the shrinking of what we call the outer layer of the brain, or the cortex,” Emily Rogalski, professor of neurology at the University of Chicago and director of its Center for Research on Healthy Aging and Alzheimer’s Diseasesays Fortune.
The cortex, she explains, is like the bark of a tree and is the layer where brain cells live.
“It’s really important for our thinking and our communication,” she says, and its shrinkage tends to occur in areas related to memory, and tends to correlate with changes in memory — which is at its peak, believe it or not, when we are just in our twenties or early thirties.
Attention and executive functions are also vulnerable. “All of these things are kind of interdependent, because you have to have good attention to remember something,” Rogalski says. “Our cognitive functions don’t rely on little islands of memory and attention, without interaction. It’s a complex system.”
Age-related memory loss is normal
A recent McKnight Brain Research Foundation Surveysays Patricia Boyle, professor of psychiatry and behavioral sciences at Rush University and a neuropsychologist at the University of California, Los Angeles. Rush Center for Alzheimer’s Diseasefound that 87% of Americans fear experiencing age-related memory loss and a decline in brain function as they age.
“But what many people don’t know is that age-related memory loss isn’t always a sign of a serious cognitive problem,” Boyle says. Fortune. “Most people don’t understand that age-related memory loss “It is usually associated with mild forgetfulness and is a normal part of brain aging and is not necessarily a sign of a serious memory problem.”
Some signs of normal aging, she said, include:
- Making a bad decision every now and then
- Missing a monthly payment
- Losing track of time
- Not being able to find the right words
- Losing items in the house
“As you age, it’s normal to see signs of cognitive aging, just as it’s normal to see physical signs of your body aging, like slower movement or more pain,” Boyle says.
Brain shrinkage accelerates with age
Brain volume continues to decline with age, including frontal lobe and hippocampusareas responsible for cognitive functions, with a rate of shrinkage that increases around age 60.
“As we age, we increase our risk of many diseases simply by getting older,” which makes sense, Rogalski says, considering the wear and tear and increasing vulnerabilities on our bodies — and the fact that, unlike hips or knees, there’s no replacement for the brain.
Aging brings the possibility of one of two types of atypical loss of cognitive function, notes Dr John Roweprofessor of health policy and aging at Columbia University’s Mailman School of Public Health: dementia and mild cognitive impairment (MCI), “an age-related change that occurs in 12 to 18 percent of people over the age of 65,” he says. “And what’s reflected in daily life is that people become more forgetful, they lose things, they miss appointments, and that can impact their daily functioning.” MCI, he adds, progresses to dementia in about 10 percent of people per year.
Some older adults have high performance
Rogalski stresses that it’s important to focus not just on what’s wrong, but on new opportunities. “One of the big challenges of aging is the stigma associated with aging and the expectations we put on people as they age — as if they’re only on a downward trajectory — and we take away activities and responsibilities that they could be doing.”
And that’s a problem in some new luxury assisted living communities, she says, which provide services ranging from room service to folding laundry. “It turns out that a lot of these everyday activities that we do, like doing dishes or just moving around, are actually really good for keeping those muscles strong.” Likewise, it’s important to keep our brain engaged and activewhich can take many forms. “It can come from maintaining social connections. It can come from learning something new. But we want to think about exercising our brains and using our bodies, including thinking about ways to practice our fine motor skills… and if those things are taken away from us and done for us, we’re not necessarily doing ourselves any favors.”
Yet, Rowe points out, “there’s a huge amount of variability. And what we’re seeing is that an increasing proportion of the older population who are very high performers are sort of super seniors.”
Enter the super-seniors…
Rogalski, through his research within the framework of the ongoing multidisciplinary project SuperAging Research Initiativeexamines evidence from biological, familial, and lifestyle perspectives to understand what makes some people appear to barely age, at least cognitively.
“We found that the super-aged, biologically speaking, appear to look different. Their brains look more like those of a 50- to 60-year-old than those of an 80-year-old,” she says, adding that their rate of shrinkage is slower than that of the average octogenarian.
“So they seem to resist this thinning of the outer layer of the brain, or the cortex, and when we measure it using really precise tools, we see that super-elder brains “In fact, older adults don’t have a decrease in muscle mass compared to people in their 50s and 60s,” she explains. In fact, there’s a region of the brain called the anterior cingulate cortex (ACC), which plays a role in motivation, decision-making, and emotional and situational cues, that’s thicker in older adults than in people in their 50s and 60s. They also found an abundance of neurons called von Economo neurons, which helps scientists have a “biological pathway” to understanding older adults.
Years ago, Rowe says FortuneRowe led a research network that studied “successful aging” at Harvard University. In one study, he followed a group of 75-year-olds for six years, testing them physically and cognitively over that time. “At the end, 25 percent were unchanged, 50 percent were worse, and the rest were average,” Rowe says, noting that those who fared best, the super-agers, shared certain lifestyle characteristics, including not living alone, education level, and financial security.
This shows that if you were to gather a group of 80-year-olds today to assess their cognitive abilities, you would get mixed results: probably a couple with dementia, one or two super-aged people, and others somewhere in between. This is not only because people’s brains evolve at different rates, but also because of differences in lifestyle, genetics, and other factors.
Ultimately, says Rowe, who points out that he himself is 80, “I don’t think we can talk about a valid average when we’re trying to reduce this to a decision about an individual. I don’t think we can assign an individual the average of an 80-year-old.”
