good old brain

| 25 Jul 2019 | 03:59

Aging is not a disease, and many of the brain changes that accompany it are normal. Even in healthy adults, parts of the brain shrink as it ages. Fortunately, aging brains do more than merely shrink. They also adapt and find ways to compensate. Imaging studies of older and younger subjects performing the same cognitive task, for example, show that some older people recruit additional brain regions and pathways to get the job done.

That flexibility is the aging brain’s secret weapon. As one study puts it, older brains have “considerable reserve potential.” But brains are like muscles — you’ve got to use them to keep them in shape.

Staying engaged and active as the years pile up is the key. Here are four things people can do that have been shown to improve cognition in older adults.

GET SOME EXERCISEResearchers have found that regular exercise can increase the amount of gray matter in the adult brain, improve cognitive function and reduce the risk of developing cognitive impairments, including memory problems. Higher aerobic fitness has been shown to reduce the risk of cognitive decline in people over 60 by as much as 40 percent. In multiple experiments, aerobically fit older adults routinely outscore their sedentary and less-active peers in tasks that measure problem-solving skills, processing speed, attention, verbal fluency and several types of memory. And while even modest amounts of exercise have been shown to confer clear cognitive benefits, studies show that sessions lasting longer than 30 minutes offer greater benefits.

In one study, published in 2017 in the online journal Frontiers in Aging Neuroscience, involving a six-month training intervention with 60 sedentary adults from 64 to 78, the people randomly assigned to aerobic exercise exhibited “a broad improvement in cognitive performance” compared to individuals assigned to stretching and toning.

And a 2018 study in the British Journal of Sports Medicine, which analyzed 39 randomized controlled trials of physical exercise interventions (the largest such analysis to date), concluded that they “are effective at improving the cognitive function of older adults, regardless of baseline cognitive status.”

Psychologist Arthur F. Kramer, director of the Center for Cognitive & Brain Health at Northeastern University, has been studying the aging brain since the 1970s. In his exploration of the effects of physical activity — “I mostly work with older adults, and we’re basically just getting people off the couch to walk more” — Kramer has his previously sedentary subjects exercise an hour a day, three days a week for periods of six months to a year. That doesn’t sound like much, because it isn’t. But it gets the job done. “Maybe they’re improving their aerobic fitness 10 or 15 percent, at the outside,” Kramer said, “but those kinds of improvements show pretty dramatic changes. Essentially, in terms of brain function, you can think of it as turning back the clock to a younger age.”

The impact of exercise on mental health, and depression in particular, was confirmed in a large study published in The American Journal of Psychiatry in 2018. Researchers followed 33,908 healthy adults for 11 years and found that regular exercise was associated with reduced incidence of future depression. “The majority of this protective effect occurred at low levels of exercise and was observed regardless of intensity,” they wrote. They estimated that “12 percent of future cases of depression could have been prevented if all participants had engaged in at least one hour of physical activity each week.”

KEEP BUSYThe relationship between busyness and cognition in older adults has recently begun to attract the attention of neuroscientists. Findings so far suggest that a calendar filled with activities and tasks that are mentally challenging, that people enjoy doing and that matter to them, can counter the negative effects of age on reasoning, intelligence and memory, and even improve those vital functions. Or, to quote a groundbreaking research paper from the Center for Vital Longevity at the University of Texas at Dallas: “Greater busyness is associated with superior cognition.”

“Mental stimulation is what really matters,” said Denise Park, founder and director of research at the center, who led the study. “And if you’re very busy you’re probably leading a mentally stimulating life.”

Park and her colleagues used a questionnaire to rank 330 people between ages 50 and 89 on a busyness scale and then subjected them to a battery of cognitive tests. (The subjects were all part of a larger, long-term project on aging called the Dallas Lifespan Brain Study.) The busiest people, folks who told the researchers that they sometimes couldn’t find enough time in the day to finish everything on their to-do lists, were decidedly sharper, with brains that solved problems more efficiently, processed strings of numbers faster and remembered lists of words better. On top of all that, age was not a factor — a busy lifestyle was as much of a benefit for people in their 80s as it was for people in their 50s.

More research is required to understand exactly how busyness makes the brain work better, but the authors of the UT Dallas paper describe several potential mechanisms. One possibility is that busyness leads to the creation of new groups of linked brain cells — neural pathways — that are needed to meet the demands of a packed and varied schedule. In addition, they write, it could be that a busy lifestyle basically forces the aging brain to be more efficient in the way it processes and stores information. Another, elegantly logical idea is that busy people “encounter more diverse stimuli, may be required to make more complex decisions, and may encounter and have to solve ill-defined problems,” all of which are believed to promote better cognition.

LEARN SOMETHING NEWThere is abundant evidence that taking classes, learning a new skill or a new language, is one of the best things people can do to keep their minds sharp. Denise Park and her team explored the cognitive benefits of new learning in another study they conducted called the Synapse Project. It was an ambitious experiment in which volunteers from 60 to 90 years old took up digital photography and quilting, complicated activities that they had never tried before. And they weren’t just dabbling. While most brain-training studies involve a few sessions in front of a computer playing different sorts of games, the Synapse Project amounted to a lifestyle change; the participants spent an average of 16.5 hours a week for three months learning about and pursuing their demanding new pastimes. The two activities were chosen because they taxed multiple cognitive functions, including reasoning, executive function and several types of memory. One group studied digital photography, one quilting, and a third group studied both. In addition, three control groups spent the same amount of time in “low challenge” social activities — reminiscing, watching movies, going on field trips and such — that did not require them to acquire any new knowledge or skills. A total of 221 people completed the program.

Initial results showed that the folks who participated in the demanding photography and quilting pursuits had a significant improvement in episodic memory when compared to the control groups. Episodic memory is a basic function that underlies just about everything you do. “It’s what you rely on to manage your life,” said Park. “It’s your memory for past events, for what you did yesterday, for your grocery list, and for what you plan to do.”

In an effort to understand how new learning could enhance brain functions, and whether the changes were lasting, Park and her team used functional Magnetic Resonance Imaging (fMRI) to examine the brains of Synapse Project participants in a follow-up study, a year after the original study ended. The people who had learned and practiced digital photography and quilting were found to have functional changes in three different parts of the brain that are involved in attention and semantic processing, a basic form of thinking in which words are assigned meaning and context. Those in the control groups did not have those brain changes. In their analysis of the fMRI findings, the researchers suggested that engaging in new, mentally challenging tasks for a sustained period of time had resulted in the “restoration of brain activity to more youth-like states.”

STAY CONNECTED Research has shown that people with strong social connections — who are socially active and get out and do things with other people — live longer, healthier lives, and when they do get sick they fare better. Friendship has been linked to everything from reduced mortality from all causes to improved cognitive performance to greater resistance to the common cold. One study showed that even casual friendships with “the more peripheral members of our social networks” carry a definite health benefit. Conversely, older people who lack these kinds of connections, who are socially isolated, are at increased risk for cognitive decline, heart disease and more.

A 2017 study involving nearly 20,000 aging adults, published in the journal Aging & Mental Health, concluded that “social participation” had as much influence on an individual’s cognitive functioning as physical health, physical activity and depression.

The role of social media was examined in a small 2017 study that looked at Facebook’s potential “as an intervention to maintain or enhance cognitive function in older adults.” Forty-one older adults were divided into three groups and spent eight weeks either on Facebook, an online diary website or on a wait-list. At the end of that period, “the Facebook group showed a significant increase in a composite measure of updating, an executive function factor associated with complex working memory tasks, compared to no significant change in the control groups.” The authors concluded that “learning and using an online social networking site may provide specific benefits for complex working memory in a group of healthy older adults.”