How Exercise Enhances Aging Brains
reposted from the New York Times
Exercise can change how crucial portions of our brain communicate as we age, improving aspects of thinking and remembering, according to a fascinating new study of aging brains and aerobic workouts. The study, which involved older African-Americans, finds that unconnected portions of the brain’s memory center start interacting in complex and healthier new ways after regular exercise, sharpening memory function.
The findings expand our understanding of how moving molds thinking and also underscore the importance of staying active, whatever our age.
The idea that physical activity improves brain health is well established by now. Experiments involving animals and people show exercise increases neurons in the hippocampus, which is essential for memory creation and storage, while also improving thinking skills. In older people, regular physical activity helps slow the usual loss of brain volume, which may help to prevent age-related memory loss and possibly lower the risk of dementia.
There have been hints, too, that exercise can alter how far-flung parts of the brain talk among themselves. In a 2016 M.R.I. study, for instance, researchers found that disparate parts of the brain light up at the same time among collegiate runners but less so among sedentary students. This paired brain activity is believed to be a form of communication, allowing parts of the brain to work together and improve thinking skills, despite not sharing a physical connection. In the runners, the synchronized portions related to attention, decision making and working memory, suggesting that running and fitness might have contributed to keener minds.
But those students were young and healthy, facing scant imminent threat of memory loss. Little was known yet about whether and how exercise might alter the communications systems of creakier, older brains and what effects, if any, the rewiring would have on thinking.
In particular, he wondered about their medial temporal lobes. This portion of the brain contains the hippocampus and is the core of our memory center. Unfortunately, its inner workings often begin to sputter with age, leading to declines in thinking and memory. But Dr. Gluck suspected that exercise might alter that trajectory.
Helpfully, as the director of the Aging & Brain Health Alliance at Rutgers, he already was leading an ongoing exercise experiment. Working with local churches and community centers, he and his collaborators previously had recruited sedentary, older African-American men and women from the Newark area. The volunteers, most of them in their 60s, visited Dr. Gluck’s lab for checks of their health and fitness, along with cognitive testing. A few also agreed to have their brain activity scanned.
Some then started working out, while others opted to be a sedentary control group. All shared similar fitness and memory function at the start. The exercise group attended hourlong aerobic dance classes twice a week at a church or community center for 20 weeks.