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Exercise Helps Keep the Brain Healthy – Why, How Needs More Study

Brain Health Briefing


Arthur Kramer of Northeastern University and the Global Council on Brain Health; Sarah Ingersoll of the University of Southern California; Sarah Lenz Lock of the Global Council on Brain Health; Jim Koenig of the National Institutes of Health; and Erin Heath of AAAS at the 7 Sept. briefing on brain health and physical activity. | Andrea Korte/AAAS

Research has shown that physical activity has a positive impact on brain health, but more work is needed to better understand the mechanisms in play to encourage people to reap the full benefits, said a panel of experts at a 7 Sept. Capitol Hill briefing on physical activity and brain health.

“Moving Toward a Healthy Brain: Physical Activity and Brain Health” was hosted by AAAS with the support of the Dana Foundation, a philanthropic organization that supports brain research through grants and educates the public about the successes and potential of brain research, and in conjunction with the Congressional Neuroscience Caucus, a bipartisan coalition of lawmakers.

“We have a good deal of research that suggests it’s a good bet to protect your body and your brain” with physical activity, said Arthur Kramer, professor of psychology and engineering and senior vice provost for research and graduate education at Northeastern University, and a member of the Global Council on Brain Health, an initiative of AARP and Age UK that seeks to provide recommendations for improving brain health based on scientific evidence.

Kramer cited several studies completed over the last few decades demonstrating the positive effects of exercise on the brain. One study of adults over 65 found that those who completed a yearlong program of aerobic exercise – one hour a day, three days a week of walking – had brain scan results that showed growth in their hippocampus, a portion of the brain central to memory. Scientists have also found a relationship between cardiovascular fitness, and the brain’s fiber tracks: the white matter that connects neurons, Kramer said.

Researchers have looked beyond the effects of exercise on the structure of the brain, and found benefits for the brain’s functions, Kramer said. As we age, functional connectivity between different brain networks tends to decrease, he said. One study found that older adults who completed a yearlong walking program were producing the same functional connectivity as adults in their 20s and 30s, he said. Such increases in connectivity are related to increases in cognition, he noted.

“If we had a drug that worked as well as exercise for the various things it works well with, we’d pay an awful lot of money for it, but it’s tough to get people to exercise,” Kramer said.

Physicians should routinely prescribe exercise for their patients, said Sarah Ingersoll, clinical assistant professor of neurology at the Keck School of Medicine at the University of Southern California. Yet “the National Academy of Medicine has said the challenge is not to figure out which dose of physical activity to prescribe, but rather how to get more people to adopt the actions that researchers know work,” Ingersoll said.

Research has shown that free gym membership and home-based programs do not motivate people to exercise, Ingersoll said. Instead, Ingersoll has drawn lessons from her work with a community exercise group for people with Parkinson’s disease that draws group members back year after year. The participants responded positively to the interpersonal aspects of being part of a team, Ingersoll said, including working with an engaging coach, and sharing experiences with like-minded teammates as they work toward a common goal.

There is still much to be learned about physical activity and the health of the brain, the presenters agreed. For instance, we do not fully understand how much exercise – and with what frequency and intensity – is necessary for brain health, Ingersoll said.

Additionally, “we still don’t understand some of the basic biological mechanisms by which exercise affects the brain,” said Jim Koenig, program director of the National Institute of Neurological Disorders and Stroke at the National Institutes of Health.

To fill these research gaps, NIH has ramped up grant funding in the area of physical activity and neurosciences throughout 2016, adding 66 new grants totaling $25.7 million this year. NIH is spending $82.8 million on this area of research. About 25 percent of the awarded grants support preclinical research for animal studies about the molecular mechanisms in the brain that change with exercise. About 75 percent of the awards support clinical studies that explore how exercise affects the brain both in healthy individuals and those with brain injuries or disorders; exercise as intervention for brain disorders; and exercise as a preventive measure, Koenig said.

While the National Institute of Aging funds the largest amount of this research, other NIH institutes are also funding research in the area, creating “truly a trans-NIH activity,” Koenig said. Additionally, the NIH this year launched a multidisciplinary Common Fund initiative to discover the molecules and pathways responsible for the benefits of physical activity, he said.

NIH is also working to update the government’s guidelines for physical activity. The 2008 guidelines call for 150 minutes of exercise per week for adults, and one hour of physical activity each day for children between 6 and 17, recommendations that have been ignored by most Americans, Koenig said. In revising the guidelines, NIH will take into consideration research on physical activity and cognition by the U.S. Department of Health and Human Services, the Centers for Disease Control and Prevention, and the President’s Council on Fitness, Sports and Nutrition. The new guidelines are slated to be released in 2018.

Kramer suggested a prescription for those who want to improve their brain health through exercise: “Do anything you enjoy at first, and then you can move on from there.”

“The best exercise is the one that you will do,” Ingersoll added.

[Associated image: kevron2001/Adobe Stock]


Andrea Korte

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