Can Aerobic Exercise Improve Cognitive Function?

Researchers using a new magnetic resonance imaging (MRI) technique have determined that adults with mild cognitive impairment (MCI) who take part in frequent aerobic exercise experience greater gains in brain volume than individuals who do only stretching exercises. 

The study, which was presented at the annual meeting of the Radiological Society of North America (RSNA) on November 30, 2016 in Chicago, Illinois, included 35 adults with MCI, who participated in a randomized, controlled trial of exercise intervention.
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These MCI patients, who the authors noted were at risk of developing Alzheimer disease, were divided into 2 groups. A cohort of 16 adults (average age 63 years) engaged in aerobic activities such as treadmill, stationary bike, or elliptical training, 4 times per week over the course of 6 months.

Meanwhile, a control group of 19 adults (average age 67 years) took part in stretching exercise with the same frequency for the same duration. The investigators acquired high-resolution brain MRIs from all patients participating in the study before and after the 6-month activity period. The researchers compared the results of those scans using conventional and biomechanical metrics in order to measure changes in brain volume and shape.

Overall, the team found that brain volume increased in most gray matter regions, including the temporal lobe. And, in comparison to the stretching group, the aerobic activity group had greater preservation of total brain volume, increased local gray matter volume, and increased directional stretch of brain tissue.

The analysis also revealed atrophy within the white matter connecting fibers among patients from the stretching group. While noting that such directional deformation is partially related to volume loss, the authors say that this is not always the case.

"I think it is well-accepted that aerobic exercise has benefits for overall health," said Christopher T. Whitlow, MD, PhD, MHA, associate professor and chief of neuroradiology at Wake Forest School of Medicine, and a senior author of the study. 

Dr Whitlow notes that more research must be conducted to determine if aerobic exercise can be used as a specific intervention to prevent or slow the progression of dementia for patients with MCI.

"But there may be specific benefits for brain wellness and cognitive function among our aging population," he said, "particularly for those with mild cognitive impairment at risk for progressing to Alzheimer disease."

—Mark McGraw

Reference:

Kim J, Baker LD, Craft S, Jung Y, Whitlow CT. Longitudinal analysis of brain degeneration in MCI using a biomechanical framework. Presented at: Radiological Society of North America 2016 Annual Meeting; November 30, 2016; Chicago, IL. Abstract SSK14-06.