New research has found that older adults who improved their fitness through a moderate intensity exercise program increased the thickness of their brain’s cortex, the outer layer of the brain that typically atrophies with Alzheimer’s disease.
According to a new study from the University of Maryland School of Public Health, the improvements were found in both healthy older adults and those diagnosed with mild cognitive impairment (MCI), an early stage of Alzheimer’s disease.
“Exercise may help to reverse neurodegeneration and the trend of brain shrinkage that we see in those with MCI and Alzheimer’s,” said Dr. J. Carson Smith, an associate professor of kinesiology and senior author of the study, published in the Journal of the International Neuropsychological Society.
“Many people think it is too late to intervene with exercise once a person shows symptoms of memory loss, but our data suggest that exercise may have a benefit in this early stage of cognitive decline.”
For the study, previously inactive people between the ages of 61 and 88 were put on an exercise regimen that included moderate intensity walking on a treadmill four times a week over a 12-week period.
On average, cardiorespiratory fitness improved by about eight percent as a result of the training in all participants, the researchers reported.
The researchers also found that the people who showed the greatest improvements in fitness had the most growth in the cortical layer, including both the group diagnosed with MCI and the healthy participants.
Both groups showed strong associations between increased fitness and increased cortical thickness after the intervention. But the MCI participants showed greater improvements compared to the healthy group in the left insula and superior temporal gyrus, two brain regions that have been shown to exhibit accelerated neurodegeneration in Alzheimer’s disease, the study found.
Smith previously reported that the participants in this exercise intervention showed improvements in neural efficiency during memory recall, and this new data adds to the evidence for the positive impact of exercise on cognitive function.
Other research he has published has shown that moderate intensity physical activity, such as walking for 30 minutes three to four days a week, may protect brain health by staving off shrinkage of the hippocampus in older adults.
Smith noted that he plans future studies that include more participants engaging in a longer-term exercise intervention to see if greater improvements can be seen over time, and if the effects persist over the long term.
The key unanswered question is if regular moderate intensity physical activity could reverse or delay cognitive decline and help keep people out of nursing homes and enable them to maintain their independence as they age, he noted.
Source: University of Maryland