A study released today reports that older adults who are physically active have larger gray matter volume in key brain areas responsible for memory and cognition. The study was conducted by researchers at the University of Pittsburgh School of Medicine and the University of California, Los Angeles (UCLA).
The researchers also discovered that people with Alzheimer's disease (AD) or mild cognitive impairment experienced less gray matter volume reduction if their exercise regimen burned more calories.
The March 2016 study, "Longitudinal Relationships between Caloric Expenditure and Gray Matter in the Cardiovascular Health Study," was published in the Journal of Alzheimer's Disease.
Over the years, I've written extensively about the brain benefits of physical activity and cardiovascular fitness. Every week, it seems that there's a new study reaffirming the neuroprotective benefits of physical exercise and aerobic fitness.
In February 2016, I wrote a Psychology Today blog post, "Can Being a Couch Potato Shrink Your Brain?" based on a study from Finland which found that being out of shape in middle age is linked to smaller brain volume later in life. The new study released today linking physical activity with increased brain volume corroborates the findings of the Finnish study from last month.
Typically, people become more sedentary as we get older. Unfortunately, sedentarism appears to cause the brain to atrophy while simultaneously increasing the risk of developing Alzheimer's disease and other types of dementia. If you need one more source of motivation to stay physically active throughout your lifespan, hopefully the latest neuroscience will inspire you to exercise more in order to maintain a healthy body, brain, and mind as you age.
"Our current treatments for dementia are limited in their effectiveness, so developing approaches to prevent or slow these disorders is crucial. Our study is one of the largest to examine the relationship between physical activity and cognitive decline, and the results strongly support the notion that staying active maintains brain health."
For the latest study, which was led by Cyrus Raji, M.D., Ph.D., formerly a student at Pitt School of Medicine and now a senior radiology resident at UCLA, the researchers examined longitudinal data that was collected from nearly 876 people (65 or older) participating in the multicenter Cardiovascular Health Study over a five-year period.
In a press release, Dr. Raji explained the findings, "Gray matter houses all of the neurons in your brain, so its volume can reflect neuronal health. We also noted that these volumes increased if people became more active over five years leading up to their brain MRI."
Raji points out that in the near future, advances in brain imaging technology may enable medical professionals to conduct baseline neuroimaging studies of people who already have mild cognitive impairment—or who are at risk for a dementia disorder—and prescribe physical activity as a way to slow down further cognitive deterioration.
"Rather than wait for memory loss, we might consider putting the patient on an exercise program and then re-scan later to see if there are any changes in the brain," Dr. Raji said.
Each participant in this study had his or her brain scanned along with taking periodic cognitive assessments. The researchers also calculated how frequently someone engaged in physical activities, such as walking, dancing, playing tennis, golf, etc. to assess their calorie expenditure or energy output each week.
Using advanced mathematical modeling, the researchers were able to identify which individuals burned the most calories. In doing so, they correlated larger gray matter volumes in the frontal, temporal and parietal lobes with energy expenditure. The size of these brain regions appeared to be directly linked to someone's regular caloric expenditure through exercise.
In fact, brain scans revealed that participants with the highest energy expenditure also had the largest gray matter volumes in key areas. These individuals were also fifty percent less likely to have developed Alzheimer's disease in the five years since the beginning of the study.
There are two important caveats. Firstly, the researchers have identified a correlation between brain size and caloric expenditure, which doesn't necessarily prove causation. Secondly, previous studies on brain-derived neurotrophic factor (BDNF) have found that exercise stimulates the birth of new neurons (neurogenesis) up to a certain point and then plateaus. The brain benefits of physical activity can reach a point of diminishing returns if you are obsessively over-exercising.
The new study from Pitt and UCLA adds to a groundswell of research showing that physical activity is good for your brain. In particular, this study highlights a previously underestimated brain benefit of burning calories through physical activity being directly correlated with increased brain volume.
Obviously, the number of calories burned through physical activity corresponds directly to the amount of time and your levels of exertion during physical activity. It's unclear from this study if burning calories and energy expenditure are simply an easy way to measure the amount of time and effort put into exercise, or if burning calories itself was somehow related to increased brain volumes.
Either way, it's clear that regular physical activity and cardiorespiratory fitness have multiple benefits for your brain, body, and mind. Burning calories through exercise can help people from all walks of life maintain a healthy heart and body mass index (BMI) while simultaneously bulking up brain volume and optimizing cognitive function.
To read more on this topic, check out my Psychology Today blog posts,
© 2016 Christopher Bergland. All rights reserved.
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