The brain already benefits from moderate physical activity

Summary: Moderate physical activity was linked to increased volume in areas of the brain associated with memory, especially in older adults. The researchers say that mild to moderate physical activity may have neuroprotective properties.

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Exercise keeps the body and mind healthy, but little is known about exactly how and where physical activity affects our brains.

“In earlier research, the brain was generally considered as a whole,” says Fabienne Fox, a neuroscientist and lead author of a current study.

“Our goal was to take a closer look at the brain and find out which brain regions affect physical activity the most.”

Extensive data from the Rhineland study

For their research, Fox and colleagues used data from the Rhineland Study, a large-scale population study conducted by DZNE in the Bonn city area. Specifically, they analyzed physical activity data from 2,550 volunteers between the ages of 30 and 94, as well as brain images obtained by magnetic resonance imaging (MRI).

To test physical activity, study participants wore an accelerometer on their upper thigh for seven days. Magnetic resonance imaging provided information particularly on the volume of the brain and the thickness of the cortex.

The more active, the greater the effects.

“We were able to show that physical activity had a remarkable effect on almost all the brain regions investigated. In general, we can say that the higher and more intense the physical activity, the larger the brain regions, either with respect to volume or cortical thickness”, Fabienne Fox summarizes the results of the research.

“In particular, we see this in the hippocampus, which is considered the control center for memory. Larger brain volumes provide better protection against neurodegeneration than smaller ones.”

However, the dimensions of brain regions do not increase linearly with physical activity. The research team found the largest, almost sudden, volume increase when comparing inactive and only moderately physically active study participants; this was particularly evident in people older than 70 years.

“In principle, this is very good news, especially for those who are reluctant to exercise,” says Ahmad Aziz, who heads the “Population and Clinical Neuroepidemiology” research group at DZNE.

“The results of our study indicate that even small behavioral changes, such as walking 15 minutes a day or taking the stairs instead of the elevator, can have a substantial positive effect on the brain and potentially counteract age-related loss of brain matter. and the development of neurodegenerative diseases. In particular, older adults may already benefit from modest increases in low-intensity physical activity.”

Young and somewhat athletic subjects who generally engaged in moderate to vigorous physical activity also had relatively high brain volumes. However, in even more active subjects, these brain regions were slightly larger. Here too it was shown: the more active, the greater the effect, although at high levels of physical activity, the beneficial effects tended to level off.

Regions of the brain that benefit the most

To characterize the brain regions that benefited most from physical activity, the research team searched databases for genes that are particularly active in these brain areas.

“Primarily, these were genes that are essential for the functioning of mitochondria, the powerhouses of our cells,” says Fabienne Fox.

This means that there are particularly large numbers of mitochondria in these brain regions. Mitochondria provide energy to our body, for which they need a lot of oxygen.

This shows a couple of ladies riding a bike.
The research team found the largest, almost sudden, volume increase when comparing inactive and only moderately physically active study participants; this was particularly evident in people older than 70 years. The image is in the public domain.

“Compared to other brain regions, this requires more blood flow. This is particularly well ensured during physical activity, which could explain why these brain regions benefit from exercise”, says Ahmad Aziz.

exercise protects

Bioinformatic analysis further showed that there is a large overlap between genes whose expression is affected by physical activity and those that are affected by neurodegenerative diseases such as Alzheimer’s, Parkinson’s or Huntington’s disease.

This could offer a possible explanation for why physical activity has a neuroprotective effect, the research team concludes.

“With our study, we were able to characterize the brain regions that benefit from physical activity in an unprecedented level of detail,” says Ahmad Aziz. “We hope that our results will provide important clues for future research.”

And also approaches for everyday use: “With our results, we want to provide a further boost to become more physically active, to promote brain health and prevent neurodegenerative diseases,” says Fabienne Fox. “Even modest physical activity can help. So it’s just a small effort, but with a big impact.”

See also

This shows a brain and red blood cells.

About this exercise and brain health research news

Author: press office
Font; DAY
Contact: Press Office – DZNE
Image: The image is in the public domain.

original research: Closed access.
“Association between accelerometer-derived physical activity measurements and brain structure: a population-based cohort study” by Fabienne AU Fox et al. Neurology


Summary

Association Between Accelerometer-Derived Physical Activity Measurements and Brain Structure: A Population-Based Cohort Study

Background and objectives:

While there is growing evidence that physical activity promotes neural health, studies examining the relationship between physical activity and brain morphology remain inconclusive. Therefore, we examined whether objectively quantified physical activity is related to brain volume, cortical thickness, and gray matter density in a large cohort study. Furthermore, we evaluate molecular pathways that may underlie the effects of physical activity on brain morphology.

Methods:

We used cross-sectional baseline data from 2,550 eligible participants (57.6% female; mean age: 54.7 years, range: 30–94 years) from a prospective cohort study. Physical activity dose (metabolic equivalent hours and step count) and intensity (sedentary, light-intensity, and moderate-to-vigorous intensity activities) were recorded with accelerometers. Brain volumetry, gray matter density, and cortical thickness measurements were obtained from 3T MRI scans using FreeSurfer and Statistical Parametric Mapping. The relationship of physical activity (independent variable) and brain structure (outcome) was examined with multivariate polynomial regression, adjusting for age, sex, intracranial volume, education, and smoking. Using gene expression profiles from the Allen Brain Atlas, we extracted molecular signatures associated with the effects of physical activity on brain morphology.

Results:

Dose and intensity of physical activity were independently associated with larger brain volumes, gray matter density, and cortical thickness of various brain regions. The effects of physical activity on brain volume were more pronounced at low amounts of physical activity and differed between men and women and by age. For example, more time spent in moderate-to-vigorous intensity activities was associated with greater total gray matter volume, but the relationship leveled off with more activity (standardized ß [95% confidence intervals]: 1.37 [0.35, 2.39] and -0.70 [-1.25, -0.15] for linear and quadratic terms, respectively). The strongest effects of physical activity were seen in motor regions and cortical regions enriched for genes involved in mitochondrial respiration.

Discussion:

Our findings suggest that physical activity benefits brain health, with the strongest effects in motor regions and regions with high oxidative demand. While young adults may particularly benefit from additional high-intensity activities, older adults may already benefit from light-intensity activities. Physical activity and the reduction of sedentary time may be essential in the prevention of brain atrophy associated with age and neurodegenerative diseases.

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