Exercise Lowers Stress-Related Brain Activity & Heart Disease Risk

New research led by Massachusetts General Hospital (MGH) suggests that physical activity can significantly reduce the risk of cardiovascular disease (CVD) by mitigating stress-related signaling in the brain. The study, published in the Journal of the American College of Cardiology, particularly highlights that individuals with stress-related conditions, such as depression, gain the most cardiovascular benefits from physical activity.

Dr. Ahmed Tawakol, an investigator and cardiologist in the Cardiovascular Imaging Research Center at MGH, spearheaded this research. The study analyzed medical records and other data from 50,359 participants in the Mass General Brigham Biobank who had completed a physical activity survey. Additionally, a subset of 774 participants underwent brain imaging tests to measure stress-related brain activity.

The researchers followed participants over a median period of 10 years, during which 12.9% developed cardiovascular disease. Participants who adhered to physical activity recommendations exhibited a 23% lower risk of developing cardiovascular disease compared to those who did not meet these recommendations. Furthermore, individuals with higher physical activity levels showed lower stress-related brain activity.

A significant finding of the study was that the reduction in stress-related brain activity was mainly driven by improvements in the function of the prefrontal cortex. This brain region is involved in executive functions such as decision-making and impulse control and plays a crucial role in modulating stress centers in the brain. The researchers accounted for other lifestyle factors and coronary disease risk factors in their analysis.

The study also found that reductions in stress-related brain signaling partially explained the cardiovascular benefits of physical activity. Among the 50,359 participants, those expected to have higher stress-related brain activity, such as individuals with pre-existing depression, experienced substantially greater cardiovascular benefits from exercise. Physical activity was approximately twice as effective in lowering cardiovascular disease risk for these individuals compared to those without depression.

Dr. Tawakol, the senior author of the study, emphasized the significance of these findings. “Physical activity was roughly twice as effective in lowering cardiovascular disease risk among those with depression. Effects on the brain’s stress-related activity may explain this novel observation,” he stated.

The study’s conclusions suggest that clinicians could inform patients about the brain effects of physical activity, especially its potential to provide greater cardiovascular benefits for individuals with stress-related conditions like depression. However, Dr. Tawakol noted that further prospective studies are needed to identify potential mediators and establish causality.

Detailed Findings and Implications

1. Participant Data and Methodology:
   • The study utilized data from the Mass General Brigham Biobank, which included 50,359 participants who completed a physical activity survey.
   • A subset of 774 participants underwent brain imaging tests, providing insights into stress-related brain activity.
   • The researchers followed participants over a median of 10 years to track the development of cardiovascular disease.
2. Cardiovascular Benefits of Physical Activity:
   • Participants who met physical activity guidelines had a 23% lower risk of developing cardiovascular disease compared to those who did not meet the recommendations.
   • The study accounted for other lifestyle variables and coronary disease risk factors, ensuring that the observed benefits were specifically associated with physical activity.
3. Brain Activity and Stress Reduction:
   • Higher levels of physical activity were correlated with lower stress-related brain activity.
   • Improvements in the prefrontal cortex function, a brain region involved in executive functions and stress regulation, were identified as key drivers of reduced stress-related brain activity.
4. Impact on Individuals with Depression:
   • The cardiovascular benefits of physical activity were significantly more pronounced in individuals with pre-existing depression.
   • Physical activity reduced cardiovascular disease risk by roughly double in these individuals compared to those without depression.
   • The study suggests that the brain effects of physical activity, particularly its impact on stress-related brain activity, may explain this enhanced benefit.
5. Clinical Recommendations:
   • The findings indicate that physical activity could be a crucial intervention for reducing cardiovascular disease risk, especially for individuals with stress-related conditions like depression.
   • Clinicians are encouraged to communicate the dual benefits of physical activity for both mental and cardiovascular health to their patients.
   • The study underscores the need for accessible, non-pharmaceutical interventions for managing depression and reducing cardiovascular disease risk.
6. Future Research Directions:
   • The researchers call for prospective studies to identify potential mediators and confirm the causality of the observed effects.
   • Further research could explore specific types of physical activity and their impact on stress-related brain activity and cardiovascular health.
   • Investigating the mechanisms behind the brain effects of physical activity could lead to more targeted interventions for both mental and cardiovascular health.

Conclusion

This study provides compelling evidence that physical activity not only benefits cardiovascular health but also reduces stress-related brain activity, particularly in individuals with depression. By improving the function of the prefrontal cortex, physical activity helps mitigate stress and its associated health risks. The findings advocate for the integration of physical activity into treatment plans for depression and cardiovascular disease, highlighting its potential as a non-invasive, cost-effective intervention. Further research is needed to fully understand the mechanisms at play and to develop optimized strategies for harnessing the benefits of physical activity for both mental and cardiovascular health.

Source: Materials provided by Massachusetts General Hospital. Content edited for style & length.