A recent study published in the Journal of the American College of Cardiology on April 15 suggests that regular exercise can play a significant role in reducing the risk of heart disease. The research indicates that exercise not only benefits physical health but also aids in stress management by influencing brain function.
According to the study’s senior author, Dr. Ahmed Tawakol, a researcher and cardiologist at the Cardiovascular Imaging Research Center at Massachusetts General Hospital in Boston, individuals with a history of depression may experience even greater heart-protective effects from physical activity. The study found that exercise was particularly potent in reducing the risk of heart attacks and strokes in this group, nearly doubling its effectiveness compared to those without a history of depression.
Dr. Tawakol suggests that the impact of exercise on the brain’s stress-related activity could explain this phenomenon, highlighting the interconnectedness between physical activity, mental health, and cardiovascular well-being.
Persistent stress can be equally detrimental to heart health as smoking or hypertension.
There is evidence indicating that prolonged stress—such as dissatisfaction with work, financial strain, or turbulent relationships—can have detrimental effects on heart health comparable to those of smoking, hypertension, or type 2 diabetes.
This begins with the amygdala, a brain region serving as the body’s alarm system. When faced with stressful circumstances, like public speaking or persistent noise from a neighbor’s dog, the amygdala becomes highly active.
Chronic anxiety disorders and depression can exacerbate this response. Research suggests that heightened stress-related brain activity can significantly predict the likelihood and timing of future heart attacks and strokes, even after adjusting for other risk factors.
This constant state of alertness in the amygdala leads to the dissemination of distress signals throughout the body. These signals can incite inflammation in the arteries, the conduits responsible for transporting blood to the heart. Over time, this inflammation can contribute to heart-related complications, such as heart attacks and strokes.
Getting the Recommended Amount of Physical Activity Lowered the Risk of Heart Attack and Stroke by 23 Percent
To delve deeper into the impact of physical activity on stress-related brain activity and its role in the risk of heart disease among individuals with and without depression, researchers examined the medical records and other data of 50,359 participants enrolled in the Mass General Brigham Biobank. These participants had completed a physical activity survey, with a subset of 774 individuals also undergoing brain imaging tests and stress-related brain activity measurements.
Over a median follow-up period of 10 years, nearly 13 percent of the participants developed cardiovascular disease. Those who met the recommended physical activity guidelines, engaging in at least 150 minutes of moderate exercise per week or 75 minutes of vigorous activity per week, experienced a 23 percent lower risk of cardiovascular disease compared to those who exercised less.
Dr. Tawakol explains, “For participants without depression, the reduction in heart attack risk appeared to level off at around 300 minutes of moderate-intensity exercise per week. This pattern is consistently observed in the literature.” Therefore, the current physical activity guidelines recommend 150 to 300 minutes of moderate-intensity exercise per week to achieve optimal reductions in the risk of heart attacks.
Engaging in physical activity reduces the risk of heart attack and stroke by effectively managing stress in the brain.
The reduction in stress-related brain signaling contributes to approximately 10 percent of the cardiovascular benefits attributed to physical activity, according to Tawakol. The main advantages of exercise for heart health stem from enhancing cardiac strength and efficiency, as well as increasing blood circulation throughout the body.
Tawakol suggests that the enhancements in stress-related brain activity may arise from decreases in amygdala activity or increases in prefrontal cortical activity.
If you liken the amygdala to a stress hormone accelerator, the prefrontal cortex acts as the brakes. In times of stress, the accelerator is pushed, triggering the body’s fight-or-flight response, while the brakes (prefrontal cortical activity) help to moderate this response.
“In essence, exercise ramps up cortical activity while dampening amygdala activity,” Tawakol explains.
Ideally, there should be a healthy balance between the two, resulting in reduced levels of stress-related brain activity, even during challenging situations.
This prompted researchers to investigate further: Are the effects even more pronounced in individuals experiencing chronic stress or depression? Tawakol suggests that if exercise influences heart health through the brain by regulating stress-related brain activity, then the benefits of exercise should be particularly significant among those with heightened stress levels.
Exercise provides dual protection for the heart in individuals with depression.
While researchers anticipated greater benefits for individuals with preexisting depression, they were astonished to discover that it offered twice the protection against heart attacks and strokes. “The impact was truly significant in these individuals,” states Tawakol.
Another notable distinction was uncovered by the researchers: while the cardiovascular advantages of exercise plateaued at 300 minutes per week for those without depression, there was no such limit for individuals with depression. Tawakol explains that in this group, additional time spent exercising, even surpassing 300 minutes, resulted in ongoing benefits. The researchers speculate that this finding may be attributed to individuals with chronic stress or preexisting depression exhibiting higher levels of stress-related brain activity at baseline.
“These findings imply that physical activity could be particularly beneficial for managing cardiovascular risk in individuals with a history of depression, as well as those experiencing significant life stress,” remarks Allison E. Gaffey, PhD, an assistant professor of medicine at the Yale School of Medicine in New Haven, Connecticut, who was not part of the study.
The authors emphasize the necessity for future studies to delve deeper into the relationship between physical activity, stress, and the brain, and to ascertain whether exercise is indeed responsible for the observed reductions in risk documented in the study.
Physical activity benefits the brain, providing immediate and long-term advantages.
Dr. Gaffey suggests that incorporating uniform screenings for stress and related psychological conditions like depression into heart disease prevention strategies could receive further backing from these findings. She proposes providing additional support for individuals with high stress or a history of depression to encourage regular physical activity.
Tawakol notes that if these findings are validated by other studies, it could prompt revisions to exercise guidelines for individuals with depression. Meanwhile, he emphasizes the importance of recognizing that physical activity can have significant effects on the brain, offering potential cardiovascular advantages for those with stress-related conditions like depression.
Tawakol highlights that understanding these additional benefits could serve as a motivating factor for individuals to engage in more physical activity. He explains that exercise yields both immediate and long-term advantages, providing a dual benefit: the immediate boost from endorphins during exercise and the structural changes in the brain associated with enhanced heart protection.
