New research indicates that physical activity lowers cardiovascular (心血管的) disease risk in part by reducing stress-related signals in the brain.
In the study, which was led by investigators at Massachusetts General Hospital (MGH), people with stress-related conditions such as depression experienced the most cardiovascular benefits from physical activity.
To assess the mechanisms (机制) underlying the psychological and cardiovascular disease benefits of physical activity, Ahmed Tawakol, MD, an investigator and cardiologist in the Cardiovascular Imaging Research Center at MGH, and his colleagues analyzed medical records and other information of 50,359 participants from the Mass General Brigham Biobank who completed a physical activity survey. A subset of 774 participants also underwent brain imaging tests and measurements of stress-related brain activity.
Over a median follow-up of 10 years, 12.9% of participants developed cardiovascular disease. Participants who met physical activity recommendations had a 23% lower risk of developing cardiovascular disease compared with those not meeting these recommendations. Individuals with higher levels of physical activity also tended to have lower stress-related brain activity.
Significantly, reductions in stress-related brain activity were driven by gains in function in the prefrontal cortex (前额叶皮质), a part of the brain involved in executive (执行的) function (i.e. decision making and impulse control). It is known to control stress centers of the brain.
As an extension of this finding, the researchers found in a group of 50,359 participants that the cardiovascular benefit of exercise was substantially greater among participants who would be expected to have higher stress-related brain activity, such as those with pre-existing depression.
Analyses accounted for other lifestyle variables and risk factors for cardiovascular disease. Moreover, reductions in stress-related brain signals partially accounted for physical activity's cardiovascular benefit.
"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," said Tawakol, who is the senior author of the study.
