MONDAY, May 17, 2021 (HealthDay News) -- In new evidence that illustrates that health issues rarely exist in a vacuum, a new study finds a link between heart health and brain function.
Existing evidence suggests that having heart disease raises one's risk of dementia, and vice versa, but a team of researchers based in London wanted to find out if this connection could be seen in a healthier population.
For the study, nearly 30,000 mostly healthy adults in the United Kingdom had MRI scans to assess their heart health. The participants also completed thinking ("cognitive") tests, measuring their ability to solve logic and reason-based problems, and showing how fast the brain processes information. Performing well on these tests is associated with better brain function.
The results revealed that those who excelled on the cognitive tests were more likely to have a healthier heart than those who tested poorly, said study co-author Nicholas Harvey, a professor of rheumatology and clinical epidemiology at the University of Southampton in the United Kingdom.
"We found that better scores for the two cognitive tests that we used, indicating better brain function, were associated with heart measures, from the cardiac [MRI] scans, which indicated a healthier heart," Harvey said. "Thus, having a healthy brain is associated with having a healthy heart, and vice versa."
The study was published online May 14 in the European Heart Journal — Cardiovascular Imaging.
Risk factors such as age, smoking, high blood pressure, alcohol intake and exercise level can affect one's risk of developing problems such as heart disease and dementia. Thus, it was important to determine if these factors were responsible for the brain-heart connection or if these organs were independently associated.
However, even after accounting for these risk factors, the relationship between heart health and brain function held steady, suggesting that some other mechanism may be responsible.
"Importantly, the association was not explained by classical risk factors for heart disease or dementia, which suggests that there may be a biological link between the two conditions, separate from the contribution to both conditions from these risk factors," Harvey said.
While the potential mechanisms linking heart and brain health are not fully mapped out, it is clear that these systems are tightly connected, said Dr. Joseph Diamond, director of nuclear cardiology at Long Island Jewish Medical Center, in New Hyde Park, N.Y.
"There are a lot of nerves from the brain directly to the heart, and we know there's a strong connection between the two," Diamond said.
According to Diamond, stress is a prime example of a health problem that has a cascading effect on different systems in the body, including the heart and brain.
"When you are dealing with individuals who have chronic stress or chronic anxiety issues, it affects a lot of parts of the body," Diamond said. He explained how many of the different hormones released in response to stress can provoke an increase in heart rate and blood pressure.
"We think that a lot of people who have chronic elevations of stress hormones may have more tendency to have atrial fibrillation [an irregular heart rate], and it may be an independent risk factor for heart disease," he said.
In light of the increasing burden of age-related problems such as heart disease and dementia, learning more about the complex causes of these diseases is essential, Harvey said.
"Our findings are highly relevant in an ever-aging global population," Harvey said. "Understanding links between these diseases enables us to optimize our assessment of older people and to potentially develop new therapies, which will target common mechanisms of aging."
The U.S. Centers for Disease Control and Prevention has more on the interconnected health of the heart and brain.
SOURCES: Nicholas Harvey, professor, rheumatology, clinical epidemiology, University of Southampton, United Kingdom; Joseph Diamond, MD, cardiologist, director, nuclear cardiology, Long Island Jewish Medical Center, New Hyde Park, N.Y.; European Heart Journal — Cardiovascular Imaging, May 14, 2021, online