By Mary Elizabeth Dallas
Medically Reviewed by Farrokh Sohrabi, MD
The heart-mind connection can be positive or negative, and so protecting your heart health could also prevent cognitive decline.
The health of your heart is linked to the health of your mind. Experts point out that this connection goes in both directions. People who are depressed are two to three times more likely to develop heart disease. Meanwhile, roughly half of all people with heart disease battle depression. “People know that their livelihood and life is in danger, and that becomes a major stress factor in the life of that individual, so we start going around and around in circles,” explained Angelos Halaris, MD, PhD, a professor of psychiatry and behavioral neurosciences and assistant dean for translational research at Loyola University's Stritch School of Medicine in Chicago. To show just how far-reaching the connection is, the risk factors that can lead to heart disease could play a role in memory loss and dementia. The good news is that taking steps to prevent heart disease and reduce stress can also help protect your mind.
A recent heart-mind connection study published in the Journal of the American Heart Association found that having heart disease and anxiety doubled the likelihood of dying from any cause in a given time period. Having depression and heart disease tripled the risk. The researchers also found that people with depression are less likely to follow through on treatments prescribed by their doctor. They are also more likely to be sedentary, overweight, and smokers, all of which increase their risk for heart disease.
“Stress is the key to understanding the association between depression and heart disease,” said Dr. Halaris. The immune system fights stress as if it were a disease or infection, he explained. When faced with stress, your body reacts by producing the hormone cortisol. Excessive amounts of cortisol can have toxic effects on your blood vessels. To meet the demands of prolonged stress, the immune system also produces proteins called cytokines. Over time, this chronic inflammatory response can contribute to arteriosclerosis (hardening of the arteries) and heart disease.
A sudden emotionally or physically stressful event could trigger a condition known as stress cardiomyopathy or broken heart syndrome. Scientists in Japan dubbed this mind-heart connection “takotsubo,” or “octopus pot,” because the heart of someone with this condition looks like a ceramic octopus trap, with a narrow upper portion and an enlarged lower portion that doesn't contract well, said cardiologist James Horowitz, MD, of NewYork-Presbyterian Hospital and Weill Cornell Medical Center. In 85 percent of cases, a major stressful event such as the death of a loved one triggers the condition, thought to develop in response to a huge amount of adrenaline. Symptoms like chest pain and shortness of breath can start in a matter of minutes or up to two days afterwards, Dr. Horowitz said. Though they may feel like they’re having a heart attack, people with stress cardiomyopathy don't usually have severe arterial blockages, he said. But the condition is treated with the same drugs used for heart attacks, including beta-blockers and ACE inhibitors. People with broken heart syndrome typically recover within days or weeks.
A new mind-heart connection study, published in the journal Circulation: Heart Failure, reveals that people with heart failure who are moderately or severely depressed have four times the risk for early death and double the risk for being hospitalized, compared with those who are not depressed. The researchers found that even people with mild symptoms of depression had almost a 60 percent increased risk for death. They also noted that just a third of those with moderate or severe depression were taking antidepressants. Halaris said that antidepressants can help reverse the body's inflammatory response to depression. “They relieve depression and associated anxiety so people start feeling better,” he said. “When stress levels go down, so does cortisol, and the risk of developing cardiovascular disease is diminished, if not outright abolished.”
The risk factors that can lead to heart disease may also play a role in dementia, Alzheimer’s disease, and memory loss, pointing to a heart disease-cognitive decline link. “Stress leads to a number of chain reactions throughout the body, including the brain,” Halaris said, adding that cortisol can be toxic to specific parts of the brain, including the hippocampus, which is responsible for emotions and memory. A study in the European Heart Journal looked at more than 4,800 men and women over the course of a decade and found that people with risk factors for heart disease, such as high cholesterol, are at greater risk for memory problems and a faster rate of cognitive decline later in life — more evidence of the heart-mind connection.
Atrial fibrillation, often called afib, is the most common cardiac arrhythmia, or irregular heart beat, affecting an estimated 2.66 million Americans. Afib puts you at greater risk for stroke. New research involving more than 31,000 people, who were 66 years old on average, found the condition was also associated with an increased risk for cognitive decline, the development of dementia, loss of independence in performing daily routines, and admission to long-term care facilities. The researchers concluded that cognitive and functional decline are key consequences of atrial fibrillation.
On the positive side, a study published in the journal JAMA Neurology revealed that managing heart disease risk factors early on can delay or lessen brain changes linked to Alzheimer's disease and age-related cognitive decline. The researchers found that adults with high blood pressure who also had genetic risk factors for Alzheimer's disease showed more buildup of a brain plaque, called amyloid protein, associated with the condition. However, adults who had these genetic risk factors but had their high blood pressure under control had the same levels of amyloid plaque as those without high blood pressure or genetic risk for the disease. "These findings provide a window into the potential benefits of controlling hypertension that goes beyond lowering the risk of strokes and other forms of heart disease," Horowitz said.
Unhealthy lifestyle habits associated with depression, such as smoking, drinking, being sedentary, and eating an unhealthy diet, can increase your risk for heart disease. They can also increase your risk for stroke and cognitive decline, including dementia. But by taking steps to protect your heart, you can also help protect your brain. Bottom line: Following a heart-healthy lifestyle could help reduce your chances of having a stroke, lower your risk for dementia, and have a significant impact on your mental abilities over time — the positive side of the heart-mind connection.