AHA’s Scientific Statement on Heart-Brain Health Connection

While the heart and brain are separate organs in your body, and we often write about them as separate entities, there is a strong connection between the two regarding health. 

The heart supplies blood carrying oxygen and nutrients to the brain, and the brain provides autonomic system control to the heart. In other words, the brain helps regulate heart rate, breathing and blood pressure (among other things).  

In a new scientific statement published on October 10, 2024, in the journal Stroke, the American Heart Association highlights research that emphasizes the connection between certain heart conditions and brain health. Here’s what you need to know.

What Heart Conditions Influence Brain Health?

After pulling recent large, long-term, well-designed studies from databases and analyzing them, researchers found that three heart conditions may influence brain health, including cognitive impairment. These three heart conditions are atrial fibrillation, heart failure and coronary heart disease. 

Prevention is key to a healthy heart and brain, says Fernando D. Testai, M.D., Ph.D., FAHA, chair of the AHA statement writing group, professor of neurology and rehabilitation and vascular neurology fellowship director at the University of Illinois College of Medicine and stroke medical director at the University of Illinois Hospital in Chicago in a press release.  

“Managing heart health from an early age is important to prevent cardiovascular disease and cardiac events, protect brain health and reduce the risk of cognitive decline in later life,” says Testai. “Dementia is commonly seen as an incurable and relentless disease that cannot be prevented. Evidence shows, however, that adopting a healthy lifestyle and identifying and treating vascular risk factors early may help preserve normal brain function and reduce the burden of Alzheimer’s disease and other related dementias.”

Let’s take a look at what they found for each heart condition. 

Atrial Fibrillation

Also referred to as AFib, atrial fibrillation is the most common heart rhythm disorder in adults. In the U.S. alone, 2.7 million adults had AFib in 2020 and that’s expected to increase to 16 million by 2050. AFib places people at a higher risk for stroke, and stroke damages the brain. 

“It’s been long recognized that different cardiac diseases can cause stroke which leads to dementia,” Testai tells EatingWell. “In addition, stroke in particular areas of the brain can lead to cardiac disorders, such as arrhythmias. In addition, several systemic conditions, such as hypertension and diabetes, can in parallel cause cardiac and brain injury.”

But there’s more to it. 

Researchers found in their literature review that just having AFib increases the risk of cognitive impairment by 39%. But why?

Well, both AFib and dementia have risk factors in common, including high blood pressure, type 2 diabetes, heart failure, smoking, vascular disease, obstructive sleep apnea and advanced age. AFib can weaken the heart over time, which means it can’t pump as much blood—including to the areas of the brain responsible for cognitive function. Less blood means less oxygen and nutrients, which can result in poor cognition. 

AFib also has something in common with Alzheimer’s disease—inflammation. Higher levels of inflammation are also associated with an increased risk of blood clots and brain injury.

Some people can feel when their heart goes out of normal rhythm but others can’t. This is why regular checkups are important, as your healthcare practitioner will be able to hear the irregularities when they listen to your heart or see them on an EKG. 

Heart Failure

While heart failure sounds like it might mean the heart stops, it actually means that the heart is weakened and doesn’t work properly. In other words, it fails to properly function. There are many possible causes of heart failure. AFib, atrial flutter, heart attack, heart valve disease, obesity, obstructive sleep apnea, high blood pressure, smoking and type 2 diabetes are just a few of them. 

Heart failure results in less blood being pumped out with each heartbeat. And since blood carries oxygen and nutrients to the brain and helps remove waste and toxins from it, you can see how this would affect brain health over time. 

Case in point: The researchers found that almost 50% of people with heart failure experience some type of cognitive impairment that may affect language, memory and/or executive function. Executive function is a group of mental skills that include the ability to plan, organize and execute tasks. It also includes impulse control and memory.  

Like AFib, heart failure influences brain health through reduced blood flow—which has been linked to mini-strokes—and chronic inflammation. Heart failure can also influence certain hormones that affect brain health. Some of the brain changes seen in people with heart failure include smaller brains due to a reduction in grey matter and damage to the brain’s white matter. 

Coronary Heart Disease

Coronary heart disease (CHD) is a general term that refers to a buildup of plaque in the heart’s arteries and can lead to a heart attack or stroke. As the plaque builds up, it narrows the width of the arteries, partially blocking them and making it harder for blood and oxygen to get to the heart. The buildup of plaque can start in childhood.

Researchers found evidence from a systematic review that included 1 million people indicating that those with CHD have a 27% higher risk of developing dementia compared to those without CHD. And following a heart attack, up to 50% of people experience some loss of brain function. 

Like the other heart conditions already mentioned, CHD is linked to brain harm through reduced blood flow and inflammation. 

How Does This Apply to Real Life?

As you can see, there are several pathways through which the heart and brain are connected, including reduced blood flow and inflammation. “There is substantial evidence demonstrating that heart disease and cognitive decline are associated with increased inflammation,” says Testai, “Thus, it’s possible that the damage in one organ can lead to systemic inflammation which may have detrimental effects in a remote organ.”

Interestingly, Testai also notes that there is emerging evidence that biomarkers of neurodegeneration—essentially signs of degeneration of the nervous system and brain—can be found in the heart. “This is associated with cardiac dysfunction and suggests that neurodegeneration and heart disease are biochemically interconnected.”

Then there’s the genetic component. “Genetic links between cardiac health and brain structure have been more recently described,” says Testai. “This suggests that both conditions, once considered indirectly related, may share genetic predispositions.”

In other words, if you have a genetic predisposition toward either heart disease or dementia, you may have a genetic predisposition toward the other one, as well.

As with any health condition, early detection is a good thing. And while there is some evidence that the course of dementia, including Alzheimer’s, may be able to be slowed down, there is currently no known cure. 

This is why prevention is really the key to a healthy heart and brain—whether you have a genetic predisposition toward disease or not. We know that changes in the brain and cardiovascular system can begin decades before symptoms show up—so today is the day to begin to make changes. 

“Although new medications with the potential to treat Alzheimer’s disease are being developed, the medical community is well aware that prevention is better than a cure,” says Testai.

It’s important to take a holistic approach to your health. You can start with the AHA’s Life’s Essential 8—which encompasses health behaviors and health factors that influence heart—and ultimately brain—health. This includes eating a heart-healthy diet, being more active, quitting tobacco and nicotine products, getting plenty of quality sleep, and managing weight, blood pressure, blood sugar and cholesterol. 

The Alzheimer’s Association has a similar list that includes the Essential 8 plus challenging your mind (learning new skills), pursuing education and protecting your head from injury. Head injuries can be prevented by wearing a helmet for certain sports and wheeled motorsports (cycling, ATVs, motorcycles, etc), wearing a seatbelt in any type of vehicle and preventing falls.

Not sure what to eat? The MIND diet covers both heart and brain health and is a fusion of the Mediterranean diet and the DASH diet, the latter of which is a diet to help reduce blood pressure. It includes foods like fruits, vegetables, whole grains, nuts, seeds, legumes and lean protein, and provides lots of fiber and healthy fats while reducing sodium, saturated fat and added sugars.

The Bottom Line

This scientific statement from the AHA supports a strong link between heart and brain health and points out several mechanisms for the connection. And while early detection is important—so get to your annual checkups—prevention is the ultimate goal regarding heart and brain health. Because changes in the arteries and brain can begin decades before any symptoms show up, it’s important to start as early as possible to prevent them from occurring. And since we can’t go back in time, today is the best day to begin these changes.