The Scary Connection Between Heart Health and Dementia

Your brain probably isn’t the first organ you think about when it comes to cardiovascular health. But the heart and brain are more connected than you might think, and you need a healthy heart in order to have a healthy brain. To better understand the connection between heart health and cognition, we spoke with board-certified neurologist, David Perlmutter, M.D., author of Drop Acid and Grain Brain, and Erik Won, M.D., Chief Medical Officer and President of Wave Neuroscience to explain the connection between heart and brain health — and what we can do to ensure the wellness of both. 

The connection between our hearts and brains

“The relationship between heart health and cognitive function is profound,” says Dr. Perlmutter. “The brain desperately depends, moment to moment, on receiving adequate blood supply from a healthy heart.” There are a lot of ways that blood flow from the heart to the brain can be slowed or hindered, he says, including heart rhythm disturbances, poor cardiac output as a consequence of heart disease, or problems with your heart’s valves. Another issue that can also arise: circuitry. “The heart and brain are both electrophysiologic organs, so they require healthy circuitry to function at their best,” Dr. Won says. 

To help us understand how the heart affects the brain, Dr. Won explains heart rate variability (HRV), which is different from your heart rate. “HRV measures the moment-to-moment variability between heartbeats, which serves as an instrument to measure autonomic tone,” he says, explaining that the autonomic nervous system is responsible for controlling your body’s unconscious functions, like breathing and heartbeat. HRV is a great way to measure our overall health — which is why devices such as Apple Watches are starting to measure it.

How heart health impacts brain health

“If the arteries in the heart are unhealthy, you can be almost certain that the brain is involved,” says Dr. Perlmutter. To use Dr. Won’s framework, it’s impossible to have a properly functioning electrical setup when you’ve got some faulty wires. “There is a growing body of evidence suggesting the health of both organs is paramount and one can impact the other,” Dr. Won says. “Lifestyle and behavioral risk factors such as obesity, hypertension, diabetes, smoking, and sedentary lifestyle are common to both the heart and brain.”

Poor heart health can cause dementia…

To help us understand the relationship between dementia and heart health, Dr. Perlmutter pointed out that while someone might be diagnosed with heart problems before they’re diagnosed with brain problems, heart issues don’t occur in a vacuum. “One of the biggest concerns related to heart health is the development of coronary artery disease,” he says, noting that the changes in your heart that lead to narrowing of the blood vessels supplying the heart muscle don’t occur in isolation — they affect the rest of your body, too.

Coronary artery disease happens when the blood vessels that supply your heart become damaged or diseased. But if this is happening in your heart, that’s a sign that blood vessels throughout your entire body are at risk for being compromised, too — including the arteries, large and small, that preserve brain function, Dr. Perlmutter says. In fact, when someone has cardiac disease, it’s incredibly unlikely that their brain is unaffected.

Cognitive problems are among the most significant issues that can arise from poor heart health, including dementia and Alzheimer’s. “Heart-related issues have been associated with cognitive decline, as well as an increased risk for the development of threatening brain issues like Alzheimer’s disease,” Dr. Perlmutter says. “Research now reveals that the very risk factors that are associated with the development of coronary artery disease in midlife predispose older adults to the development of dementia.”

There are two main ways in which coronary disease harms the brain. “First, a diseased heart threatens the brain directly by not pumping adequate amounts of blood,” Dr. Perlmutter says. “Second, the very fact that the heart arteries are diseased indicates that the same process is already at work in the brain, and throughout the entire body.” 

…and poor mental health can cause heart problems

We’re always being told to reduce stress for the sake of our health. While we might think of stress as more emotional and less tied to our brain health, it actually is: Brain-oriented actions like meditating and being mindful are notorious for lowering stress levels. 

“Cardiovascular disease is a known risk factor for cognitive decline and development of dementia,” Dr. Won says. He points to the Interheart study, which was composed of 25,000 volunteers spanning 52 countries, and identified emotional stress as a key risk factor — accounting for one-third of heart attacks and strokes.

Additionally, your emotional and mental health are connected to your risk of heart disease. “These effects can arise both directly, through biological pathways, and indirectly, through risky health behaviors,” Dr. Won says. “People experiencing depression, anxiety, stress, and PTSD may experience physiologic effects on the body, such as increased inflammatory biomarkers, cardiac reactivity, reduced blood flow to the heart, and heightened levels of cortisol.” So being stressed out can actually leave its mark on the body. Dr. Won says that stress can be the cause of issues like calcium buildup in your arteries and heart disease.

Ways to keep your heart and brain healthy

The good news here is that we have the power to reduce the risk of both brain and heart problems through lifestyle — and both your brain and heart have extremely similar lifestyle needs. “The notion of a ‘heart-healthy’ lifestyle would certainly translate to being ‘brain-healthy’ as well,” Dr. Perlmutter says. Here are a few ways to improve both your heart and brain wellness, helping to prevent heart problems like cardiovascular disease and coronary artery disease, as well as cognitive problems like dementia: 

Address your mental health

Seeking care is absolutely key to managing mental health difficulties. “There’s a strong relationship between various mood disorders like depression and risk for both the development of coronary artery disease as well as cognitive decline,” Dr. Perlmutter says. “These days, rates of depression are increasing dramatically, and it’s quite likely we will see higher rates of heart and brain issues as a consequence.” So if you’ve been considering seeing a professional to help with a mood disorder but feel like you just don’t have the time, this is a good reminder that your mental health is incredibly important — including your brain and heart.

Exercise, exercise, exercise

No surprise here: Exercise is notoriously important for keeping our bodies (and all their organs) feeling their best. “Increase daily activity with moderate exercise at least three times a week,” Dr. Won says. Perlmutter takes things a step further, suggesting we engage in both an aerobic program and resistance exercise for a minimum of 30 minutes every day.

Sleep on it

It’s a favorite activity for many, but it can be so tough to get all the Zzzs we need. Dr. Won considers adequate sleep the most important lifestyle element to keeping our hearts and brains healthy. 

Dr. Perlmutter recommends a wearable device to track your sleep habits. “This makes it easy to gain a great understanding of how well you’re sleeping,” he says. “This way, you can tell not just the duration of your sleep each night but also the quality of your sleep. Knowing this information allows you to make changes in things like how late you have your dinner, helps you understand your sensitivity to afternoon caffeine, and even consider the effects of exposure to blue light in the evening, which can threaten sleep.”

Minimize sugar and refined carbs

It’s always a bummer to hear, but it comes up pretty much anytime anyone talks about staying healthy: sugar and refined carbs just aren’t a match for a healthful lifestyle. “Even mild elevation of blood sugar — well below the threshold of diabetes — poses a significant threat to heart health and brain health, as well,” Dr. Perlmutter says. 

Monitor your blood pressure

Lastly, your blood pressure is vital to the health of both your heart and brain. “Elevated blood pressure is one of the biggest threats for the development of heart disease, as well as Alzheimer’s,” Dr. Perlmutter says. 

The final word

There’s no being healthy without having a well-functioning heart and brain, and the two are strongly interconnected. We often see heart issues manifest prior to obvious cognitive ones, but the presence of heart problems indicates that our brain function is being compromised. Heart problems can cause brain problems, and the reverse is true as well, with brain troubles also causing heart troubles. While no illness is 100% preventable, we can take lifestyle steps to ensure our hearts and brains stay as healthy as possible. These include getting adequate sleep, reducing our intake of sugar and refined carbohydrates, exercising, addressing mental health issues, and monitoring our blood pressure.