What Causes Heart Disease? 9 Things Doctors Need You to Know
Taking care of your heart can help you live a long and healthy life. Here's what causes heart disease, according to cardiologists. (Plus, what steps you can take to prevent it.)
You wear a seat belt and drive carefully to avoid accidents, you stock up on antioxidant-laden foods to prevent cancer, but you might not realize all the things you should be doing to fight the No. 1 killer in the world: heart disease.
It’s “very common,” says Suzanne Steinbaum, attending cardiologist, a fellow of the American College of Cardiology and American Heart Association, and expert for the American Heart Association. In Canada, about 1 in 12 Canadians over the age of 20 live with a diagnosed heart disease and it’s the second leading cause of death nationally.
That’s the bad news—but the good is that heart disease is highly preventable. “Research shows that about 80 percent of all cardiovascular disease can be prevented by controlling high blood pressure, diabetes, and high cholesterol, along with adopting healthy lifestyle behaviors such as eating a healthy diet, staying physically active, and maintaining a healthy weight,” Dr. Steinbaum says.
Knowing what causes heart disease—and doing something about it—is more likely to add years to your life than almost anything else you can do. “The more risk factors you have, the greater the chance of developing a buildup of plaque in the arteries, which could lead to a heart attack,” Dr. Steinbaum says. “Smoking, physical inactivity, obesity, high blood pressure, and high cholesterol are some of the main controllable—meaning they can be managed with lifestyle changes and medication—risk factors for heart disease.”
First, let’s talk about what exactly heart disease is, and then how to prevent it. We’ll also look at some of the things heart doctors do to protect their own hearts.
What is heart disease?
Heart disease is more accurately heart diseases, as there are at least six different types of heart disease.
“Heart disease is a broad term and describes a variety of conditions,” says Courtney Jordan Baechler, a cardiologist and researcher at the Minneapolis Heart Institute Foundation. “I often like to think of heart disease like a house. You can have problems with your plumbing, or arteries, which we commonly refer to as coronary artery disease.”
When people refer to “cardiovascular disease,” they are usually talking about narrowing or blockages in the arteries, she says. Those blockages can cause heart attacks, strokes, erectile dysfunction, or leg pain and cramping (called peripheral artery disease), depending on where they are located.
Or, “you can have problems with your electricity, the rhythm of the heart; you can have problems with the structure of your heart, valve disease or heart pump function problems known as heart failure.”
Types of heart disease
The most common disease of the arteries is the buildup of plaque in the walls of the arteries or atherosclerosis, Dr. Steinbaum says. This causes coronary artery disease, the most common type of heart disease in Canada.
“It can lead to symptoms of chest pain, or angina, due to lack of ability of the arteries to deliver oxygen to the heart muscle,” Dr. Steinbaum says. “Or, it can cause a heart attack in an acute situation, when the heart muscle doesn’t receive any oxygen, and there is severe chest pressure, shortness of breath, sweating, nausea or vomiting, jaw pain, or back pain.”
The most common disease of the electrical system is an irregular heartbeat called an arrhythmia, says Dr. Steinbaum, and atrial fibrillation is the most common type.
“There is pressure on the atrium [the heart’s upper chambers], and this can cause there to be an irregular and erratic firing of impulses from the atrium—this scattered impulse can cause ‘fibrillation,'” she says. “It is due to multiple risk factors that can lead to the issue, such as high blood pressure, valvular [heart valve] disease, or smoking.”
The most common disease of the muscle is called cardiomyopathy, which is a condition that causes the heart’s muscles to become stiff or weak, Dr. Steinbaum says. “This can happen due to issues like hypertension [high blood pressure], which can make the heart stiffer, or a heart attack, which can make the heart function weaker and cause the heart to get bigger and not pump as well,” she says.
Common problems with the flaps that open and close when the heart pumps are valvular heart diseases. This includes mitral regurgitation, in which blood flows backward through the mitral valve, and aortic stenosis, in which the aortic valve doesn’t open and close properly, according to the American Heart Association.
“Aortic stenosis is common with aging and is associated with high blood pressure and high cholesterol. Common symptoms are chest pain, passing out, or developing heart failure, with fluid in the lungs and swelling of the legs,” Dr. Steinbaum says. “Mitral regurgitation can also be associated with shortness of breath and palpitations.”
Do genetics cause heart disease?
Yes, but you can take steps to lessen the risk even if heart disease runs in your family.
“Family history, ethnicity, gender, and age can all play a role in the risk of heart disease,” says Dr. Steinbaum. “If you have a strong family history, then get your numbers checked at age 20, which includes cholesterol and blood pressure. With a family history, it is important to know your own personal risk to take steps to prevent disease, such as diet and exercise, and medication if needed.”
Your family history is actually only a small part of your risk.
“Patients have been surprised to find out that genetics or family history is only about 15 to 20 percent of your overall risk of developing heart disease,” Dr. Baechler says. “I find patients feel very empowered that just because your mother, father, grandmother, or grandfather had heart disease, it’s not written in stone that this will happen to you. That means that about 85 percent of coronary artery disease risk—the ‘plumbing’—is preventable, which is also empowering.”
High blood pressure and cholesterol
High blood pressure and high cholesterol are the two leading causes of heart disease affected by your lifestyle. “All these conditions are linked,” says John P. Higgins, a sports cardiologist at McGovern Medical School at UTHealth in Houston. They’re associated with worsening blood vessel function, including narrowing and blockage of arteries, stiff arteries, blood clotting, and inflammation, he says.
“Make sure you know your blood pressure—the goal is 120/80—and your cholesterol,” Dr. Baechler says. “Know those numbers. If it’s high and not quickly responsive to the suggestions we have, make sure you get it treated with medications. Medications when, used appropriately, help save lives.”
Suggestions for changes to your lifestyle can make a huge difference as well.
An unhealthy diet can increase the risk of obesity and type 2 diabetes (which causes high blood sugar that can cause damage), and high blood pressure and cholesterol, all of which are associated with heart disease.
“As the typical American diet has become more filled with sugars and simple carbohydrates, we are able to see the impact of disease on the rates of diabetes, obesity, and eventually heart disease,” Dr. Steinbaum says. “As we have seen an increase in diabetes and obesity in the U.S. over the past several decades, we are seeing an increase in the risk of cardiovascular disease.”
For optimal health, the American Heart Association recommends that adults enjoy an overall healthy eating pattern that emphasizes foods like vegetables, fruits, nuts, legumes, and whole grains along with fish, lean protein, and dairy foods. “Studies show heart health benefits when these foods and polyunsaturated fats replace foods high in saturated fat, dietary cholesterol, trans fats, sodium (salt), processed meats, refined (low fibre) carbohydrates, and sweetened beverages,” Dr. Steinbaum says.
Dr. Higgins recommends plant-based diets to avoid the unhealthy fats in animal products, and the Dietary Approaches to Stop Hypertension (DASH) diet and the Mediterranean diet, which generally reduce the risk of heart disease with healthy nutrients. “They do so by lowering blood pressure, lowing cholesterol, and improving vascular [blood vessel] function,” he says.
By improving the cells’ function lining the blood vessels, the arteries can remain flexible, grow new blood vessels, provide a barrier to toxins to reduce inflammation, prevent blood clotting, and prevent narrowing and blockage of arteries, he says.
Lack of exercise
Sorry, couch potatoes: A sedentary lifestyle can help cause heart disease. It’s best to get moving and raise your heart rate to keep it pumping strong.
“The American Heart Association recommends adults get at least 150 minutes per week of moderate-to-vigorous activity, 75 minutes per week of vigorous activity, or a combination of both,” Dr. Steinbaum says. “Getting your heart rate up to a moderate intensity for 30 minutes five days a week has been shown to decrease the incidence of cardiovascular disease.”
“Exercise lowers blood pressure, lowers bad (LDL) cholesterol, raises good (HDL) cholesterol, increases nitric oxide, which improves vascular function, and improves mood, too,” Dr. Higgins says. “Other benefits of exercise include improving bone strength, diabetes, and weight reduction.” First, he recommends getting cleared by your doctor to start a new exercise program.
Any amount of exercise will help, but ideally, “a typical regimen consists of alternating days of aerobic exercise—walking, jogging, step aerobics, stair climbing, elliptical, swimming—with strength and resistance training such as weight lifting,” Dr. Higgins says. But you should start slow. “For all exercise, when you are just a beginner, go easy and increase your exercise by no more than 10 percent per week,” he says.
“For example, I would recommend for beginners to start to walk 15 minutes three days a week, and on alternate days do 10 repetitions of 10 major muscle groups at a weight that is easy for you,” Dr. Higgins says. “Next week, increase the aerobic exercise time and the weights no more than 10 percent. Once you are comfortable with walking for 30 minutes, you may try walking four minutes and jogging one minute, for a total of 30 minutes.”
Then once you’ve been exercising regularly for three months, Dr. Higgins suggests, a typical workout week might consist of 30 minutes of walking, jogging, swimming, or cycling on Monday, Wednesday, and Friday; and 30 minutes of weight training, balance, and stability on Tuesday, Thursday, and Saturday. “Remember, always warm up and cool down for five to 10 minutes to improve performance and reduce injuries,” he says.
Smoking and drinking
Smoking and drinking too much alcohol are unsurprisingly also not good for your body, and can raise the risk of heart disease. The toxic chemicals in cigarettes damage blood vessels and raise cholesterol. All the doctors we spoke to suggested quitting smoking.
Like smoking, alcohol in excess can increase cholesterol and damage arteries, and raise blood pressure. The extra calories also can cause you to gain weight.
It’s best to stick to the standard guidelines for alcohol intake, which are no more than two drinks a day for men and one for women.
Busy work and family lifestyles—not to mention living through the Covid-19 pandemic—makes reducing this cause of heart disease very hard. “One factor relevant to the times we are living in now is stress, which can cause people to overeat, drink too much alcohol, and smoke, which are all behaviors that can increase the risk of heart disease,” Dr. Steinbaum says.
“Stress itself can increase stress hormones and inflammatory markers, leading to high blood pressure, high cholesterol, and inflammation within the lining of the arteries, leading to plaque formation.” This narrows and clogs the arteries, leading to heart disease.
Mental health disorders
Along with stress, other mental health factors can contribute to heart disease risk by causing physical effects on the body. Heart rate, blood pressure, and the stress hormone cortisol can go up when you have anxiety, depression, or other mental health issues.
“We know that up to 30 percent of your risk of developing heart disease comes from poor mental health. We absolutely need to decrease the stigma of getting help around mental illness,” Dr. Baechler says.
“Remember, for all of us, that good mental health is a muscle we need to practice just like exercise, so start with 10 minutes of something that helps create calm and happiness—perhaps this is meditation, guided imagery, listening to relaxing music. There are lots of free options available.”