Just about every day brings a new buzzword or trend promising to shield us from heart disease -- the No. 1 killer of both men and women. Some ways to boost heart health have sound science to back them up. Others are pure hype.
To put the latest prevention strategies into perspective, WebMD talked to Amit Khera, MD, a professor of medicine and director of preventive cardiology at the University of Texas Southwestern Medical Center.
Q: Do any of the new diet trends, like the keto diet, protect the heart?
One thing that people absolutely can't assume is that a weight loss diet is a heart-healthy diet, or a healthy diet in general. There are some data that people can lose weight on a keto diet, but in many circumstances, their cholesterol goes up.
Q: What about a vegan or vegetarian diet?
Plant-based diets are generally healthy, but it depends what you eat. Everyone just assumes that vegetarian and vegan diets are heart-healthy, but they can be unhealthy if people who are on them drink soda and eat cookies and fried foods.
Q: Do we need to cut out sugar to lower our heart risks?
We always look for the boogeyman, focus on it for a decade or so, and then move on. The boogeyman was saturated fat for years. Now it's sugar. The problem is, it's like playing whack-a-mole. When we stopped eating saturated fat, we started eating high-fructose corn syrup and carbs. Now we're going to say it's sugar and go back to eating a lot of fat. The point is to eat a healthy pattern and not look for one boogeyman.
Q: What is the best diet for heart health?
The only diet that has solid research behind it for heart health is the Mediterranean diet. The Primary Prevention of Cardiovascular Disease with a Mediterranean Diet (PREDIMED) study showed that there was a 30% lower risk of heart attacks and stroke in people who followed a Mediterranean diet. There's no other diet, not a single one out there, with that level of evidence.
Q: What's the latest advice on daily aspirin therapy?
Aspirin may lower the risk of heart attacks and strokes a little bit, but it causes serious bleeding risks. For that reason, in people who've never had a heart attack or stroke, the most recent guidelines don't recommend aspirin therapy to prevent them for most people. People with a very strong family history of heart attack and stroke whose risk of bleeding is low may decide to go on daily aspirin therapy after talking to their doctor. If you've already had a heart attack or stroke, you still need to take aspirin. That advice hasn’t changed.
Q: We've known for a long time that smoking increases heart risks, but what about e-cigarettes?
We certainly don't know as much about e-cigarettes as we know about cigarettes, but there is research coming out. The short answer is that there do seem to be some negative health effects. E-cigarettes have nicotine in them. They also contain other chemicals and liquids, and no one knows what the adverse health effects of those ingredients might be. We've seen this explosion in e-cigarette use among children, and we worry what this might mean for the future.
Q: How much sleep is best when it comes to protecting our heart?
People who sleep too little or too much seem to have more adverse heart effects. Some people need more sleep than others, but something in the 7- to 9-hour range is optimal for most people.
Q: What effects might our electronic devices have on our heart?
There's a good and a bad effect. The bad effect is the blue light. It certainly affects circadian rhythm and sleep quality. That may have an effect on heart health, but we don’t know that. Also, when people are on their devices, they're not out engaging in exercise and other activities. The flip side is that many people use their device to track their calories, blood pressure, and steps. It helps them stick to health-related behaviors.
Q: What types of exercise deliver the most heart benefits?
Aerobic activity is the cornerstone of cardiovascular disease prevention. If your goal is to prevent a heart attack and stroke, then you want to do at least 150 minutes of moderate physical activity, like brisk walking, a week. Or do 75 minutes of vigorous activity, which includes jogging or riding a bike. The recommendation is that everyone also do at least 2 days a week of resistance exercise, such as weightlifting. That seems to lower blood pressure and improve insulin resistance.
Q: What new information have we learned about the connection between stress and heart disease?
We are definitely seeing that chronic stress can affect blood flow to the heart and some other adverse parameters, like inflammation. The challenge is, everybody's response to stress is probably a little bit different. Some people may have more resilience than others, and there are different types of stress. There are some techniques to combat stress, like meditation. There's evidence that people who practice mindfulness meditation techniques can lower their blood pressure.
Q: Many Americans are digging into their genes to learn about their heart risks. How helpful is this?
Some diseases are called monogenetic, meaning there is one gene that causes them. If you have that gene, your risk is higher. Occasionally, that may affect what treatments are right for you or what screenings you need. The problem is that heart disease is polygenetic. Many genes cause it. There are polygenetic risk scores in development. Rather than look for one gene, they take millions of genetic variants and essentially come up with a score. The more of these variants you have, the higher your risk for heart disease. If your risk is higher, you can be more aggressive about the things you can control, like cholesterol and high blood pressure.
Q: How might our gut microbiome affect our heart health?
We always think of ourselves as independent beings, and we don't realize that we're really carriers of billions of beings inside of us. We have a relationship with the bacteria living in our gut. Researchers have discovered that when you eat red meat, bacteria in the gut take the meat and produce something called TMAO, which seems to damage your blood vessels and heart. We're now looking at what dietary patterns may favorably affect the microbiome. It's still early, and there are no definitive answers yet.
Q: Which heart screening tests do you recommend?
One test worth mentioning is a coronary calcium scan, which is essentially a CT scan of the heart. The purpose is to identify people who have a buildup in their arteries without symptoms and may be at high risk for heart disease and stroke but don't know it. Those people will need more intensive treatment, including medicines.
Q: Based on the latest research, what changes have you made to your own heart health routine?
First and foremost, I try to do a lot better with diet. I eat the colors of the rainbow. I walk around the perimeter of the grocery store and spend a lot more time in the vegetable aisle and stay away from the processed foods. I also appreciate the importance of habitual exercise. I’ve always exercised, but now I make it a standard part of my routine.