Is Sugar the Real Cause of Heart Disease?


Is Sugar the Real Cause of Heart Disease?

For years, doctors pointed the finger at a high-fat diet as a major cause of heart disease. As a result, people gradually cut back on nutritious foods like eggs due to their high cholesterol content and shied away from fats in general. But evidence that dietary fat, even saturated fat, is a promoter of heart disease is weakening. In fact, some forms of fat, like the monounsaturated fats in nuts and olive oil, may be protective. For example, nut consumption has been linked with a lower risk of heart disease.

Now, attention is turning towards another dietary component as a promoter of heart disease – one that most Americans eat too much of. It’s sugar and other sweeteners such as high-fructose corn syrup and refined carbohydrates that are adding to the heart disease burden. One out of two people dies of heart disease and it’s clear that lifestyle factors, including diet, matter.

Why focus on sugar as a promoter of heart disease? A study published in the JAMA Internal Medicine found a clear link between sugar consumption and a greater risk for coronary artery disease, the most common heart disease killer.

This study showed men and women who consumed 17 to 21% of their calories in the form of sugar had a 38% greater risk for dying from coronary artery disease or a heart attack, relative to those who ate 8% or less of their calories from sugar. The average person consumes 22 teaspoons of sugar daily while the American Heart Association recommends no more than 6 teaspoons for women and 9 teaspoons daily for men. Most of us are WAY over those recommendations!

How Sugar May Contribute To Heart Disease

How might sugar contribute to heart disease? When you eat sugar or refined carbohydrates, you get an insulin spike. When insulin levels rise, especially if you have insulin resistance, it triggers inflammation that damages the inner wall of blood vessels and makes it harder for the vessel wall to function properly. Blood vessels are normally elastic, giving them the ability to open and close in response to blood flow. Ongoing inflammation causes the walls to harden and become stiff. Over time, this can lead to high blood pressure, heart disease or a heart attack.

Sugar can damage your blood vessels in other ways too. According to researchers at the University of Warwick, sugar binds to cholesterol and changes its properties, making it smaller, denser, and stickier. It’s small, dense cholesterol particles that are most strongly linked with blood vessel damage that leads to stroke and heart attack.

In addition, a diet rich in sugar and refined carbohydrates can lead to weight gain. That’s a problem since obesity is linked with a greater risk for heart disease, partially by causing insulin resistance. If you have insulin resistance or type 2 diabetes, you’re at double the risk of dying from heart disease. That’s why it’s so important to avoid excessive weight gain if you care about the health of your heart.

Soft drinks sweetened with sugar or high-fructose corn syrup have also been linked with a greater risk for high blood pressure. Many soft drinks and energy drinks contain high-fructose corn syrup, a sweetener that raises blood triglycerides, another risk factor for heart disease.

As you can see a diet high in sugar and refined carbs act at a variety of different levels to damage blood vessels and increase the risk for heart attack and stroke.

Heart Disease, Is Sugar Really the Culprit?

No doubt about it – sugar is bad news, not just for your heart but for your overall health as well. Is a high sugar diet bad not so much because of the sugar but because people who eat sugar eat fewer healthy foods like fruits and vegetables?

According to Dr. Teresa Fung, a nutrition professor at the Harvard School of Public Health, even people who eat an overall healthy diet have a greater risk for heart disease if they eat a lot of sugar. You’d think with all the bad news about sugar, we’d be eating less of the “sweet stuff,” but in reality consumption of sugar has risen dramatically over the last 30 years.

Are All Sugars Bad?

The biggest threat to your heart and blood vessels are sugars added to processed foods and processed foods themselves. The natural sugars you get from eating fruit, like apples, oranges, and berries, come in a “complete package” that includes fiber. The fiber in these foods slows absorption and reduces the rapid rise in blood sugar and insulin you get when you consume sugar in the absence of fiber. Plus, these foods contain healthy phytochemicals that protect against heart disease in other ways, possibly by reducing inflammation.

Avoid “Sneaky” Sugars

Read labels and know sugar in its many “disguises.” There are more than 70 names for sugar. Know them and learn to recognize them on ingredient lists. Added sugar hides in a variety of places you wouldn’t necessarily expect – condiments, yogurt, cottage cheese, salad dressings, soup mixes etc. Although whole fruit is healthy, despite its natural sugar, fruit juices usually are not because they’ve been stripped of their fiber. Consume fruit juice and beverages with added sugar in moderation or not at all. Stay away from refined carbohydrates as well.

The Bottom Line

At the very least, sugar has calories with no nutritional value. Plus, some research suggests it’s addictive. Once you start reading labels religiously, you’ll discover it’s in most packaged foods, even ones that don’t taste sweet. Not only does sugar likely increase the risk of heart disease – it contributes to insulin resistance, tooth decay, weight gain, and, possibly some forms of cancer. If you crave something sweet, reach for nature’s candy – a whole piece of fruit and enjoy its natural goodness without the guilt.



JAMA Intern Med. 2014 Apr;174(4):516-24. doi: 10.1001/jamainternmed.2013.13563.

American Heart Association. “Added Sugars Add to Your Risk of Dying from Heart Disease”

The Doctor Will See You Now. “From Bad Cholesterol to Worse”

Harvard Health Publications. “Eating too much-added sugar increases the risk of dying with heart disease”


Related Articles By Cathe:

The Pros and Cons of Various Natural Sweeteners

6 Myths About Heart Disease in Women – Debunked

6 Powerful Ways that Plant-Based Foods Lower Your Risk for Heart Disease

Beyond Sodium: is Sugar What’s Raising Your Blood Pressure?

Can Drinking Coffee Lower Your Risk for Heart Disease?


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