Does Sugar Affect Your Cholesterol?
Have a sweet tooth? Join the club. While you probably know that overindulging in sugary foods and drinks can contribute to weight gain and obesity, you may not realize that your sugar intake can also affect your cholesterol levels, making it a key contributor to heart disease. We asked the experts to break down the relationship between sugar, cholesterol, and heart health.
What Is Cholesterol?
Cholesterol is a waxy fat-like substance that your liver makes. It helps build protective layers, called membranes, around the cells in your body. It also contributes to the production of certain hormones as well as vitamin D and bile, which helps you digest food. In other words, despite its bad rap, cholesterol plays an important role in your body.
Your body makes all the cholesterol that you require. However, your diet can contribute cholesterol as well, causing your level to rise. Foods that are high in saturated fat, like red meat, are mainly responsible for high cholesterol. When your cholesterol rises, so does your risk of heart disease. That’s why it’s important to lower your cholesterol if it has become elevated.
Experts divide cholesterol into two types. They are:
- Low-density lipoprotein (LDL) cholesterol. Often referred to as bad cholesterol, LDL cholesterol contributes to the buildup of plaque in your arteries, a process called atherosclerosis. Plaque, made from cholesterol and other substances, can prevent blood from flowing normally in your blood vessels. Blockages caused by plaque can trigger a heart attack or stroke. For that reason, you want low levels of this type of cholesterol relative to the total amount of cholesterol in your blood.
- High-density lipoprotein (HDL) cholesterol. This is frequently called good cholesterol. It helps rid your body of LDL cholesterol by absorbing it as it travels through your bloodstream and then carrying it back to your liver. There, it gets flushed from the body as waste. You want high levels of this cholesterol relative to the total amount of cholesterol in your blood.
When your doctor talks to you about having high cholesterol, odds are that she is referring to either your total cholesterol (a panel that measures LDL, HDL, and a type of fat in the blood called triglycerides—more on that in a minute) or your LDL level specifically.
How Can Sugar Impact Cholesterol Levels?
A main culprit behind high cholesterol is the fat in your diet, in particular saturated fat found in animal products. (Which is why your doc may suggest limiting red meat if your cholesterol numbers are high.) However, sugar also has an impact. It may raise your total cholesterol and affect the balance of LDL and HDL.
“Diets high in sugar cause the liver to create more LDL, and diets high in sugar also lower HDL cholesterol,” says Eric Ascher, D.O., a family medicine physician at Lenox Hill Hospital in New York City.
Exactly how excess sugar upsets the balance of cholesterol in the blood isn’t fully understood, but it involves the activation of certain chemical pathways that lead the liver to make more LDL and less HDL. In addition, since the extra sugar isn’t needed for energy, the liver converts it into fat in the form of triglycerides. Sugar also appears to inhibit an enzyme that helps break down and remove triglycerides from the body.
“The purpose of triglycerides is to provide fuel to muscles for muscular activity and to store energy in fat cells in case of starvation,” explains Carl E. Orringer, M.D., professor of clinical medicine and director of Preventive Cardiovascular Medicine at the University of Miami Miller School of Medicine in Miami, FL.
However, just like LDL cholesterol, having too high a level of triglycerides is cause for concern. High triglycerides are a risk factor for heart disease, heart attack, stroke, and more.
In 2020, researchers published a study in the Journal of the American Heart Association on the impact of sugary beverages—think soft drinks—that linked having more than one 12-ounce sugary drink per day with a 98% greater incidence of low HDL.
The study also showed that people who drank more than 12 ounces of soda or other sugar-sweetened beverages per day were more than 50% more likely to have high triglyceride levels (defined in the study as 175 milligrams per deciliter or higher) than those who drank less than one such beverage per month.
Research on Sugar and Cardiovascular Disease
Since sugar can raise LDL levels, and we know elevated LDL puts you at great risk for heart trouble, perhaps it’s not surprising that sugar is, in fact, linked to heart disease. Dr. Orringer points to a major study, published in Circulation, that found the risk of dying from cardiovascular disease rose with increasing amounts of sugar in a person’s diet. The study looked at consumption of sugars added to sugary drinks, fruit drinks, different types of desserts, cereal, and breads. These sugars don’t occur naturally in the foods (in contrast to the sugar in foods like fruit).
The study found that people who got 10% to 24% of their daily calories from added sugar were about one-third more likely to die of heart disease over a period of about 15 years than those who got less than 10% of their total calories from added sugar. Surprised? Wait til you read this: People who got more than 25% of their calories from added sugar were at a whopping 275% greater risk of dying from heart disease.
“The reason behind this increased risk has not been clearly established,” says Dr. Orringer, “although it may be due to worsening of the blood triglyceride and cholesterol levels and increased blood vessel inflammation.”
Another study, published in BMC Medicine in 2023, also found a strong link between sugar intake and heart disease. The study looked at the eating habits and health of more than 110,000 people in the United Kingdom. The main finding: Each 5% increase in added sugar as a percentage of total calories in the diet increased the risk of heart disease by 6% and the risk of stroke by 10%.
And a recent review of studies on sugar’s impact on heart health, published in the Journal of the American College of Cardiology, confirms that consuming added sugar is associated with a significant increase in the risk of heart disease, even if you have a normal body weight and an otherwise healthy diet. Most added sugar comes from soda and other sugar-sweetened drinks, the authors note.
How to Limit Sugar in Your Diet
If you’ve got a major sweet tooth, cutting back on sugar is like telling a caffeine addict to forgo their morning cup of coffee: Not easy. Focus on the positives. Remind yourself that your efforts will help you protect your heart. “It’s all about readiness to make positive changes,” says Dr. Orringer.
It’s not necessary to swear off all sugary treats, but Dr. Ascher says moderation is critical. You’ve probably heard that before, and wonder: What exactly does moderation look like? The American Heart Association (AHA) recommends that most women limit added sugars to six teaspoons (a teaspoon of sugar equals 4 grams) or less per day. Most men should consume no more than nine teaspoons daily. For reference, a typical piece of frosted chocolate cake has about 55 grams of sugar, or more than 13 teaspoons. So if you’re feeling like cake, you might want to share it!
Note that sugar can appear under various names on food labels, including some with a faux health halo. Aside from regular sugar, look for brown rice syrup, honey, molasses, agave, and coconut sugar, as well as corn syrup and high-fructose corn syrup. All of these are added sugars, no different to your body than plain old white sugar. Either way, the nutrition label will break out total sugar grams as its own line item, no matter its source. It’s a good idea to check the label even (or especially) on foods that seem to be healthful, like protein bars and cereals. These can pack quite a lot of added sugar. If a product you’re eyeing turns out to be a sugar-bomb, look for a no- or low-sugar alternative.
Remember: Sugary drinks are the most common source of added sugar. If you drink a lot of soda or other sugar-sweetened beverages, make some substitutes, suggests Dr. Ascher. Swap a can of unsweetened sparkling water for a can of soda or sweetened fruit-flavored drink. Diet soda is an option too, though some research has suggested that people who eat foods and drinks with zero-calorie sweeteners end up compensating for the calories they saved by eating more later in the day. (The evidence overall is mixed, and the AHA says such sweeteners can be part of a healthy diet.)
You may also want to limit how much 100% juice you drink. Even though it does not have added sugar, it still has a lot of (natural) sugar and calories per volume. For example, a glass of orange juice has 23 grams of sugar. To cut the sugar and calories, try diluting your juice with some water (plain or sparkling), or add a bit of fresh fruit to your water for flavor, Dr. Ascher recommends.
It can be helpful to work with a registered dietitian nutritionist, who can help you cut excess sugar from your diet plus coach you on other dietary changes. Consider asking your doctor for a referral to one, especially if you have already been diagnosed with heart disease, Dr. Orringer suggests.
And above all, he says, don’t give up if you fall into old habits occasionally. Few people do a perfect job of avoiding sweets, and you shouldn’t expect to.
“Small steps are better than no steps,” says Dr. Orringer. “Attention to eating high quality foods 90% of the time with occasional consumption of less healthy foods on special occasions is probably the approach that will work best for most people.”