You may know fats in your blood, called lipids, are bad for your heart. But did you know sugar can also be bad for your heart? Read on to learn how your sweet tooth can have a negative effect on your cholesterol count.
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How Sugar Affects Cholesterol
"Sugar can increase your cholesterol and your risk for cardiovascular disease, but it depends on the type of sugar," explains Kevin Boblick, MD, a Chicago-area internal medicine doctor specializing in cholesterol, hypertension and diabetes at the Loyola University Medical Center.
"The sugar that you want to avoid is refined and added sugar, not healthy, complex sugars found in fruits, vegetables and whole grains."
As the Cleveland Clinic explains it, when you eat too much sugar, your body uses the hormone insulin to move sugar out of your blood and into your cells. If you eat more sugar than you can use for energy, the sugar gets stored as fat. A sugar-filled diet also causes your liver to make more low-density protein ( LDL) cholesterol, the bad type, and less high-density lipoprotein (HDL) cholesterol, the good kind, says Cleveland Clinic.
Not all sugars have the same effect, however. According to the Harvard T.H. Chan School of Public Health, the worst offender is what's known as simple sugar, or refined sugar — the type you use to sweeten food or drink. Because it's easy to digest, it can cause your blood sugar (glucose) to rise very quickly.
By comparison, complex sugars (often called complex carbohydrates) take longer for you to digest, so sugar is released more gradually into your bloodstream, avoiding a spike or sudden sugar high. This is the type of sugar that occurs naturally in some foods, such as whole grains and vegetables.
How Sugar Affects Triglycerides
Triglycerides are another way that sugar can negatively affect your cholesterol and heart health.
According to the Mayo Clinic, if you consume more calories than you can use, which can happen if your diet includes a lot of high-carbohydrate foods, your body converts those calories into triglycerides, which are a type of lipid found in your blood. Simple carbs — simple sugars — are easily converted into triglycerides, and so is alcohol, which is high in calories and sugar, Mayo says.
If your triglyceride level gets too high, it increases your risk for heart disease. That's because as your triglyceride level goes up, your HDL cholesterol level goes down, and it's higher levels of HDL that help keep your risk for heart disease in line, explains Harvard Health Publishing.
Ways to reduce your triglyceride levels, advises Mayo Clinic, include avoiding refined sugar and carbs, limiting alcohol, choosing healthier fats and exercising.
Sugar and Metabolic Syndrome
"Simple sugars are converted to fat, which contributes to metabolic syndrome, another risk factor for heart disease," Dr. Boblick says. The National Heart, Lung and Blood Institute (NHLBI) explains that metabolic syndrome is a grouping of risk factors, including having high blood sugar, that can collectively increase your risk for heart disease, stroke and diabetes.
To be diagnosed with metabolic syndrome, you need to have at least three of five risk factors, which, in addition to high blood sugar, are belly fat, high triglycerides, low HDL cholesterol and high blood pressure. Your risk for metabolic syndrome goes up with the number of risk factors you have, notes NHLBI.
Becoming more prevalent as adult obesity rates rise, metabolic syndrome may soon be a bigger risk for heart disease than smoking, the institute notes. The best ways to prevent metabolic syndrome, says NHLBI, is to make heart-healthy lifestyle changes that include managing stress, getting high-quality sleep, keeping a healthy weight with regular exercise and making heart-healthy food choices.
"When thinking about sugar and cholesterol, you need to see the forest, not the trees, and avoid getting caught up in numbers," Dr. Boblick says. "The key is moderation and eating healthy sugars."
One way to do this, according to the Harvard School of Public Health, is to understand the glycemic index, which is a ranking that indicates how fast your body converts the carbs or sugars in a food into glucose. Foods that are high on this index contain sugar that raises glucose levels quickly and are not considered heart-healthy. Foods low on the glycemic index contain carbs that are digested more slowly and are more heart healthy.
Harvard suggests that you stick to low glycemic sugars (bran cereals; fruits and vegetables like apples, oranges and carrots; beans and lentils; nuts; and skim milk; among others) and avoid high glycemic foods (such as baked potatoes and french fries, sugar-sweetened drinks, candy bars, white rice and white pasta).
Read more: 10 foods You Don't Realize Are Packed With Sugar
- Cleveland Clinic: “Why a Sweet Tooth Spells Trouble for Your Heart”
- Kevin Boblick, MD, internist, Loyola University Medical Center, Maywood, Illinois
- Harvard T.H. Chan School of Public Health: The Nutrition Source: “Carbohydrates and Blood Sugar”
- Mayo Clinic: “Triglycerides: Why Do They Matter?”
- Harvard Health Publishing: “Should You Worry About High Triglycerides?”
- National Heart, Lung and Blood Institute: “Metabolic Syndrome”
- National Heart, Lung and Blood Institute: “Heart-Healthy Living”