Not all carbohydrates are equal -- especially when it comes to their effect on cholesterol. Some carbohydrates raise cholesterol, while others lower it. You find carbohydrates in breads, cereals, grains, milk, yogurt, fruits, vegetables, and foods that contain added sugars. All carbs are converted into glucose -- which is also known as blood sugar -- in the body and carbs can be used immediately for energy or stored for later use. Research suggests that the quantity and type of carbohydrates consumed can affect cholesterol.
Cholesterol and Triglycerides
Cholesterol is in the fats in your blood. High cholesterol is the buildup of these fats, which can lead to heart disease or stroke. Two types of cholesterol exist: LDL, which is also known as low-density lipoprotein and HDL, which is also known as high-density lipoprotein. LDL is the "bad" cholesterol, because it causes a buildup of plaque in the arteries. HDL is the "good" cholesterol, because it helps the body get rid of excess LDL in the blood by carrying it away from the organs to the liver, so that it can be removed. Triglycerides are another type of fat found in the blood, and high triglyceride levels also increase the risk for heart disease.
Research on Carbs and Cholesterol
Carbohydrate consumption from refined carbohydrates that are high in sugar and low in fiber such as cookies and cakes, is associated with lower levels of HDL and higher levels of LDL and triglycerides, which is associated with an increased risk for heart disease. Very high carbohydrate intakes of more than 60 percent of total calories -- along with excess sugar consumption -- are associated with an increase in triglycerides, according to the National Heart, Lung and Blood Institute. A 2005 OmniHeart study by Johns Hopkins Medical Institutions compared three diets that emphasized either protein, monounsaturated fat or carbohydrate and found that the protein and monounsaturated fat diets were more effective in reducing the risk factors for heart disease than the high-carbohydrate diet.
Breaking Down the Carbohydrates
A food's glycemic index -- which is how fast it increases blood sugar -- may affect your cholesterol. The glycemic index of a food depends upon a handful of factors, including the type of starch, fiber content and fat content of that food. For example, a refined or processed food such as white bread, has a higher glycemic index than whole-wheat bread. Additionally, ripe foods tend to have more sugar, while lower fat foods digest faster and cause blood sugar to rise more rapidly, causing them to have a higher glycemic index. In general, whole grains, beans, fruits and vegetables are not only healthy but also have a low glycemic index. Women who eat a high-glycemic index diet are more than twice as likely to develop heart disease, according to a 2010 study published in the "Archives of Internal Medicine."
Soluble Fiber Plays a Role
Although refined carbohydrates may raise your cholesterol, healthier carbohydrates with whole grains and fiber can help lower your cholesterol. The beneficial effects of a low-glycemic diet that contains whole grains may because of its high-fiber content. In particular, soluble fiber has been shown to block cholesterol and fats from absorption, thus lowering the LDL cholesterol. Foods high in soluble fiber include kidney beans, oatmeal, barley, pears, apples and prunes. Aim for five to 10 grams of soluble fiber each day to lower your total cholesterol and your LDL cholesterol. For example, it is possible to meet this goal if you have half a cup of oatmeal for breakfast, half a cup of kidney beans for lunch, one apple for a snack and one medium artichoke with dinner.
To improve your cholesterol, eat only a moderate amount of carbohydrates. Everyone has individual requirements, but it can be helpful to have less than 60 percent of your calories come from carbohydrates. Choose carbohydrates that have whole grains, are high in fiber and low in sugar, and include fruits and vegetables. Try replacing unhealthy, high-glycemic carbohydrates -- such as chips or cookies -- with either whole grains or healthy fats, such as nuts or guacamole.
- Centers for Disease Control and Prevention: Carbohydrates
- Diabetes.org: All About Cholesterol
- CDC Nutrition Information for Professionals: Dietary cholesterol.
- JAMA: Caloric Sweetener Consumption and Dyslipidemia Among U.S. Adults
- NIH: Replacing Some Carbohydrates With Protein and Unsaturated Fat May Enhance Heart Health Benefits
- American Heart Association: Triglycerides: Frequently Asked Questions
- Science Daily: Women Who Eat Foods With High Glycemic Index May Be at Greater Risk for Heart Disease
- DrMirkin.com: Carbohydrates and HDL Cholesterol