Restricting intake of saturated and trans fats as well as cholesterol in the diet are common recommendations for lowering high blood cholesterol. However, it should also be noted that carbohydrates, or sugar, can also have a deleterious impact on your cholesterol levels. In fact, there is evidence that you can show a significantly greater improvement in your lipid profile by reducing the amount of carbohydrate than by consuming a low-fat diet.
Mechanism
A review published in "Lipids" in 2010, found several studies linking low-carbohydrate diets and improved lipoprotein profiles. These studies reported cholesterol levels were improved by either lowering dietary carbohydrate content or losing weight. An article published in 2006 in "Nutrition & Metabolism" suggests this is due to the effects carbohydrate restriction has on insulin. Insulin is produced and circulated throughout the body when blood glucose levels are high, to encourage cells to take up the extra glucose and also encourages lipid production. Restricting carbohydrate intake, changes the metabolic regulation of fat and decreases the amount circulating in the blood.
Intake Levels
A study published in the April 2005 edition of the "Journal of Nutritional Biochemistry" found that among premenopausal, overweight women, those consuming a diet consisting of less than 53 percent of calories from carbohydrates had lower LDL-C than those consuming a diet with more than 53 percent of calories from carbohydrates. The researchers note subjects consuming fewer carbohydrates also consumed more cholesterol and fat, specifically greater amounts of mono- and poly-unsaturated fats, while those in the high carbohydrate group took in more glucose and fructose. The study suggested that changes in cholesterol profile may be related to the amount of carbohydrate as well as the type of fat consumed.
Lipid Profile
To decrease risk of heart disease, total cholesterol levels should be below 200 mg/dL, low-density lipoprotein cholesterol, or LDL-C, below 100 mg/dL, high-density lipoprotein cholesterol, or HDL-C, above 40 mg/dL and triglyceride levels below 150 mg/dL. Lifestyle changes such as increasing exercise and improving diet are recommended to improve cholesterol levels and decrease disease risk.
Dietary Guidelines
The Therapeutic Lifestyle Changes diet guidelines recommend getting 50 to 60 percent of your total calories from healthful, fiber-filled whole grain carbohydrates as these foods provide the maximum nutrients. Include oats, barley, legumes, fruits and vegetables, brown rice, whole grain breads and pasta. Avoid highly processed white flour breads, pasta and dessert. Diets should contain less than 7 percent total calories from saturated fat, which is found primarily in fatty cuts of meat, poultry skin, lard, butter and whole milk, desserts, fried and fast foods. Trans fat, the fat used in many processed foods, should be avoided as research has shown cholesterol-raising effects. The diet suggests increasing healthy unsaturated fats to up to 30 percent of your total calories to reduce total and LDL cholesterol. These fats are found in vegetable oils, nuts, avocados and olives.
References
- "Lipids"; Atherogenic Dyslipidemia: Cardiovascular Risk and Dietary Intervention; Kiran Musunuru; October 2010
- "Nutrition and Metabolism"; Low Carbohydrate Diets Improve Atherogenic Dyslipidemia Even in the Absence of Weight Loss; Richard D Feinman, et al.; June 2006
- "Cholesterol"; Dietary, Anthropometric, and Biochemical Determinants of Plasma High-Density Lipoprotein- Cholesterol in Free-Living Adults; Erick Prado De Oliveira, et al.; 2011
- "The Journal of Nutritional Biochemistry"; Carbohydrate Intake is Correlated with Biomarkers for Coronary Heart Disease in a Population of Overweight Premenopausal Women; I.E. Lofgren; April 2005
- Cleveland Clinic: Nutrition- Cholesterol Guidelines
