High blood cholesterol levels increase the risks of cardiovascular diseases, such as heart attack and stroke. Medical consensus is that total blood cholesterol above 200 mg/dL is in need of intervention, either pharmaceutically or through dietary changes. Diets high in fiber, especially soluble fiber, have the ability to lower blood cholesterol levels naturally and without the side effects of statin-type drugs.
Cholesterol
Cholesterol is a unique substance in that the body manufacturers it within the liver, but it is also a common component of many foods, especially animal-based varieties. Cholesterol is necessary for many bodily processes, including building and maintaining cell walls and synthesizing hormones. However, too much cholesterol can contribute to atherosclerosis, or clogged arteries from plaque formation. This in turn increases blood pressure, strains the heart and increases the risk of embolism or stroke. Cholesterol is composed of two main types: high-density lipoprotein -- or HDL -- considered the more beneficial type, and low-density lipoprotein -- or LDL -- considered more harmful.
Dietary Fiber
Dietary fiber includes all the parts of plant-based foods that the body cannot digest or absorb. Thus, it passes relatively intact through the stomach and intestines, but it plays important roles in maintaining health. Fiber is commonly classified as insoluble fiber, which does not dissolve in water, or soluble fiber, which dissolves in water to form a gel-like substance. Insoluble fiber promotes the movement of material through the intestines and increases fecal bulk, which benefits those suffering from constipation. Good sources of insoluble fiber include whole-wheat flour, wheat bran, nuts, many vegetables and some fruits. According to MayoClinic.com, soluble fiber is the type able to lower blood cholesterol and glucose levels. Good sources of soluble fiber include oats, peas, beans, citrus fruits, apples, carrots, barley and psyllium.
Soluble Fiber and Cholesterol
When soluble fiber turns into a sticky, gel-like substance within the body, it binds to cholesterol-rich bile. With the help of insoluble fiber, the bound components are efficiently transported out of the body. According to "Biochemical, Physiological and Molecular Aspects of Human Nutrition," while soluble fiber ferments in the intestines, a type of fatty acid is released that travels to the liver and stimulates it to produce less cholesterol, resulting in a reduction of total blood cholesterol levels. Soluble fiber also has a higher affinity for binding to LDL cholesterol.
Dietary Fiber Intake
Increasing dietary fiber intake is a good idea for most people, not just those with high cholesterol levels. According to "Contemporary Nutrition," daily requirements of dietary fiber are 25 g for women and 38 g for men. Reducing saturated fats found in animal fat, dairy products and fried foods is another aspect of cholesterol management. In addition to simply eating more fruits, vegetables and grains, you may follow these tips to increasing fiber intake: eat your fruits and vegetables raw and with the skin when possible; start your morning with a high-fiber breakfast; eat high-fiber snacks, such as popcorn; and drink more water, as fiber absorbs a lot of it as it travels through your digestive system.
References
- "Harrison's Principles of Internal Medicine"; A. Fauci, et al.; 2008
- MayoClinic.com: Dietary Fiber: Essential for a Healthy Diet; Mayo Clinic staff; November 2009
- "Biochemical, Physiological and Molecular Aspects of Human Nutrition"; Martha Stipanuk; 2006
- "Contemporary Nutrition"; Gordon M. Wardlaw; 2010
