Many people in the United States consume considerably less than fiber on a daily basis than they should. According to the University of California, the average American consumes 14 g of dietary fiber per day, which is less than half the recommended amount. A low fiber diet not only precludes the body from its positive health benefits, but it also contributes to the development of adverse health conditions.
Types of Fiber
Dietary fiber is derived from plants, but the body cannot absorb or digest it. Therefore, it travels through the digestive track and is excreted in the form of a solid. Fruits, vegetables, beans and whole grains are good sources of fiber. Dietary fiber can be either soluble or insoluble. Soluble fiber dissolves in water, whereas insoluble fiber does not. Beans, peas, carrots, apples and citrus fruits contain soluble fiber. Many vegetables, wheat bran and nuts contain insoluble fiber.
Digestion
Different types of fiber have different effects on the body. Soluble fiber aids in the regulation of blood sugar levels. It also decreases the amount of low-density lipoproteins, or "bad" cholesterol. This is especially true of oats, oat bran and beans. Insoluble fiber plays a major role in digestion. It is responsible for moving material through the digestive system. Additionally, insoluble fiber increases stool bulk by retaining water, thereby alleviating tension within the colon. Tension within the colon increases the risk of diverticulitis. Insoluble fiber also prevents and alleviates constipation, as well as promotes regularity.
Health Benefits
Diets high in fiber aid in weight loss. Since fiber remains undigested in the stomach until it is excreted from the body, it results in a feeling of fullness. As a result, it can suppress appetite and curb cravings. According to the American Cancer Society, soluble fiber has been shown to reduce blood cholesterol levels, which in turn lowers the risk for heart disease. Unfortunately, there is only weak evidence to support the impact of fiber on susceptibility to cancer.
Mortality
The relationship of dietary fiber and mortality was the focus of a study published in the February 2011 issue of "Archives of Internal Medicine." This study looked at the deaths of a cohort of men and women, who participated in the National Institutes of Health's AARP Diet and Health Study over the course of nine years. The results indicated a strong relationship between dietary fiber intake and reduced risk of death. Specifically, researchers found that dietary fiber decreased the risk of death from cardiovascular, respiratory and infectious diseases in men and women.
References
- Mayo Clinic.com; Dietary Fiber Essential For a Health Heart; Nov. 19, 2009
- GICare.com: High Fiber Diet
- Center for Nutrition Policy and Promotion: Trends in Dietary Fiber in the U.S. Food Supply
- "Archives of Internal Medicine"; Dietary Fiber Intake and Mortality in the NIH-AARP Diet and Health Study; Y. Park, et al.; February 2011
- Colorado State University; Dietary Fiber; J. Anderson, S. Perryman, et al.; Dec. 2010
- American Cancer Society; Fiber; Oct. 31, 2008
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