According to a January 2010 review in "The Journal of the American Medical Association," over two-thirds of Americans are either overweight or obese, which significantly increases their risks for heart disease and diabetes. In an effort to ameliorate this risk, the American Heart Association has disseminated lifestyle guidelines, which include a heart-healthy diet. The daily consumption of fiber is one important component of the AHA's recommendations.
Metabolic Syndrome
The precursor for both diabetes and heart disease is a constellation of physiologic abnormalities known as metabolic syndrome. High blood pressure, increased waist circumference, insulin resistance and dyslipidemia, manifested by a high triglyceride level or a low HDL level, characterize metabolic syndrome; if you exhibit any three of these characteristics, you have metabolic syndrome. A June 2004 review in "American Family Physician" outlined the various harmful effects of metabolic syndrome including increased inflammation, abnormalities in blood vessel walls and an increased tendency for blood clotting.
Fiber and Metabolic Syndrome
According to a September 2010 article in the "Journal of Clinical Gastroenterology," dietary fiber can favorably modify several factors that contribute to metabolic syndrome. Fiber slows the absorption of glucose from your diet and decreases blood glucose levels following your meals. Lower blood glucose levels mean lower insulin levels, which helps to reduce your blood pressure. Fiber can also help increase HDL levels and lower total cholesterol and triglyceride levels -- all desirable changes.
Types of Fiber
Not all dietary fiber is the same. Water-soluble fiber, which can be metabolized by gut organisms into physiologically active byproducts, is more effective for reducing blood sugar, insulin levels and cholesterol than insoluble fiber, which simply absorbs water and adds bulk to your stool. Fruits, vegetables, whole grains, tubers and legumes often contain both types of fiber. Psyllium and beta glucan from oats and barley are good sources of water-soluble fiber. The AHA recommends that you consume 4 to 5 servings of fruits and vegetables and the equivalent of three 1-ounce servings of whole grains daily.
Considerations
Increasing the consumption of fruits, vegetables and whole grains is a lifestyle change that nearly anyone can adopt. If you have irritable bowel syndrome, an inflammatory bowel disease, such as ulcerative colitis or celiac disease, talk with your doctor before you make any radical changes in your diet. Likewise, if you take prescription drugs, keep in mind that dietary fiber can interfere with the absorption of your medications. Consult with your physician or pharmacist about interactions between your prescriptions and dietary fiber.
References
- "The Journal of the American Medical Association"; Prevalence and Trends in Obesity Among US Adults, 1999 -- 2008; K. Flegal, et al.; January 2010
- American Heart Association; Nutrition Center: Healthy Diet Goals; 2011
- "American Family Physician"; Metabolic Syndrome: Time for Action; D. Deen; June 2004
- PubMed.gov: The Right Fiber for the Right Disease: An Update on the Psyllium Seed Husk and the Metabolic Syndrome; A. Giacosa, M. Rondanelli; September 2010
