Written By: Owennie Lee, RD
Last Updated on:
With the recommended intake of fiber between 25 and 38 grams per day, many of us may feel we have to resort to fiber supplements to even come close to the target. But you may want to ask yourself what benefits of fiber you are really after before shelling out your money, because not all fiber supplements are the same.
Fiber Supplements 101
A survey of the most popular fiber supplements in the marketplace reveals that they are almost always made up of a single type of soluble fiber. One tablespoon of these supplements typically has 3-4 grams of fiber. Most soluble fibers can help alleviate constipation by holding on to water in the digestive tract, making stools softer and easier to pass. Certain types of soluble fiber that are viscous (e.g., beta-glucan, pectin, and psyllium) have also been proven to help lower blood cholesterol. Insoluble fibers, although they can help with constipation, are almost never found in fiber supplements because they don’t dissolve in water, making them difficult to take.
Common Types of Fiber Found in Supplements
- Psyllium (e.g., Metamucil) is a viscous, soluble fiber that is the most common fiber source in supplements. Psyllium’s cholesterol-lowering ability has earned the FDA’s approval, allowing foods containing psyllium to make a health claim about reducing risk of heart disease. However, a major disadvantage of psyllium is that it thickens rather quickly and may not be as easy to incorporate into beverages. Psyllium is also fermented by bacteria in the colon and can cause bloating and flatulence.
- Inulin (e.g., Fiber Choice and Benefiber in Canada) is a non-viscous, soluble fiber that is also known as a prebiotic. It is extracted from foods such as chicory root. Aside from fiber supplements, inulin is also being added to myriad food products, such as yogurt and bread, to boost fiber content. Inulin is tasteless, colorless, odorless, and textureless, making it extremely easy to incorporate into foods and beverages. However, inulin is not effective in reducing cholesterol, nor does it offer much help with regularity. In addition, the fermentation of inulin produces more hydrogen and total gas than psyllium and wheat dextrin, according to a study published in January 2010 by a group of University of Minnesota researchers.
- Wheat Dextrin (e.g., Benefiber in the U.S.) is another type of non-viscous, soluble fiber that is considered a bulk-forming laxative. Since it is non-viscous, it does not form a gel in the digestive tract that binds with cholesterol, rendering it ineffective in lowering blood cholesterol. It is fermented in the colon to produce gas.
- Methylcellulose (e.g., Citrucel) is a viscous, soluble fiber that is a derivative of cellulose. Its manufacturers claim that because it is not fermented in the colon, methylcellulose tends to cause less bloating and flatulence.
Fiber from Food vs. Fiber Supplements
Isolated fibers, such as those found in fiber supplements, don’t perform the same as fiber from food. With food, not only do you get a combination of insoluble and soluble fibers, you also get all the other nutrients that foods have to offer. Some stellar choices that combine great nutrition and high fiber include lentils (1/2 cup delivers 7.8 grams of fiber) and oat bran cereal (5.7 grams per 1/2 cup). In addition, the old-fashioned prune has actually been proven to be more effective in promoting regularity than psyllium, according to a study published in April 2011 by a group of researchers from the University of Iowa Carver College of Medicine.
The Bottom Line
Including more high-fiber foods in your diet is certainly the way to go if you want to hit the recommended fiber intake. If you decide to take fiber supplements, select the type that provides the benefits that you are after. Different products under the same brand name may contain different sources of fiber, so be sure to check the ingredients list. With all fiber supplements, start slowly to let your system adjust, and drink plenty of water because otherwise they can cause choking or blockage of your digestive tract.
Owennie is a registered dietitian with a soft spot for chocolate and coffee. She is a believer in balance and moderation, and is committed to keeping healthy eating enjoyable and fun. Owennie received her dietetics training in Vancouver, and is a member of Dietitians of Canada and the College of Dietitians of British Columbia. She has experience in a wide variety of settings, such as clinical nutrition, long-term care and outpatient counseling. Owennie has also worked for a community nutrition hotline and participated regularly as a guest radio host, where she enjoyed sharing her passion and knowledge about food and nutrition with people.