Do All Fiber Supplements Lower Cholesterol Levels?


Fiber is an important part of any healthy diet. Although fiber is mostly known for improving digestive health, studies have also shown that certain types of fiber can also help lower your cholesterol levels.

Types of Fiber

There are two types of fiber that are incorporated into various fiber supplements: soluble and non-soluble fiber. Soluble fiber can be further divided into two types: nonviscous and viscous.

Viscous, soluble fiber becomes a thick gel when it comes in contact with liquids in the digestive tract. Due to this characteristic, this viscous, soluble fiber can bind to cholesterol in the small intestine, preventing its absorption into the bloodstream and allowing it to be eliminated in the feces. Insoluble fiber and nonviscous, soluble fiber do not possess the ability to bind to cholesterol in the small intestine.

Fiber supplements are available over the counter in your local pharmacy, grocery store, or health foods store in the form of a tablet or powder. Two types of supplements containing soluble fiber have studies supporting their effectiveness in slightly reducing LDL cholesterol levels, whereas other types of widely-available fiber supplements may not be as effective in lowering your cholesterol.

Fiber Supplements That Work

  • Psyllium (Products: Konsyl, Metamucil, various store brands) - Psyllium is a type of viscous, soluble fiber found in a variety of whole grain foods, but is also found in supplements such as Konsyl and Metamucil. Psyllium has been the most extensively studied soluble fiber, either administered alone as a supplement or included in a variety of grains. Studies have shown that doses anywhere between 5 and 15 grams per day were able to lower LDL levels between 5 and 20%. Triglyceride and HDL levels were not significantly affected in these studies.
  • Methylcellulose (Products: Citrucel, various store brands) - Methylcellulose is a modified form of cellulose, and is found in fiber supplements such as Citrucel. This viscous, soluble fiber does not have as many studies supporting its use for lowering cholesterol as psyllium. However, the few studies that have examined methylcellulose state that an average of 5 gram per day could reduce LDL cholesterol levels by about 8%. HDL and triglyceride levels did not appear to be affected in these studies, either.

    Fiber Supplements That May Not Lower LDL

    There are other soluble fiber supplements that do not have studies in place to support their use in lowering cholesterol levels, but can still be used for digestive health. This includes:

    • Polycarbophil (Products: FiberCon, FiberLax, various store brands) - Polycarbophil is a viscous form of soluble fiber, but studies have not been able to show that it can lower LDL cholesterol in comparison to psyllium and methylcellulose.
    • Wheat Dextrin (Products: Benefiber, various store brands) - Wheat dextrin is a nonviscous form of soluble fiber. It is not able to form a gel-like material within the small intestine, and therefore cannot bind cholesterol.

    Using Fiber Supplements

    The American Heart Association recommends consuming at least 25 grams of fiber daily. If you are unable to get enough fiber into your diet, taking a supplement may seem like a good solution to including diet. However, you should not exclusively rely on supplements to supply fiber into your diet.

    There are plenty of delicious, fiber-rich foods that you can incorporate into your diet that not only supply you with the fiber you need - they can also introduce additional vitamins and other nutrients to your meals. 

    Ways to Include Fiber-Rich Foods in Your Cholesterol-Lowering Diet

    You should always consult with your physician before adding fiber to your cholesterol-lowering regimen.

    When using fiber supplements, you should follow the directions on the packaging. Fiber supplements should be taken with a whole glass of water in order to prevent choking. The doses should be divided throughout the day in order reduce some of the gastrointestinal side effects associated with taking fiber, such as abdominal cramping and bloating.

    Signs that You Are Getting Too Much Fiber in Your Diet

    Unless otherwise stated by your physician or pharmacist, you should not take fiber supplements around the same time as you take certain vitamins and other medications, since fiber may lower their effectiveness.


    Anderson JW, Baird P, Davis RH et al. Health benefits of dietary fiber. Nutr Rev 2011;64:188-205.

    Chutkan R, Fahey G, Wright WL et al. Viscous versus nonviscous soluble fiber supplements: Mechanisms and evidence for fiber-specific health benefits. J Am Acad Nur Pract 2012;24:476-487.

    Whole Grains and Fiber. American Heart Association Website. Accessed June 13, 2016.

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