Is a fiber supplement right for you?
Fiber is a type of complex carbohydrate that the human body cannot digest. Instead of breaking down into sugar molecules called glucose, it instead passes through the body undigested. Fiber helps regulate the body’s use of sugars, helps feed and support the beneficial bacteria in the large intestine and helping to keep hunger and blood sugar in check.
The Food and Nutrition Board of the US Institute of Medicine recommends a total daily fiber intake of 38 g/day for men and 25 g/day for women. However, the average American consumes only about 17 g/day of dietary fiber, and dietary fiber intake might be closer to 10 g/day in those following a low-carbohydrate diet.
Types of Fiber
Fiber comes in two varieties, both are beneficial to health:
Soluble fiber, dissolves in water and includes plant pectin and gums. As soluble fiber dissolves, it creates a gel that may improve digestion. Foods with soluble fiber include oatmeal, chia seeds, nuts, beans, lentils, apples and blueberries.
Insoluble fiber, which does not dissolve in water, can help food move through your digestive system by bulking up bowel movements, promoting regularity and helping prevent constipation. Foods with insoluble fibers include whole wheat products (especially wheat bran), quinoa, brown rice, legumes, leafy greens, nuts, seeds and fruits like pears and apples. Many foods have both soluble and insoluble fibers.
What are the benefits of fiber?
Soluble fiber
Lowering cholesterol: Soluble fiber prevents some dietary cholesterol from being broken down and digested. Over time, soluble fiber can help lower cholesterol levels in the blood. Aim for five to 10 grams or more of soluble fiber a day for cholesterol lowering benefits. β-glucan (found in oat bran), raw guar gum, and psyllium are the types of fiber shown to lower cholesterol.
Stabilizing blood sugar (glucose) levels: Soluble fiber slows down the digestion rate of other nutrients including carbohydrates. This means meals containing soluble fiber are less likely to cause sharp spikes in blood sugar levels.
Lowering blood pressure: A 2018 meta-analysis of 22 randomized control trials found an overall reduction in blood pressure in people using fiber supplements or diets enriched with soluble fiber. Further analyses showed that psyllium in particular could reduce systolic blood pressure.
Reducing the risk of cardiovascular disease: By lowering cholesterol levels, stabilizing blood sugars, lowering blood pressure, and decreasing fat absorption, regularly eating soluble fiber may reduce the risk of heart disease and circulatory conditions.
Feeding healthy gut bacteria: Some soluble fiber-rich foods benefit our microbiome. They act like fertilizers that stimulate the growth of healthy bacteria in the gut.
Insoluble fiber
Preventing constipation: As an indigestible material, insoluble fiber moves through the gastrointestinal tract absorbing fluid and sticking to other byproducts of digestion that are ready to be formed into stool. Insoluble fiber speeds up the movement and processing of waste, helping the body optimize normal elimination and reduce constipation.
Lowering the risk of diverticular disease and cancer: By preventing constipation and intestinal blockages, insoluble fiber helps reduce the risk of developing small folds and hemorrhoids in the colon. It may also reduce the risk of colorectal cancer.
Both Soluble and insoluble fiber
Feeling satiated or full longer after meals: Soluble fiber slows down how quickly foods are digested, meaning most people feel full longer after fiber-rich meals. Insoluble fiber physically fills up space in the stomach and intestines, furthering the sensation of being full. These properties can help people manage their weight.
Helping lower disease risk: Due to fiber’s many health benefits, a high-fiber diet is associated with a lower risk of many diseases, including obesity, cardiovascular disease, diabetes, metabolic syndrome and others.
Where to find fiber naturally
Good food sources of fiber include whole grains, whole fruit and vegetables, legumes, nuts and seeds.
Some Food Sources of Dietary Fiber Linus Pauling Institute Oregon State University
Types of fiber supplements:
β-Glucans
β-Glucans are soluble fibers found naturally in oats, barley, mushrooms, yeast, bacteria and algae. β-Glucans extracted from oats, mushrooms, and yeast are available in a variety of nutritional supplement capsules without a prescription.
Glucomannan
Glucomannan, sometimes called konjac mannan, is classified as a soluble fiber isolated from konjac flour. Glucomannan is available as powder and in capsules, which should be taken with plenty of liquids.
Pectin
Pectins are soluble fibers most often extracted from citrus peels and apple pulp. Recipe for pectin-rich stewed apples.
Inulins and oligofructose
Inulins and oligofructose, extracted from chicory root are used as food additives. They are also classifies as prebiotics because of their ability to stimulate the growth of potentially beneficial Bifidobacteria species in the colon. Inulin is produced by many plants and is composed mainly of fructose. A number of dietary supplements and packaged “high fiber foods” containing inulins and oligofructose.
Guar gum
Raw guar gum is used as a thickener or emulsifier in many food products. Dietary supplements containing guar gum have been marketed as weight-loss aids, but there is no evidence of their efficacy. Unlike guar gum, partially hydrolyzed guar gum (PHGG, Sunfiber) has no effect on serum cholesterol or blood sugar levels. However, PHGG is a low FODMAP fiber and is less likely to trigger bloating or cramping in people with irritable bowel syndrome.
Psyllium
Psyllium, a soluble, gel-forming fiber isolated from psyllium seed husks, is available without a prescription in laxatives, ready-to-eat cereal, and dietary supplements. Psyllium (the main component of Metamucil) is proven to be effective to lower serum cholesterol and improve blood sugar balance. Because it also normalizes stool form, psyllium is the only fiber recommended by the American College of Gastroenterology to treat chronic constipation and irritable bowel syndrome.
Wheat Dextan
Wheat dextrin (Benefiber) is a form of wheat starch. The manufacturers considers it gluten-free because it contains less than 20 parts per million (ppm) of gluten. However, people with gluten intolerance or celiac disease should not use Benefiber unless directed by a doctor.
Polycarbofil
Polycarbofil (Fibercon) is a synthetic polymer that is used as stool stabilizer to treat constipation, diarrhea and abdominal discomfort.
Methylcellulose
Methylcellulose (Citrucel) found in fiber supplements is a synthetic product derived from cellulose. Methylcellulose is not broken down and digested in the intestines, but rather absorbs water and becomes gel-like to add bulk to the stool. Because methylcellulose does not ferment, it may cause less gas and bloating in some individuals.
Polydextrose
Polydextrose is a complex carbohydrate made from glucose. It is made in a lab and is not digested by the body. Polydextrose is often used as a prebiotic to support the growth of beneficial bacteria in the microbiome.
**Do not take fiber supplements within 1 hour of other medications or some supplements including calcium, iron, and zinc. Fiber can interfere with absorption.