Is Inulin a Safe Fiber Supplement?

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You may not have heard of inulin, but you’ve probably consumed it in one of many processed foods that use this form of fiber to replace sugar and fat. Unlike a lot of artificial and chemical food additives, inulin occurs naturally in a variety of fruits and vegetables. As with any additive, there are often questions about its safety, but the FDA has added inulin to its list of GRAS foods, or those foods generally recognized as safe.


Inulin is a starchy carbohydrate found in fruits, vegetables and herbs including artichokes, onions, leeks, bananas and asparagus, while the intravenous medicinal form of inulin is often extracted from chicory root. Inulin isn’t digested or absorbed in your stomach, but passes on through to the intestinal tract where it boosts beneficial bacteria in improving bowel function. Food manufacturers add inulin to their products because it allows them to increase fiber content while decreasing calories.


As reported in the October 2010 issue of the “British Journal of Nutrition,” a group of healthy subjects who consumed 10 grams daily for three weeks of inulin extracted from artichoke had significantly higher levels of bifidobacteria and lactobacilli -- probiotic bacteria that help maintain the natural balance of organisms in your intestines. Researchers at the University of Reading in the UK gave obese subjects with high cholesterol 7 grams per day of inulin or a placebo over four weeks. Those results, published in June 2003 in “Revista Medica de Chile,” showed that the inulin reduced levels of total cholesterol and harmful LDL cholesterol as compared to those who received a placebo.

Gastrointestinal Effects

Although there haven’t been reports of any significant side effects from inulin, very high doses can cause gastrointestinal problems, as seen in healthy subjects given inulin supplements that led to nausea, excess gas, bloating, flatulence and diarrhea or constipation. The researchers in that study, which was published in the "Journal of the American Dietetic Association" in June 2010, found the subjects were generally able to tolerate 10 grams per day of natural inulin or 5 grams of a biochemically altered "sweet" inulin called oligofructose.


A 1999 survey in the “Journal of Nutrition” estimated that the daily consumption of inulin by people in both the United States and Europe peaked at around 10 grams, with a more typical intake of between 1 to 4 grams. The survey added that the safety of inulin for use in foods has been evaluated by many legal authorities worldwide and inulin is accepted in most countries as a food ingredient that can be used without restrictions in food manufacturing.

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