Ask the Expert: Inulin

Question: I’ve heard a lot about inulin. What is it and why should I be concerned about it?

Answer: You may have noticed inulin as an ingredient in products such as Stonyfield Farms yogurt, Weight Watchers cereals, Atkins Advantage nutrition bars and Fibersure fiber supplement. Inulin is a soluble dietary fiber found naturally in more than 35,000 plant foods such as chicory root, artichokes, asparagus, leafy green vegetables, onions, leeks, garlic, oatmeal, flax, barley, berries, bananas, and legumes. Most inulin that is present as an ingredient in foods or supplements is extracted from chicory root or synthesized from sucrose.

Inulin is a prebiotic—an indigestible substance in food that promotes the growth of normal healthful bacteria, including probiotics, in the large intestines. The word probiotics derives from the Greek term “for life.” The main function of prebiotics is to enhance the effects of these beneficial probiotics. Prebiotics and probiotics appear to work synergistically to maintain a healthy intestinal tract. They help the intestines keep out toxins and pathogens while allowing nutrients to be absorbed. If a food contains both prebiotics and probiotics, it is synbiotic.

Preliminary studies suggest that prebiotics may enhance the absorption of minerals, particularly calcium. Prebiotics might also be helpful in the treatment of irritable bowel syndrome and the management of bowel problems. Animal studies suggest prebiotics may play a role in the prevention of colon cancer. Inulin might prove to help lower blood cholesterol and triglycerides, but human studies are inconclusive.

In short, it is widely accepted that probiotics and prebiotics exert health benefits related to their interactions with the gastrointestinal tract. But further scientific research is needed to establish a direct relationship between these two functional food ingredients and disease risk reduction.

Inulin occurs naturally in foods, so it is considered to be a food rather than an additive. Because it has been part of man’s diet for centuries, it is assumed to be safe. However consuming large amounts (more than 10 to 20 grams per day) may cause flatulence. Although inulin is safe for the vast majority of people who have food allergies, there have been very few isolated cases of chicory allergy.

Should you try to incorporate a prebiotic like-inulin into your diet? Products like Stonyfield Farms' yogurt and Fibersure are good ways to get some extra inulin. But if you eat a healthy plant-based diet you are already getting inulin in the most ideal way: from fruits, vegetables, whole grains, and legumes. What does a healthy diet look like? Half of your lunch or dinner plate will be vegetables, one quarter will be whole grains, and no more than a quarter will be animal protein. Fruit and non-fat or low-fat dairy can be added on the side. Unlike inulin in processed foods and supplements, inulin in whole plant foods comes packaged with thousands of beneficial phytochemicals that are associated with lower rates of cancer and disease.

Marlene Lesson, MS, RD, LDN, CDE, is the nutrition director of Structure House, a residential weight loss facility in Durham, N.C. that offers a unique behavioral approach to weight loss and healthy lifestyle change. For information, visit www.StructureHouse.com or call 800-553-0052.