Inulin (not insulin) and oligofructose are found naturally in plants, and can also be synthesized. Inulin is a general term for fructose polymers. These are the compounds that there are two or more of the fruit sugar fructose. Oligofructose is a subtype of inulin. It is also called fructooligosaccharide, which is often abbreviated to FOS.
What are the potential benefits of inulin and FOS?
Different types of inulin and FOS have different levels of sweetness, though none are as sweet as sugar.
Inulins are not digested by most of the major enzymes in upper part of the gut, so most of it passes through to the lower part of the gut. The inulin is then digested by bacteria in the lower gut.
Since there is no significant digestion of inulin and FOS in the upper part of the gut there is little release of sugars, so they only cause a small increase in blood glucose. Therefore, some people recommend high inulin foods or artificial sweeteners using FOS for diabetics.
Inulin and FOS can also help with weight loss. They are considered low calorie and have about a quarter of the calories of sugars. Both can be used as a sweetener and their “starch-like” texture can be used to replace flour and sometimes fat in a range of foods. Inulin is found in a number of foods currently. Development of foods containing inulins is a very active area, so in the near future there is going to be a wide range of foods containing inulins and FOS.
There is preliminary evidence that inulins may help with regulation of appetite. Also a recent study suggests that FOS may lower blood pressure.
Inulins have also been shown to increase the absorption of calcium and magnesium in the gut, which is helpful for bone density. Research has shown that many of us are calcium and magnesium deficient.
Inulin is considered soluble fiber, so it can help with constipation and contribute to intestinal health, and possibly lower the risk of colon cancer. Since it does stimulate gut bacteria, it suggested that increasing intake of inulin and FOS should be done gradually, to minimize problems with gas.
Since inulin is used by bacteria in the lower gut it can be considered a form of probiotic, since it stimulates the growth of bacteria (intestinal flora), including bacteria such as Bifidobacteria which are considered “good” bacteria. Most types of probiotics that are available consist of high levels of bacteria that are considered beneficial. However, one problem is that these bacteria in drinks, yogurts, powders etc. have to survive the acid of the stomach and the enzymes etc, of the upper gut to make it to the lower gut. Inulin since it feeds the bacteria already in the gut is an alternative method.
Different plants have different amounts of inulin. Jerusalem artichoke (sunchoke, a member of the sunflower family – image is of sliced Jerusalem artichoke) has some of the highest levels. I am quite fond of Jerusalem artichoke and now have another good reason to eat them. Never tried them? They had a mild flavor. To try them, just scrub them well, slice them and then fry them and serve them as a side. There are tons of recipes on the web.
Other foods that contain significant levels of inulin and FOS are onion, garlic, banana, chicory and leeks.
