Evaluation of safety of inulin and oligofructose as dietary fiber

Regul Toxicol Pharmacol. 1999 Dec;30(3):268-82. doi: 10.1006/rtph.1999.1349.


In the United States, most individuals consume far less dietary fiber than the daily value (DV) set at 25 g. The average daily consumption for inulin and oligofructose is estimated to be between 1 and 4 g in this country, with a higher intake of 3 to 11 g seen in Europe. Inulin and oligofructose are soluble, fermentable dietary fibers, of low net caloric value having many of the possible health benefits attributed to fiber. Such fiber consists of poly- and oligomers of fructose joined by beta(2-->1) fructosyl-fructose bonds. This class of fiber has been studied in a series of standard toxicological test systems. The studies have demonstrated that inulin-type fructans, when administered in the diet at high levels, do not result in mortality, morbidity, target organ toxicity, reproductive or developmental toxicity, or carcinogenicity. Several in vitro studies have also shown the absence of mutagenic or genotoxic potential. The only basis for limiting use of such fiber in the human diet relates to gastrointestinal tolerance. A series of clinical studies has been reported which shows that up to 20 g/day of inulin and/or oligofructose is well tolerated. As foods marketed in the United States bear labels stating both the quantity per serving size and the corresponding percentage of the daily value (% DV) of fiber, consumers can make appropriate choices and decisions about daily consumption without exceeding individual tolerance.

Publication types

  • Review

MeSH terms

  • Animals
  • Dietary Fiber / adverse effects*
  • Humans
  • Inulin / adverse effects*
  • Mice
  • Oligosaccharides / adverse effects*
  • Randomized Controlled Trials as Topic
  • Rats


  • Dietary Fiber
  • Oligosaccharides
  • oligofructose
  • Inulin