Xylitol

Xylitol, also called wood sugar or birch sugar, is a five-carbon sugar alcohol that is used as a sugar substitute. It can be extracted from birch, raspberries, plums, and corn, which is primarily imported from China and is the most popular source due to its potential renewability, unlike birch trees.

Xylitol, gram for gram, is roughly as sweet as sucrose, but contains 40% less food energy. Its formula is C₅ H₁₂ O₅, with relative mass 152.15 amu.

It is very popular in Finland, which is considered its "home country". Many Finnish confectioneries employ xylitol, or have a xylitol version available. In 2004, Trident gum was reformulated to include xylitol.

Medical applications

Dental care

Xylitol is a toothfriendly sugar substitute. In addition to discouraging tooth decay by replacing dietary sugars, xylitol may actively aid in repairing minor cavities caused by dental caries. Recent research confirms a plaque-reducing effect and suggests that the compound, having some chemical properties similar to table sugar, attracts and then "starves" harmful micro-organisms, allowing the mouth to remineralize damaged teeth with less interruption. (However, this same effect also interferes with the yeast micro-organism and others, so xylitol is inappropriate in making bread, for instance.) The United States Army, acting on this data, will soon pack xylitol-sweetened gum in MREs (meals ready to eat). [1]

Diabetes

Possessing approximately 40% less food energy, xylitol is a low-calorie alternative to table sugar, and is absorbed more slowly than sugar; thus it doesn't contribute to a rapid rise in blood sugar level and the resultant insulin response.

Osteoporosis

Xylitol also appears to have potential as a treatment for osteoporosis. A group of Finnish researchers have found that dietary xylitol prevents weakening of bones in laboratory rats, and actually improves bone density.^1,²

Ear infection

Studies³ [2] have shown that xylitol chewing gum can help prevent ear infections (acute otitis media); the act of chewing and swallowing assists with the disposal of earwax and clearing the middle ear, whilst the presence of xylitol prevents the growth of bacteria in the eustachian tubes which connect the nose and ear. [3]

Health concerns

Xylitol, like most sugar alcohols, can have a mild laxative effect at high doses. It has no known toxicity, though; people have consumed as much as 400 grams daily for long periods with no ill effects. For canines, however, xylitol can cause serious – possibly life-threatening – problems. Dogs ingesting large amounts of products sweetened with xylitol may have a sudden drop in blood sugar, resulting in loss of coordination, depression and seizures within 30 minutes of consumption. [4]

References

¹ Mattila PT, Svanberg MJ, Jämsä T, Knuuttila ML (2002). Improved bone biomechanical properties in xylitol-fed aged rats. Metabolism 51(1):92-6. (online abstract)
² Mattila, PT (1999). Dietary xylitol in the prevention of experimental osteoporosis: Beneficial effects on bone resorption, structure and biomechanics. Dissertation, Institute of Dentistry, University of Oulu. (online)
³ Uhari M, et al. (1998). A novel use of xylitol sugar in preventing acute otitis media. Pediatrics, 102(4): 879–974.