Xylitol (from Greek ξύλον - xyl[on], "wood" + suffix -itol, used to denote sugar alcohols) is an organic compound with the formula (CHOH)₃(CH₂OH)₂. This achiral species is one of three isomers of 1,2,3,4,5-pentapentanol. This sugar alcohol is used as a naturally occurring sugar substitute found in the fibres of many fruits and vegetables, including various berries, corn husks, oats, and mushrooms. It can be extracted from corn fibre, birch, raspberries, plums, and corn. Xylitol is roughly as sweet as sucrose with only two-thirds the food energy.

Extraction of xylitol

Xylitol (Finnish ksylitoli) was first derived from Birch trees in Finland in the 20th century and was first popularised in Europe as a safe sweetener for people with diabetes that would not impact insulin levels. Today, using hardwood or maize sources, the largest manufacturer globally is the Danish company Danisco, with several other suppliers from China.

Properties

One teaspoon (5 mL) of xylitol contains 9.6 calories, as compared to one teaspoon of sugar, which has 15 calories. Xylitol contains zero net effective carbohydrates, whereas sugar contains 4 grams per 5 mL. Xylitol has virtually no aftertaste, and is advertised as "safe for diabetics and individuals with hyperglycemia". This is because sugar-alcohols have less impact on a person's blood sugar than regular sugars.

Dietary use worldwide

Xylitol is widely used in Finland, its "home country". Many Finnish confectioneries employ xylitol, or have a xylitol version available. Virtually all chewing gum sold in Finland is sweetened with xylitol.

The formerly Spanish company Chupa Chups, now Italian, makes a xylitol-based breath mint, Smint, that it markets worldwide.

In China, Japan, and South Korea, xylitol is found in wide assortment of chewing gums. There is brand of gum named "Xylitol" in all three countries; Japan also has a brand called "Xylish". In addition, when Extra introduced xylitol-containing products to Hong Kong and Guangdong, the word "xylitol" is transcribed into Cantonese as "晒駱駝" (Jyutping: saai³ lok⁶ to⁴), which literally means "suntan camel", and the camel is used as a figurative icon in its advertisements.

In 2004, popular North American Trident gum was reformulated to include xylitol, but not as the main sweetener (which are still aspartame, sorbitol and maltitol). The green apple flavor can be found without aspartame. It is also found in Smokey Mountain Snuff, and IceBreakers brand Ice Cubes Gum from Hershey. A discontinued sugarless gum, Carefree Koolerz, was sweetened exclusively with xylitol. Xylichew, made in Finland (available in US), is also sweetened exclusively with xylitol.

In 2006, William Wrigley Jr. Company reformulated their Orbit gum to contain xylitol and released it under the name "Orbit Complete". Critics have noted that the amount of Xylitol in some chewing gums is small, and other sugar alcohols may be used in larger amounts. Xylimax gum and mints have 1 gram of xylitol per piece, and xylitol is the only sweetener. (available in USA)

Medical applications

Dental care

Xylitol is a "tooth friendly" sugar. Early studies from Finland in the 1970s found that a group chewing sucrose gum had 2.92 decayed, missing, or filled (dmf) teeth compared to 1.04 in the group chewing xylitol gums. In another study, researchers had mothers chew xylitol gum 3 months after delivery until their children were 2 years old. The researchers found that the xylitol group had "a 70% reduction in cavities (dmf)." Recent research confirms a plaque-reducing effect and suggests that the compound, having some chemical properties similar to sucrose, attracts and then "starves" harmful micro-organisms, allowing the mouth to remineralise damaged teeth with less interruption. (However, this same effect also interferes with yeast micro-organisms and others, so xylitol is inappropriate for making yeast-based bread, for instance.)

Xylitol based products are allowed by the U.S. Food and Drug Administration to make the medical claim that they do not promote dental cavities.

A recent study demonstrated that a water additive for animals containing xylitol was effective in reducing plaque and calculus accumulation in cats.

Diabetes

Possessing approximately 40% less food energy, xylitol is a low-calorie alternative to table sugar. Absorbed more slowly than sugar, it doesn't contribute to high blood sugar levels or the resulting hyperglycemia caused by insufficient insulin response.

Osteoporosis

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

Ear and upper respiratory infections

Studies 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 (auditory tubes or pharyngotympanic tubes) which connect the nose and ear. This action that xylitol has on bacteria in the back of the nose is explained on the following referenced website about the nasal application of xylitol. When bacteria enter the body they hold on to the tissues by hanging on to a variety of sugar complexes. The open nature of xylitol and its ability to form many different sugar-like structures appears to interfere with the ability of many bacteria to adhere. Xylitol can be applied nasally through a saline solution containing xylitol.

Infection

Xylitol has been found to increase the activity of neutrophils, the white blood involved in fighting many bacteria. This effect seems to be quite broad, acting even in cases such as general sepsis

Candida yeast

A recent report suggests that consumption of xylitol may help control oral infections of Candida yeast; in contrast, galactose, glucose, and sucrose may increase proliferation.

Benefits for pregnant or nursing women

Xylitol is not only safe for pregnant and nursing women, but studies show that regular use significantly reduces the probability of transmitting the Streptococcus mutans bacteria, which is responsible for tooth decay, from mother to child during the first two years of life by as much as 80%.

Concerns

Xylitol, like most sugar alcohols, has a laxative effect, because sugar alcohols are not fully broken down during digestion. It has no known toxicity, and people have consumed as much as 400 grams daily for long periods with no apparent ill effects.

Dogs ingesting foods containing high doses of xylitol (greater than 100 milligram of xylitol consumed per kilogram of bodyweight) have presented with low blood sugar (hypoglycaemia) which can be life-threatening. Low blood sugar can manifest as loss of coordination, depression, collapse and seizures as soon as 30 minutes after ingestion. Intake of very high doses of xylitol (greater than 500 - 1000 mg/kg bwt) has also been implicated in liver failure in dogs, which can be fatal.

See also

• Other sugar alcohols: mannitol, sorbitol, erythritol, maltitol, lactitol
• Herbal sweetener: stevia
• Artificial sweeteners: aspartame, sucralose
• L-xylulose reductase

References