Expanding the Utility of Xylitol

Xylitol is a white crystalline substance similar in appearance to sugar with a much sweeter taste but approximately one third fewer calories. It is extracted from xylan with the main sources obtained from beech and birch hardwood barks and corn cobs. It is also found in rice, straw, oat, wheat and cotton seed hulls, various nut shells, fruits (plums, strawberries, raspberries), vegetables (mushrooms, endive, cauliflower), and naturally produced, to some degree, in the human body.

Xylitol quickly dissolves with a refreshing, cooling sensation. As a polyol, it is absorbed slowly and incompletely from the small intestines into the blood. Little or no insulin is metabolized during the absorption process. Any remaining portions of xylitol in the blood are broken down in the large intestines. Chemically, it is a five carbon sugar alcohol (prevents the growth of bacteria or an alkaline enhancement) compared to sugar, which is a six carbon sugar alcohol (promotes bacteria and fungi growth and is acid-forming).^1,2

CARIES CONTROL

Briefly stated, bacteria (Streptococcus mutans) are located in the biofilm on tooth surfaces to form a sticky environment. S. mutans metabolize the sugars (fermentable carbohydrates) entering the mouth, causing the sugars to metabolize into lactic acids. The acids create a lower pH level, thus demineralizing the tooth surface, which ultimately leads to caries formation. When xylitol is present, S. mutans are attracted to the xylitol over other sugars. The bacteria cannot metabolize xylitol, causing a disruption in their protein synthesis. This results in a decrease in the number of S. mutans and, as a result, the pH level returns to homeostasis.³

Xylitol may contribute to dental decay reduction via: the reduction of S. mutans in plaque and saliva, the interruption of acid production, the reduction of plaque accumulation, and the support of the remineralization process of tooth enamel.^4,5 The most effective mode of administration is to chew gum containing xylitol. Recommended dosages range from 6 g to 10 g of xylitol daily, three to five times per day, for 5 minutes each time.^5,6

RESEARCH

In 1982-1984, the Ylivieska Study enrolled 258 children aged 11-12 who chewed 7 g-10 g of xylitol gum daily, which resulted in a 30% to 60% reduction in new decay.⁷ Five years later, the authors re-examined the children and participants still experienced a 55% reduction in the rate of caries.⁸

The Belize Study, 1989-1993, was a comprehensive 40-month study that used 1,277 subjects who were separated into nine groups, with each group chewing one type of gum.^9,10 The authors concluded that regular use of polyol-based chewing gum reduced caries rates in young children, with xylitol being the most effective sugar substitute. The Belize Study re-examined the subjects 5 years later and found significant reductions in caries even after the use of xylitol had ended.¹¹ These studies suggest the value of xylitol during tooth eruption.

Hayes reviewed 14 clinical studies from 1966-2001 using sugar substitutes, xylitol, and sorbitol, for reduction in dental caries outside the United States. Studies consistently displayed 30% to 60% reduction in dental caries from using xylitol chewing gum or toothpaste. The highest decay rate reductions were found in subjects using xylitol.¹²

BENEFITS BEYOND ORAL HEALTH

Xylitol may not only be useful in caries reduction. New benefits are being discovered that may aid patients ranging from children with acute otitis media (AOM) to elderly people with candidiasis.

Finnish researchers studied 306 children in day care nurseries with histories of repeated AOM. Half of the children chewed xylitol-sweetened gum after all meals and snacks (two pieces, five times per day for 2 months) and half of the children chewed regular gum. Incidence of AOM in xylitol chewers (12%) dropped by almost half from regular gum chewers (21%).¹³ Some AOM may have been prevented through the swallowing that accompanies chewing gum, which automatically helps clear the middle ear canal. Since chewing of xylitol gum indicated a decrease in alpha-hemolytic streptococci for AOM, this same theory could possibly hold true for reducing sinus infections, as similar streptococcal are involved.

In a 3-month Finnish study on AOM, 857 healthy day care center children were randomized into five treatment groups. The groups included a control syrup, xylitol syrup, control chewing gum, xylitol gum, and xylitol lozenge. Results indicated AOM incidences were lower in children who had received xylitol lozenge (20% decrease), xylitol syrup (30% decrease), and xylitol gum (40% decrease) with less need for antimicrobials than control group children. Xylitol appeared to result in a local inhibitory action with pneumococci and H. influenza,^13,14 however the actual health impact of the inhibition is unknown.

Diabetes management has three major goals: to control blood glucose, lipids, and weight. Xylitol is absorbed slowly in the body so the rise in blood glucose and insulin needed to metabolize glucose is greatly reduced. It is possible that oral consumption will not increase blood glucose levels. Xylitol’s caloric value of 2.4 calories per gram versus 4.0 for sugar has the potential to aid in weight control for individuals.⁶

Cancer patients experience numerous inconveniences with their illnesses. Treatment may cause xerostomia, burning mouth sensation, vomiting, acid reflux, eating limitations, and excessive sleeping. Xylitol products can help reduce xerostomia by increasing saliva flow, which helps neutralize the pH level and inhibit S. mutans.15-17

Tooth decay, debris-covered dentures, or poor oral hygiene may contribute to seniors increased levels of plaque, causing oral infections like candidiasis. A 12-month English study of 111 frail but healthy seniors aged 60 and over were divided into three groups with 1) no gum, 2) chewing xylitol gum, and 3) chewing xylitol gum with an antimicrobial for 15 minutes, two pieces, two times per day.¹⁸ Researchers found that the groups chewing xylitol gum lowered their risk for developing candidiasis (fungal or yeast infection) and angular cheilitis.¹⁸

ADVERSE EFFECTS

Xylitol has no known toxicity, carcinogenicity, or permanent side effects. One adverse effect may be several days of osmotic diarrhea (if more than 100 g per day is consumed by adults or 45 g per day in children) or gastrointestinal symptoms such as gas, bloating, or cramping, an effect similar to eating high-fiber foods. After ingesting polyols, symptoms gradually subside after several days with reduced intake of polyol foods. Polyols may then be gradually added back into the diet.^3,5

Some Jewish children have a disorder known as Pentosuria, a congenital enzyme defect and are unable to digest xylitol. Xylitol is absorbed into the body and the urine causing a positive sugar test for diabetes, misdiagnosing a disease when none exists.¹⁹

Finally, individuals with temporomandibular joint (TMJ) disorder may need to refrain from chewing the gum. Instead, candy, mints, or other xylitol products should be consumed.⁵

PRODUCT AVAILABILITY

Xylitol is available in other products such as candy, mints, toothpastes, mouthwashes, mouth sprays, nose sprays, baby mouth wipes, and more. Always read the ingredient label. In order to reap the most benefit, xylitol should be one of the first three ingredients, preferably first when selecting a gum or other products for their dental benefits.

REFERENCES

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15. Rekola M. Comparative effects of xylitol- and sucrose-sweetened chew tablets and chewing gums on plaque quantity. Scand J Dent Res. 1981;89:393-399.
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17. Soderling E, Alaraisanen L, Scheinin A, Makinen KK. Effect of xylitol and sorbitol on polysaccharide production by and adhesive properties of Streptococcus mutans. Caries Res . 1987;21:109-116.
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From Dimensions of Dental Hygiene. October 2006;4(10): 34-37.