What is xylitol?

Xylitol is a naturally occurring sweet substance which chemically belongs to the family of the so-called sugar alcohols [aka polyols]. In its store-bought form, xylitol looks and tastes like regular sugar (but has c. 40% less calories and, at least currently, is more expensive).

The name xylitol derives from the Greek “xylon” [hardwood], with the suffix -itol denoting sugar alcohols (other sugar alcohols are for instance erythritol, mannitol, sorbitol, maltitol etc., names which you may recognise from various sugarfree and/or diet food labels).

Xylitol in small amounts is found in many fruits and vegetables. The human liver also produces between 5 and 15 grams a day since xylitol forms an intermediate product in carbohydrate metabolism.

Xylitol's humble beginnings and rise to dental fame

Since its discovery in the late 19th century, xylitol was little used outside of laboratory settings due to the expense involved in its production. It only rose to greater significance when the former Finnish Sugar Company developed an economically viable procedure for xylitol manufacture in the 1960s (xylitol is extracted for instance from corn and birch wood).

Things really started to "move" from the early 1970s when scientists at the Finnish Turku University set out researching and demonstrating xylitol's surprising dental health and cavity-preventing benefits in a series of ground-breaking studies.

Xylitol's dental health benefits: fighting and preventing cavities (tooth decay)

The following gives a simplified overview of what xylitol has been found to accomplish in the human dentition, dental plaque and oral flora via a number of clinical/prospective caries trials. Most of these studies have been carried out using chewing gums or large pastilles with high xylitol concentrations. (For greater details, the interested reader is referred to the published literature available online and offline [compare Xylitol studies].)

So here are some of the virtues discovered in xylitol:

Xylitol effectively prevents tooth cavities.

  • Xylitol does not support the growth of cariogenic Streptococcus mutans (“caries bacteria”) due to S. mutans' inability to metabolize Xylitol.
  • Both after short- and long-term use, xylitol significantly reduces the amount of mutans streptococci in plaque and saliva.
  • The growth of lactobacilli is reduced during long-term use of xylitol chewing gums.
  • Xylitol shows effects which promote tooth remineralisation. For instance, saliva containing xylitol has been found to be more alkaline than saliva containing other types of sugar.[9]

Xylitol beneficially affects oral plaque properties and oral flora, i.e. makes plaque less cariogenic, for instance in the following ways.

  • Xylitol is not transformed to harmful acids in dental plaque.
  • When consumed after eating fermentable food components (sugar, starch...), Xylitol actively prevents acid production in dental plaque (enamel dissolves when the pH decreases below 5.7).[9]
  • Regular xylitol consumption reduces the adhesivity and amount of plaque, making it easier to brush off.

Xylitol protects children's teeth.

  • In toddlers, xylitol consumption during the emergence of their primary dentition provides long-term protection against cavities. Xylitol consumption is particularly beneficial if early signs of tooth decay/caries bacteria colonisation are present.
  • Impressive mother-and-child studies involving three groups under different treatment (xylitol/chlorhexidine/fluoride varnish): one group of mothers started chewing xylitol gum c. 3 months after childbirth and continued that program over a period of 21 months (while their children received no treatment). Results: the children of those mothers who had used xylitol were infected with mutans streptococci to a significantly lower degree than the children of mothers who had not chewed xylitol gum (but had been treated with chlorhexidine or fluoride varnish).[7]

    Since tooth decay can also be an infectious (transmissible) disease, early colonisation of the child’s teeth with S. mutans can occur via the mother's or other caretaker's saliva. As has been shown, a mother regularly consuming xylitol when the child’s primary teeth are emerging decreases the risk of infecting her child with S. mutans 5-fold, which in turn significantly lowers subsequent cavity formation in her child.


  • Xylitol apparently improves the absorption of B vitamins and calcium. In animal experimentation (with rats)[1], xylitol has been shown to have prophylactic effects re osteoporosis.
  • The temporary suppression of Streptococcus mutans resulting from oral chlorhexidine rinses is maintained if the chlorhexidine application is followed by xylitol consumption.
  • Xylitol enhances the effect of fluoridated toothpaste and other conventional methods to prevent cavities. Finnish professor Kauko K. Mäkinen, eminent xylitol researcher and author of the German-language book "Der Einsatz von Xylit in der Kariesprophylaxe" [The Use of Xylitol in Caries Prophylaxis], writes,

    "Clinical studies carried out under 'real-life' conditions have shown that the xylitol ingested was at least as effective or more effective than various fluoride programmes tested simultaneously.... It's obvious that the best results are from studies where xylitol and fluoride were applied concurrently. Xylitol and fluorides use different chemical mechanisms against cavities. In other words the effects of xylitol and fluorides are largely cumulative, which suggests that both should be used simultaneously to obtain the most effective prophylaxis against tooth decay." (but compare Xylitol and/or fluoride?)"[2]
  • Xylitol also boasts a number of confirmed non-dental medicinal benefits, one of which is that regular consumption of xylitol-containing products prevents or reduces acute middle ear infection (otitis media) in children by inhibiting pathogens associated with this ailment. Additionally, Xylitol is antiketogenic (lowers the level of free fatty acids in serum) and has no known adverse effects on the central nervous system, hormone production and neurotransmitters.

Are there any safety issues with xylitol?

Long-term clinical studies have confirmed the safety (non-toxicity to humans) of xylitol, with reportedly even daily intakes of 200 and 430 g being tolerated by some people.

The Finnish have used it since the second World War (thus doing their own mass human experiment) and in spite of Finnish xylitol research authority Prof Mäkinen even suggesting that women start using xylitol during pregnancy, we are still waiting to read about the first Finnish monster babies being born [irony off].

If xylitol truly had any negative effects on human health or procreation, it can be reasonably assumed that vested interests such as sugar manufacturers whose business is directly threatened by xylitol would have long since been shouting it from the rooftops.

Even Wikipedia - not exactly known for being partial to anything in the medical field that smacks of "alternative" (I have repeatedly seen it censor "alternative" data) - finds nothing bad to say about xylitol except for a perfectly justified caveat regarding dogs (see below Xylitol and dogs).[6]

Xylitol like most sugar alcohols does have a laxative effect (due to the fact that sugar alcohols are not completely broken down during digestion - that is one reason why eating lots of fruit - a natural source of xylitol - can give you the runs) but thankfully, the effect is less harsh than for instance with its "cousin" sorbitol and the human body (apparently with a few exceptions, compare Footnote 3) is able to gradually adapt.

A slow increase in consumption is recommended (speaking from personal experience here ;-). The amounts considered sufficient for daily dental care (5-10 g) in the vast majority of cases seem to be too low to cause any adverse effects.[3]

The safety of xylitol is reflected in numerous "official" approvals in dozens of countries concerning its use in food (particularly oral hygiene or dietary products), pharmaceuticals and cosmetics. In fact the WHO itself has carried out xylitol studies in Thailand, Polynesia and Hungary.

A PDF titled "Safety of Xylitol When Consumed by Humans: A Review of the Literature©" by Ray A. Wagner M.D. can be downloaded from www.spiffies.com/v/PDF/Study_xylitol_safety.pdf .

For anyone still feeling uneasy about xylitol, as mentioned above the amounts recommended for dental care are well within the range of what our body naturally manufactures each and every day.

Update: And if you just follow the highly recommended practice of rinsing your mouth and brushing your teeth with xylitol sugar, you do not ingest any xylitol at all (apart from the minuscule amounts that may penetrate via your oral mucosa into your lymphatic vessels).

Xylitol and diabetics

Since Xylitol's initial metabolism doesn't require insulin, is low glycemic and only slowly converted and absorbed (i.e. has a limited impact on blood sugar levels), it's also suitable for diabetics. In the later stages of xylitol metabolism, the xylitol molecule does become part of glucose and glycogen molecules, i.e. the glucose thus created does require insulin to be handled.

For this reason, one author recommends limiting the daily xylitose intake of diabetics to 60 grams to avoid high blood sugar and related complications.

Xylitol for children

(Following up from Xylitol protects children's teeth)
Xylitol products have been given to small children from two years upwards, with small children using small products and school children being able to also use products designed for adults (in fact, Finland has entire xylitol programs in place for its young generation). Due to xylitol's above-mentioned mild laxative effect, it is recommended to introduce it gradually until the effective dose is attained.

Xylitol for adults with special needs

People wearing orthodontic braces, suffering from dry mouth (xerostomia)[5], (mechanically or otherwise) unable to brush their teeth properly as well as mentally retarded patients may find it difficult to keep dental plaque at bay. Thanks to its unique action on plaque and easy applicability, xylitol can help in these cases (more under Other helpful xylitol applications).

Xylitol and dogs (as well as other animals)

To be on the safe side, Xylitol is best not used with dogs and other non-humans. While there are conflicting observations and studies, the "negative" reports re hypoglycemic (insulin-increasing) effects on dogs are concerning enough to warrant total xylitol "abstinence" at least for your canine friend(s).[6]

Factors that can interfere with Xylitol's beneficial effects

The presence of certain ionic surfactants (surface active agents) such as sodium lauryl sulfate (SLS) in toothpaste can prevent xylitol from functioning as it typically does. Also, ingesting large amounts of saccharose, glucose or fructose can sometimes "mask" the positive effects of xylitol. (Prof. Mäkinen)[8]

A question of taste

Xylitol reportedly gives a pleasant cooling sensation when dissolving in the mouth (I haven't really noticed). This characteristic advantageously adds to its use in chewing gums and pastilles. Unlike some other sugar substitutes, Xylitol has no unpleasant after-taste.


When making your own homemade toothpaste from natural ingredients, you can add xylitol for a delicious sweet taste and all the mentioned benefits.

Due to its sweet taste, xylitol allows to disguise healthy things and products with it which do not taste good when eaten alone, including bitter supplements, herbs etc. This can be used to advantage for instance with fussy children who resist strong flavours (just make sure to not override what is actually the expression of a healthy instinct).

You could make a healthy cocoa beverage for example sweetened with xylitol and with healing herbs etc. added.

Summary of a successful dental xylitol program for healthy adults

(translated from Prof. Mäkinen's above-mentioned book "Der Einsatz von Xylit in der Kariesprophylaxe")

  • Eat small amounts frequently in the course of the day.
  • Use sugarfree products that are exclusively or mostly sweetened with Xylitol. Ideal are products for chewing or sucking which boast a high Xylitol content, if possible “sweetened 100% with Xylitol".
  • Apply at least 3 times a day. 5 times daily could be even better.
  • Use on a daily basis.
  • Consume immediately after meals or snacks containing sugar and/or starch.
  • Additional preventative effects can be obtained by using xylitol before any meals or snacks.

Following the above program, you will easily ingest the amounts considered sufficient for effective daily dental care (5-10 g). If feasible, the daily xylitol dose should be larger than 5 g.

Important update October 2010: see rinsing mouth and brushing teeth with xylitol sugar, the best and most cost-effective way of using xylitol has stopped both tooth decay and healed periodontitis/gum disease.

Buying xylitol and xylitol products

In addition to the simple xylitol sugar (available in both sugar-grain size and in more powdery consistency), a range of sugarfree chewing gums, pastilles and similar candies as well as xylitol-based toothpastes is on offer both on and offline.

As with other products, frequently the best prices seem to be found online (use a price comparison site to find the best deal and I'd also make sure to buy from a company with ethical standards).

Additionally, be sure to only purchase products 100% sweetened with xylitol and containing a minimum of artificial ingredients, particularly no aspartame (also marketed as 'NutraSweet', 'Spoonful’, ’Equal Measure’, 'Equal', ‘Canderal’ (E951), ‘Benevia’, etc.)[4], artificial colours or other sweeteners except the tooth-friendly sugars listed here.

Another important consideration may be to watch out for and avoid GMO-derived xylitol (such as xylitol produced from genetically modified corn). On the other hand, xylitol as a chemically pure product does not retain any original particles from the substance it was made of, so avoiding GMO would be really more of a political statement (certainly important in my eyes).

Also compare Buying xylitol sugar from non-GMO/GMO-free sources/not made from corn in China.

If you don't want or can't chew xylitol gums

As mentioned above, there are various xylitol candies, mints etc. which can be used as alternatives eg in elementary schools where gum chewing may not be tolerated. These chewing gum alternatives are also helpful for dry-mouth patients, people with malocclusion, partial dentures etc.

Important update October 2010: see rinsing mouth and brushing teeth with xylitol sugar, the best and most cost-effective way of using xylitol has stopped both tooth decay and healed periodontitis/gum disease.

Cooking with xylitol

See Books: Xylitol - the dental miracle sugar.

Xylitol's dental applications & anticariogenic properties: studies galore!

Here is an incomplete but nevertheless extensive list of xylitol studies researching this low-calorie sugar substitute's effects on dental health, conducted in various countries (but mostly in Finland).

  • Xylitol and dental caries: an overview for clinicians. (www.ncbi.nlm.nih.gov/pubmed/12693818) - overview of studies (2003)
  • Karle, E., Gehring F. (1975) Wirkung der Zuckeraustauschstoffe Fructose, Sorbit und Xylit auf Kariesbefall und Plaqueflora der Ratte. Dtsch. Zahnärztl. Z. 30:356-363.
  • The rocky road of xylitol to its clinical application. J. Dent. Res. 2000; 79: 1352.
  • Comparison of Erythritol and Xylitol Saliva Stimulants in the Control of Dental Plaque and Mutans Streptococci. Caries Research 2001;35:129-135.
  • A 24-month clinical study of the incidence and progression of dental caries in relation to consumption of chewing gum containing xylitol in school preventive programs. J. Dent. Res. 1990; 69: 1771.
  • The effect of polyol-combinant saliva stimulants on S. mutans levels in the plaque and saliva of patients with mental retardation. Special Care Dentistry 2002; 22(5): 187-193.
  • Effect of polyol gums on dental plaque in orthodontic patients Am. J. Orthod. Dentofac. Orthop. 1995; 107: 497.
  • Xylitol gums and caries rates: A 40-month cohort study. J. Dent. Res. 1995; 74: 1904.
  • Acceptance of the xylitol chewing gum regiment by preschool children and teachers in a Head Start program: a pilot study. Pediatr. Dent. 2001; 23:71.
  • Effect of xylitol chewing gum on salivary streptococcus mutans in preschool children. ASDC J. Dent. Child. 2002; 69: 81-6, 13.
  • Sealants and xylitol chewing gum are equal in caries prevention. (2000) Acta Odontol. Scand. 58:279-284.
  • Initial acquisition of mutans streptococci by infants: evidence for a discrete window of infectivity. (1993) J. Dent. Res. 72:37-45.
  • Xylitol: a review of its action on mutans streptococci and dental plaque – its significance. (1995) Int. Dent. J. 45:77-92.
  • The effect of various sugars on the formation and chemical composition of dental plaque. (1971) Int. Dent. J. 21:302-321.
  • Effect of sugars and sugar mixtures on dental plaque. (1972) Acta Odontol. Scand. 30:235-257.
  • Turku Sugar Studies I-XXI. (1975) Acta Odontol. Scand. 33 (Suppl. 70):1-349.
  • Xylitol chewing gum in caries prevention. (1987) Academic Dissertation, University of Turku.
  • Long-term effect of xylitol chewing gum in the prevention of dental caries: a follow-up 5 years after termination of a prevention program. (1993) Caries Res. 27:495-498.
  • Xylitol chewing gums and caries rates: a 40-month cohort study. (1995) J. Dent. Res. 74:1904-1913.
  • The optimum time to initiate habitual xylitol gum-chewing for obtaining long-term caries prevention. (1999) J. Dent. Res. 78:797-803.
  • A descriptive report of the effects of a 16-month xylitol chewing-gum programme subsequent to a 40-month sucrose gum programme. (1998) Caries Res. 32:107-112.
  • Xylitol and caries prevention – is it a magic bullet? Br. Dent. J. 2003; 194: 429.
  • Xylitol candies in caries prevention: results of a field study in Estonian children. (2000) Community Dent. Oral Epidemiol. 28:218-224.
  • Xylitol, sweeteners, and dental caries. Pediatr. Dent. 2006; 28:154.
  • Mutans streptococci response to xylitol chewing gum. J. Dent. Res. 2006; 85: 177.
  • Linear response of streptococci to increasing frequency of xylitol chewing gum use: a randomized controlled trial. [ISRCTN43479664]. BMC Oral Health 2006; 6: 6.
  • Occurrence of dental decay in children after maternal consumption of xylitol chewing gum: a follow-up from 0 to 5 years of age. (2000) J. Dent. Res. 79:1885-1889.
  • Influence of maternal xylitol consumption on acquisition of mutans streptococci by infants. (2000) J. Dent. Res. 79:882-887.
  • Influence of maternal xylitol consumption on mother-child transmission of mutans streptococci: 6-year follow-up. (2001) Caries Res. 35:173-177.
  • Effect of xylitol-supplemented diets on the progression and regression of fissure caries in the albino rat. (1980) Caries Res. 14:16-23.
  • Effect of dentifrices containing either xylitol and glycerol or sorbitol on mutans streptococci in saliva. (1991) Caries Res. 25:449-453.
  • Caries-preventive effect of dentifrices containing various types and concentrations of fluorides and sugar alcohols. (1991) Caries Res. 25:74-79.
  • Enhanced anticaries efficacy of a 0.243% sodium fluoride/10% xylitol/silica dentifrice: 3-year clinical results. (1995) Am. J. Dent. 8:231-235.
  • Effect of sorbitol, xylitol, and xylitol/sorbitol chewing gums on dental plaque. (1989) Caries Res. 23:378-384.
  • Effect of xylitol on the growth and metabolism of Streptococcus mutans. (1975) Caries Res. 9:177-189.
  • Xylitol chewing gum in caries prevention: a field study in children. JADA. 1988; 177: 315.
  • Oral biochemical status and depression of Streptococcus mutans in children during 24- to 36-month use of xylitol chewing gum. (1989) Caries Res. 23:261-267.
  • Properties of whole saliva and dental plaque in relation to 40-month consumption of chewing gums containing xylitol, sorbitol, or sucrose. (1996) Caries Res. 30:180-188.
  • Comparison of erythritol and xylitol saliva stimulants in the control of dental plaque and mutans streptococci. (2000) Caries Res. 35:129-135.
  • The effect of high oral dosage of xylitol and sucrose on the biochemical properties of whole saliva in human volunteers after long-term regular consumption of xylitol. (1981) Proc. Finn. Dental Soc. 77:262-270.
  • Latest dental studies on xylitol and mechanism of action of xylitol in caries limitation. (1989) In: Grenby, T.H. (ed.) Progress in Sweeteners. pp. 331-362. London: Elsevier.
  • Caries-risk-reducing effects of xylitol-containing chewing gum and tablets in confectionary workers in Finland. (1992) Community Dent. Health 9:3-10.
  • Maintaining mutans streptococci suppression with xylitol chewing gum (2000). J. Am. Dent. Assoc. 131:909-916.

Studies positing Xylitol-tolerant S. mutans strains

For the sake of completeness, I will add that there also seem to be certain studies showing some Streptococcus mutans strains becoming xylitol-resistant or tolerant. For those interested, feel free to look up the studies "Cariogenic traits in xylitol-resistant and xylitol-sensitive mutans streptococci" (www.ncbi.nlm.nih.gov/pubmed/11929556) and "How xylitol-containing products affect cariogenic bacteria" (www.ncbi.nlm.nih.gov/pubmed/11991460?dopt=Citation).

I wouldn't rule out the possibility that there are flaws in these studies (such as introducing factors as cited above under "Factors that can interfere with Xylitol's beneficial effects" and others, too low concentrations etc.

In any case, as usual the proof of the pudding is in the eating, simply exchange the word pudding with xylitol :-) and watch your own experience. If you notice your teeth feeling smoother and your breath being fresher as well as other signs of a less bacteria- and plaque-laden mouth, you know that xylitol is working for you.

Important update: see Do Streptococcus mutans (cavity-causing bacteria) get used to xylitol?.

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1 Please note that Healing Teeth Naturally is a strong opponent of the use of animal experimentation on both ethical and scientific grounds. For the reasons compare for instance Animal Experimentation Unscientific.

2 Re the advisability of using conventional fluoridated products, see "Fluoride ruins teeth" and the very impressive testimonial "Salt water brushing has healed cavities where fluoride toothpaste had failed".

3 I've seen two cases of oversensitivity to xylitol and other sugar alcohols, expressed as severe gastrointestinal troubles setting in immediately after toothbrushing with toothpastes containing this type of sweetener and after chewing similarly sweetened sugar-free gum.

Update: Meanwhile, a few other reports have surfaced of severe overreaction (constant diarrhea etc.). Judging by rat experiments where groups of rats were fed large doses of xylitol for the equivalent of many human years, the ability to adapt seems to depend on the presence or absence of a certain intestinal "bug". Rats who did not harbour the organism as a part of their gut flora were able to adapt after a while, while those who did carry it were unable to adapt, i.e. continued to have gas and diarrhea throughout the experiment. 

4 Compare Cancer causes: aspartame.

5 See Dry mouth (xerostomia): On causes, remedies & treatments of inadequate natural production of saliva.

6 A reminder here that a dog weighing 10 kilograms (approx. 22 pounds) can also be killed by c. 190 g (6.7 oz) of dark chocolate (another fact pointing to animal experimentation being useless and actually misleading when it comes to humans).

7 One factor apparently not taken into account in the above study is the fact that the group with the best results CHEWED GUM while the other groups did not benefit from additional exercise of their teeth and jaws. See Dental health prerequisite number 6: proper mastication - exercise your teeth and gums by chewing well why this could account for part of the positive effect presently wholly ascribed to xylitol.

8 This is likely due to the systemic effect of sugar on dentinal fluid flow.

9 Background on the importance of saliva pH under Tooth remineralisation & demineralisation.

All Healing Teeth Naturally articles on nutrition and dental health