Can I take xylitol or xylitol products along when travelling by air?

Here are some "empirical values" derived from experiences with airport security controls:

Drops in your hand luggage will always pass, but xylitol gel is less easy.

Xylitol in powder form, transported in a small box, bag or old tablet bottle is accepted at the hand luggage control. Larger amounts than this can be a problem in some countries.

It may be best to take along granular xylitol sugar which looks exactly like table sugar (and of course tastes the same as well).

Does xylitol affect fructose metabolism?

No, xylitol doesn't affect fructose metabolism and hereditary fructose intolerance.

The xylitol I bought looks and tastes SO much like sugar, how can I be sure it is a pure form of xylitol?

Xylitol in granular (as opposed to powder) form DOES look exactly like normal granular sugar and basically tastes exactly the same. You can check the label if you are unsure, it should say something to the effect of 100% pure xylitol. For an additional consideration, compare Are all xylitols created equal or are there differences in quality?.

For the real sticklers - know that xylitol is heat-stable and only caramelizes after being heated for several minutes to above 200°C (at a temperature of approximately. 100°C no caramelization occurs). So to find out whether you have xylitol or table sugar (or perhaps a mix), all you need is a cooking thermometer and some patience.

A simpler method has been used by a site visitor: put a teaspoon of sugar on a dry frying pan next to a teaspoon of xylitol and heat the pan. The table sugar will caramelize and smoke while xylitol will simply melt and turn into a smooth clear paste or drop. After cooling a few minutes, the sugar will be rock hard while the xylitol will still be paste-like (once hardened, the xylitol drops can be stored near-indefinitely and sucked like candy[1]).

Do Streptococcus mutans (cavity-causing bacteria) get used to xylitol?

A laboratory study by Badet, C et al., published in Archives of Oral Biology, Volume 49, Issue 2, S. 161-164 (February 2004) under the heading "Adaptation of salivary Lactobacillus strains to xylitol" has indeed established that S. mutans and other bacterial strains can learn to utilize xylitol and produce acid from it.

That said, this study was conducted in vitro and to date has not been verified in vivo on human beings. Empirical experiences I have read about would indicate that even after years of application, xylitol doesn't lose its effectiveness. Dentist Dr. Bruhn suspects that xylitol's effect is due to numerous factors and not just to the selective inhibition of certain oral pathogens.

A 2006 study by Tanzer et al.: "Streptococcus mutans: Fructose Transport, Xylitol Resistance, and Virulence", published in the Journal of Dental Research, 85(4):369-373 (full text version available at, proposes an interesting explanation for the fact that with regular xylitol use, tooth decay is prevented even after S. mutans have become resistant. As Dr. Bruhn has summarised it:

"The non-resistant streptococci have a transporter for fructose which ... also transports xylitol into the bacterial cell. But xylitol inhibits the energy metabolism of the bacterial cell and the bacterium starves to death. The resistant streptococci don't have that special transporter, only others which transport fructose but not xylitol. That's why they are able to survive under xylitol since xylitol is not transported into them. Luckily for us, the missing xylitol transporter is linked to the inability to form plaque and attack enamel and particularly dentine. The xylitol-resistant streptococci don't possess this ability, in other words, they are unable to do much damage at all (decreased virulence)."

Why do my teeth appear smoother after using xylitol?

Xylitol dissolves plaque and due to complex formation with calcium and magnesium seems to distinctly assist in the enamel's remineralisation, another probable cause of its tooth-smoothening effect.

Incidentally, once the enamel has been remineralised, it could be that any additional complex formation leads to deposits such as in the (one-off) case of a site visitor who swished with xylitol granules a whopping ten times a day for six weeks. As he reported, he started getting a hard film on his teeth which felt rough to his tongue and which was invisible unless he used disclosing tablets, at which point it showed up like plaque. This deposit however "came off after 4 minutes of brushing" and should also have yielded to using less xylitol rinses, and perhaps a strawberry treatment as for tartar, but it's best of course to not overdo the xylitol rinses in the first place. For the record, there ARE tooth deposits which are not cavity-inducing, as described for instance by dentists Dr. Heard and Dr. Price in their respective books.

Are all xylitols created equal or are there differences in quality?

A very committed participant of a discussion forum on the subject of xylitol for mouth rinses etc. reported that the Chinese xylitol she had bought turned out to be less effective for her teeth, plaque formation, mouth odour etc. than the European (Finnish?) xylitol she had previously used.

As she researched the possible reasons she learned that certificates of purity made out in China are not necessarily to be taken at face value but rather that Chinese xylitol could well be adulterated occasionally and contain say only 80% xylitol for instance while the remainder would be cheaper sugars.

While the above was true for that particular person, this is really just a one-off case I have seen reported with a rather minor "side effect" of possibly adulterated xylitol. Let no-one be scared who tries to be thrifty for whatever reason of buying whatever cheaper xylitol they can find. After all, xylitol will work even when combined with cariogenic table sugar, see If I don't brush my teeth after eating sweets but simply pop half a teaspoon of xylitol, why would that work?.

Also see Is xylitol made from birchwood the same as the xylitol made from corn? (Do both serve tooth and gum health the same way?), Buying xylitol sugar from non-GMO/GMO-free sources/not made from corn in China and The xylitol I bought looks and tastes SO much like sugar, how can I be sure it is pure?.

Which xylitol grain size (large crystals or powdered sugar) is the best choice?

Xylitol sugar comes in several particle sizes from granular to finely powdered consistency. According to dentist Dr. Bruhn, they all work the same, with a small difference existing in how they feel in the mouth.

One person reported that when she used the finer powder which dissolved more quickly in her mouth, she ended up using more xylitol than when she had used the granular variety, leading to higher overall costs. She also reported that using the granular xylitol, her teeth became smooth much more easily than with the powdered xylitol.

Also worth mentioning: xylitol sold in powdered form apparently tends to become stale. You can avoid this by buying granular xylitol and preparing your own powdered sugar when the need arises, using a blender.

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1 Compare What's best to use - xylitol chewing gum, xylitol drops/candy, xylitol gel or simply xylitol sugar (powder)?.

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