Wednesday, June 1, 2011

Xylitol: The sugar substitute that helps to prevent tooth decay

Wouldn't you find it amazing if you were told that there was a sweet tasting food item that, if just consumed in moderation on a daily basis over time, could reduce your potential for experiencing tooth decay on the order of 30 to even 70%. And, in addition, this food's beneficial effect could persist for some years even after you had discontinued consuming it?

Well, actually, this "miracle" food item does exist. It's a sugar substitute called xylitol. And while an absolute consensus regarding its exact mechanism of action and degree of benefit does not yet exist, there seems to be little reason why a person shouldn't use xylitol or xylitol formulated products as one of the means by which they can help to minimize their risk for dental cavities.

What is xylitol?

Xylitol is a member of a class of compounds called the "sugar alcohols." They get this name because, on a molecular basis, their makeup displays characteristics of both sugar compounds and alcohols. (Don't worry, if you decide to use xylitol as an anti-cavity measure there is no chance that you will be come inebriated. That effect is caused by another type of alcohol.) The scientific name for the sugar alcohols is "polyols." Another polyol, and one you may be familiar with, is sorbitol.

Sugar alcohols can be used as sugar substitutes.

Because our taste buds recognize polyols as tasting sweet, they can be used as sugar substitutes. In the case of xylitol, its relative sweetness in comparison to table sugar is 100%. This means that the same amount of xylitol or sucrose placed in a cup of coffee will impart the same degree of sweetness to the beverage. As an added benefit, xylitol does not have an aftertaste like that associated with so many sugar substitutes.

The term "sugar" is usually used to reference the compound sucrose. Sucrose is the granulated "table sugar" that we use for cooking or to sweeten beverages and our morning cereal. Of course other sugars exist too. Fructose is one of these. It can be found both naturally occurring in the foods we eat or as a sweetener added to them during processing. Both sucrose and fructose are well known for being important food sources for the bacteria that form tooth decay.

How does xylitol help to prevent tooth decay?

Tooth decay forms underneath dental plaque. Tooth decay is caused by acids produced by bacteria.

Cavity formation is a process where a tooth becomes damaged (looses mineral content) due to the action of the acidic byproducts produced by oral bacteria (most notably Streptococcus mutans) when they metabolize (consume) dietary sugars (especially sucrose).

This process is termed demineralization and it can take place in those regions on a tooth's surface that are covered by dental plaque due to the highly acidic environment that can develop at this interface. (Acids that leach from dental plaque into saliva have much less potential to cause damage because they are more readily diluted and buffered).

The precise way by which xylitol produces its anti-cavity effects has yet to be fully determined. And, in fact, it seems that its decay prevention benefits are probably created by more than one mechanism.

What is known is that xylitol usage promotes situation where the overall level of acid production created by cariogenic bacteria (decay causing bacteria) is reduced. A less acidic environment at the tooth-dental plaque interface means that there is less opportunity for the demineralization of tooth structure to occur.
While a number of different types of bacteria have been identified as being capable of causing tooth decay, the most studied of these is Streptococcus mutans. It's been reported that xylitol can produce its effect on bacteria other than Streptococcus mutans (most notably Streptococcus sobrinus). However, on our pages we typically only refer to Streptococcus mutans since it is the most studied in regards to this topic.

Where does xylitol come from?

In case you are wondering, xylitol is a naturally occurring compound. It is found in many of the fruits and vegetables that we consume such as raspberries, strawberries, plums, and cauliflower. Our bodies produce xylitol as a normal metabolic intermediate. On a manufacturing and production basis, xylitol is typically derived from trees (birch and beech) or corn cobs.

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