Sugars, Sugar Substitutes, and Tooth Decay
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The world is complicated, and growing more so all the time. Complication applies to the sweeteners we find in our foods as well: many have been developed in the last 100 years, and many foods use sweeteners in new and often hard to detect ways, complicating things further.
As far as reducing the role of sweeteners in causing tooth decay, however, things are very simple: the less time cavity-causing sweeteners spend in our mouths, the better off we are. That said, it’s helpful to look at how some sweeteners cause cavities, misconceptions about sweeteners, types of sweeteners, and some non-dental considerations about sweeteners.

How sweeteners cause tooth decay
Tooth decay happens in a host environment (our mouth, with its saliva and teeth). In that environment, bacterial microflora (known as “plaque”) live, feeding on sugars or other fermentable carbohydrates, such as highly refined flour. Time is the last ingredient: the longer oral bacteria can feed, the greater the impact on our teeth.
The interaction of these elements is simple, at its most basic level. The bacteria in the mouth feed on sugars, and produce acids that over time dissolve the minerals that make up our teeth. That mineral loss can also lead to breakdown of the inner organic dental tissue (the “dentin”).
Preventing tooth decay is a combination of strengthening the host environment (ensuring good saliva flow, for example), diminishing the presence of bacteria (through cleaning and brushing), and reducing the food available for those bacteria (through minimizing the sugars present in the mouth and the time it’s available to bacteria).
Misconceptions about sugars and sugar substitutes
Misconception #1: Sweeteners are sugars
One frequent misconception is that sweeteners are sugars. While some sweeteners are sugars, others aren’t. It’s only the sweeteners that provide food for bacteria – sugars – that cause dental caries.
Misconception #2: Some sugars are better for our teeth than others
Another misconception is that some sugars are better than others for our teeth. Actually, the bacteria that cause cavities don’t care very much whether the sugar they feed on is sucrose, glucose, maple sugar, honey, or something else. Bacteria like “natural” sugars just as much as any other type.
People have a lot of ideas about which sweeteners are conducive to tooth decay and which are not. Many of those ideas are incorrect. Bacteria however are not confused. The sweeteners they like are precisely the sweeteners that are bad for our teeth. It doesn’t matter whether the sweetener is natural or synthetic, ancient or modern, fashionable or not in vogue. If bacteria like to eat it, that sweetener is bad for our teeth.
Misconception #3: Sugar in our stomach is bad for our teeth
Yet another misconception is that sugar not in our mouths can harm our teeth. There might be many things wrong with too much sugar in our diets, but once the sugar leaves our mouth it cannot harm our teeth. Whether it leaves when we clean our teeth, or when we swallow and rinse away our food, once out of the mouth sugar has been removed from the environment of cavity creation.
Types of sweeteners
Sweeteners are much more than just sugars: as the table below shows, the category includes refined sugars, partly refined sugars, cooked sugars, raw sugars, sugar alcohols, synthetic “sugars”, and synthetic “sugar alcohols”. To complicate things further, many of these sweeteners have more than one name.
If we remember however that the only sweeteners that cause tooth decay are those that oral bacterias use as food, then things are simpler. Basically, oral bacteria eat fermentable carbohydrates, and if you look at the table you will see that virtually everything we think of as natural or refined sugars are bad for our teeth. There are a few exceptions: some are not bad, but they are in the minority.

Xylitol
On the other hand, no synthetic sweeteners are fermentable carbohydrates, so none of them provide food that oral bacteria would eat. A small number are actually good at preventing cavity formation, in that they do things such as inhibiting the formation of plaque.
This isn’t to say that synthetic sweeteners are “better” than naturally formed sweeteners, just that they are not conducive to cavity formation. Other considerations are involved, and will be discussed at the end of this blog post.
Sweetener |
Promotes tooth decay? |
Also known as . . . |
Refined sugars |
||
Sucrose |
Bad for teeth |
table sugar, granulated sugar, cane sugar, beet sugar, “pearl sugar”, “decorating sugar”, icing sugar, confectioner’s sugar, caster sugar |
Fructose |
Bad for teeth |
agave nectar, fruit sugar, levulose |
Glucose |
Bad for teeth |
corn syrup, dextrose |
Tagatose |
Not bad for teeth |
“Naturlose” |
High fructose corn syrup |
Bad for teeth |
glucose-fructose, isoglucose, glucose-fructose syrup, HFCS 42 (processed foods and breakfast cereals), HFCS 55 (soft drinks) |
Inverted sugar |
Bad for teeth |
invert sugar, trimoline |
Maltose |
Bad for teeth |
brown rice syrup, maltobiose, malt sugar |
Trehalose |
Bad for teeth |
“Treha”, mycose, tremalose |
Galactose |
Bad for teeth |
glucose lactique |
Lactose |
Bad for teeth |
milk sugar |
Partly refined sugars |
||
Brown sugar |
Bad for teeth |
“Sugar in the Raw” |
Other refined sugars |
||
Glycyrrhizin |
Not bad for teeth |
licorice |
Rebaudioside |
Not bad for teeth |
“Truvia”, “Sweetleaf”, rebiana, Reb A, “PureVia”, stevia leaf |
Cooked sugars |
||
Maple syrup |
Bad for teeth |
maple sugar, maple toffee |
Sorghum syrup |
Bad for teeth |
sorghum molasses, sweet sorghum |
Cane sugar molasses |
Bad for teeth |
treacle, blackstrap molasses |
Raw sugars |
||
Honey |
Bad for teeth |
— |
Yacón syrup or powder |
Not bad for teeth |
— |
Lucuma powder |
Not bad for teeth |
— |
Monk fruit |
Not bad for teeth |
— |
Sugar alcohols |
||
Glucerol |
Not bad for teeth |
glycerin |
Xylitol |
Good for teeth |
“Xylosweet” |
Sorbitol |
Not bad for teeth |
glucitol |
Maltitol |
Not bad for teeth |
“SweetPearl” |
Mannitol |
— |
[Not a food sugar] |
Lactitol |
Not bad for teeth |
NH4-Redox |
Erythritol |
Good for teeth |
“Zsweet” |
Synthetic sugars |
||
Saccharin |
Not bad for teeth |
“Sweet’n Low”, “Sweet Twin”, “Necta Sweet”, “Equal Saccharin”, acid saccharin, Calcium saccharin, sodium saccharin |
Sucralose |
Not bad for teeth |
trichlorosucrose, “Splenda”, “Equal Sucrose”, “Natrataste Gold”, “SukraPlus”, “Sukrana”, “Cukren”, “Nuvella” |
Aspartame |
Not bad for teeth |
APM, aspartyl-phenylalanine-1-methyl ester, “Equal”, Aminosweet, “Candarel”, “NatraTaste Blue”,”NutraSweet” |
Advantame |
Not bad for teeth |
— |
Neotame |
Not bad for teeth |
— |
Acesulfame potassium |
Not bad for teeth |
“Sunett”, “Sweet One”, acesulfame K, Ace K. “Equal Spoonful”, ACK |
Synthetic sugar alcohol |
||
Isomalt |
Not bad for teeth |
— |

Artificial Sweeteners
Sweeteners: Other considerations
As mentioned, sweeteners don’t really divide into “good sweeteners” and “bad sweeteners”. Many sweeteners that are not harmful to our teeth may have other drawbacks, such as disrupting digestion. Sweeteners that are harmful to our teeth can also have other drawbacks, such as effects on the body’s production of insulin (leading to diabetes, for instance) or causing weight gain. Some are potentially carcinogenic; others are just not well understood at all. Some sweeteners offer benefits in the form of antioxidants, or nutrients in small amounts.
Sweeteners are often not easily identifiable, as well. Many are integrated in foods we don’t think of as “sweet”, such as ketchup or bread.
What is the bottom line? Simply think of food in your mouth as also food for cavity-causing bacteria: so brush regularly, minimize snacking, and ensure that foods spend as little time as possible sitting in the nooks and crannies of our mouths, feeding the cycle that can cause cavities. It’s not that complicated.