Do Sugar Substitutes Cause Tooth Decay?

With the high caloric intake of sugar and the bad rap corn syrup gets, it is no wonder the sugar substitute market has boomed in the United States. 

Monk fruit, stevia, erythritol, agave, sorbitol, and xylitol are amongst the most popular of the sugar substitutes. 

The Questions 

What exactly are these sugar substitutes? Where do they come from? How do we know if they are good for us? If they are sugar-free, can they cause tooth decay? 

Answering each of these questions can lead to a better understanding of the connection between oral health and sugar substitutes. 

Monk Fruit: What is it? 

Monk fruit or luo han guo was originally derived from China and Northern Thailand as a medicinal plant. Chinese monks were found cultivating monk fruit in the 13th century for medicinal purposes. Monk fruit was historically used for inflammatory conditions and ailments associated with high fevers. 

In the United States, monk fruit was introduced as a zero-calorie sweetener once the fruit of the plant went through a pureeing and extracting process to allow the monk fruit extract to have zero calories per serving. This extraction process has morphed monk fruit into a more palatable sweetener which is known to be 100-400 x sweeter than sugar. The Food and Drug Administration has regarded the monk fruit as GRAS, Generally Recognized As Safe. Monk fruit became prevalent in multiple healthy food products and amongst those who were looking for a safe sugar alternative.

Agave plants

Agave: What is it? 

Agave syrup, derived from the agave plant, is sweeter than sugar but has more calories. Ideally, you can use less agave to obtain the same palatable sweetness as sugar. 

Agave reached its newly found fame for having a low glycemic index. It started to hit the shelves as a liquid alternative for syrups and sweeteners. 

The glycemic index is measured by how quickly the blood glucose level rises after 2 hours of eating or drinking a particular food or drink. Agave has a low index because it has minimal amounts of glucose sugars. However, agave does have a high concentration in fructose sugars. 

Studies have shown that regular fructose intake is associated with a higher risk of fatty liver disease and insulin resistance, which can impair blood sugar control in the long run. These facts may make agave a less desirable alternative to sugar. 

Stevia: What is it? 

Stevia in the form of the sugar substitute is known as Reb A sweetener. The raw stevia is derived from the flowering stevia plant. It goes through a refining and extraction process to get to the Reb A. That extract is used as the popular sugar substitute. 

Stevia has GRAS approval from the FDA. This sugar substitute is 250-300 times sweeter than regular sugar, so a minimal amount is needed to have the same desired sweetness. 

What is sugar alcohol? 

Sugar alcohol is neither sugar nor alcohol. It was coined sugar alcohol because chemically speaking they resemble part sugar and part alcohol. Sugar alcohols have notoriously been associated with gastrointestinal (GI) discomfort. Sugar alcohols can cause GI discomfort because of the way they are absorbed in the body. Sugar alcohols are incompletely absorbed which causes it to be sent to the gut. While sugar alcohol is in the gut, it gets fermented by bacteria in the intestines. This process can cause a laxative effect and other gastrointestinal symptoms. 

Each sugar alcohol is absorbed in a different percentage, which leads to a range of GI effects dependant on the absorption rate. If more is absorbed into the bloodstream, then less is left for the gut absorption, hence causing less GI upset. 

Sugar alcohols have been recommended to be eaten in smaller quantities to help minimize the irritability in the bowels. 

What is Sorbitol? 

Sorbitol is a sugar alcohol that contains fewer calories than traditional cane sugar and is often added to sugar-free foods and drinks. Sorbitol only has about 65% of the sweetness as sugar. So it is not a direct sugar substitute in terms of sweetness. Sorbitol does have a low glycemic index. 

What is Erythritol? 

Erythritol is an extremely low-calorie sugar alcohol. It is much sweeter than sugar. About 90% of erythritol is absorbed through the bloodstream and excreted into urine unchanged. 

This means only 10% of the erythritol is absorbed into the gut, which leads to less GI issues, whereas sorbitol tends to cause more bloating and irritability because more sorbitol is absorbed into the intestinal tract causing bowel discomfort. 

With a better understanding of these sugar substitutes, the next question can be asked… 

What is Tooth Decay? 

The outer hard layer of the tooth is made up of enamel. Tooth decay is when the enamel is destroyed by bacteria in an acidic environment. Once the enamel is destroyed, the soft deeper part of the tooth is exposed and decay continues to erode these soft surfaces. 

Tooth Decay, Dental Caries, and Cavities 

These three interchangeable words are all used to describe the destruction of the teeth caused by bacteria in an acidic environment. 

Tooth Destruction Process 

There are a few steps in the dental decaying process. 

First: When you have a build-up on your teeth of sugar, bacteria will thrive as this is a food source. Certain types of caries-causing bacteria will continue to grow and multiply when their food source is present. This bacteria causes an acidic environment. 

Second: As the bacteria eat the sugar, the microorganisms multiply and grow. This bacteria helps the formation of a thin biofilm known as plaque. Plaque is comprised of many things including water, food, and bacteria. 

Third: Once there is a solid layer of plaque, the tooth starts to dissolve. The thick bacteria film will start attacking the enamel due to the acidity which causes erosion and little holes in the outer layer of the tooth. 

Fourth: Once the enamel has a hole, the bacteria can easily erode to the deeper soft layers of the tooth causing decay to rapidly spread. As food enters the hole in the tooth, it is harder to clean, causing more erosion. 

Now that tooth decay has been defined, it can help explain that neither the sugar or sugar substitutes are responsible for causing the cavities directly. The bacteria creates the acidic environment which erodes the tooth causing dental decay. 

The Bacteria Does Not Act Alone 

The bacteria thrives in an environment that is sticky, residue-filled, and full of sugar. So if you are eating foods or drinking beverages that either causes sugar deposits or residue film, you are aiding the bacteria to grow in your mouth.

Variety of sweetners

Sugar Substitutes: Hinder or Help? 

Sugar substitutes can both hinder and help oral hygiene. It depends on what the sugar substitute is paired with. The sugar substitute is not eaten alone. Depending on what you are eating will determine if you are promoting or preventing the bacteria to thrive. Remember a sticky, filmy, and acidic environment promotes tooth decay. 

Answering the following questions will aid in answering if the sugar substitute helps or hinders oral hygiene. 

Is the sugar substitute in a sticky, gummy snack? If so, that can leave a film residue onto the dental enamel. The film residue can be hard to clean. This will start the dental decay process. 

Is the sugar substitute in a diet or low-calorie soft drink? If the substitute is in a low-calorie drink, it will further harm the dental enamel. The other ingredients in the soda are corrosive, which is harmful to the teeth. This aids in the decaying process. 

Is the sugar substitute in chewing gum? If the answer is yes, this can be beneficial to your pearly whites. If you are unable to brush your teeth after a meal, chewing gum made with a sugar substitute aids in oral hygiene. When you are chewing gum, saliva is produced. This saliva will help cleanse and protect your teeth. Saliva serves as an acid neutralizer to your mouth. The saliva produced while chewing gum can also assist in oral hygiene by sweeping away little food particles adhered to your teeth. 

As noted above, the sugar substitutes do not directly cause tooth decay. The sugar substitutes can help oral hygiene when added to a sugarfree gum. Besides chewing gum, sugar substitutes are often added to foods or drinks that can aid in the production of bacteria by providing a food source or acidic environment, this will promote tooth decay. 

Dental Health is Important 

Good oral health can help prevent dental caries, gingivitis, bad breath, and much more. The more you know and understand about oral hygiene, the more preventative measures you can take. If you take care of your mouth, you can help prevent complications as you get older. 

Poor oral hygiene, especially gum disease, has been linked to preterm labor, stroke, heart disease, and diabetic complications. 

If you have questions about oral hygiene and your dental health, we are here to help you. Our well-trained dental staff is knowledgeable in oral hygiene and can help you with any concerns you may have with your oral health.

You have taken a great step in oral hygiene by educating yourself. Please reach out to us if we can assist you in any way. We would love to see your smile.