Sugar’s Impact on Tooth Decay

How Sugar Leads to Tooth Decay

Sugar's Impact on Tooth Decay
While it is common knowledge that sugar is bad for teeth, many people are fuzzy about the actual process of how things move from a surgery meal to a cavity. The sugar does not directly create tooth decay, but starts the ball rolling that ends with decay. The force behind how sugar damages teeth has to do with bacteria. Below is information about how sugar impacts oral health. If you have questions, please feel free to contact our Dentist in Portland.

How does sugar effect teeth?

Everyone’s mouth is full of different types of bacteria. On average there are 72 different strains of bacteria living inside an individual’s mouth. It may sound like a bad thing to have so much bacteria in our mouths, but much of it is beneficial. Microbiota, as the bacteria are called, generally have either an innocuous or symbiotic relationship with their host. Probiotics, a symbiotic kind of bacteria, assist with breaking down foods and start a healthy digestive process. Other examples of the “good bacteria” shield gums and teeth from damage otherwise caused by acidity.

The “bad bacteria” is not symbiotic but has a damaging effect on teeth. One of the most common forms of bad bacteria is streptococcus mutans. Streptococcus mutans feeds on bits of sugars and starches left in the mouth after a eating. It creates a by-product of acid that breaks down enamel, the protective outer-layer on teeth.

The acid produced by sugar-eating bacteria leaches away at the minerals in the enamel. Remineralization is a natural process that generally keeps the impact of the acid in check. Minerals such as calcium and phosphates in a person’s saliva repair those that have been removed by the acid. However, when a high-sugar diet increases the amount of acid-producing bacteria, the acid becomes too much for the natural remineralization to keep up with. This is the point where holes in the enamel lead to cavities and tooth decay.

Additionally, some bacteria use the sugar to form a sticky layer that helps the bacteria stay in place and form colonies. This sticky layer is called plaque. Plaque buildup is basically an acid-producing layer that sits against the teeth and holds the acid against the enamel. Since brushing does not remove plaque, it has a particularly damaging impact, eating away at the teeth and even the gums, connective tissue, and eventually the bones.

A diet high in sugars and starches gives harmful bacteria, like streptococcus mutans, plenty to feed on, thereby increasing the population. Creating a high level of beneficial bacteria is an important to improve the ecosystem in your mouth. In fact, cleaning out all bacteria would not be healthy. The good bacteria are important to healthy digestion and improves overall health. A good balance of beneficial bacteria can also limit the harmful strains of bacteria. The best way of accomplishing this is to eat a healthy diet.

How can you minimize harmful bacteria in the mouth?

Keeping starches, like pasta and potatoes, to a minimum and increasing a diet of raw foods, fruits, vegetables, nuts, and seeds will help feed the beneficial bacteria and limit what the harmful bacteria needs to thrive. When you do have a meal that is high in starch or sugar, it is best to brush and floss your teeth as soon as you can. If you are not able to do that right away, at least rinsing the mouth out will help reduce the leftover particles of food. Use a gentle mouthwash, not one with harsh antiseptic agents that kill both the good and bad bacteria. Rinsing with water will also help, when there is nothing else available.

The best idea is not to eat unhealthy foods but since a rare few people are able to keep up with that one-hundred percent of the time, removing as much of the sticky starches and sugars from the mouth right after consuming them is the best prevention to reduce harmful bacteria in your mouth.

What is the impact of sugary drinks?


Sugary drinks, like soda, not only have a very high level of sugar to feed the bad bacteria in your mouth, they are also acidic. That acidity, combined with the acid produced by harmful bacteria amplifies the breaking down of enamel, gums, and connective tissue. Bacteria then have access to the inner part of the tooth where the pulp and root can be damaged.

You may think that ingesting acids and sugars in a liquid form means it does not stay in the mouth long; research has shown that the acid continues to attack teeth for about 20 minutes.

Many sweetened beverages use high fructose corn syrup as the sweetener. High fructose corn syrup is much more harmful to teeth than cane sugar or fructose that naturally occurs in fruit juice. Additionally, fruit juices often come with extra sweetener added, and they also naturally contain acid.

What about natural sugars, like fruit?

Eating fruit involves taking in the fiber along with the fruit juice; fiber lessens the effect of acid. The whole fruit also contains less concentrated amounts of fructose than fruit juice alone. A single 8 ounce glass of orange juice takes about 3 or 4 oranges to make. You are unlikely to eat 3 or 4 oranges in one sitting, but you are likely to drink a glass of juice in a short period of time. This means you take in more acid and fructose by drinking juice than eating the whole fruit. Citrus fruits are particularly high in acid.

Sure, fruit juice does contain vitamins and minerals necessary to maintain health. It is okay to drink juice in moderation. Swishing out your mouth with water when you are done will help remove some of the sugar and acids. It is also a good idea to brush your teeth afterward, but wait about 30 minutes as the acid may have weakened the enamel and vigorous brushing while the acid is still having its effect can be damaging.

This play between what you eat and how it impacts your oral health boils down to acid-causing bacteria. Focus your diet on whole foods, and limit processed, starchy, and sugary foods and drinks and you can improve the beneficial bacteria in your mouth while decreasing the harmful strains. This will go a long way toward protecting your teeth from damage.

For more information, see our friendly dentist in Portland.