How Sugar Causes Cavities and Destroys Your Teeth

But as science has progressed, one thing is certain — sugar causes tooth decay.
That said, sugar on its own is not the culprit. Rather, the chain of events that takes place afterward is to blame.
This article takes a detailed look at how sugar affects your teeth and how you can prevent tooth decay.
Your Mouth Is a Battleground
Many different types of bacteria live in your mouth. Some are beneficial to your dental health, but others are harmful.
For example, studies have shown that a select group of harmful bacteria produce acid in your mouth whenever they encounter and digest sugar (1).
These acids remove minerals from the tooth enamel, which is the shiny, protective, outer layer of your tooth. This process is called demineralization.
The good news is that your saliva helps to constantly reverse this damage in a natural process called remineralization.
The minerals in your saliva, such as calcium and phosphate, in addition to fluoride from toothpaste and water, help the enamel repair itself by replacing minerals lost during an “acid attack.” This helps strengthen your teeth.
However, the repeated cycle of acid attacks causes mineral loss in the enamel. Over time, this weakens and destroys the enamel, forming a cavity.
Simply put, a cavity is a hole in the tooth caused by tooth decay. It’s the result of harmful bacteria digesting the sugar in foods and producing acids.
If left untreated, the cavity can spread into the deeper layers of the tooth, causing pain and possible tooth loss.
The signs of tooth decay include a toothache, pain when chewing and sensitivity to sweet, hot or cold foods and drinks.
Drinking Sugary and Acidic Beverages
In addition to sugar, these drinks have high levels of acids that can cause tooth decay.
In a large study in Finland, drinking 1–2 sugar-sweetened beverages a day was linked to a 31% higher risk of cavities (8).
Also, an Australian study in children aged 5–16 found that the number of sugar-sweetened drinks consumed was directly correlated to the number of cavities found (9).
What’s more, one study involving more than 20,000 adults showed that just one occasional sugary drink resulted in a 44% increase in the risk of losing 1–5 teeth, compared to those who did not drink any sugary drinks (10).
This means that drinking a sugary drink more than twice daily nearly triples your risk of losing more than six teeth.
Fortunately, one study found that reducing your sugar intake to less than 10% of daily calories decreases your risk of tooth decay (11).
Sipping on Sugary Beverages
If you constantly sip sugary drinks throughout the day, it’s time to rethink that habit.
Research has shown that the way you drink your beverages affects your risk of developing cavities.
One study showed that holding sugar-sweetened beverages in your mouth for a prolonged time or constantly sipping on them increased the risk of cavities (3).
The reason is partly because this exposes your teeth to sugar for a longer time, giving the harmful bacteria more opportunity to do their damage.
Eating Sticky Foods
“Sticky foods” are those that provide long-lasting sources of sugar, such hard candies, breath mints and lollipops. These are also linked to tooth decay.
Because you retain these foods in your mouth for longer, their sugars are gradually released. This gives the harmful bacteria in your mouth plenty of time to digest the sugar and produce more acid.
The end result is prolonged periods of demineralization and shortened periods of remineralization (3).
Even processed, starchy foods such as potato chips, tortilla chips and flavored crackers may linger in your mouth and cause cavities (12, 13).