Week 16 – Why Sugar Is Your Teeth's Worst Enemy (And What to Do About It)
Most people know that sugar is “bad for your teeth.” But do you know why? The answer lies in some fascinating biology happening inside your mouth right now — and understanding it could change how you think about every sip of soda or bite of candy.
The Bacteria Living in Your Mouth
Your mouth is home to hundreds of species of bacteria, most of them harmless. But one — Streptococcus mutans — is particularly troublesome. This bacterium thrives in dental plaque, the sticky film that forms on your teeth throughout the day.
When you eat or drink something sugary, S. mutans gets to work immediately. It ferments those sugars through a process called glycolysis, producing lactic acid as a byproduct.
The Critical pH Threshold
Your mouth normally sits at a neutral pH of around 7.0. Within minutes of sugar exposure, S. mutans activity can drop that pH to below 5.0. The critical number to know is 5.5 — the point at which your tooth enamel begins to dissolve.
Enamel is the hardest substance in the human body, made up of tightly packed hydroxyapatite crystals. But it has one major weakness: acid. When pH drops below 5.5, hydrogen ions attack those crystals, breaking them apart in a process called demineralization.
Why Frequency Matters More Than Amount
It’s not how much sugar you eat that matters most — it’s how often you expose your teeth to it. Every time you consume sugar, your mouth enters an acid attack phase that lasts 20–30 minutes. If you’re sipping a sugary drink slowly over an hour, you’re essentially keeping your mouth in a constant state of acid attack.
What You Can Do
- Limit sugar frequency
- Brush twice daily with fluoride toothpaste
- Drink water
- Don’t sip sugary drinks slowly
- Visit your dentist regularly
Tooth decay affects over 2.5 billion people worldwide, but the biology that drives it is well understood — and so are the habits that stop it.