Great news! Chewing gum can actually prevent cavities. It can also help you stop smoking and lose weight, and it increases your ability to concentrate. But before you get too excited, there are also some reasons why gum might not be right for you. When in doubt, ask your dentist.

Why gum is good for teeth

It’s mostly about the saliva. Chewing gum stimulates saliva production, and saliva is the mouth’s natural defense system. Saliva helps to clean away stray bits of food that might lead to bacteria growth. It also helps restore pH balance after consuming foods that are acidic or alkaline. So if you chew gum after a meal, more saliva will be generated and your teeth will thank you for it.

That said, not all gum is created equal. Gum that contains sugar can actually promote cavities and should be avoided. Ideally, look for gum that is sweetened with xylitol, a substance that has proven health benefits (PDF).

Xylitol: a powerful cavity fighter

Despite the scientific name, xylitol is a naturally occurring sugar alcohol that actively prevents cavities. Don’t let the word alcohol throw you off though: sugar alcohols won’t make you tipsy. They are just sugars that have latched onto a couple of extra hydrogen atoms, and that configuration makes them indigestible to the bacteria in your mouth. However, because they are based on sugar, they still taste sweet.

Xylitol is special among sugar alcohols, because it raises the pH of the mouth and prevents cavity-causing bacteria from growing. If you chew xylitol gum regularly, the amount of streptococcus mutans (a common cavity-causing bacteria) decreases. Meanwhile, healthy “good” bacteria grow, making it harder for new colonies of streptococcus mutans to settle in.

The following (very retro-looking) video demonstrates how chewing gum is made and why xylitol protects your teeth, including a tour of a chewing gum factory and a cute animation of xylitol attacking bad bacteria:

Chewing gum and weight loss

There are also several health benefits to chewing gum that have nothing to do with your mouth. For instance, a number of studies have suggested that chewing gum causes many people to consume (slightly) fewer calories. The effect isn’t very large, so gum alone won’t do much, but as part of a healthy diet, it can help you achieve your goals.

That said, not everyone responds the same way. Chewing gum prevents snacking for some people, but it stimulates hunger for others. If gum causes you to eat more, you obviously won’t lose any weight. On the other hand, if chewing gum prevents you from snacking, you should see a benefit.

Drawbacks of chewing gum

Gum chewing isn’t right for everyone, and you can certainly overdo it. Here are some of the common reasons you might want to avoid gum:

  • Jaw pain (TMJ). If you have issues with the joints in your jaw, chewing gum can aggravate the issue. For serious cases of temporomandibular joint disorder (TMJ), gum chewing can cause harm.
  • Bloating. Some people report bloating from gum chewing. This happens because the chewing motion causes you swallow a lot of air, which then travels through the digestive system.
  • Laxative effects. In larger doses, xylitol becomes a laxative. Don’t overdo it!
  • Migraines in teens. Too much gum chewing can lead to migraines in adolescents.

Despite those issues, however, gum chewing can benefit most people. If you’re having issues, talk to your dentist. Otherwise, feel free to pop a piece of xylitol gum in your mouth.