Chewing gum regularly is a bit like going to the gym. Just as strength training leads to larger-sized muscle fibres, chewing gum makes your saliva gland cells larger and more efficient. This means you not only create more saliva while you are chewing the gum, but also during 'rest periods' when you're not chewing anything. And it's during these rest periods that saliva has a big influence on the sorts of bacteria that grow in your mouth.
Chewing sugar-free gum can also really help those at high risk of tooth decay, such as teenagers (whose diet is often not as good as it should be); people who drink a lot of soft drinks or sports drinks; and those whose saliva production is affected by medication, exercise, or lifestyle.
ABC expert: Professor Laurence Walsh Published 04/02/2010