Dental decay

The worst offenders

We compared the sugar content and acidity of 85 processed foods and drinks and categorised them as high, moderate or low risk.

• High-risk foods or drinks contain a lot of sugar and also have high acidity. These include some muesli bars and processed fruit snacks; high-risk beverages include soft drinks, fruit cordials and fruit drinks. Unfortunately, many of these foods are promoted as “healthy” snacks for kids’ lunch boxes.
• Moderate-risk products either contain a lot of sugar or have high acidity, but not both.
• Low-risk products contain less sugar and are not highly acidic.

Foods

All the confectionery products we tested are in the high-risk category. Two brands, Wonka Fruit Tingles and Warheads Juniors Extreme Sour Hard Candy, stand out as the worst. They contain more than 80% sugar, and they’re more acidic (with pH values of 2.35 and 2.06 respectively) than any other food or drink on test. They also have high acid reserves, making it harder for saliva to neutralise the acid, so the teeth are exposed for longer.

Of greater concern is the fact that some of the muesli bars we tested, as well as other products promoted for kids’ lunch boxes such as processed fruit snacks, fall into the high-risk category. These foods are often sticky, which increases the time the teeth are exposed to sugar and acid. Uncle Tobys Fruit Fix and Robern Frubears also have high acid reserves, further increasing their potential to damage teeth.

Drinks

Fizzy drinks feature prominently in the high-risk category. Market leader Coca-Cola packs 10 teaspoons of sugar into a 375mL can of Coke; it’s also very acidic (pH 2.53) as it contains phosphoric acid. Pepsi contains even more sugar and is even more acidic (pH 2.45). Sugar-free “diet” alternatives such as Coke Zero and Pepsi Max can also damage teeth.

Caffeine-loaded V Energy drink stands out as having a higher acid reserve than most other soft drinks. Fruit cordials such as Golden Circle Pineapple Crush, and fruit drinks such as Pop Tops Apple Blackcurrant Drink, can also be in the high-risk category. Fruit juices, often seen as healthy, can cause dental erosion due to their acidity. Studies show that fruit juices are the most resistant to saliva’s buffering effect, followed by fruit-based carbonated drinks.

The Australian Beverages Council argues drinks leave the mouth quickly and are less likely to cause tooth decay than foods that stick to the teeth. However, they can still cause erosion. A study of children in the UK found dental erosion was associated with consumption of fizzy drinks (and to a lesser extent, fruit juices).

*Nathan Cochrane is a dental researcher at the Cooperative Research Centre (CRC) for Oral Health Science.