Eating apples can be up to four times more damaging to teeth than carbonated drinks, according to new research.
Wine and lager also increase the risk of dental damage but pickled onions and grapefruit, which are consumed less frequently, do not.
‘It is not only about what we eat, but how we eat it,’ says Professor David Bartlett, head of prosthodontics at King’s College London Dental Institute, who led the study.
‘Doctors quite rightly say that eating apples is good, but if you eat them slowly the high acidity levels can damage your teeth. The drinks most often associated with dietary erosion, particularly cola, showed no increased risk.
The results emphasize that dietary advice should be targeted at strong acids rather than some of the commonly consumed soft drinks.’
In the new study, the researchers looked for links between tooth wear at several sites in the mouth, and diet in more than 1,000 men and women aged 18 to 30.
They looked for damage to the 2mm surface enamel of their teeth, and at the dentine, the main supporting structure of the tooth beneath the enamel, and compared it with diet.
People who ate apples were 3.7 times more likely to have dentine damage, while carbonated drink consumers had no additional risk.
Fruit juice increased the likelihood of damage to the enamel around the top of the teeth near the gums fourfold, while lager, which is acidic, raised the chances of dentine damage threefold.
Some apples contain as much as four teaspoons of sugar which contributes to raised acid levels in the mouth.
Dr Glenys Jones, nutritionist at the Medical Research Council’s Human Nutrition Research unit, says: ‘Fruit can be acidic and obviously does have a sugar content but I would not want anyone to be discouraged from consuming fruit and fruit juices.’
One suggestion is to eat your apple with milk or a piece of cheese as both contain calcium, which neutralizes acid. Drinking water immediately after eating an apple will also help, washing away harmful effects.
Dr Jones adds: ‘Drinking fruit juice and smoothies with a straw is a way of protecting your teeth.
‘Brushing your teeth before eating acidic foods can also help because it provides a barrier between the food and the teeth.’