Dentists have issued a warning about popular fruit drinks and smoothies after it emerged some can be as acidic as vinegar.
Fruity drinks are commonly given to children by well-meaning parents to ensure they get their ‘five a day’.
But an investigation found many contained a high acid level which can erode tooth enamel.
The warning came as official figures revealed dental problems were the third most common reason for child hospital admissions last year.
A This Water drink with lemons and limes had a pH level of 2.7 – more acidic than vinegar, at 2.9.
This is at the upper end of the acidity scale in which 7 is neutral and 1 is extremely high.
Tooth enamel begins to be destroyed higher than level 5.5 on the scale.
Other drinks tested – including Tropicana orange juice, Copella apple juice and Innocent smoothies – all had acid levels ranging between 3.3 and 3.8. The most acidic was Coca-Cola, with a pH level of 2.5.
Dr Kathy Harley, dean of the dental faculty at the Royal College of Surgeons, said many parents are unaware that the combination of high acid and sugar can destroy young teeth.
She warned last year that 50 per cent of five-year-olds have signs of damage to their tooth enamel caused by excess acid in their diet.
Manufacturers are not required to publish the acid levels in drinks.
Department of Health figures show dental problems were the third most common reason for children to be admitted to hospital in England in 2011-12 – beaten only by viral infections and disorders related to premature birth.
Government advice states that everyone should have five portions of fruit and vegetables a day, with 150ml of fruit juice counting as one portion.
Dr Harley said it would be better if children met the target by eating fruit with meals and for juice to be a ‘once a week treat’.
Dentists also advise drinking water after having juice to wash away some of the acid.
This Water said its products were “not meant for children’, adding, “The recipe in question is made with fresh lemon and lime juice so it is going to have a natural acidity.”
Dentists said that rather than consuming fruit or fruit juices as a snack, they were better consumed at meal times or accompanied with something containing calcium, such as cheese, which neutralises acid.
Children should be encouraged to drink water afterwards to wash away some of the acid, but not to brush their teeth until at least an hour afterwards, as teeth are weakened by exposure to acid, they said.
In 2008 Innocent Drinks, now majority owned by Coca Cola, had an advertisement campaign in which its products were billed as “Simple, natural refreshment’ banned by the Advertising Standards Authority for failing to inform consumers about the sugar content of its juice drinks.
A spokesman for This Water drinks said the products were “not meant for children and are not marketed as such.”
–Daily Mail, London