The main cause of tooth decay is sugar and any discussion about fluoride should include the health impacts of soft drinks, says Nelson Marlborough District Health Board principal dental officer Roby Beaglehole.

Sugar was the common risk factor in tooth decay, obesity and type 2 diabetes, which was likely to bring the New Zealand health system “to its knees” in 10 to 15 years, he said.

The country needed a national strategy to reduce sugar consumption.

“From a public health policy perspective, we need to target sugar, in particular sugar-sweetened beverages like Coke, Pepsi and Powerade.”

A 1.5-litre bottle of Coke had 40 teaspoons of sugar and was the No 1 selling item in New Zealand supermarkets, he said.

The Government needed to treat sugary drinks the same way it treated alcohol and tobacco, through taxation and limiting companies’ advertising and sponsorship deals. The tax needed to be at least 20 per cent to be effective, Dr Beaglehole said.

“And we need to limit access by removing sugary drinks from vending machines,” he said.

“McDonald’s sponsor children’s soccer where the player of the day gets a free Big Mac voucher. So if we are talking about fluoride, let’s also discuss sugar. If you can reduce sugar consumption across the population that can have a massive impact on a number of diseases. People think that’s a bit radical but type 2 diabetes will probably bring the health system to its knees in our lifetime.”