A 20 per cent tax on sugar-sweetened beverages could prevent 3.7 million cases of tooth decay, generate nearly $1.4 billion in revenue, and collectively add hundreds of thousands of healthy years to Australians' lives, according to new research from Griffith University published in BMJ Public Health.
What the Sugar Tax Research Found
The Griffith University study used a computer-based simulation to model the long-term health and economic effects of a levy on non-alcoholic drinks with added sugar — including soft drinks and most juices — applied across Australia over a 25-year horizon.
Researchers found the tax would not only prevent 3.7 million cases of tooth decay, but also avert 191,000 cases of gum disease and 115,000 cases of complete tooth loss. Beyond oral health, the study estimated the measure would generate approximately half a million health-adjusted life years for the 2019 Australian population over their lifetimes, factoring in both dental improvements and reductions in weight-related illness.
The modelling showed that for every 1 per cent rise in the price of sugary drinks, consumption would be expected to fall by 1.2 per cent. If a 20 per cent tax were passed on in full to consumers, the study predicted a 24 per cent reduction in consumption overall.
Co-author and Griffith University public health professor Lennert Veerman said the benefits were wide-ranging. "The study also estimates a 20 per cent sugar tax would generate approximately half a million health-adjusted life years for the 2019 Australian population over their lifetime, both from dental health improvements and reductions in weight-related illness," he said.
Australia's Sugar and Dental Health Problem
The research paints a stark picture of the nation's current health landscape. As of 2017–2018, roughly 9.1 per cent of Australian adults reported drinking sugar-sweetened beverages every day. Meanwhile, nearly one-third of Australians aged 15 and older had untreated tooth decay or cavities.
Oral diseases ranked among the top 10 diseases by health burden in Australia, contributing to 2.4 per cent of the country's total health burden. Globally, oral diseases affect an estimated 3.5 billion people, making them a growing public health concern. For Australians already navigating complex health decisions — including those exploring weight-management treatments — the findings underscore the importance of systemic, population-level prevention.
Researcher Marco Peres from SingHealth Duke-NUS in Singapore emphasised that a sugar tax works at a structural level rather than placing the burden on individuals. "It does not rely solely on individuals changing their behaviour but helps create an environment in which healthier choices become easier," he said. "This is particularly important if we want prevention strategies to reach the whole population and reduce health inequalities."
International Precedent and the Case for Action in Australia
Australia would not be acting alone. According to the World Health Organization, 116 countries already have an excise tax on at least one type of sugar-sweetened beverage.
The United Kingdom introduced such a tax in 2018, set at either 19.4 or 25.9 pence per litre depending on sugar content. The UK government reported it led to a 46 per cent reduction in the sugar content of soft drinks, with nearly 90 per cent of the market now sitting below the threshold at which the tax applies.
In Australia, a 2024 parliamentary inquiry into the nation's diabetes epidemic formally recommended introducing a 20 per cent tax on sugary drinks. The Parliamentary Budget Office estimated that — after accounting for collection costs and a reduction in GST revenue — the tax would raise nearly $1.4 billion over the following two financial years.
The Australian Medical Association declared at the time it was "100 per cent behind" the measure. The study also noted there is strong public support in Australia for policies aimed at reducing sugar intake, suggesting the political conditions for reform may be closer than many assume.
The study suggested that revenue raised could be directed toward strengthening health services and funding a universal healthcare approach to dental care — areas advocates say remain critically underfunded.
