A landmark Australian study has found that a 20 per cent tax on sugar-sweetened beverages could prevent nearly four million cases of tooth decay, generate close to half a million extra years of healthy life, and raise almost $1.4 billion in revenue — reigniting debate over whether Australia should follow dozens of other countries in taxing sugary drinks.
The research, conducted by Griffith University and published in BMJ Public Health, used computer-based modelling to project the health and economic consequences of a sugar tax applied to non-alcoholic drinks with added sugar — including soft drinks and most juices — across a 25-year horizon.
What the sugar tax research found
The study's headline findings are striking. A 20 per cent levy, if fully passed on to consumers, is projected to produce a 24 per cent reduction in sugar-sweetened beverage consumption — roughly 1.2 per cent less consumption for every 1 per cent rise in price. Over the lifetimes of the 2019 Australian population, that translates to:
- 3.7 million fewer cases of tooth decay
- 191,000 fewer cases of gum disease
- 115,000 fewer cases of complete tooth loss
- Approximately 500,000 health-adjusted life years gained, from both dental improvements and reductions in weight-related illness
Griffith University public health professor and co-author Lennert Veerman said the gains would extend well beyond oral health. "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.
The researchers also suggested that revenue raised by the tax could be directed toward strengthening health services and funding a universal healthcare approach to dental care.
Why oral health is a key concern
Australia's oral health picture provides urgent context for the findings. As of 2017–2018, around 9.1 per cent of Australian adults reported drinking sugar-sweetened beverages every day, while nearly one-third of Australians aged 15 and older had untreated tooth decay or cavities. Oral diseases account for 2.4 per cent of Australia's total health burden and rank among the country's top 10 diseases by impact.
Globally, oral diseases affect an estimated 3.5 billion people, making them one of the most widespread public health challenges in the world.
Marco Peres from SingHealth Duke-NUS in Singapore, who contributed to the research, stressed that a sugar tax works differently from individual behaviour campaigns. "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 Australian momentum
Australia would not be breaking new ground. According to the World Health Organization, 116 countries currently levy 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 — and subsequently reported a 46 per cent reduction in the sugar content of soft drinks, with nearly 90 per cent of the market now falling below the taxable threshold.
In Australia, a 2024 parliamentary inquiry into the country's diabetes epidemic formally recommended introducing a 20 per cent sugar tax. The Parliamentary Budget Office estimated the measure would raise nearly $1.4 billion over two financial years, after accounting for collection costs and a reduction in GST receipts. The Australian Medical Association declared it was "100 per cent behind" the proposal at the time.
The study also notes that there is already strong public support within Australia for policies designed to reduce sugar consumption — a political foundation that advocates argue makes the case for action harder to ignore.
With fresh evidence now on the table, pressure is likely to grow on policymakers to answer the $1.4 billion question: how long can Australia afford to wait?
