A new Australian study has found that drinking just one can of diet soda a day may raise the risk of developing type 2 diabetes by 38%. The study shows that the risk from artificially sweetened soft drinks is even greater than that from regular sugary drinks, which were linked to a 23% higher risk.
Researchers from Monash University, RMIT University, and the Cancer Council Victoria tracked over 36,000 Australian adults for nearly 14 years. The study was led by Distinguished Professor Barbora de Courten, Associate Professor Allison Hodge, and PhD student Robel Hussen Kabthymer.
Published in the journal Diabetes & Metabolism, the findings raise new concerns about the health effects of both sugar-sweetened and diet drinks. The research adds to growing global evidence that artificially sweetened beverages are not a safe alternative to sugary drinks.
"Drinking one or more of these beverages each day, whether sweetened with sugar or artificial substitutes, was linked to a significantly higher chance of developing type 2 diabetes," said Mr. Hussen Kabthymer.
Professor de Courten, senior author of the study, said the findings challenge the common assumption that artificially sweetened beverages are a safer choice.
​​​​"Artificial sweeteners are often recommended to people at risk of diabetes as a healthier alternative, but our results suggest they may pose their own health risks," she said.​​​
​​​​While the link between sugary drinks and diabetes could largely be explained by obesity, the connection between artificially sweetened drinks and type 2 diabetes remained strong even after adjusting for body weight, suggesting a potentially direct effect on metabolism.​​​
Professor de Courten said the findings have important implications for public health policy.
​​​"We support measures like sugary drink taxes, but our study shows we also need to pay attention to artificially sweetened options. These are often marketed as better for you, yet may carry their own risks. Future policies should take a broader approach to reducing intake of all non-nutritive beverages."
​​​​The study analysed data from the long-running Melbourne Collaborative Cohort Study, also known as Health 2020, involving participants aged 40-69 years, and adjusted for diet, exercise, education, and health history.
Type 2 diabetes affects around 1.3 million Australians and more than 500 million people worldwide, with the vast majority of cases linked to diet and lifestyle.
