Diet soft drinks linked to heart disease and diabetes risks, WHO warns

Regularly drinking diet soft drinks could raise the risk of health problems like heart disease and type 2 diabetes. These beverages often contain artificial sweeteners and caffeine but offer little nutritional value. Now, new research is prompting fresh discussions about their long-term effects on the body. A standard 375ml can of Coca-Cola holds around seven teaspoons of sugar—nearly 40 grams. Diet versions, such as Diet Coke, replace sugar with artificial sweeteners like aspartame. While these alternatives avoid sugar, concerns have grown over their impact on gut health and potential links to cancer.

In 2023, the World Health Organization (WHO) classified aspartame as possibly carcinogenic. However, the organisation stressed that most people consume safe amounts, with risks only appearing if someone drinks around 14 cans daily. Australia's food regulator, FSANZ, reviewed the evidence but kept aspartame's safety status unchanged as of 2026, leaving no new warnings or restrictions on products containing it.

Cutting back on very sweet foods or drinks can change how people taste sweetness over time. Many find that after reducing intake, overly sweet items start to taste unpleasant. While an occasional diet drink is unlikely to create a craving for sugary foods, health experts still advise moderation for those who consume them daily.

Australians drink nearly 60 litres of soft drink per person each year. Emerging studies suggest some artificial sweeteners may disrupt gut bacteria or irritate the digestive system. Yet, regulators maintain that current consumption levels remain within safe limits. The debate over diet drinks continues, with evidence pointing to possible risks from high intake. The WHO's classification of aspartame has not led to stricter rules in Australia, where authorities still consider it safe in permitted amounts. For now, health advice focuses on moderation rather than complete avoidance.