Question & Answer

The Evidence

• Aspartame is an artificial sweetener that is low in calories. It is added to many foods and drinks. Because it is about 200 times sweeter than sugar, a much smaller amount of aspartame is needed to achieve a taste like sugar. It is therefore a popular replacement for sugar in low-calorie foods, including table-top sweeteners, chewing gum and food supplements.  However, over 90% of exposure to aspartame by humans is through artificially sweetened drinks.
• Since aspartame first began to be added to drinks in the 1980s, there has been a concern that it may have adverse health effects, in particular that aspartame may be linked with cancer.
• We looked for studies and recommendations to see if consuming drinks containing aspartame is associated with cancer.
• We found some information from both the International Agency for Research on Cancer (IARC) and the Joint FAO/WHO Expert Committee on Food Additives (JECFA).
• The IARC said that aspartame could possibly cause cancer in humans but said that there is limited evidence about it.
• The World Health Organisation published a systematic review in 2022 that looked at the health effects of the use of non-sugar sweeteners (NSS), which included aspartame. This review included 283 studies, but only 5 studies looked at the link between aspartame in drinks and cancer. Overall, these 5 studies did not find an association between aspartame-containing drinks and cancer, but the evidence is weak.
• A cohort study published later in 2022, presents an update on the findings of The NutriNet-Santé study in France. This study found an association between the consumption of aspartame in foods and drinks and overall cancer, breast cancer and obesity-related cancers.
• While three other studies found an association between artificially sweetened beverages and liver cancer, these studies do not specifically look at aspartame. Also, we can’t rely on these findings as they could be due to chance or other reasons not captured by the studies.
• Overall, the evidence that consuming aspartame containing drinks causes cancer in humans is limited, and more research is needed.

Guidelines and recommendations

• JECFA advised that there should be no change to the current acceptable daily aspartame intake of 40 mg/kg body weight. An adult weighing 70kg would need to consume more than 9–14 cans of soda per day to exceed the acceptable daily intake, assuming no other intake from other food sources.
• The IARC said that aspartame could possibly cause cancer in humans but said that there is limited evidence about it.