What is aspartame, the 'possible carcinogen' in diet sodas, sugar-free juices?

Aspartame, a popular artificial sweetener found in Diet Coke, chewing gum, yoghurt and other food products, is set to be declared a possible carcinogen next month by a World Health Organization arm, Reuters reported on Thursday.

What is aspartame?

Discovered in 1965 by American chemist James Schlatter, aspartame is about 200 times sweeter than the regular table sugar. It was approved by the US Food and Drug Administration in 1974 for use as a tabletop sweetener and as an additive in chewing gum, breakfast cereals and dry bases for foods.     

Why aspartame?

Despite its intense sweetness, aspartame has an almost zero calorific value and no bitter aftertaste like saccharin, and grew in popularity as a more diet-conscious consumer emerged. 

What products contain aspartame?

The low-calorie sugar substitute can be found in soft drinks, gelatin, confectionery, desserts, and sugar-free cough drops. It is also used to enhance flavoring of baked and canned foods, powdered drink mixes, candy and puddings.

Have companies moved away from aspartame?  

Aspartame's use in food products has been debated for decades and has also prompted some companies to remove the compound from their products. 

PepsiCo removed aspartame from some US diet sodas. Although the company brought it back a year later, it again removed the ingredient in 2020. 

General Mills' Yoplait also removed aspartame from its yogurts in 2014. The brand's low-sugar products now contain alternative sweeteners like sucralose. 

What other artificial sweeteners are in use?

Saccharin, sucralose and neotame are among five other artificial sweeteners alongside aspartame authorised by a WHO expert committee on food additives.

The FDA has also approved usage of three types of plant- and fruit-based sweeteners, including extracts obtained from the stevia plant, swingle fruit extracts and a group of proteins called Thaumatin. 

Is aspartame used outside of the US?

More than ninety countries, including the UK, Spain, France, Italy, Denmark, Germany, Australia and New Zealand have reviewed aspartame and found it to be safe for human consumption and allow its use. 

While the FDA pins the acceptable daily intake for aspartame at 50mg/kg of body weight per day, the European regulatory body recommends a slightly lower ADI at 40mg/kg/day.