What is the heated debate about Aspartame?
Does aspartame cause cancer?
We do not know. And neither do the IARC scientists. That is why aspartame has been grouped into category 2B, which means “possibly carcinogenic to humans”. Other compounds included in the 2B category are, for example, Aloe vera and pickled vegetables (Asian style).
What does a categorisation into 2B “Possibly carcinogenic to humans” actually mean?
It means that there is limited scientific evidence – which is not conclusive – that the substance in question is carcinogenic in humans, and/or there are some animal studies that have shown carcinogenicity.
What is considered an acceptable quantity of aspartame that one can safely consume?
The evaluations by IARC, only indicates if is carcinogenic or it is likely to be carcinogenic. However, this information alone does only provide half of the story. We need additional information to understand the risk associated to the consumption, for example, how much it is consumed and for how long. As an example, alcohol is classified in category 1 (there is solid evidence that the substance causes liver cancer), but the risk of cancer increases with the amount consumed and the frequency. Everything we consume has an associated risk, including the glass of beer or wine we enjoy on a terrace in the summer. And remember, aspartame is not categorised in category 1, but in the much lower category 2B.
Who evaluates the risk?
This type of assessment is done by the Joint FAO/WHO Expert Committee on Food Additives (JECFA). This expert group does not only consider carcinogenicity information but also other adverse effects, and the lack of them, shown in scientific studies. JECFA evaluated aspartame for the first time in 1981 and set the ADI (acceptable daily intake) to 40 mg/kg body weight/day. The ADI is the daily amount of the substance that can be consumed safely. Since then, JECFA has evaluated the safety of aspartame several times to consider new scientific information (additional human, animal studies and daily intake estimates). The last revision was conducted this year in parallel to the evaluation of aspartame by IARC. And JECFA confirmed that the ADI of 1981 remains current, at 40 mg/kg body weight/day.
How does the ADI mean in practical values? For example, how many cans of Coke Light can we drink per day to not exceed the ADI?
It depends on your body weight. A person weighing 75 kg can safely consume 3 g of aspartame every day (40 mg/kg bw [ADI]*75 kg). According to Coca-Cola, Coca Cola Light and Zero in Switzerland contain 130 mg/L. A 75 kg-person could safely drink 23 L Coke or 70 cans of 0.33 L per day. If this volume of liquid was consumed in one day, the aspartame quantity would be the least of the persons’ concerns. And for a 6-year old child of 20 kg this would still be more than 6 litres Coke Zero or Light every day to reach the ADI – a significantly higher volume of liquid most humans consume on average per day (1-3 L).
How is aspartame regulated in Europe and the USA?
The authorization of aspartame in the European Union as a food additive (E 951) falls under Regulation (EC) No 1333/2008, which governs the use of food additives. Aspartame is an approved sweetener in the EU, used in various food products such as beverages, desserts, candies, dairy items, chewing gums, energy-reducing and weight control products, as well as a table-top sweetener. The safety of Aspartame has also been assessed by the EU’s Scientific Committee for Food (SCF, most recently in 2002), and the European Food Safety Authority (EFSA, most recently in 2011): EFSA, according to Article 32 of Regulation (EC) No 1333/2008, EFSA is responsible for conducting a safety evaluation of food additives before their approval for use in the EU. Like JECFA, EFSA has determined the acceptable daily intake (ADI) for aspartame to be 40 mg/kg body weight (bw)/day.
In the USA aspartame is authorized as well, as a sweetening agent, sugar substitute, and flavour enhancer for the uses stated in 21 CFR 172.804: therefore, it may be safely used in food in accordance with good manufacturing practice unless specific limitations are set (e.g. in baked goods and baking mixes, the amount of the additive is not to exceed 0.5 percent by weight of ready-to-bake products or of finished formulations prior to baking).
In both regulatory systems, the additive shall be clearly listed in the ingredients list and a warning about the content of phenylalanine is mandatory. The latter is intended for those suffering from the rare disorder of phenylketonuria, which is an inherited genetic disorder that results in decreased metabolism of the amino acid phenylalanine and can lead to intellectual disability, seizures, behavioral problems, and mental disorders. Therefore, individuals with this disorder have to restrict their diet to foods with low levels of phenylalanine.