In 2023 the World Health Organization classified aspartame as "possibly carcinogenic to humans."
Aloe vera extract and pickled vegetables sit in the same group.
Group 2B is about the strength of the evidence, not the size of the risk
The International Agency for Research on Cancer (IARC) sorts substances by how sure we are that they cause cancer, not by how dangerous they are.
Group 2B means the evidence is limited. How much you would have to consume is not part of the question.
| Group | Meaning | Examples |
|---|---|---|
| Group 1 | Carcinogenic | Tobacco, alcohol, processed meat |
| Group 2A | Probably carcinogenic | Red meat, drinks above 65°C |
| Group 2B | Possibly carcinogenic | Aspartame, pickled vegetables, aloe vera |
Processed meat is Group 1, two steps above aspartame. Eating sausage every day while worrying about zero cola has the order backwards.
The daily limit is still 40 mg
JECFA, the joint FAO/WHO expert committee on food additives, published its review the same day and kept the acceptable daily intake at 40 mg per kg of body weight. That is the value set in 1981.
Here is the WHO's own example. With 200 to 300 mg of aspartame in a can, a 70 kg adult would have to drink more than 9 to 14 cans a day to pass the limit.
| Body weight | Daily limit | In cans |
|---|---|---|
| 50 kg | 2,000 mg | About 7–10 cans |
| 60 kg | 2,400 mg | About 8–12 cans |
| 70 kg | 2,800 mg | About 9–14 cans |
If it still nags at you
- •Products without aspartame: check the label for stevia, monk fruit or allulose
- •Make half your drinks sparkling water: your exposure drops by half
- •With phenylketonuria, avoid aspartame. That is a separate issue from cancer
People with phenylketonuria (PKU) must not consume aspartame. The back of the package says "contains phenylalanine."
What changed is what we know, not aspartame
The WHO statement said safety at commonly used amounts is not a major concern, and that better research is needed.
Group 2B is closer to a note saying "look again" than to a conclusion.
Aspartame was discovered in 1965. Sixty years of study and it still sits at "limited evidence," which is itself information about how small the risk is.
Sources · IARC and JECFA aspartame evaluations (2023-07-14) · WHO press release · Korea's Ministry of Food and Drug Safety food additives code