Aspartame is an artificial sweetener that has become a common part of many modern diets. It is found in products labeled "light" or "sugar-free", such as soft drinks, yogurts, chewing gum, medicines and vitamin supplements. Its great advantage is that it sweetens up to 200 times more than sugar, but with almost zero caloric intake. However, its safety has been the subject of debate since its appearance in the 1980s.
Various international bodies have been assessing the potential risks of aspartame consumption for decades. These are the main pronouncements:
1. FDA (Food and Drug Administration, U.S.A.) Since 1981, the FDA has approved the use of aspartame as a sweetener. The agency has reviewed more than 100 studies before authorizing its consumption and maintains that aspartame is safe at recommended doses. The Acceptable Daily Intake (ADI) established by the FDA is 50 mg per kilogram of body weight.
2. EFSA (European Food Safety Authority). In 2013, EFSA conducted one of the most comprehensive reviews to date. It evaluated more than 600 studies and concluded that there is no evidence linking aspartame to cancer, brain damage or neurological problems, if consumed within established limits. Its ADI is 40 mg/kg.
3. WHO (World Health Organization) In July 2023, WHO published a report in conjunction with IARC (International Agency for Research on Cancer), which classified aspartame as "possibly carcinogenic to humans" (group 2B). This classification generated concern, but WHO itself clarified that the evidence is limited and inconclusive, and that moderate consumption is still safe.
"We are not advising people to stop consumption altogether. We are pointing out that more research is needed," explained Dr. Francesco Branca, director of WHO's Department of Nutrition.
For a 70-kilogram person, the ADI established by WHO (40 mg/kg) is equivalent to consuming up to 14 cans of diet soda per day. In other words, the usual amounts consumed by the average person are well below the risk limit.
An important caveat is that aspartame contains phenylalanine, an amino acid that people with phenylketonuria cannot metabolize. For those with this genetic condition, aspartame can be dangerous and should be avoided completely. For this reason, all products with aspartame carry a visible warning for people with PKU.
The most rigorous studies and the world's most prestigious health agencies agree: aspartame is safe when consumed in moderate amounts. Although some recent research has called for further evaluation of its possible long-term effects, the current evidence does not justify alarmism. For most people, occasional or regular consumption within recommended limits does not pose a health risk.