Aspartame

Animal and lab studies only

• Concern

  Cancer in animals⁶

  In animal studies, aspartame was linked to more cases of several types of cancer.

• No harm found

  DNA damage⁷

  In lab and animal studies, aspartame showed no signs of causing mutations or cell changes.

• Concern

  Cancer risk in rodents⁸

  In animal studies, aspartame was linked to cancer, though some experts question how those tests were run.

• Concern

  Heart and blood vessel risk⁹

  In animal studies, aspartame sped up hardening of the arteries in mice with high blood fat.

• Concern

  Stomach cancer risk¹⁰

  In lab studies, aspartame may affect proteins tied to stomach cancer, but scientists do not yet know if this happens in people.

Study type not stated

• Open question

  Mood and cancer risk²

  Scientists do not yet know whether daily aspartame intake causes mood changes or raises cancer risk in people.

• Open question

  Brain and mood effects³

  Scientists do not yet know whether aspartame causes brain or mood problems, because the data is not consistent.

• Open question

  Overall health effects⁴

  A review found studies on aspartame’s effects on weight, diabetes, children, unborn babies, allergies, and cancer need more research.

• Concern

  Cancer risk in people⁵

  Experts looked at the research and said aspartame is possibly cancer-causing in people.

The signal at the top counts the findings in people and in animal and lab studies. A concern in studies of people outranks animal and lab studies, and “No concerns” needs at least two findings in people. Findings whose study type is not stated are shown but not counted. This page is a reference, not medical advice. It describes what regulators and published research say. Talk to a doctor or dietitian about your own diet.