Sweetener

Studies in people

• Open question

  Gut bacteria and weight³

  Scientists do not yet know whether sweeteners help or hurt weight, blood sugar, or gut bacteria over time.

• Concern

  Heart and stroke risk⁴

  People who ate more artificial sweeteners had more heart and stroke problems, though this study cannot prove cause.

• Open question

  Gut bacteria and metabolism⁵

  In human studies, sweeteners' effects on gut bacteria and metabolism differ between trials, and some but not all find changes.

• Concern

  Gut symptoms⁶

  In people, eating sweeteners daily for five weeks was linked to more diarrhea, constipation and stomach burning.

Study type not stated

• Open question

  Blood sugar control⁷

  In mice and some people, non-caloric sweeteners changed gut bacteria and led to higher blood sugar.

• Open question

  Stool test limits⁸

  Scientists still disagree about whether low calorie sweeteners change gut bacteria, and stool tests may not show what happens in the gut.

• Open question

  Weight and diabetes risk⁹

  Scientists are still learning how sweeteners affect weight, appetite and type 2 diabetes risk.

• Open question

  Gut bacteria¹⁰

  Sweeteners like aspartame and saccharin may change gut bacteria, and some may affect how the body handles sugar.

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 one finding in people. When most findings in people point one way, the page leans that way (“Mostly”), and every finding is still shown. 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.