Aspartame and type 2 diabetes: possible mechanisms
What it found
In people, animals and lab tests, aspartame has been linked to changes that could make blood sugar control worse in type 2 diabetes, but the evidence is mixed and the author says it is still debatable.
What they found
Studies in people
Blood glucose in people
Some human studies found no big difference in blood glucose after aspartame, while one study found blood glucose went down in 40% of people, up in 20%, and stayed the same in 40%. This mixed result is part of why the effect is still debated.
Animal and lab studies
Blood glucose in animals
In mice, rats and zebrafish, aspartame raised fasting glucose, worsened insulin sensitivity, or caused glucose intolerance. One rat study found no significant change in blood glucose even though cortisol rose.
Cortisol and stress
In rats, aspartame at 75 mg/kg/day for 90 days increased corticosterone (cortisol), a hormone that can work against insulin. The author says this may be one way aspartame could affect blood sugar in diabetes.
Gut bacteria
In rats and mice, aspartame changed the gut bacteria and was linked to higher fasting glucose and impaired insulin tolerance. The author says this may be another route to glucose problems.
Oxidative stress
Many animal and lab studies found aspartame increased free radicals in blood, brain, liver, kidney, heart and immune organs. The author links this to inflammation and insulin resistance.
Studies in people and animals
Weight and appetite
Some human studies found higher BMI with diet drinks, and animal studies found aspartame caused greater weight gain than sugar even with similar calories. The author suggests this may be because sweet taste without calories disrupts appetite control.
What the authors conclude
“Aspartame and its metabolites are safe for T2D is still debatable due to a lack of consistent data.”
Also in their conclusions
- They conclude that aspartame use in type 2 diabetes may lead to weight gain rather than weight loss.
- They say aspartame may act as a chemical stressor, increasing cortisol levels, which interfere with insulin pathways.
- They suggest that aspartame consumption regulations should be revisited and international guidelines reviewed.
How it was done
People with type 2 diabetes often use aspartame to cut down on sugar and manage blood glucose. The author wanted to pull together studies on how aspartame might affect the body in ways linked to type 2 diabetes.
The author reviewed published studies in people, animals and lab tests that looked at aspartame and blood glucose, insulin, weight, gut bacteria, stress hormones and oxidative stress. No new experiments were done.
What it can’t tell you
- Most of the evidence comes from animals or lab tests, so it cannot show what happens in people with type 2 diabetes.
- Human studies are limited, often small, and rely on self-reported aspartame intake, which may not be accurate.
- The review cannot prove that aspartame causes type 2 diabetes or makes it worse, only that some studies suggest possible links.
Who paid
- Authors work at
- University of Pretoria, South Africa
The paper
- Title
- Aspartame: Should Individuals with Type II Diabetes be Taking it?
- Type
- ReviewThe authors read earlier studies and describe what they found. It isn’t a new study.
- Evidence
- Studies in people · animals · lab
- Summarised from
- Full text
- Cite
- Choudhary AK (2018). Aspartame: Should Individuals with Type II Diabetes be Taking it?. Current diabetes reviews. doi:10.2174/1573399813666170601093336Free full textPubMed 28571543DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error