New Study Says Sugar Substitute in Zero Sugar Sodas, Diet Sodas, Gum and Other Foods May Raise Risk of Stroke

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Aspartame — the artificial sweetener found in everything from Diet Coke and sugar-free chewing gum to children’s medications — may raise the risk of the most common type of stroke by causing inflammation and disrupting blood vessel health and blood flow, according to new research.

Published last month (July 2025) in Scientific Reports, the study is the first to combine advanced computer modelling techniques to examine how aspartame interacts with processes in the body that can lead to a stroke or affect its severity, its authors said.

The findings add to longstanding concerns about the sugar substitute’s impacts on the brain and heart.

“Given that aspartame is one of the most pervasive artificial sweeteners used in the global food industry, its cumulative effects from long-term, low-dose exposure may indirectly affect cerebrovascular [brain blood vessel] health through metabolic interference,” the researchers said.

Ischemic stroke, which accounts for about 87% of all strokes in the U.S. and is a leading cause of death globally, occurs when a blood clot blocks a brain blood vessel, cutting off oxygen and causing brain cells to die. Common risk factors include high blood pressure, smoking and Type 2 diabetes.

Aspartame — also marketed as NutraSweet, Equal, Sugar Twin and AminoSweet — is up to 200 times sweeter than sugar and promoted as a way to cut calories and sugar intake, especially for people with diabetes.

Its safety has been debated for decades, with studies linking aspartame consumption to chronic diseases, weight gain and even aggressive brain cancer.

This study provides preliminary systematic insights into the potential neurotoxicity mechanisms of aspartame, its authors said. They found that aspartame strongly binds to and influences five key genes that code for proteins linked to ischemic stroke.

These proteins help regulate inflammation (the body’s response to injury or infection), blood pressure, and the strength and function of blood vessels. Disruptions may:

  • Raise blood pressure.

  • Trigger inflammation in the brain and blood vessels.

  • Weaken blood vessel walls and the brain’s protective barrier (blood-brain barrier), allowing harmful substances to enter the brain and worsen a stroke. [MORE]