A diet heavy in seven sugar substitutes has been linked to faster cognitive decline, according to neurology experts.
The sweeteners – aspartame, saccharin, acesulfame-K, erythritol, xylitol, sorbitol, and tagatose – are found in ultraprocessed food and drinks like soda, protein bars, yogurt, and low-calorie desserts.
People who ingested more than 190 milligrams of the sweeteners, on average each day for a year, showed 62 percent faster declines in thinking and memory skills than those who consumed 20 mg. A can of diet soda contains about 200 mg of sweetener and a packet of Sweet’N Low has 20 mg.
The cognitive decline is equivalent to about a year and a half of aging, said researchers from the American Academy of Neurology.
The link was found in people under the age of 60 but not in those who were older. For people with diabetes, the link was even stronger. People with diabetes are more likely to use artificial sweeteners as sugar substitutes.
“Low- and no-calorie sweeteners are often seen as a healthy alternative to sugar, however our findings suggest certain sweeteners may have negative effects on brain health over time,” Dr. Claudia Kimie Suemoto, of the University of São Paulo, said in a statement.
The research, conducted in Brazil, tracked the health of 12,772 adults with an average age of 52 over a range of time periods up to eight years.
Participants were sorted into three groups based on how much artificial sweetener was in their daily diet, and their cognitive ability tested at the beginning, middle, and end of the study.
But it wasn’t just the highest consumers of sweeteners that were impacted - those in the middle group had cognitive decline that was 35 percent faster than the lowest group.
Eating foods with aspartame, saccarin, acesulfame-k, erythritol, sorbitol and xylitol was associated with a faster decline in overall cognition, particularly in memory.
Sorbitol, commonly used in sugar-free gum, was consumed the most, at an average of 64 mg a day.
There was no link between the consumption of tagatose and cognitive decline. Tagatose is used in chocolate and other sweets, cereals, soft drinks, and ice creams.
However, the researchers said the findings do not definitively mean that sweeteners are the cause of cognitive decline, and that other factors could be at play.
For one, not all artificial sweeteners and sugar substitutes on the market were included. Study participants also recorded their own diets so they may not have noted everything they ate.
Aspartame, saccharin, and acesulfame-K are authorized as food additives in the United States and are considered safe for the general population, according to the Food and Drug Administration. The FDA also considers erythritol, tagatose, sorbitol, and xylitol to be safe.
Xylitol has been linked to heart attack and stroke in people who consume more than 30 grams, or about a single scoop of keto-friendly ice cream, according to the Cleveland Clinic. Erythritol has also been linked to risk of cardiac events.
Xylitol and Erythritol are both derived from plants and can cause gastrointestinal problems, according to Harvard Medical School. Artificial sweeteners, which are made using chemicals, are also related to gut issues.
Aspartame, which is commonly used in soda, was classified as “possibly carcinogenic” by the International Agency for Research on Cancer in July 2023. But, a panel of international experts from the World Health Organization and the Food and Agriculture Organization said the same month that it does not pose a health concern.
“More research is needed to confirm our findings and to investigate if other refined sugar alternatives, such as applesauce, honey, maple syrup or coconut sugar, may be effective alternatives,” Suemoto said.
