A long-term Brazilian study has cast fresh doubt on the wisdom of swapping sugar for artificial sweeteners. Tracking more than 12,700 adults for eight years in a longitudinal study, researchers divided participants into three groups based on consumption of low- and no-calorie sweeteners—including aspartame, saccharin, acesulfame-K, erythritol, xylitol and sorbitol. Only tagatose, a naturally occurring sweetener, emerged unscathed.
Those in the highest intake bracket—consuming an average of 191 mg daily, about the sweetener equivalent of a can of diet soda—suffered cognitive decline approximately 62% faster than those with minimal consumption (20 mg/day), equating to an extra 1.6 years of brain ageing. Even moderate consumers suffered cognitive decline 35% faster (roughly 1.3 years) than those consuming minimal amounts.
The most pronounced effects fell on individuals under 60 and those with diabetes—a curious and perhaps worrisome finding suggesting early and mid-life dietary habits may have long-term consequences for brain health.
Notwithstanding the size and duration of the study, its observational design means it can demonstrate correlation, not causation. Dietary data was self-reported at baseline only, and residual confounders—other factors that may cause cognitive decline—may confuse the the results. Still, the findings have prompted editorial commentary in Neurology to question whether sugar substitutes—once considered as safer alternatives—might accelerate the very health decline they were meant to prevent.
In addition, earlier studies have demonstrated a correlation between some artificial sweeteners and changes to the gut microbiome that trigger glucose intolerance, a higher risk of fatty liver disease and increased inflammation. In July 2023 the WHO’s cancer arm (IARC) classified the sweetener aspartame as possibly carcinogenic to humans.
As the world pours artificial sweeteners into everything from sodas to yogurt, these studies serve as a reminder that it may be prudent, especially for diabetics, to limit sweet foods to fruit.
More on this:
Research article (in English)
For more stories like this on Switzerland follow us on Facebook and Twitter.
