I have long warned that artificial sweeteners aren’t the harmless sugar substitutes they’re made out to be. Now, a new study confirms those concerns, revealing that people who consumed the equivalent of just one diet soda per day experienced a 62 percent faster decline in memory and thinking skills compared to those who consumed the least. That amounts to nearly two extra years of brain aging.

The worst outcomes were seen in those who consumed the most artificial sweeteners, especially people with diabetes — a group often encouraged to choose diet options. Participants scored lower in memory, processing speed, and verbal fluency. Not all sweeteners were equally harmful, but aspartame, saccharin, and acesulfame potassium stood out for their association with cognitive decline.

These findings hit especially hard for younger adults regularly exposed to these additives. While industry groups continue to insist artificial sweeteners are safe, science now suggests otherwise. What was once dismissed as fringe concern is now gaining mainstream validation.