Artificial Sweeteners Speed Brain Aging, Drug Interactions May Make It Worse

Artificial sweeteners may accelerate cognitive aging, and combined exposure with common medications could worsen the risk, according to two studies highlighted by an American Academy of Neurology update. A Brazilian study following 12,772 adults over about eight years, published in Neurology, found that people consuming roughly the amount found in one diet soda can daily experienced cognitive decline 62% faster than those consuming nearly none. Researchers translated the gap into 1.6 additional years of brain aging, with the highest intake group averaging 191 mg/day of sweetener, comparable to aspartame in a can. Six of seven sweeteners analyzed, including aspartame and saccharin, were linked individually to faster decline, while tagatose showed no association. A second Cambridge University study in Molecular Systems Biology reported that several of the same sweeteners suppress beneficial gut bacteria, with effects becoming significantly stronger when sweeteners are taken alongside prescription drugs, including a widely used antidepressant. Together, the findings challenge the “safe swap” narrative after a WHO guideline in 2023.