Artificial Sweeteners and Cognitive Decline

Do Artificial Sweeteners Accelerate Cognitive Decline?

Researchers followed 12,772 adults participating in the Brazilian Longitudinal Study of Adult Health and compared reported consumption of seven low- and no-calorie sweeteners with changes in cognitive testing over approximately eight years. Participants with the highest intake experienced faster declines in overall cognition, memory and verbal fluency than those consuming the least.

The association appeared more pronounced among adults younger than 60 and people with diabetes. However, this was an observational analysis: dietary intake was self-reported, and factors such as cardiometabolic health, food choices and reasons for using sweeteners may have influenced the results. The study therefore identifies a potential risk signal rather than demonstrating that sweeteners directly age the brain.

How Could Sugar Substitutes Affect Brain Health?

Scientists are investigating whether frequent exposure to certain sweeteners could affect glucose regulation, inflammation, vascular health or communication between the gut and brain. These pathways are biologically relevant because diabetes, hypertension and other vascular risk factors are established contributors to cognitive impairment and dementia.

Different sweeteners have distinct chemical properties and should not automatically be treated as one uniform category. The study assessed substances including aspartame, saccharin, acesulfame potassium and several sugar alcohols, but it was not designed to determine a safe threshold or prove a specific biological mechanism. Controlled trials and studies using objective exposure measurements are needed.

Should People Stop Using Artificial Sweeteners?

The World Health Organization advises against relying on non-sugar sweeteners for long-term weight control, noting that available evidence does not show lasting benefits for reducing body fat and may indicate undesirable long-term associations. That conditional guidance excludes people with pre-existing diabetes and does not address the safety limits established for individual additives.

People can reduce dependence on intensely sweet foods by choosing water, unsweetened drinks, whole fruit and minimally processed meals. Anyone using sugar substitutes to manage diabetes should discuss major dietary changes with a clinician or registered dietitian, since replacing sweetened products with added sugar could worsen glucose control.