High Intake of Artificial Sweeteners Tied to Faster Cognitive Decline, Brazilian Study Finds
Researchers report the highest consumers experienced about 1.6 years of additional brain aging and a 62% faster decline in thinking and memory over eight years.
A large Brazilian cohort study published in the journal Neurology found that adults who reported the highest intake of artificial sweeteners had significantly faster declines in thinking and memory skills compared with lower consumers.
Researchers followed 12,772 adults with an average age of 52 for eight years. Participants completed dietary questionnaires at baseline that captured consumption of beverages and foods containing artificial sweeteners; investigators then tracked changes in cognitive test scores over the study period. The group with the highest reported intake of artificial sweeteners showed a decline in cognitive performance equivalent to roughly 1.6 years of extra brain aging and a 62% faster decline than lower-consumption groups.
The analysis focused on seven low-calorie sweeteners commonly found in sodas, energy drinks, flavored water, yogurt and low-calorie desserts; examples named in the report include aspartame, saccharin, acesulfame-K, erythritol and xylitol. The associations were strongest among adults younger than 60 and among participants with diabetes. In contrast, participants older than 60 did not show a clear link between higher artificial sweetener consumption and faster cognitive decline.
Investigators used repeated cognitive testing to estimate changes in memory and thinking skills across the cohort. The study adjusted for a range of potential confounders, including age, education, lifestyle factors and health conditions, though the authors noted that residual confounding cannot be ruled out. Dietary intake was based on self-reported questionnaires, which can introduce measurement error, and the observational design means the findings do not establish causation.
The paper discusses possible pathways that could account for the observed association, including metabolic and vascular mechanisms that have been proposed in other research, but it concludes that further work is required to determine whether artificial sweeteners directly contribute to cognitive decline or whether they are markers for other risk factors.
Clinical relevance may depend on context and individual health profiles. The study's finding that younger adults and people with diabetes showed stronger associations suggests that future investigations should explore age- and disease-specific effects and examine dose–response relationships. The authors call for replication in other populations and for studies that can more directly assess biological mechanisms.
Public health experts and clinicians often weigh potential risks and benefits of substituting sugar with low-calorie sweeteners, especially for people managing weight or glucose levels. This study adds to a growing literature examining long-term outcomes associated with artificial sweetener exposure but does not, on its own, resolve questions about causality or safe consumption thresholds.
Until additional evidence is available, experts commonly recommend that individuals discuss dietary choices with their health care providers, particularly those with chronic conditions such as diabetes. Researchers emphasized the need for randomized trials or mechanistic studies to better establish whether reducing artificial sweetener intake would slow cognitive aging or prevent decline.