A pilot study conducted in Buenos Aires from January 2023 to December 2024 has identified a statistically significant association between regular yerba mate consumption and reduced risk of cognitive impairment in adults aged 50 and above. The findings, while preliminary and limited by the study's sample size, add to a growing corpus of evidence suggesting that the bioactive compounds in Ilex paraguariensis may exert neuroprotective effects — a possibility with particular relevance in Argentina, where both mate consumption and life expectancy are high.
Study Design: A Two-Year Observational Window
The research team recruited participants from the Buenos Aires metropolitan area, stratifying them by mate consumption habits into regular consumers (defined as daily consumption of at least one liter of mate) and non-consumers. All participants underwent a battery of standardized neuropsychological assessments at baseline and at 12-month intervals, including tests of logical memory (immediate and delayed recall), serial word learning, attention span, and executive function. Confounding variables — including education level, physical activity, alcohol consumption, and cardiovascular risk factors — were controlled for in the statistical analysis.
Results: Memory and Learning Advantages
Regular yerba mate consumers demonstrated significantly better cognitive performance across multiple domains. The most pronounced differences were observed in logical memory — both immediate recall, which tests the ability to retain narrative information after a single exposure, and delayed recall, which measures retention after a 20- to 30-minute interval. Serial word learning, a test that assesses the capacity to acquire and retain new verbal information across repeated trials, also showed a statistically significant advantage in the mate-consuming group.
Proposed Mechanisms: Antioxidants and Enzyme Modulation
The investigators note that their findings are consistent with previous research indicating that yerba mate enhances antioxidant defenses and reduces the activity of acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) — two enzymes whose elevated activity is associated with cognitive decline and Alzheimer's disease progression. Yerba mate is rich in chlorogenic acid, caffeoylquinic acid derivatives, and rutin — polyphenols that have demonstrated neuroprotective properties in both animal models and cell culture studies. Additionally, the caffeine and theobromine content of mate may contribute to acute cognitive enhancement through adenosine receptor antagonism.
Caveats and Next Steps
The authors emphasize that this is a pilot study, and its results — while promising — require validation in larger, multi-center cohorts before any clinical recommendations can be made. The observational design cannot rule out the possibility of reverse causation (cognitively healthier individuals may be more likely to maintain complex social rituals like mate-drinking) or residual confounding. The research team has called for prospective randomized controlled trials to establish whether mate consumption plays a causal role in cognitive preservation, and if so, what dose and duration are required to achieve meaningful neuroprotection.