Impact of Olive Oil Fatty Acids and Bioactive Compounds on Cognitive Function in Adults: A Systematic Review

Background: The global increase in life expectancy has led to a higher prevalence of age-related cognitive decline, highlighting the need for effective non-pharmacological interventions. This systematic review aimed to evaluate the potential effects of olive oil, particularly its bioactive compounds and fatty acid profile, on cognitive function in adults Methods: A comprehensive literature search was conducted in PubMed, Scopus, and EBSCO in accordance with PRISMA 2020 guidelines, including peer-reviewed studies published in English between 2015 and 2025. A total of six studies met the inclusion criteria and were included in the final qualitative synthesis, comprising five randomized controlled trials and one prospective cohort study. Risk of bias was assessed using the Cochrane Risk of Bias tool (RoB 2) and the Newcastle–Ottawa Scale. Results: The findings suggest that consumption of extra virgin olive oil (EVOO), particularly high-phenolic varieties, may be associated with improvements in cognitive domains such as memory, attention, executive function, and global cognition. However, the evidence is derived from a limited number of heterogeneous studies with relatively small sample sizes. Most of the available data relate to high-phenolic EVOO and olive-derived bioactive compounds, while studies directly examining the role of fatty acid composition remain limited. Proposed mechanisms include reduced blood–brain barrier permeability, enhanced brain functional connectivity, and the neuroprotective effects of compounds such as hydroxytyrosol and oleuropein. Conclusions: While the findings suggest potential cognitive benefits of EVOO, the current evidence remains preliminary and insufficient to establish causality. Therefore, results should be interpreted with caution. Further large-scale, well-designed randomized controlled trials are required to confirm these associations and clarify the specific contributions of fatty acids and bioactive compounds.