Extra virgin olive oil may better preserve cognitive function than refined

A two-year analysis of 656 adults in the PREDIMED-Plus study reported that participants who used virgin olive oil had smaller declines in cognitive tests and greater gut microbiome diversity than those who used refined olive oil.

Researchers analyzed data from 656 adults aged 55 to 75 enrolled in the PREDIMED-Plus trial to examine links between olive oil type, the gut microbiome, and cognitive changes. Participants were diagnosed with overweight or obesity and metabolic syndrome, and researchers collected data on olive oil use, gut microbiota composition, and cognitive test results over two years. The study was published in Microbiome and led by Jordi Salas-Salvadó and colleagues at Universitat Rovira i Virgili. The team aimed to explore whether the gut microbiota could be one pathway connecting olive oil consumption to cognitive outcomes. Key findings: - The analysis used data from 656 participants aged 55–75 followed for two years in the PREDIMED-Plus project. - Participants who reported using virgin olive oil showed smaller declines in cognitive measures and greater gut microbiota diversity over the study period compared with those using refined olive oil. - Consumption of refined olive oil was associated with a reduction in microbiome diversity over time in this cohort. - Authors and interviewed experts noted that virgin (cold-pressed) olive oil retains bioactive compounds such as polyphenols and antioxidants that are reduced by industrial refining, which may explain microbiome differences. - The research team said further work is planned, including replication in other populations, longer follow-up, and more detailed microbiome (metagenome) and metabolomic analyses. Summary: In this study population, olive oil type was associated with differences in both cognitive change and gut microbiome diversity over two years. Researchers describe these findings as preliminary and recommend further studies with different populations, longer follow-up, and more detailed biological analyses to clarify how microbiome changes might relate to long-term cognitive outcomes.