A new study reveals that regular consumption of virgin olive oil, but not refined alternatives, is associated with slower cognitive decline in older adults. Researchers found that the benefits appear to be linked to a more diverse and healthy gut microbiome. The study, published in Microbiome, adds to growing evidence supporting the neuroprotective effects of the Mediterranean diet.
Key Findings of the Study
The research followed over 650 overweight or obese adults aged 55-75 with no initial signs of cognitive impairment. Over two years, participants’ olive oil intake, gut bacterial profiles, and cognitive performance were tracked.
Those who consumed higher amounts of virgin olive oil showed improvements or preservation in cognitive areas such as overall thinking speed, decision-making skills (executive function), and verbal abilities. Conversely, higher intake of common, refined olive oil was tied to reduced microbial diversity in the gut and faster cognitive decline.
The Gut-Brain Connection
The study provides the first human evidence to specifically analyze how olive oil interacts with gut microbiota and cognitive function. Researchers analyzed stool samples and found that participants consuming more virgin olive oil had more diverse gut microbial communities.
Specific bacterial species, notably Adlercreutzia, showed a statistically significant link between olive oil consumption and improved cognitive performance. This suggests that the benefits occur through the gut-brain axis, where gut bacteria influence brain health.
Why This Matters
Cognitive decline and dementia rates are rising globally, making preventative strategies increasingly important. The findings reinforce the idea that the quality of fat matters as much as the quantity.
“Extra virgin olive oil not only protects the heart, but can also help preserve the brain during aging,” says Dr. Jordi Salas-Salvadó.
The research opens doors for new nutrition-based prevention strategies. Prioritizing extra virgin olive oil over refined versions could be a simple, accessible way to protect brain health.
The full study is available in Microbiome (J. Ni et al., 2026).
