A 2026 study published in the journal Microbiome adds a new mechanism to the case for extra virgin olive oil: a link between the gut microbiome and cognitive function in older adults.
What the study found
Researchers tracked 656 overweight or obese adults with metabolic syndrome over two years, comparing those consuming extra virgin olive oil against those consuming refined olive oil. The extra virgin group showed improved cognitive function and greater gut microbiota diversity. Notably, the researchers identified a specific gut bacterium, Adlercreutzia, that appeared to mediate roughly half of the observed cognitive benefit — a rare case of researchers tracing a nutrition-and-brain-health link to a specific biological pathway.
Why extra virgin, specifically
The comparison group used refined olive oil, which strips out the polyphenols and micronutrients that extra virgin retains through minimal processing. The researchers’ findings point to those retained compounds — not just the fat profile common to all olive oil grades — as central to the cognitive effect observed.
FAQ
Does this mean any olive oil improves brain health? No — the study specifically compared extra virgin against refined olive oil, suggesting the effect is tied to compounds that processing removes, not to olive oil generally.
Is this related to earlier 2026 studies on olive oil and mortality risk? It’s a separate study with a different focus — this one examines cognitive function via the gut microbiome, while earlier 2026 research looked at all-cause mortality risk.
Source: Medical Xpress