Virgin olive oil appears to protect cognitive health, but new research from Spain demonstrates how. Virgin, not refined, olive oil changes the gut microbiota—the collection of bacteria, viruses and such--in our digestive system. Our digestive system feeds nutrients to other parts of the body, including the heart and brain. This study shows people who consumed virgin olive oil showed improved cognitive function compared to those who consumed refined olive oil. Another part of the study, appearing in the journal Microbiome, confirmed the quality of the fat we consume is just as important as quantity. Authors say at a time when cases of cognitive decline and dementia are on the rise, this study drives home the importance of diet quality.