Olive oil is a key part of the Mediterranean diet and is known for its benefits for heart and metabolic health. Recent research suggests that extra unrefined olive oil may also support brain health by improving gut microbiome diversity and helping maintain cognitive function as people age. This study examines the connection between olive oil quality, gut bacteria, and cognitive performance.
Brain Benefits of Olive Oil
Extra unrefined olive oil might be your secret tool for maintaining a sharp mind as you age. Unlike refined oils, unrefined olive oil retains vital compounds that promote both gut diversity and cognitive performance.
Study Explores Olive Oil, Gut, and Brain Health
"This is the first prospective study in humans to specifically analyze the role of olive oil in the interaction between gut microbiota and cognitive function," says Jiaqi Ni, first author of the article and researcher at the URV's Department of Biochemistry and Biotechnology.
The study followed 656 adults, aged 55–75, who were overweight or obese and had metabolic syndrome—a set of factors increasing the likelihood of cardiovascular disease. Over two years, as part of the PREDIMED-Plus project, participants' diets were monitored, with an emphasis on unrefined versus refined olive oil consumption, and analyses of their gut microbiota. Cognitive performance was also tracked.
Gut Health and Cognitive Improvement
Results revealed significant differences based on the type of olive oil consumed. Participants using unrefined olive oil showed cognitive improvements and a more diverse gut microbiome—considered an indicator of better overall health. In contrast, those using refined olive oil experienced a decline in microbiome diversity.
One key finding was the presence of Adlercreutzia microbe in participants consuming unrefined olive oil. This specific microbe may serve as a marker linking olive oil consumption to better cognitive health. This suggests that part of the oil's benefits for the brain may come from how it affects the gut microbiome.
Why Unrefined Olive Oil Stands Out
The key difference between unrefined and refined olive oils lies in their production methods. Unrefined olive oil is obtained through mechanical extraction, preserving beneficial compounds. Refined olive oil, however, undergoes industrial processing to remove impurities.
While refining improves shelf life and taste consistency, it also strips away valuable components such as antioxidants, polyphenols, and vitamins. Not all olive oils offer benefits for cognitive function, explains Jiaqi Ni, emphasizing the importance of choosing unrefined varieties.
Quality of Oils Matters for Brain Health
This research adds to mounting evidence that diet plays a crucial role in cardiovascular and cognitive health through its influence on the gut microbiota. Jordi Salas-Salvadó, principal investigator of the study, stresses that quality matters, highlighting that the quality of lipids we consume is just as important as the quantity. Unrefined olive oil not only protects the heart but can also help preserve the brain as we age.
A Simple Strategy for Aging Populations
As the global population ages, co-directors Nancy Babio and Stephanie Nishi point out the broader implications of these findings. "With rising cases of cognitive decline and dementia, improving diet quality—particularly prioritizing unrefined olive oil over refined options—offers a simple, effective, and accessible way to protect brain health."
The study suggests that unrefined olive oil may help protect brain health by supporting a healthier gut microbiome. Its preserved antioxidants and polyphenols highlight the importance of choosing high-quality products. The research was led by the Human Nutrition Unit at URV’s Department of Biochemistry and Biotechnology, with support from IISPV-CERCA, CIBER, Carlos III Health Institute, and contributions from researchers at Wageningen University and Harvard University.
