The Mediterranean diet is rich in vegetables, fruits, lentils, and fish, and cooking is often done with olive oil, known to contain phenols (beneficial chemicals known to have positive effects on cognition). Researchers recently investigated whether the additional use of different types of olive oil as a supplement could prevent cognitive decline in older volunteers following a Mediterranean diet. This small clinical trial followed 150 MCI participants over 12 months. They were randomized into three groups: those who ate a Mediterranean diet and took the supplement Greek High Phenolic Early Harvest Extra Virgin Olive Oil, those who ate a Mediterranean diet and took Moderate Phenolic Extra Virgin Olive Oil as a supplement, and a control group that only ate a Mediterranean diet. In the supplement groups, volunteers took 3 tablespoons daily of their respective olive oil. After a year, all those in the control group performed the same or worse in cognitive tests, while those in both olive oil supplement groups demonstrated improved cognitive function. The Greek High Phenolic Early Harvest Extra Virgin Olive Oil group showed the most improvement in tests of daily functioning, but both supplement groups showed significant improvement in working memory and verbal processing. Interestingly, both supplements were also shown to be effective in volunteers carrying the APOEɛ4 gene, which is associated with a higher risk of Alzheimer’s disease. These results suggest that the use of supplemental olive oil may improve cognition in older adults with MCI.
Tsolaki M, et al. A randomized clinical trial of Greek High Phenolic Early Harvest Extra Virgin Olive Oil in mild cognitive impairment: The MICOIL Pilot Study. J Alzheimers Dis. 2020;78:801-817. doi:10.3233/JAD-200405.