People living in the Mediterranean have a much lower risk of contracting Alzheimer’s disease than those of us stuck in other parts of the world. Researchers looking for an explanation nailed down an association between extra virgin olive oil and low rates of the disease. They attributed olive oil’s disease-fighting power to high amounts of monounsaturated fats. But now, however, new research shows that a natural substance found in olive oil called oleocanthal is the real hero, Phys.org writes.

Past studies have identified oleocanthal as the likely candidate behind olive oil’s protective effects, but this study helped fill in the blanks of how specifically it bestows that advantage. In trials with mice, oleocanthal protected nerve cells from the kind of damage that occurs from Alzheimer’s disease. It decreased the accumulation of beta-amyloids—the amino acid–based plaques that scientists believe cause Alzheimer’s—in the brain and boosted production of the proteins and enzymes that researchers think play roles in removing those same plaques