When it comes to our bodies we all know that the good fats are best.

But what about our brains?

The results published online May 18 in the journal Annals of Neurology has shown that the cognitive function of older women who ate monounsaturated fats was better than those who ate saturated and trans fats.

Compared with those women who ate the lowest amounts of saturated fats, women in the highest saturated-fat category showed worse overall cognition and memory over the four years of testing. Women who ate the most mono-unsaturated fats, which can be found in olive oil, had better patterns of cognitive scores over time. Trans fats weren’t associated with changes in cognition over time, the researchers reported.

With diseases such as Alzheimer’s and dementia on the rise, the benefits could be greater that simply better memories and improved cognition.

Preventive measures to stem the increase of debilitating brain illness could benefit millions.