Stop us if you’ve heard this one before: We should all eat lots of vegetables and fruits, little red meat, plenty of fish, whole grain breads and few fats. Blah, blah, blah, right?

But what if scientists could now show you that such plant-heavy diets, like the Mediterranean and its close cousin, the MIND diet, made you roughly one-third less likely to get Alzheimer’s?

The evidence is in our brains.

Researchers from Chicago’s Rush University studied the brains of nearly 600 people as part of their Memory and Aging Project. The participants volunteered to have their brains examined posthumously, because Alzheimer’s is best detected in brain tissue under a microscope.

Those who followed one of the two diets most closely had fewer of the hallmark signs of Alzheimer’s — sticky beta-amyloid [am-uh-loid] plaques and tau [tow] tangles in the brain — when autopsied.

The researchers also found that those who better adhered  to the diets had amyloid buildup in their brain at a level more typically found in someone 19 years younger.

Both diets call for fruits and vegetables, whole grains, beans, seeds, fish and nuts. There is heavy emphasis on extra-virgin olive oil rather than butter or other fats. Refined-sugar sweets are rare. The MIND diet, short for Mediterranean-DASH Diet Intervention for Neurodegenerative Delay, stresses leafy green vegetables and berries.

We get it if you’re not ready to swear off French fries and chocolate cake forever. But try it in small bites, so to speak. Swap whole grain for your white bread. Have fruit instead of a slab of pie.

It is certainly food for thought.