Psychologist and writer Timothy Leary almost got it right. Turn on (the stove); tune in (to amino acids); and drop out (of the 20% to 25% of folks 65 and older who have mild cognitive impairment, and the 10% with full-on dementia).

A new lab study in published in the journal Science Advances has identified the essential amino acids that protect the brain from neurodegeneration. In fact, they "robustly rescued" lab mice from existing cognitive damage.

Research has long shown that lack of healthy protein can contribute to age-related loss of mental agility. But you can make sure your diet supports brain health by including foods that deliver specific amino acids, which are the building blocks of protein.

Here’s your amino acid diet plan:

• Lysine from black beans, quinoa, pumpkin seeds, and soy

• Leucine from beans, legumes, and soy, as well as (low-fat and nonfat) dairy

• Phenylalanine from nuts, fish, beans, soy, poultry, and (low-fat and nonfat) diary 

In the lab experiment, those three essential amino acids were supplemented with others: isoleucine, histidine, valine, and tryptophan. They're found in nuts, peanuts, and seeds, as well as whole grains, fish, and poultry. And valine is in vegetables and mushrooms.

One thing to note: A study on lab mice found that isoleucine seems to cause aging of muscles and the liver. It's found in meat, fish, poultry, eggs, cheese, lentils, nuts, and seeds.