A balanced diet, along with regular exercise, can help protect the brain and ward off mental disorders.

Omega-3 fats in particular provide many benefits, including improving learning and memory and helping to fight against mental disorders such as depression, schizophrenia, and dementia. Children who have high amounts of omega-3 fats in their diets tend to perform better in school in reading and spelling, and have fewer behavioral problems, he said.

The omega-3 fat docosahexaenoic acid, or DHA, may be especially important. It reduces oxidative stress and enhances synaptic plasticity and learning and memory, and is the most abundant omega-3 fatty acid in cell membranes in the brain.

Folic acid and curcumin may also have beneficial brain effects. At the same time, junk food and fast food negatively affect the brain's synapses. Several molecules related to learning and memory are adversely affected by unhealthy diets.