Just a handful of walnuts a day can have a profound impact on your how well you think and remember. That’s the conclusion of a large analysis from the National Health and Nutrition Examination Surveys (NHANES). Researchers found that people of all ages who ate 13 daily grams of walnuts performed better on cognitive function tests that measured information processing, memory and concentration. Previous research has shown similar results, including evidence that a walnut-rich diet can slow or prevent the progression of Alzheimer’s.
Walnuts may also help your brain decide that you don't need all that junk food. A small study found that people who consumed walnut smoothies for five days exhibited more activity in the region of the brain associated with feeling full, even when shown images of foods high in fat of calories (cakes, onion rings). This means that walnuts could help you control your appetite and manage your weight. (It also means that, in some way, walnuts are controlling your brain.)
One reason walnuts are so good for your mind is their high levels of alpha linoleic acid (ALA), an omega-3 fatty acid shown to boost brainpower. Walnuts are also loaded with free-radical-fighting antioxidants, particularly vitamin E. Other nuts with brain-healthy nutrients include almonds, pistachios and macadamias.