You've probably heard the expression, "you are what you eat." It may be a cliché, but it's true. What you eat plays a direct role on your brain's cognitive (thinking) abilities, and may influence your risk of developing mental illness, age-related cognitive decline, or Alzheimer's disease.

While many studies on diet have explored the role of specific nutrients, recently there's been a flurry of research evaluating the effect of the whole diet, not just specific foods, on mental health. For example, a study in Australia found that a whole foods diet might prevent mental illness, especially anxiety and depression, in women. Women who ate a traditional (healthy) diet were 30 percent less likely to develop mental illnesses, while their counterparts who consumed a typical western diet (high in fats and sugars) had a 50 percent increase in their risk.

Another recent study found that older adults who ate a heart-healthy diet-fruits and vegetables, olive oil, legumes (beans), fish, and moderate amounts of wine-experienced less of a mental decline with age.

It appears that certain nutrients influence our body at the molecular and cellular level. They support vital systems and processes we need to maintain cognitive function.

You can make a few simple diet changes to improve your cognitive functioning and potentially reduce your risk for developing depression, anxiety, or Alzheimer's disease.

Increase your consumption of omega-3 fatty acids. These healthy fats are highly concentrated in the brain and are critical for proper brain functioning. A deficiency of omega-3, on the other hand, impairs learning and memory.

Fresh fish, such as salmon, flaxseeds, and walnuts are loaded with omega-3s. Interestingly, participants in the Australian study mentioned above obtained a large percent of their omega-3 fatty acids from meat. In Australia-unlike the United States-livestock is pasture raised so their meat is rich in omega-3s.

Avoid junk food. Processed foods are high in trans and saturated fats, which adversely affects your brain.

Eat foods high in antioxidants. Antioxidants protect the body and brain from disease. Berries, spinach, broccoli, potatoes, vegetable oils, nuts, orange juice, yeast, and green leafy vegetables are loaded with powerful antioxidants, such as vitamin E, alpha lipoic acid, and folate.

If you won't change your diet for your own benefit, do it for your grandchildren. There is increasing evidence that the nutritional effects of diet on cognitive function may have long-term implications: you may pass along permanently altered genes to future generations.

Sources

Caroline Cassels." Whole Diet May Ward Off Depression and Anxiety." American Journal of Psychiatry Published online January 4, 2010. Medscape Medical News. Web. 15 January 2010. http://www.medscape.com/viewarticle/715239

Doheny, Kathleen. "Mediterranean Diet May Improve Cognitive Function." EB 2010, Experimental Biology Meeting, Anaheim, Calif., April 24-28, 2010. Medscape Medical News. Web. April 2010. http://www.medscape.com/viewarticle/720876

Cassels, Caroline. "Lower Folate Levels Increase Risk for Depressive Symptoms, Particularly in Women." Psychosomatic Medicine. Published online September 14, 2010. Medscape Medical News. Web. September 2010. http://www.medscape.com/viewarticle/729355

Marshall, Gad A. MD. "Mediterranean Diet, Physical Activity, Cognitive Function, and Dementia Risk." Medscape Medical News. Web. 1 February 2010. http://www.medscape.com/viewarticle/714765

Cassels, Caroline. "Two Weeks of Lifestyle Changes Improve Cognitive Function." American Journal of Geriatric Psychiatry 14 (2006): 538-545. Medscape Medical News. Web. 25 July 2006.

http://www.medscape.com/viewarticle/541537

Gómez-Pinilla, Fernando. "Brain foods: the effects of nutrients on brain function." National Review of Neuroscience  9(7) (2008): 568-578. Web. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2805706/