After focusing on lifestyle changes such as diet and exercise exclusively for the prevention and treatment of physical ailments, scientists are waking up to the fact that the brain is part of the body, too. Researchers from Australia and Norway recently declared, “there are … an increasing number of studies suggesting that the same modifiable lifestyle behaviors [poor diet, physical inactivity, and smoking] are … risk factors for common mental disorders.” Can better mental health be as simple as making the choice to live better?
Researchers from Spain caution that “in general, evidence has been found for the effects of isolated nutrients or foods, and not for dietary patterns.” [Emphasis ours.] However, these same researchers have found evidence to support a protective effect against depression of the Mediterranean dietary pattern and a higher risk of depression associated with greater fast food and commercial baked good consumption. Similarly, Australian researchers working in East London found an association between poor diet and poor mental health in teens. British researchers found a similar association in middle-aged people: processed food consumption is associated with poor mental health, and whole food consumption is associated with good mental health.
The Spanish researchers note that other lifestyle factors could be common to people with poor diets and people with depression, mentioning low physical activity and use of tobacco products and illicit drugs as factors other than diet that may have deleterious effects on health. They recommend additional observational studies (studies in which data is collected, but participants are not instructed as to how to behave) as well as randomized prevention trials in which some participants at high risk for depression are given dietary interventions that may prevent mental illness.
What diet is optimal for good mental health? Researchers do not currently agree, but there are a few key resources to investigate. The USDA describes its “health eating index” (HEI) in an article and provides several links to additional materials. (Researchers in Baltimore, Maryland, found an association between higher HEI scores and a reduced risk of depression. )The Mayo Clinic offers this information regarding the components of the Mediterranean diet. Journalist Michael Pollan’s book In Defense of Food contains a few guidelines for avoiding processed foods, such as avoiding any packaged food containing an ingredient that you can’t pronounce.