Most of us have heard the term “brain food,” and we’re all familiar with certain phenomena associated with what we eat, like how the tryptophan in turkey has us all napping shortly after Thanksgiving dinner. But did you know that tryptophan — also found in salmon, spinach, nuts, and seeds — plays an important role in boosting your mood, too? There are a number of other links between healthy foods and mental health, including the potential to lower your risk of depression through dietary choices. 

You can think of your brain like a biological engine that’s running 24/7, meaning it needs a never-ending supply of fuel — which comes from the food you eat. In the same way that supplying a car engine with the wrong type of fuel can damage its efficiency (or even ruin it), your daily food choices affect your brain. 

By consuming an abundance of vitamins, minerals, antioxidants that negate free radical damage, you promote healthy brain functioning — and with that comes a better mood. If you eat a lot of sugar and starch, on the other hand, you allow inflammation and poor insulin regulation to wreak havoc on your brain’s functionality.

Diet and Depression

A 2014 study in the American Journal of Clinical Nutrition went beyond simply examining the link between depression and individual dietary nutrients, pointing out that such studies mostly led to inconsistent results. Instead, they studied the effects of overall diet. By pulling together 21 studies, they performed a meta-analysis, identifying two major dietary patterns that reduce risk of depression. In particular, the results showed a significant correlation between a high intake of fruit, vegetables, fish, and whole grains and a reduced risk of depression. 

A second meta-analysis of 22 separate studies examined the association between a Mediterranean diet and risk of depression. In conclusion, the authors stated that high adherence to the diet appeared to have a preventative effect, regardless of the age of the participants. 

Finally, a third study, this one a randomized trial, also concluded that a Mediterranean diet reduced the risk of depression — especially when supplemented with nuts (tryptophan, anyone?).

More to come

Nutritional science is still in its early stages, and “nutri-psychiatry” is even newer. As we come to understand more about the brain, more about the digestive system’s microbiome, and more about the interaction between the two, we’ll inevitably uncover even more connections between diet and mood. In the meantime, there’s already plenty of evidence to indicate that it’s time we start taking the phrase “food for thought” a lot more literally.