Depression: your happiness may depend on your diet

Is there such a thing as brain food? Does our happiness depend on the food we eat?

We are familiar with the saying „You are what you eat.“ We know that a nutritious diet is the key to good physical health. But what about mental health? A study published in the recent issue of British Journal of Psychiatry indicates that diet also play a role in mental health, specifically depression.

Dietary patterns

Using again data from the good old Whitehall study which consisted of London-based civil servants aged 35 to 55, the researchers looked at the dietary patterns of 3486 people. The participants were asked to fill in the Food Frequency Questionnaire which was customized to include commonly consumed British foods. A list of 127 foods was included in the questionnaire and the participants were asked how often they consume these foods per day. In addition, the participants were also asked to fill in a questionnaire that evaluates depressive symptoms.

From the data, two dietary patterns emerged, namely:

• The whole food pattern includes lots of fresh fruit, vegetables, whole grain products, and fish
• The processed food pattern includes  lots of sugary food, fried food, processed meat, high-fat dairy products, and refined grain products. This pattern is also the one most similar to the so-called Western diet.

After a 5-year follow up period, the study results showed that participants who went for the processed food patterns had a higher tendency to develop depression. Even after correcting for “potential confounding factors such as age, socioeconomic status, education, marital status, total energy intake, other health behaviors, and other health status”, the study results remain the same.

According to the lead study author Dr. Tasnime N. Akbaraly:

“The study can be an argument to help convince patients who have unhealthy eating behaviors that consuming a healthy diet not only controls excess weight but also may lower the risk of depression.”

So what’s in the food that affects the brain?

This is supposedly the first study to investigate the link between diet and depression. The authors propose several mechanisms to explain this link.

• Sugar consumption and insulin resistant processes have been linked to depression.
• Processed food or Western diet is associated with cardiovascular disorders, also linked to depression.
• Oxidative stress processes have also been associated with depression. Fresh fruit and vegetables are rich in antioxidants that counteract oxidative stress.
• Fresh vegetables contain lots of folate, a mineral that may affect levels of neurotransmitters implicated in depression.
• Fish contains lots of polyunsaturated fatty acids that might also reduce depression.

Dr. Akbaraly continues:

“In my opinion, the protective effect of diet on depression comes from a cumulative and synergistic effect of different nutrients from different sources of foods, rather than the effect of one isolated nutrient. If that’s the case, it’s important to assess the impact of the overall diet on health outcome, as people don’t eat isolated nutrients.”

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