Two diets that may reduce depression risk

In November 2018, researchers in Australia, Finland, France, Spain, and the UK, published a study in Molecular Psychiatry, a peer-reviewed journal focused on explaining the “biological mechanisms underlying psychiatric disorders and their treatment”. The study investigated the connection between healthy eating and risk of depression.

The researchers conducted a meta analysis on 41 previously published articles that explored the connection between diet and depression.

What did the researchers find?

The researchers discovered that two diets stood out as having the strongest connection to lower odds of depression for participants who followed them most closely.

Participants who most closely followed the Mediterranean diet were 67% less likely to have depression when compared to those who followed the diet the least. As well, participants who had the least inflammatory diet were 76% less likely to have depression when compared to those who had the most inflammatory diet.

Why these 2 diets?

What is it about these two diets that gives them a strong connection to lower depression odds? Well, first, they share some features:

  • Higher fruit intake
  • Higher vegetable intake
  • Higher nut intake
  • Lower processed meat intake
  • Lower trans fat intake
  • Moderate alcohol intake

According to the researchers, several

“factors have been proposed to cause diet-induced damage to the brain, including oxidative stress, insulin resistance, inflammation, and changes in vascularization, as all these factors can be modified by dietary intake and have been associated with occurrence of depression”

And diets high in fruit, vegetables, and nuts; low in processed meat and trans fat; and that include only moderate alcohol consumption have antioxidative and anti-inflammatory qualities, which may help prevent the “diet-induced” brain damage the researchers mentioned.

So, what’s next?

The researchers outlined in their conclusion that the research to date is limited, so there’s still a need for more research, particularly to rule out reverse causality. Even so, there are a couple of related points that other researchers have raised since.

No need to wait for more research.

For example, one researcher, when summarizing the above study, suggested that even though the researchers recommend further study, there is no harm in implementing diet intervention as a part of treatment:

“There are no drawbacks or downsides to recommending healthy dietary interventions such as the Mediterranean diet and/or avoiding pro-inflammatory foods when discussing depression or prevention of this disorder. On the other hand, the clear potential benefits in reducing the burden of depression or avoiding this disorder altogether by incorporating diet change into treatment is compelling. Patients experiencing severe depression may find it difficult to muster the energy needed to plan and modify a diet. Catching such patients (those at risk for depressive episodes) at early stages may help lower this barrier. Providers should discuss diet with patients and help them adopt such an intervention into an overall treatment and wellness plan.”

Diet is still underprescribed.

In addition, an American researcher published an editorial earlier this year in the journal Psychiatric Annals. She highlighted that despite “evidence-based integrative health modalities, such as exercise, yoga, nutrition, or mindfulness, [yielding] great promise as adjunctive treatments of depression” and despite that research shows that these options are becoming more popular, only 10–30% of health care providers are prescribing them to their patients with depression.

According to the editorial, one reason why prescription of integrative health solutions is so low may be “a lack of synthesis of data for each approach and useful recommendations for clinicians”.

The above study is one more study among a growing body of research showing a connection between what we eat and our mental health. Here at Truehope, we’ve been promoting nutrition as mental health treatment for over 20 years.

And we hope that as the body of research investigating the connection between nutrition and mental health grows in number, strength, and robustness, nutritional solutions may become the mainstream treatment option for optimal mental health.