Food for Mood: 3 Major Trials with Exciting Findings

In the scientific community, food for mood is glamorously known as nutritional psychiatry. It is quickly becoming a lively field as more rigorous randomized controlled trial (RCTs) are carried out. Indeed, it is a fairly new study area. One of the first study linking diet quality and common mental disorders was only published a little over a decade ago.

Are there high quality clinical trials on nutritional psychiatry?

The evidence linking dietary fiber intake and depression are scarce but incredibly consistent. The biggest studies are 1) the SMILES Study, 2) the PREDIMED trial, and 3) the SUN Project.

The Supporting the Modification of lifestyle in Lowered Emotional States Study (SMILES Study)

The first randomized controlled trial to explicitly seek an answer the question:

If I improve my diet, will my mental health improve?

Findings

Patients with major depressive episodes who followed the modified Mediterranean diet had a greater improvement in their depressive symptoms compared to patients given only social support. This benefit does not depend on physical activity or body weight.

The PREDIMED trial (Prevención con Dieta Med-iterránea)

The largest dietary intervention to date.

Findings

Mediterranean diet prevents depression among type 2 diabetes participants.

The Seguimiento Universidad de Navarra (SUN) Project

Investigating roles of added sugar and carbohydrate quality (low or high in fiber) in risk of depression.

Findings

Participants with higher intake of added sugar shows higher risk of depression

Participants consuming better quality carbohydrates has 30% less risk of depression

Higher added sugars and lower quality of carbohydrate consumption were associated with depression risk in this cohort

Other epidemiological studies

Other than sugar, what food helps with mental well-being?

The more you consume fiber from wholegrain cereal, vegetables and fruits, the less likely it is for you to experience depressive symptoms. Here are some evidence supporting this:

46 high fibre recipes for mains and desserts to try

Understandably, we need more randomized controlled trials that can prove a cause and effect. However, we need to first acknowledge the most common pitfall of diet and behavioural health studies. These studies are prone to reverse causation; poor diet can be a cause or a consequence of a disorder. Often, nutritional issues have a complex and multidimensional nature. This is also true for behavioural health disorders.

Takeaway

Mental and behavioural disorders are complex and have no single cause. Risks can be attributed to social support, stress, alcohol and drug use, sex, gender, socioeconomic status, endothelial dysfunction, diet, genetic and epigenetic factors, inflammation, medical illnesses.

However, evidence so far have been consistent. A healthy diet is protective of cardiovascular disease, hypertension and diabetes could also be protective of mental health disorders. But most importantly, change does not have happen overnight. A gradual introduction to a more wholesome, highly-varied and minimally-processed foods to your diet will work wonders.