The SMILES trial (Supporting the Modification of lifestyle In Lowered Emotional States) was a landmark 2017 study that provided the first randomized controlled trial evidence that dietary improvement can significantly treat moderate to severe depression. 

Led by Professor Felice Jacka at Deakin University’s Food & Mood Centre in Australia, the study highlighted the importance of the gut-brain connection in mental health. 

Here are the key details:

The Dietary Approach: 

Participants were assigned to a 12-week dietary intervention based on a Modified Mediterranean Diet (ModiMedDiet). It focused on nutrient-dense, whole foods rather than calorie restriction. 

• Key Food Groups: High intake of vegetables, fruit, legumes, whole grains, nuts, seeds, olive oil, and fish.
• Moderate Consumption: Lean red meat, chicken, and dairy.
• Reduced Intake: Processed foods, sweets, fried foods, and sugary drinks.
• Key Nutritional Focus: High fibre, antioxidants, and anti-inflammatory nutrients. Symprove Probiotic Supplement

Key Findings

• Significant Improvement: After 3 months, 32% of those in the diet group met the criteria for remission of depression, compared to only 8% in the social support (control) group.
• Direct Correlation: The greater the improvement in diet quality, the greater the reduction in depressive symptoms.
• Cost-Effectiveness: The study found that a healthy diet was actually cheaper than the participants' previous diets, and it was considered cost-effective from a health sector perspective. National Institutes of Health. 

Gut Health Connection

The trial supports the understanding that the gut microbiota—the trillions of bacteria living in the gut—plays a key role in regulating mood and brain function. The diet was designed to reduce inflammation and promote a healthy, diverse microbiome, which can help alleviate anxiety and depression.

At Chef de la Maison this is one of our core beliefs and it drives us forward with purpose. Social impact food and good mood food starts in the kitchen.