What is the Smiles Trial?

The Smiles Trial, officially known as the "Supporting the Modification of Lifestyle in Lowered Emotional States" trial, was a controlled study conducted by Dr. Felice Jacka. It assessed the impact of a modified Mediterranean diet, termed the ModiMed diet, on individuals with moderate to severe depression over a twelve-week period. The diet focused on enhancing diet quality by supporting the consumption of twelve key food groups which included whole grains, vegetables, fruit, legumes, low-fat unsweetened dairy, raw unsalted nuts, omega-3 rich fatty fish, lean red meat, chicken, eggs, and olive oil, while reducing "extra" foods like sweets, refined cereals, fried and fast food, processed meats, and sugar drinks.

The trial found that implementing this diet led to about 30% of the participants achieving remission in their clinical depression. This highlighted the potential significant benefits of dietary changes even in severe cases of depression, challenging the previous belief that lifestyle modifications were only effective for mild or subclinical depression conditions 1 2.