You are what you eat, and what you eat can affect how you feel
A few years ago, Professor Felice Jacka completed the world's first dietary intervention trial for people diagnosed with Major Depressive Disorder. Her SMILES trial proved that a modified Mediterranean diet (fruits, vegetables, olive oil, seafood, whole grains, poultry, moderate red wine, but unlike other Med diet trials did not restrict red meat) improved mood symptoms in people with major depressive disorder compared to a control group eating a Western (high processed food) diet. The effect size of the diet was similar to medication.
But science is fickle: one trial is some evidence, but can it be repeated? Other researchers followed up with the HELFIMED study. In this protocol, adults who self-reported with depression were randomized to receive food hampers and cooking workshops plus fish oil supplements were compared to controls with depression who attended social groups every two weeks for three months.
Patients were recruited from primary care doctors, newspapers, television and radio interviews, and social media. Those who were already eating a high-quality diet were excluded. Those who met criteria for depression via the "Depression Anxiety Stress Scale" were then randomized to the treatment versus the control group. People were withdrawn from the study if they started other depression treatment and various other reasons (those already on antidepressants or in therapy at the beginning of the study could continue; this was about 36% of the sample). In the end, 47 completed six months in the experimental group and 38 in the control.
The intervention involved an interactive nutrition education session led by a dietitian and nutritionist. They had fortnightly cooking workshops with recipes focusing on affordable meals that had been previously trialed in cooking workshops with the chronically mentally ill. They were also given omega3 supplements. The control group had a social interaction with snacks (cookies, cheese, tea, and coffee) and games.
The results? The diet training group had a significant improvement in dietary score (meaning closer adherence to a Mediterranean diet) and higher levels of omega 3s measured in the blood at the end of the trial. Depression scores improved 45% in the diet trial group and 26.8% in the social group, which persisted at six months.
The dietary trial group also had improved quality of life scores.