A Mediterranean-style dietary intervention supplemented with fish oil improves diet quality and mental health in people with depression: A randomized controlled trial (HELFIMED)

Nutritional Neuroscience

Dec 2017

DOI: 10.1080/1028415X.2017.1411320

Citations:453

Influential Citations:18

Interventional (Human) Studies

Enhanced Details

Methods

Two-arm randomized controlled trial in adults aged 18-65 with self-reported or diagnosed depression; 152 randomized (75 MedDiet, 77 Social); single-blind during baseline; follow-ups at 3 and 6 months; primary outcomes DASS-21 and AQoL-8D; secondary measures PANAS, Mediterranean diet adherence (14-item), SDQ; RBC fatty acids; baseline: 105 female and 47 male; 38% reported a depression diagnosis; 36% taking antidepressants.

Intervention

Fish oil capsules: 2 daily; each capsule 450 mg DHA and 100 mg EPA; total daily intake 900 mg DHA and 200 mg EPA; duration 6 months.

Results

Mediterranean-style diet with fish oil improved diet quality and mental health compared with social control. At 3 months, MedDiet group showed greater improvements in Mediterranean diet adherence and diet quality, including more vegetables, fruit, wholegrains, nuts, legumes, and vegetable diversity, and less unhealthy snacks and meat; depression scores declined more (about 45% vs 26.8% in control) and mental health QoL improved more; improvements persisted at 6 months. Correlations showed diet improvements and erythrocyte PUFA changes associated with better mental health. Magnitude of benefit included ~60% fewer individuals with extremely severe depression, ~72% fewer with anxiety, and ~69% fewer with stress in the MedDiet group. Interpreted as feasible strategy to improve mood/quality of life in depressed adults; effects sustained over 6 months.

Limitations

Single-blind design; self-reported outcomes and diet records; reliance on self-reported depression; relatively high dropout (63% MedDiet, 49% Social at 6 months); limited generalizability to diagnosed depression; sample skewed toward women; longer-term sustainability requires further study.

Abstract

Objectives: We investigated whether a Mediterranean-style diet (MedDiet) supplemented with fish oil can improve mental health in adults suffering depression. Methods: Adults with self-reported depression were randomized to receive fortnightly food hampers and MedDiet cooking workshops for 3 months and fish oil supplements for 6 months, or attend social groups fortnightly for 3 months. Assessments at baseline, 3 and 6 months included mental health, quality of life (QoL) and dietary questionnaires, and blood samples for erythrocyte fatty acid analysis. Results: n = 152 eligible adults aged 18–65 were recruited (n = 95 completed 3-month and n = 85 completed 6-month assessments). At 3 months, the MedDiet group had a higher MedDiet score (t = 3.95, P < 0.01), consumed more vegetables (t = 3.95, P < 0.01), fruit (t = 2.10, P = 0.04), nuts (t = 2.29, P = 0.02), legumes (t = 2.41, P = 0.02) wholegrains (t = 2.63, P = 0.01), and vegetable diversity (t = 3.27, P < 0.01); less unhealthy snacks (t = −2.10, P = 0.04) and red meat/chicken (t = −2.13, P = 0.04). The MedDiet group had greater reduction in depression (t = −2.24, P = 0.03) and improved mental health QoL scores (t = 2.10, P = 0.04) at 3 months. Improved diet and mental health were sustained at 6 months. Reduced depression was correlated with an increased MedDiet score (r = −0.298, P = 0.01), nuts (r = −0.264, P = 0.01), and vegetable diversity (r = −0.303, P = 0.01). Other mental health improvements had similar correlations, most notably for increased vegetable diversity and legumes. There were some correlations between increased omega-3, decreased omega-6 and improved mental health. Discussion: This is one of the first randomized controlled trials to show that healthy dietary changes are achievable and, supplemented with fish oil, can improve mental health in people with depression. show less