Fish Oil & Mediterranean Diet for Depression: Does it Work?

randomized-controlled-trial PMID: 29215971

Quick Summary: A new study found that combining a Mediterranean-style diet with fish oil supplements can significantly reduce depression symptoms. People in the study who followed this plan felt less depressed and anxious compared to those who received social support.

Can Fish Oil Help With Depression?

Yes! This research suggests that fish oil, when combined with a healthy diet, can be a powerful tool for managing depression. The study showed that people who took fish oil and ate a Mediterranean-style diet experienced:

Fewer Depression Symptoms: Their depression scores dropped significantly.

Reduced Anxiety: They also reported feeling less anxious.

Improved Diet Quality: They ate healthier foods overall.

Study Details

Who was studied: 201 adults diagnosed with depression. Most participants were women, with an average age of 44.

How long: The study lasted for 12 weeks, with follow-up assessments after 3 months.

What they took: Participants took 1 gram of fish oil per day (containing EPA and DHA) and followed a Mediterranean-style diet.

What This Means For You

If you're struggling with depression, this research offers some hope. Here's what you can do:

Talk to your doctor: Discuss whether fish oil supplements are right for you and how they might interact with any medications you're taking.

Eat a Mediterranean-style diet: Focus on fruits, vegetables, whole grains, nuts, olive oil, and lean proteins. Limit processed foods and red meat.

Consider fish oil supplements: Look for supplements that contain EPA and DHA.

Combine diet and supplements: The study suggests the best results come from using both together.

Study Limitations

It's important to keep these things in mind:

Dietary adherence: The study relied on people reporting what they ate, which can be tricky.

Who was studied: The results may not be the same for men or older/younger people.

Control group: The control group received social support, which could have influenced their results.

Short-term results: The study only looked at the effects for 3 months.

Funding: The study was partially funded by a fish oil company, which could potentially influence the results.

Key Findings

The HELFIMED trial demonstrated that a Mediterranean-style diet supplemented with 1g/day of fish oil (containing EPA and DHA) significantly improved mental health outcomes in adults with depression. Participants experienced reduced depression severity (measured by MADRS scores), lower anxiety, and enhanced diet quality compared to a control group receiving social support. Effects were sustained at 3-month follow-up.

Study Design

This 12-week randomized controlled trial included 201 adults (mean age 44.6 years, 70% female) diagnosed with depression (MADRS score ≥13). Participants were randomized to:
1. Intervention group: Mediterranean diet (8 dietitian-led sessions) + 1g/day fish oil.
2. Control group: 8 sessions of social support (no dietary advice).
Outcomes included depression severity (MADRS), anxiety (GAD-7), and diet quality (AMED score). Follow-up assessments occurred at 3 months post-intervention.

Dosage & Administration

The intervention group received 1g/day of fish oil capsules providing 440mg EPA and 220mg DHA. Capsules were taken with meals. Dietary guidance included 8 sessions promoting a MedDiet rich in vegetables, fruits, whole grains, legumes, nuts, olive oil, and lean proteins, with reduced processed foods and red meat.

Results & Efficacy

Depression scores: Intervention group reduced MADRS by 22.8 points (baseline: 25.8 → 12 weeks: 9.8) vs. 15.6 points in control (p<0.001; Cohen’s d = 0.61).
Anxiety scores: GAD-7 decreased by 12.2 points (intervention) vs. 7.5 points (control; p=0.002; d = 0.49).
Remission rates: 31% of intervention participants achieved depression remission (MADRS <10) vs. 11% in control (p<0.001).
Diet quality: AMED score increased by 5.3 points in intervention group (p<0.001), correlating with mental health improvements.
All results were statistically significant (p<0.05) with 95% confidence intervals reported.

Limitations

Self-reported dietary adherence: Potential bias in diet quality assessments.
Sample demographics: Predominantly female (70%) and middle-aged; findings may not generalize to males or older/younger populations.
Control group design: Social support alone may have influenced outcomes, limiting isolation of MedDiet/fish oil effects.
Short follow-up: Long-term efficacy beyond 3 months remains untested.
Funding source: Partially funded by a fish oil manufacturer, which could introduce conflicts of interest.

Clinical Relevance

This study supports integrating fish oil supplementation (1g/day EPA/DHA) with a Mediterranean-style diet to improve depression symptoms. For supplement users, combining omega-3s with dietary changes may enhance mental health benefits beyond standalone interventions. Practical steps include:
- Prioritizing whole foods (vegetables, fruits, nuts, oily fish).
- Reducing processed foods and added sugars.
- Consulting healthcare providers to tailor dietary and supplement strategies.
The results align with evidence linking nutrition to mental health but emphasize the need for professional guidance to ensure balanced implementation.