Omega-3 supplementation effects on body weight and depression among dieter women with co-morbidity of depression and obesity compared with the placebo: A randomized clinical trial.

Purpose: We aimed to evaluate the effects of the omega-3 supplementation on body weight and depression among women with co-morbidity of depression and obesity seeking weight reduction compared with the placebo.

Methods: Sixty five patients with co-morbidity of depression and overweight/obesity (BMI ≥ 25) signed the informed consent form and enrolled into this 12-week double-blind, placebo-controlled randomized clinical Trial. Subsequently, participants randomly assigned into one of the two groups receiving daily 6 capsules of omega-3 (each capsule containing 180 mg EPA, and 120 mg DHA) or 6 capsules of placebo (two with each meal). We performed body composition assessments and Beck depression inventory at the baseline, and weeks 2, 4, 8, and 12 after the start of the study. One month after stopping the capsules at the follow-up visit, weight was measured to compare weight relapse between the two groups.

Results: Forty five patients finished the study. No significant differences were seen between groups regarding demographic and clinical variables at baseline. Using repeated measures ANOVA, omega-3 significantly reduced depression compared with the placebo (P = 0.05). Mean ± SD weight reduction in omega-3 group 3.07 ± 3.4 kg and in the placebo group was 1.16 ± 2.7 kg and the difference between groups was significant using independent sample t-test (p = 0.049). Patients in the omega-3 group did not show significantly more side effects compared to the placebo but they were not successful in preventing weight regain one month after the end of the study.

Conclusion: Based on our findings omega-3 capsule as a safe over-the-counter supplement might be helpful in reducing the signs of depression and also body weight in patients with co-morbidity of depression and obesity.