Effects of omega-3 supplementation on psychological symptoms in men with prostate cancer: Secondary analysis of a double-blind placebo-controlled randomized trial.

backgroundIn the general population, a higher omega-3 polyunsaturated fatty acids intake is associated with lower levels of several psychological symptoms, especially depression. However, the existing evidence in cancer is equivocal.

methodsThis phase IIB double-blind, placebo-controlled trial was aimed at comparing the effects of eicosapentaenoic acid monoacylglyceride (MAG-EPA) supplementation and high oleic acid sunflower oil (HOSO; placebo) on depression levels (primary outcome) and other symptoms (anxiety, fear of cancer recurrence, fatigue, insomnia, perceived cognitive impairments; secondary outcomes). Participants, recruited in a prostate cancer clinic, were randomized to MAG-EPA (3.75 g daily; n = 65) or HOSO (3.75 g daily; n = 65) for 1 year post-radical prostatectomy (RP), starting 4-10 weeks before surgery. Patients completed self-report scales at baseline (before RP) and 3, 6, 9, and 12 months after: Hospital Anxiety and Depression Scale (HADS), Fear of Cancer Recurrence Inventory (FCRI), Insomnia Severity Index (ISI), Fatigue Symptom Inventory (FSI), and Functional Assessment of Cancer Therapy-Cognitive Function (FACT-Cog).

resultsAnalyses showed significant reductions in HADS-depression, HADS-anxiety, FCRI, ISI, FSI-number of days, and FACT-Cog-impact scores over time. A significant group-by-time interaction was obtained on FACT-Cog-Impact scores only; yet, the temporal change was significant in HOSO patients only.

conclusionsSeveral symptoms significantly decreased over time, mainly within the first months of the study. However, MAG-EPA did not produce greater reductions than HOSO. Omega-3 supplementation does not seem to improve psychological symptoms of men treated with RP.