Efficacy of fish oil and its components in the management of psoriasis: a systematic review of 18 randomized controlled trials.

Context: Fish oil and omega-3 polyunsaturated fatty acids (ω-3 PUFAs) have anti-inflammatory properties, but their effect on psoriasis and its comorbidities remains inconclusive.

Objective: The aim of this quantitative systematic review was to evaluate the efficacy and safety of fish oil and its components in the treatment of psoriasis and its comorbidities.

Data Sources: PubMed, Embase, Cochrane Central Register of Controlled Trials, China Network Knowledge Infrastructure, China Science and Technology Journal Database, and Wanfang databases were searched from inception to March 30, 2019.

Study Selection: Randomized controlled trials were eligible for inclusion if they measured the effect of fish oil and its components in the treatment of patients with psoriasis.

Data Extraction: Eighteen randomized controlled trials involving 927 study participants were included.

Results: Monotherapy with fish oil or ω-3 PUFAs had no effect on the Psoriasis Area and Severity Index (PASI) score (P = 0.47), lesion area (P = 0.34), or pruritus (P = 0.62). Fish oil or ω-3 PUFAs combined with conventional treatments, however, resulted in a decreased PASI score (mean difference [MD], -3.92; 95%CI, -6.15 to -1.69; P = 0.0006) and lesion area (MD, -30.00; 95%CI, -33.82 to -26.18; P < 0.0001). Safety evaluation suggested no between-group differences. Fish oil and its components reduced certain risk factors for obesity, cardiovascular disease, and metabolic disease in patients with psoriasis and also regulated several inflammatory mediators.

Conclusions: Overall, when combined with conventional treatments, fish oil and its components may have beneficial effects on psoriasis and its comorbidities, including obesity, cardiovascular disease, and metabolic disease.

Systematic Review Registration: PROSPERO registration number CRD42019128631.