The active ingredients in fish oils that are known to contain anti-inflammatory activities are omega-3 polyunsaturated fatty acids (ω-3 PUFAs). The use of fish oil supplements could therefore be effective in treating inflammatory diseases. Fish oil supplements have been suggested as a therapeutic option for psoriasis. In a new study, researchers looked at the effects fish oil supplements have on psoriasis.
This was a meta-analysis of randomized controlled trials (RCTs); The Central, Emabse and Medline databases were searched on January 24, 2018 for relevant RCTs investigating the effects of fish oil supplements on psoriasis. RCTs were included if participants had psoriasis, if the study intervention was fish oil / ω-3 PUFA supplement versus placebo or other active treatment, and if published in English. The researchers used the Cochrane Collaboration tool to determine the risk of bias in selected studies. The primary results included the severity of the disease, as measured by the PASI score (Psoriasis Area and Severity Index) or the affected body surface, and adverse events. Other results were the degree of psoriasis signs (erythema, scaling and induration) and the degree of itching.
A total of 13 RCTs with 625 patients were identified. In 11 RCTs, fish oil supplement was administered orally either in a capsule or in oil, and in the remaining two RCTs it was administered intravenously as a lipid emulsion. In three experiments, capsules contained a combination of fish oil and evening primrose oil. Five RCTs found that fish oil supplementation was beneficial for patients with psoriasis, but the other eight found no significant benefit compared to the control treatment.
Three RCTs with 337 patients had suitable meta-analysis data. Using the PASI score, fish oil supplementation was not associated with reduced disease severity (mean difference -0.28; 95% confidence interval -1.74 to 1.19).