Researchers tested whether an oral supplement made from herring roe oil (HRO) could change signs of inflammation in adults with mild-to-moderate psoriasis. In this randomized controlled trial, 64 participants received either HRO or a placebo for 26 weeks. Blood markers of systemic inflammation were measured, and skin improvement was tracked using the PASI50 scale.
Compared with placebo, HRO was associated with significant reductions in several inflammation indices by week 26, including the systemic immune-inflammation index (SII), the systemic inflammation response index (SIRI), and the platelet-to-lymphocyte ratio (PLR). Among participants who started with lower baseline SII, the rate of PASI50 response was higher in the HRO group. The study did not report detailed safety data, adverse events, or effect sizes, and it did not identify a primary outcome.
This was a post hoc analysis, meaning the findings were explored after the trial and should be considered preliminary. The study did not report whether participants or researchers were blinded, and some patients were excluded if they lacked baseline blood counts. Because this was a small, exploratory analysis, the results show an association between HRO and changes in inflammatory biomarkers, not a proven cause-and-effect benefit.