Effect of Fish-Derived Lipids on Inflammation Status and Health-Related Quality of Life in Women with Endometriosis.

The short version

This randomized controlled trial of 46 women with endometriosis explored whether a fish-derived lipid supplement (a mixture of marine omega-3 fats such as EPA and DHA, plus compounds called squalene and alkylglycerols) adds anything to a Healthy Eating Plate diet. Endometriosis is a long-term, estrogen-dependent condition in which tissue similar to the uterine lining grows outside the uterus. Researchers increasingly describe it as an inflammatory condition, in which signaling proteins called cytokines (messengers that coordinate immune cells) help drive pelvic pain. Omega-3 fats are known to influence these immune pathways, but evidence in endometriosis has been limited, so the team treated the work as exploratory. Women aged 22 to 48 with confirmed endometriosis were randomly assigned to one of two groups for 12 weeks. Both groups followed an individualized Healthy Eating Plate diet with meal plans from a dietitian. One group also took the fish-derived lipid product, dosed by body weight (0.5 mL per kilogram daily). Blood and stool samples were collected before and after to measure five cytokines and fecal calprotectin (a marker of gut inflammation). Pain was rated on a 0 to 10 visual analog scale, and quality of life was scored with the 30-item Endometriosis Health Profile. The clearest signal was in IL-10, a cytokine that restrains immune activation: levels rose in the supplement group and the adjusted difference between groups was significant (about 5-fold higher; 95% CI 1.32 to 19.48; p = 0.019). Other cytokines gave mixed results, with IL-1β, TNF-α, and IL-6 landing right at the edge of significance (p = 0.050 to 0.057) and fecal calprotectin unchanged. Average pain scores dropped within the supplement group (5.0 to 4.3; p = 0.011), yet the difference between groups was not significant. A pain drop of at least 1 point was more common with the supplement (73.9% versus 34.8%; adjusted risk ratio 2.11, meaning roughly twice the likelihood). Quality-of-life scores did not differ between groups, and the paper did not report safety outcomes. The authors describe the pain and IL-10 findings as hints worth testing rather than proof of benefit, since most outcomes showed no consistent advantage over diet alone. The study was small, lasted only 12 weeks, had no placebo, relied on self-reported food records, and ran many secondary analyses without statistical correction. The supplement was also a complex mixture, so the effects cannot be pinned on omega-3 fats alone. The authors call for larger, longer trials that measure fatty acid levels in blood and examine immune cells directly.

Key findings

• A 12-week randomized trial in 46 women with endometriosis tested a fish-derived lipid supplement (a mixture of marine omega-3 fats and related compounds) added to a Healthy Eating Plate diet against the diet alone.
• The supplement group had a clearly higher level of IL-10 (a cytokine, or immune messenger protein, that helps restrain immune activation), with an adjusted fold-change of 5.07 (95% CI 1.32 to 19.48; p = 0.019).
• Most other outcomes did not differ between groups after adjustment, including the other cytokines, fecal calprotectin (a stool marker of gut inflammation), average pain on a 0 to 10 scale, and every domain of the Endometriosis Health Profile-30 quality-of-life questionnaire.
• A pain reduction of at least 1 point was more common with the supplement (73.9% versus 34.8%; adjusted risk ratio 2.11), though the 2-point threshold showed no difference.
• The authors call the findings exploratory and hypothesis-generating because the study was small, short, unblinded, and tested a complex mixture rather than isolated omega-3 fats.

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