Effects of Flaxseed Oil Omega‑3 Fatty Acids Supplementation on Regression and Metabolic Status in Endometrial Hyperplasia: A randomized, Double‑Blind, Placebo‑Controlled Trial

Background: Data on the effects of omega‑3 fatty acid supplementation on clinical symptoms and metabolic profles in patients with endometrial hyperplasia (EH) are limited. This intervention was performed to assess the effects of omega‑3 fatty acid supplementation on clinical symptoms and metabolic profles in patients with endometrial hyperplasia (EH). Methods: This randomized, double‑blind, placebo‑controlled trial was conducted among 40 women diagnosed with simple endometrial hyperplasia (EH). EH diagnosis was performed based on specifc diagnostic procedures of biopsy. Participants were randomised into two groups to intake 1,000 mg omega‑3 fatty acid supplements from flaxseed oil (n = 20) or placebo (n = 20), twice a day for 12 weeks. Fasting blood samples were taken at baseline and after the 12‑week intervention to determine related markers. Results: Compared with the placebo, omega‑3 fatty acid supplementation signifcantly decreased fasting plasma glucose (FPG) (‑7.1 ± 9.6 vs. +2.0 ± 4.9 mg/dL, P = 0.001), serum insulin levels (‑1.5 ± 4.6 vs. +1.6 ± 3.9 µIU/mL, P = 0.02) and homeostasis model of assessment‑insulin resistance (HOMA‑IR) (‑0.4 ± 1.1 vs. +0.4 ± 1.0, P = 0.02). In addition, a signifcant increase in plasma total antioxidant capacity (TAC) (+102.6 ± 69.6 vs. +5.0 ± 37.1 mmol/L, P < 0.001) and total glutathione (GSH) levels (+63.6 ± 84.9 vs. ‑3.0 ± 69.4 µmol/L, P = 0.01) were seen following the supplementation of omega‑3 fatty acid compared with the placebo. Omega‑3 fatty acid supplementation had no signifcant effect on regression, lipid profles, and other biomarkersof inflammation and oxidative. Conclusions: In conclusion, we found that omega‑3 fatty acid administration for 12 weeks to subjects with EH signifcantly improved FPG, insulin, HOMA‑IR, TAC and GSH levels, but did not influence regression, lipid profles, and other biomarkers of inflammatory and oxidative stress.