The Effects of Flaxseed Oil Omega-3 Fatty Acids Supplementation on Metabolic Status of Patients with Polycystic Ovary Syndrome: A Randomized, Double-Blind, Placebo-Controlled Trial

Exp Clin Endocrinol Diabetes. 2018 Apr;126(4):222-228. doi: 10.1055/s-0043-119751. Epub 2017 Nov 8.


Objective: This study was conducted to evaluate the effects of flaxseed oil omega-3 fatty acids supplementation on metabolic status of patients with polycystic ovary syndrome (PCOS).

Methods: This randomized double-blind, placebo-controlled trial was conducted on 60 women with PCOS according to the Rotterdam criteria aged 18-40 years old. Participants were randomly assigned into two groups to receive either 1,000 mg flaxseed oil omega-3 fatty acids (n=30) or placebo (n=30) twice a day for 12 weeks. Metabolic, endocrine, inflammatory factors were quantified at baseline and after the 12-week intervention.

Results: After the 12-week intervention, compared to the placebo, flaxseed oil omega-3 supplementation significantly decreased insulin values (-2.6±7.7 vs.+1.3±3.9 µIU/mL, P=0.01), homeostasis model of assessment-estimated insulin resistance (-0.7±1.7 vs.+0.3±0.9, P=0.01), mF-G scores (-1.2±1.7 vs. -0.1±0.4, P=0.001), and increased quantitative insulin sensitivity check index (+0.01±0.02 vs. -0.01±0.02, P=0.01). In addition, supplementation with flaxseed oil omega-3 resulted in significant decreases in serum triglycerides (-5.1±20.9 vs.+9.7±26.1 mg/dL, P=0.01), VLDL-cholesterol (-1.0±4.2 vs.+1.9±5.2 mg/dL, P=0.01) and high-sensitivity C-reactive protein (hs-CRP) (-1.6±3.1 vs.+0.2±1.5 mg/L, P=0.004) compared to the placebo. We did not see any significant effect of flaxseed oil omega-3 supplementation on hormonal and other lipid profiles, and plasma nitric oxide levels.

Conclusions: Overall, flaxseed oil omega-3 supplementation for 12 weeks in women with PCOS had beneficial effects on insulin metabolism, mF-G scores, serum triglycerides, VLDL-cholesterol and hs-CRP levels, but did not affect hormonal and other lipid profiles, and plasma nitric oxide levels.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Adolescent
  • Adult
  • Biomarkers / blood
  • Blood Glucose / metabolism
  • Dietary Supplements
  • Double-Blind Method
  • Fatty Acids, Omega-3 / pharmacology*
  • Female
  • Humans
  • Insulin / blood*
  • Insulin Resistance / physiology*
  • Linseed Oil / pharmacology*
  • Lipids / blood
  • Nitric Oxide / blood
  • Oxidative Stress / drug effects
  • Polycystic Ovary Syndrome / blood*
  • Young Adult


  • Biomarkers
  • Blood Glucose
  • Fatty Acids, Omega-3
  • Insulin
  • Lipids
  • Nitric Oxide
  • Linseed Oil