Omega 3 supplementation reduces C-reactive protein, prostaglandin E2 and the granulocyte/lymphocyte ratio in heavy smokers: An open-label randomized crossover trial

Ingrid Elisia; Michelle Yeung; Sara Kowalski; Jennifer Wong; Hossein Rafiei; Roger A Dyer; Sukhinder Atkar-Khattra; Stephen Lam; Gerald Krystal

doi:10.3389/fnut.2022.1051418

Omega 3 supplementation reduces C-reactive protein, prostaglandin E₂ and the granulocyte/lymphocyte ratio in heavy smokers: An open-label randomized crossover trial

Front Nutr. 2022 Dec 1:9:1051418. doi: 10.3389/fnut.2022.1051418. eCollection 2022.

Authors

Ingrid Elisia¹, Michelle Yeung¹, Sara Kowalski¹, Jennifer Wong¹, Hossein Rafiei¹, Roger A Dyer², Sukhinder Atkar-Khattra³, Stephen Lam³, Gerald Krystal¹

Affiliations

¹ The Terry Fox Laboratory, BC Cancer Research Centre, Vancouver, BC, Canada.
² Analytical Core for Metabolomics and Nutrition, BC Children's Hospital Research Institute, Vancouver, BC, Canada.
³ Department of Integrative Oncology, British Columbia Cancer Research Institute, Vancouver, BC, Canada.

Abstract

Objectives: Given the current controversy concerning the efficacy of omega 3 supplements at reducing inflammation, we evaluated the safety and efficacy of omega 3 on reducing inflammation in people with a 6-year lung cancer risk >1.5% and a C reactive protein (CRP) level >2 mg/L in a phase IIa cross-over study.

Materials and methods: Forty-nine healthy participants ages 55 to 80, who were still smoking or had smoked in the past with ≥30 pack-years smoking history, living in British Columbia, Canada, were randomized in an open-label trial to receive 2.4 g eicosapentaenoic acid (EPA) + 1.2 g docosahexaenoic acid (DHA)/day for 6 months followed by observation for 6 months or observation for 6 months first and then active treatment for the next 6 months. Blood samples were collected over 1 year for measurement of plasma CRP, plasma and red blood cell (RBC) membrane levels of EPA, DHA and other fatty acids, Prostaglandin E₂ (PGE₂), Leukotriene B₄ (LTB₄) and an inflammatory marker panel.

Results: Twenty one participants who began the trial within the active arm completed the trial while 20 participants who started in the control arm completed the study. Taking omega 3 resulted in a significant decrease in plasma CRP and PGE₂ but not LTB₄ levels. Importantly, the effect size for the primary outcome, CRP values, at the end of the intervention relative to baseline was medium (Cohen's d = 0.56). DHA, but not EPA levels in RBC membranes inversely correlated with PGE₂ levels. Omega 3 also led to a significant reduction in granulocytes and an increase in lymphocytes. These high-dose omega 3 supplements were well tolerated, with only minor gastrointestinal symptoms in a subset of participants.

Conclusion: Omega 3 fatty acids taken at 3.6 g/day significantly reduce systemic inflammation with negligible adverse health effects in people who smoke or have smoked and are at high risk of lung cancer.ClinicalTrials.gov, NCT number: NCT03936621.

Keywords: CRP; DHA; EPA; PGE2; blood cells; smokers.

Associated data

ClinicalTrials.gov/NCT03936621