Omega-3 Index and Clinical Outcomes of Severe COVID-19: Preliminary Results of a Cross-Sectional Study

Int J Environ Res Public Health. 2021 Jul 21;18(15):7722. doi: 10.3390/ijerph18157722.


The potentially detrimental effects of the worldwide deficiency of Omega-3 fatty acids on the COVID-19 pandemic have been underestimated. The Omega-3 Index (O3I), clinical variables, biometric indices, and nutritional information were directly determined for 74 patients with severe COVID-19 and 10 healthy quality-control subjects. The relationships between the OI3 and mechanical ventilation (MV) and death were analyzed. Results: Patients with COVID-19 exhibited low O3I (mean: 4.15%; range: 3.06-6.14%)-consistent with insufficient fish and Omega-3 supplement consumption, and markedly lower than the healthy control subjects (mean: 7.84%; range: 4.65-10.71%). Inverse associations were observed between O3I and MV (OR = 0.459; C.I.: 0.211-0.997) and death (OR = 0.28; C.I.: 0.08-0.985) in severe COVID-19, even after adjusting for sex, age, and well-known risk factors. Conclusion: We present preliminary evidence to support the hypothesis that the risk of severe COVID-19 can be stratified by the O3I quartile. Further investigations are needed to assess the value of the O3I as a blood marker for COVID-19.

Keywords: COVID-19; Omega-3 Index; Omega-3 fatty acids; inflammation.

MeSH terms

  • Animals
  • COVID-19*
  • Cross-Sectional Studies
  • Docosahexaenoic Acids
  • Eicosapentaenoic Acid
  • Fatty Acids, Omega-3*
  • Humans
  • Pandemics
  • SARS-CoV-2


  • Fatty Acids, Omega-3
  • Docosahexaenoic Acids
  • Eicosapentaenoic Acid