In a study published in the journal Life Sciences, researchers conducted a systematic review to assess the impact of polyunsaturated fatty acid (PUFA) levels on coronavirus disease 2019 (COVID-19)-related hospitalization and mortality.
Study: The effect of polyunsaturated fatty acids on the severity and mortality of COVID patients: A systematic review. Image Credit: Studio Romantic/Shutterstock
Background
Studies show that COVID-19 mortality, from the causative organism severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is closely associated with a sizable increase in inflammatory cytokines, leading to a cytokine storm. PUFAs have been shown to play a crucial role in regulating immune pathways as well as inflammatory responses.
Since PUFAs are lipophilic in nature, they can also disrupt the viral envelope and change its dynamics, thus inactivating viruses. Hence this study evaluated the effect of PUFAs on COVID-19 prognosis.
About the study
The team conducted a comprehensive search on Scopus, PubMed, and Web of Science. They performed the search using the following keywords in the databases for systematic identification: COVID‐ 19, COVID, SARS‐CoV‐2, SARS COV- 2 Infection, Coronavirus Disease 19, SARS‐ CoV‐ 2, Coronavirus Disease, COVID19, Fatty Acids, Omega-3 Fatty Acid, Omega-3, Omega-6, n 3 Fatty and Omega-9. They used the OR and AND operators with these keywords.
The review was based on Preferred Reporting Items for Systematic Reviews (PRISMA). The inclusion criteria for the review were studies focusing on the evaluation of the impact of PUFAs on disease severity, ICU admission, hospital admission, and mortality among COVID-19 patients, articles in the English language, and all original research papers. Exclusion criteria for this review were articles written in other languages, reviews, case reports, and letters to the editors.
The End-Note X7 software was utilized to manage the articles included in the study. During screening and study selection, duplicate articles were removed using the software and the remaining articles were evaluated and selected using their title and abstract.
Results
In this systematic review, there were several crucial findings on the relationship between the risk of COVID-19 and the levels of omega-3 and omega-6 fatty acids. Omega-3 supplements were 12 to 21% effective in reducing COVID-19 risk. Most of the studies highlighted the increasing disease severity and the need for hospitalization and mechanical ventilation in patients with a PUFA deficiency.
A Belgium-based study found that serum levels of PUFA were higher with lower COVID-19 severity and serum levels of monounsaturated fatty acids (MUFA) were higher with higher disease severity.
One study found that the mean serum omega-3, omega-6, and omega-9 fatty acid levels were significantly different in COVID-19 patients compared to healthy individuals. A study conducted in China showed that patients with asymptomatic COVID-19 had decreased levels of omega-3 fatty acids, including oleic acid and omega-3 PUFAs. Also, compared to healthy controls, omega-3 fatty acids were decreased by 35% in asymptomatic COVID-19 patients.
Moreover, the deficiency of omega-3 and omega-6 PUFA biomarkers was found to increase the risk of severe disease and hospitalization by almost three times, and the consumption of omega-3 PUFA supplements seemed to reduce the risk of severe disease and hospitalization. Barberis et al. noted that the levels of fatty acids such as arachidonic acid and oleic acid were directly associated with COVID-19 severity and ICU admission.
Many studies reported that omega-3 fatty acid deficiency also increased mortality in COVID-19 patients. However, the authors warned that in critical cases, elevated fatty acid levels in the lungs of the patients and a cytokine storm were found to be the reasons for death in COVID-19 patients.
A study conducted in Chile observed that the COVID-19 mortality risk was over three times higher in patients who had low omega-3 PUFA levels, while the risk decreased in patients with high levels of omega-3 PUFA. Furthermore, Asher et al. reported that the risk of COVID-19 mortality was reduced by 75% in patients with an omega-3 PUFA index above 5.7%.
Conclusion
This review investigated the potential role played by omega PUFAs as an effective adjunct therapy in mitigating COVID-19-related inflammation and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) replication. The findings from the literature showed that omega-3 PUFAs and their metabolites can regulate COVID-19-related complications and enhance the immunological defense against SARS-CoV-2 entry and replication.
The evidence presented by this systematic review showed that PUFAs can be a preventative, safe, and inexpensive method to decrease COVID-19 risk. However, the risk of consuming high doses of omega-3 supplements prior to or during SARS-CoV-2 infection must be investigated.
SARS-CoV-2 hijacks cholesterol trafficking to fuel infection and evade immune responses