Medical research has found that average intakes of omega-3 fatty acids are low in modern diets, particularly compared to historical intakes and in relation to generous dietary provision of omega-6 fats. Lacking omega-3 fats, cells instead incorporate more proinflammatory lipid species into their membranes, with consequent alteration in immune-related signaling and functional immune balance. Obesity and other immunometabolic disorders have been scientifically linked to lower omega-3 intakes. In investigations of healthy aging, omega-3 intakes have also been identified as a factor influencing the development of frailty, chronic dysfunction, and biological aging processes that impact health and wellness over time.
The Omega-3 Index is defined as the percentage of combined eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in the fatty acids of red blood cells. Higher values for this longer-term biomarker for omega-3 status have been linked to better outcomes in studies of cardiovascular, neurocognitive, and neuropsychiatric function as well as on total mortality. In the Framingham Offspring study, Omega-3 Index values also related inversely to blood levels of cytokines such as interleukin-6, C-reactive protein, and others.
In this pilot study, 100 hospital patients with the required clinical data and blood samples were assessed for Omega-3 Index and risk for death after admittance for COVID-19. Incidence of death was compared against four ranges of Omega-3 Index values: Quartile 1 below 4.0%, Quartile 2 from 4.0% to under 4.7%, Quartile 3 from 4.7% to under 5.7%, and Quartile 4 being 5.7% and above.