Due to SARSCoV 2 (Severe Acute Respiratory Syndrome coronavirus 2) infection, coronaviruses are unique infectious diseases that can affect both humans and animals by inflicting respiratory diseases (1). Since late February 2020, COVID-19 has expanded significantly in China and has spread quickly to more than 200 nations worldwide (2). Corona outbreak quickly became the most serious threat to global health (3). It is not surprising that this outbreak has turned into the pandemic with the greatest impact of this century (4, 5).
The hematological system (alterations of hemostasis), the pulmonary system (acute hypoxic respiratory failure, pneumonia, pulmonary embolism, and pulmonary fibrosis), the cardiovascular system (coronary artery atherosclerosis and myocardial infarction), the nervous system, and all other organ systems in the human body are also affected by this virus (6). In severe situations, when the innate immune system is too activated, there is progressive inflammation, and there is a cytokine storm, especially in the airways, which results in the development of cytokine release syndrome (7, 8). Accordingly, COVID-19 has placed a heavy financial strain on the world's economy and health (9, 10). Nutritional state plays a significant part in the host's ability to fight off viral infections (11). In fact, healthy eating can maintain and strengthen the immune system (12). Numerous research have looked into possible connections between diet and immunological response (13). Recent data has shown that dietary supplements may be beneficial for COVID-19 patients. Supplementing with more nutrients than is advised, such as vitamin D, C, E, zinc, and omega-3 fatty acids, could be advantageous (14, 15).
Inflammation and acquired immunological responses are mediated by omega-3 polyunsaturated fatty acids (n3-PUFAs), which can also enhance anti-inflammatory responses (16). Recent research has shown that n3-PUFAs, such as eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and -linoleic acid (ALA), can improve cell membrane stability, regulate immune function, block hyper-inflammatory reactions, and lower the incidence of multiple organ dysfunction syndrome (MODS), systemic inflammatory response syndrome (SIRS), and infection-related complications (17).
Doaei et al. (18) reported that Omega-3 supplementation improved the levels of several parameters of respiratory and renal function in critically ill patients with COVID-19. Shakoor et al. (19) found the effects of vitamins C, D, E, zinc, selenium, and omega-3 fatty acids on the immune system and their possible benefits to those suffering from COVID-19 are presented. All of the nutrients mentioned have a feasible role in the support of COVID-19 patients. According to research by Pluta et al. (20) after 6 months of follow-up, patients with chronic kidney disease who took one omega-3 capsule per day that contained 1000 mg of n3-PUFAs, including 330 mg of EPA, 220 mg of DHA, and 100 mg of other acids like alpha-linolenic acid (ALA), had lower urinary excretion of monocyte chemoattractant protein-1 (MCP-1). White blood cell (WBC) count and serum CRP and MCP-1 levels did not vary all that much, though.
Given suggestive evidence of the beneficial effects of n3-PUFAs on the immune system and the contradictory results of recent studies concerning the effects of omega-3 fatty acids in patients with viral infections, we aimed to investigate the relationship between omega-3 intake and the severity and symptoms of COVID-19 ill patients with COVID-19.