Do Diet and Dietary Supplements Mitigate Clinical Outcomes in COVID-19?

Abstract

The coronavirus disease 2019 (COVID-19) has caused a pandemic and upheaval that health authorities and citizens around the globe are still grappling with to this day. While public health measures, vaccine development, and new therapeutics have made great strides in understanding and managing the pandemic, there has been an increasing focus on the potential roles of diet and supplementation in disease prevention and adjuvant treatment. In the literature, the impact of nutrition on other respiratory illnesses, including the common cold, pneumonia, and influenza, has been widely demonstrated in both animal and human models. However, there is much less research on the impact related to COVID-19. The present study discusses the potential uses of diets, vitamins, and supplements, including the Mediterranean diet, glutathione, zinc, and traditional Chinese medicine, in the prevention of infection and severe illness. The evidence demonstrating the efficacy of diet supplementation on infection risk, disease duration, severity, and recovery is mixed and inconsistent. More clinical trials are necessary in order to clearly demonstrate the contribution of nutrition and to guide potential therapeutic protocols.

Keywords: COVID-19; SARS-CoV-2; diet; dietary supplement; nutrition; vitamin.

Figure 1

Proposed modulation of the immune pathway by diet. The Western diet, consisting of high fat, refined sugar, and saturated carbohydrates, leads to increased obesity, as well as an increase in TH1 and cytotoxic T cells, resulting in a low-grade inflammatory state. This inflammatory pathway is exacerbated in COVID-19 through the virus’s ability to increase pro-inflammatory cytokines, resulting in ARDS and other morbid complications. In contrast, the Mediterranean diet, consisting of fruits, vegetables, nuts, and fish maintains lean adipose tissue, contributing to a balanced immune system and absent or improved inflammatory state. Nuclear factor kappa B (NF-kb), tumor necrosis factor alpha (TNF-α), interleukin-1 beta (IL-1β); interleukin-6 (IL-6); interferon gamma (IFNγ); interleukin-2 (IL-2); reactive oxygen species (ROS); acute respiratory distress syndrome (ARDS).