Diet and Nutritional Factors in the Prevention and Treatment of COVID-19: An Umbrella Review

Abstract

Background: There is growing interest in the use of natural therapies for the prevention and treatment of COVID-19 and related illnesses. The aim of this review was to identify and examine the systematic and narrative reviews reporting on the relationship between diet or nutritional status and COVID-19. Methods: This paper is part of an umbrella review of studies related to natural health products and therapies for the prevention or treatment of COVID-19, as a follow-up to a live review that was conducted by the World Naturopathic Federation. PubMed and Google Scholar were searched for systematic and narrative reviews. Results: Seven narrative reviews and four systematic reviews were included. The reviews included evidence suggesting that dietary patterns and nutritional status are important modifiable risk factors relevant to the prevention and treatment of COVID-19. Three systematic reviews reported an association between poor nutritional status and greater COVID-19 severity or death. Narrative reviews suggested a possible benefit of the Mediterranean diet, fibre-rich diets, and antioxidant-rich fruits and vegetables. Conclusion: The research suggests that nutrition status is a significant factor in the progression of COVID-19 infection. While more clinical and interventional evidence is needed to precisely understand the impact of diet, dietary constituents, and nutritional status on modifying COVID-19 risk, the findings of this review highlight the importance of following existing dietary guidelines to support healthy immune function.