The Role of Diet and Specific Nutrients during the COVID-19 Pandemic: What Have We Learned over the Last Three Years?

Abstract

Nutrients and diets have an important impact on our immune system and infection risk and a huge number of papers have been published dealing with various aspects of nutrition in relation to SARS-CoV-2 infection risk or COVID-19 severity. This narrative review aims to give an update on this association and tries to summarize some of the most important findings after three years of pandemic. The analysis of major studies and systematic reviews leads to the conclusion that a healthy plant-based diet reduces the risks for SARS-CoV-2 infection and especially COVID-19 severity. Regarding micronutrients, vitamin D is to the fore, but also zinc, vitamin C and, to some extent, selenium may play a role in COVID-19. Furthermore, omega-3-fatty acids with their anti-inflammatory effects also deserve attention. Therefore, a major aim of societal nutritional efforts in future should be to foster a high quality plant-based diet, which not only exerts beneficial effects on the immune system but also reduces the risk for non-communicable diseases such as type 2 diabetes or obesity which are also primary risk factors for worse COVID-19 outcomes. Another aim should be to focus on a good supply of critical immune-effective nutrients, such as vitamin D and zinc.

Plant-Based Diet and Supplements Reduced COVID-19 Severity and Mortality in Elderly Patients with Multiple Comorbidities (Part 2: Exploring the Underlying Mechanisms of Successful Intervention)

“…Reviewing the historical record from the start of the 20th century, it is evident that a diet emphasizing plant-based foods and adopting a healthier lifestyle has safeguarded numerous individuals from various pandemics [143,144]. Furthermore, our extensive knowledge of supplementation will enrich our understanding of how to combat COVID-19 and may also motivate us to prepare for future pandemics.…”

Immune Mechanisms Underpinning Long COVID: Collegium Internationale Allergologicum Update 2024

“…Dietary components can directly or indirectly influence immune function. Nutrients that directly impact immunological processes include niacin (vitamin B3), vitamins C and E, selenium, zinc, and the omega-3 (n-3) fatty acids docosahexaenoic acid, and eicosapentaenoic acid [145,146]. However, there is no evidence currently that these nutrients can affect long COVID outcomes and sufficient intake according to national guidance should be recommended.…”