Nutrition and COVID-19 susceptibility? A systematic review
This is a summary of the following paper: James P, Ali Z, Armitage A, Bonell A, Cerami C, Drakesmith H et al (2021) The Role of Nutrition in COVID-19 Susceptibility and Severity of Disease: A Systematic Review. The Journal of Nutrition 0, 1-25. https://academic.oup.com/jn/article/151/7/1854/6274856
Many nutrients have powerful effects on the immune system with the potential to alter susceptibility to COVID-19 infection, progression to symptoms, the likelihood of severe disease and survival. However, nutrition information has long been miscommunicated to the public and nutrition-related myths regarding COVID-19 protection and treatment have been widely prevalent during this pandemic. This review investigates the latest evidence on how malnutrition across all its forms (under- and over-nutrition and micronutrient status) may influence both susceptibility to, and the progression of, COVID-19.
The authors synthesised information on 13 nutrition-related components and their potential interactions with COVID-19: overweight, obesity and diabetes, protein-energy malnutrition, anaemia, vitamins A, C, D and E, poly-unsaturated fatty acids, iron, selenium, zinc, antioxidants and nutritional support. For each section they provided a) a background narrative review summarising the relevant material, b) a systematic search of the literature and c) a screen of six clinical trial registries. Searches took place between 16th May and 11th August 2020.
In the final narrative synthesis, the authors summarise 22 published articles, 38 pre-print articles and 79 trials. Despite the wealth of literature being published, the evidence directly linking nutritional status to the risk and progression of COVID-19 is still sparse due to the lack of high-quality data. The authors conclude that currently there is limited evidence that high-dose supplements of micronutrients will either prevent severe disease or speed up recovery. However, the results of clinical trials are eagerly awaited. Given the known impacts of all forms of malnutrition on the immune system, public health strategies to reduce micronutrient deficiencies and undernutrition remain of critical importance. Furthermore, there is strong evidence that the prevention of obesity and type-2 diabetes will reduce the risk of serious COVID-19 outcomes.