Effective food hygiene principles and dietary intakes to reinforce the immune system for prevention of COVID-19: a systematic review

BACKGROUND: This study aimed at reviewing effective food hygiene principles and dietary intakes to reinforce the immune system for prevention of corona virus disease 2019 (COVID-19). METHODS: The systematic literature search was performed in three databases from Jan. 2020 up to 10(th) July 2020. English articles that focused on nutrition, food, immunity and corona virus were searched. Systematic and narrative reviews were included. RESULTS: After evaluation of search papers, 27 relevant articles were used in this review. The importance of nutrients, phytochemicals, probiotics and some spices were highlighted for enhancing immunity during the COVID-19 pandemic. A healthy dietary pattern with proper energy intake provides sufficient nutrients. The unhealthy dietary pattern is linked with inflammation and risk factors related to high mortality in patients with severe COVID-19 infection. Different thermal procedures have been used for the inactivation of viruses. It is recommended not to consume raw or undercooked animal products. CONCLUSIONS: It is critical to ensure that the nutritional needs of the population are met and sustained based on standards during a COVID-19 pandemic. Clear advice on adequate calorie intake and an optimal healthy diet to support the immune function should be provided. Good hygiene practices must be performed by everyone and done in the food industry.