Food Ingredients and Active Compounds against the Coronavirus Disease (COVID-19) Pandemic: A Comprehensive Review

Abstract

As media reports have noted, the COVID-19 pandemic has accelerated market mainstreaming of immune-boosting food bioactives, supplements, and nutraceuticals. However, most studies reporting on the potential of bioactives against COVID-19 transmission have been uploaded as preprints with little opportunity to revise content for benefit and impact. The current review discusses current best evidence and information underpinning the role of food ingredients and bioactive compounds in supporting immune functions in humans and animals, specifically in the prevention and treatment of COVID-19 disease. Up to now, some evidence from randomized population and clinical trials has suggested that vitamin D levels may be linked to COVID-19 transmission and severity. Numerous theoretical studies have pointed to polyphenols and particularly flavonoids as potential inhibitors of SARS-CoV-2 infection. There is also inconclusive evidence to support the future use of β-glucan to address COVID-19 due in part to variability in immune response arising from heterogeneity in polysaccharide branch and chain length for different sources and the absence of a standardized extraction method. To confirm the promising outcomes and hypotheses for bioactive compounds, more randomized and controlled clinical studies are needed. The results of such studies would have a profound effect on the prospects of food supplements and nutraceuticals as potential prophylaxis against COVID-19 and serve to help consumers to protect themselves during the post-lockdown recovery era.

Functionality of Food Components and Emerging Technologies

“…Natural antioxidants have also been proposed as UV booster agents in sunscreens and preservatives to fortify vegetable oils, meats, and other foods [ 15 , 27 , 28 , 29 , 30 , 31 ]. Flavonoids like epigallocatechin gallate and kaempferol, and polyphenolic acids such as protocatechuic have been suggested as potential inhibitors of the main SARS-CoV-2 protease in molecular docking studies [ 7 ].…”

“…An exception is the flavonoid database developed by the USDA [ 61 ]. Recently, some evidence from a randomized population and clinical trials has proposed that vitamin D levels may be linked to COVID-19 transmission and severity [ 7 ].…”

“…Vitamins are a variety of dietary compounds necessary for the correct maintenance of the body’s functions. There is an increased interest in the vitamin supply through the diet through minimally processed and nutritious foods and drinks [ 7 ]. Depending on their solubility, vitamins can be classified into soluble (e.g., vitamins C and B) and fat-soluble (Vitamins D, A, K, and E) groups [ 191 ].…”

“…On the other hand, consumers continuously become more aware that proper food is directly connected to their physical wellbeing and can prevent nutrition-related diseases [ 5 , 6 , 7 ]. Morever, following the catastrophic effects of the COVID-19 pandemic, immunity is among people’s highest priority in the era, and subsequently, consumers are eager to turn their diets to healthier choices [ 8 , 9 ].…”

The effects on European importers’ food safety controls in the time of COVID-19

“…In the time of COVID-19, several measures within the food system have been explored for prophylaxis and prevention. These include the use of functional foods, bioactive ingredients and nutraceuticals ( Galanakis et al, 2020 ), food safety practices within workplaces and restaurants ( Gomes de Freitas & Stedefeldt, 2020 ), and tools and instruments to facilitate the transition of the food industry to the new normal ( Nakat & Bou-Mitri, 2021 ). Efforts are also being made to devise instruments capable of detecting and analysing the possible transmission of the virus through the food supply chain ( Rizou et al, 2020 ).…”