ABSTRACT
The COVID-19 has had a significant impact on people's lives and livelihoods in Zimbabwe, particularly the elderly and those suffering from underlying conditions. Generally, COVID-19 has increased the use of immune-boosting foods and nutritional supplements as preventative and therapeutic interventions. Small grains, such as sorghum and millets, have long been mainstays of the Zimbabwean diets, both in rural and urban settings. There is, however, scarcity of data linking the nutritional content and phytochemistry of small grains grown in Zimbabwe's drylands to COVID-19 prevention and treatment. The current study investigates, critically synthesises, and identifies gaps in the role of sorghum and millets in boosting human immune systems, with a focus on COVID-19 prevention and treatment. The systematic literature review approach was adopted to gather information on how small grains can contribute to COVID-19 management. In Zimbabwe, sorghum and millets meal are used to prepare different foods, including porridges and most traditionally fermented foods, such as nonalcoholic beverages. Although there is no conclusive evidence that sorghum and millets boost immunity, presence of significant quantities of minerals, vitamins, and phytochemicals in sorghum and millets derived foods indicates their importance in improving immune system performance. Additionally, the high concentration of resistant starch in sorghum and millets has been linked to a delayed release of glucose into the circulation, resulting in reduced chances of underlying conditions, such as diabetes and hypertension. Furthermore, millets and sorghum are important sources of antioxidants, such as quercetin, curcumin, and ellagic and polyphenols, particularly flavonoids that have been identified as possible inhibitors of SARS-CoV-2 infection. With inconclusive evidence to support contributions of millets and sorghum in COVID-19 prevention and treatment, more randomised and controlled clinical trials are required to confirm their significance. The outcomes of such studies would significantly affect the possibilities of expanding nutritional interventions in the fight against COVID-19. © The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Switzerland AG 2023.