Traditional Food Use and Ethnomedicinal Contexts of Turnip (Brassica rapa L.): A Scoping Review of Composition, Food Processing, and Health-Related Evidence

Turnip (Brassica rapa L.) is widely cultivated for food and has documented ethnomedicinal uses. This scoping review mapped the international literature on turnip, with detailed synthesis focused on turnip materials associated with selected regional food and ethnomedicinal traditions in China. Searches covered seven bibliographic databases. The bibliographic map comprised 771 records, of which 397 were selected for detailed synthesis. Regional uses varied in plant part and preparation method. The clearest evidence concerned composition and processing: constituent profiles differed by provenance, plant part, and analytical method, whereas changes in composition and product quality depended on the product and process. Animal and cell studies reported effects of specific extracts, fractions, and multicomponent formulations on hypoxia tolerance, endurance, tissue injury, inflammation, redox regulation, metabolism, and the gut microbiota, but mechanistic findings did not converge across preparations and models. The few human studies addressed mainly hypoxia or exercise and supportive care during chemotherapy; differences in design, preparations, and outcomes precluded reproducible conclusions about any defined turnip food or ethnomedicinal preparation. Overall, this review clarifies the current evidence on turnip as a food resource, documents its ethnomedicinal contexts, and identifies priorities for future research and product development.