Abstract
Kale (Brassica oleracea var. acephala) is a non-heading leafy vegetable of the Brassicaceae family, widely recognized for its dense nutritional profile and diverse phytochemical composition. This review provides a comprehensive and up-to-date synthesis of kale's botanical characteristics, cultivation practices, chemical constituents, biological activities, and applications in pharmacy, functional foods, and cosmetics. Importantly, this work highlights the novelty of kale's multifunctional role. Kale is particularly rich in vitamins (A, C, K), minerals (Ca, Fe, K), dietary fiber, glucosinolates, polyphenols, carotenoids, flavonoids, and chlorophylls, which contribute to its classification as a "superfood." In this article the discussion of the health-promoting effects of glucosinolates and their enzymatic degradation products, such as isothiocyanates, indoles, and nitriles, highlighting their antioxidant, anti-inflammatory, anticancer, antimicrobial, and lipid-lowering properties, was performed. Moreover, key compounds including sulforaphane, indole-3-carbinol (I3C), and diindolylmethane (DIM) are emphasized for their roles in chemoprevention, hormonal regulation, and cellular protection. The review also summarizes recent in vivo and clinical studies demonstrating kale's potential in reducing the risk of chronic diseases such as cardiovascular disorders, type 2 diabetes, and hormone-related cancers. The effects of kale on the composition of the gut microbiome, glycemic control, and cholesterol metabolism are also discussed. Advances in plant biotechnology, including micropropagation, somatic embryogenesis, and metabolite enhancement, are also discussed. Overall, this review supports the integration of kale into health-oriented dietary strategies and highlights its relevance in preventive medicine, food innovation, and cosmeceutical development.