<p>The proliferation of malignant cells involves uncontrolled cell division in various human organs, which can lead to tumors. Although often effective, conventional chemotherapy is frequently accompanied by adverse effects and limited selectivity. Consequently, interest is growing in natural bioactive compounds derived from plant sources, particularly cereals, for their potential antiproliferative properties. In light of the above considerations, this review synthesizes current knowledge on the bioactive constituents in functional cereal-based beverages, with an emphasis on mechanisms of action that inhibit malignant cell growth. The key compounds identified include phenolic metabolites, flavonoids, bioactive peptides, and short-chain fatty acids (SCFAs), which exert antiproliferative effects primarily by inducing caspase-dependent apoptosis and modulating pro and antiapoptotic proteins such as BAX and BCL2L1 (<i>Bcl-xL</i>). In addition, cereal processing methods, including malting and fermentation, enhance the bioavailability and efficacy of these molecules. Overall, the evidence discussed underscores a promising role for cereal-derived functional beverages as adjuncts in cancer prevention and gastrointestinal health and supports further research on their bioaccessibility, bioavailability, and clinical applications.</p> Graphical Abstract <p></p>