Integrated Nutraceutical Strategies in Cancer Prevention and Therapy: A Comprehensive Review of Radiosensitization, Chemosensitization, and Molecular Mechanisms

Cancer remains a leading cause of mortality globally, characterized by multifactorial pathophysiological components including genetic mutations, oxidative stress, and chronic inflammation. Conventional therapies such as chemotherapy and radiotherapy (RT), while effective, often lack specificity, leading to significant toxicity in normal tissues and the development of resistance. In recent decades, nutraceuticals—bioactive compounds derived from food sources—have emerged as promising complementary agents. This review integrates data from multiple studies to explore the multifaceted role of nutraceuticals in oncology. We examine their classification, market trends, and molecular mechanisms, with a specific focus on their ability to sensitize cancer cells to radiation and chemotherapy through the modulation of reactive oxygen species (ROS), inflammation, and epigenetic pathways. Furthermore, we analyze the specific impact of nutraceuticals on colorectal cancer (CRC), highlighting the critical role of the gut microbiota, prebiotics, and marine-derived compounds. Finally, we discuss the regulatory landscape and the challenges of bioavailability that currently hinder the clinical translation of these natural agents.