Role of Antioxidants in Cancer Prevention: A Meta-Analysis of Past Research

Abstract

Cancer remains one of the leading causes of mortality worldwide, prompting extensive research into preventive strategies. Antioxidants have emerged as molecules of significant interest due to their ability to neutralize reactive oxygen species (ROS) and mitigate oxidative stress, a key contributor to carcinogenesis. This review paper presents a comprehensive meta-analysis of past research examining the role of antioxidants in cancer prevention. Through systematic examination of epidemiological studies, clinical trials, and mechanistic investigations, we evaluate the efficacy of dietary and supplemental antioxidants including vitamins C and E, carotenoids, polyphenols, and selenium in reducing cancer risk. The analysis reveals complex and sometimes paradoxical relationships between antioxidant intake and cancer outcomes, with evidence suggesting protective effects in certain populations and cancer types, while other studies demonstrate null or potentially harmful effects, particularly with high-dose supplementation. The review synthesizes findings from observational studies indicating inverse associations between dietary antioxidant consumption and cancer incidence, contrasted with randomized controlled trials showing limited preventive benefits. We critically analyze methodological considerations, dose-response relationships, bioavailability issues, and the influence of oxidative stress levels on antioxidant efficacy. This comprehensive analysis provides insights into future research directions and clinical implications for antioxidant use in cancer prevention strategies