Caffeine in Sport: Performance Enhancer or Hidden Player in Cancer Biology? A Narrative Review

Caffeine is one of the most widely used ergogenic aids in sport, known for its performance-enhancing effects on endurance, strength, and cognitive function. Beyond these well-established roles, emerging evidence suggests that caffeine may also influence biological pathways associated with carcinogenesis. This narrative review provides a sports-oriented perspective on caffeine as a bioactive compound with potential implications extending beyond performance. Current evidence indicates that caffeine modulates mechanisms such as DNA damage response, apoptosis, oxidative stress, and immune regulation. While experimental findings suggest possible anticancer effects, human evidence remains inconsistent and largely observational. Given the widespread and repeated use of caffeine in athletic populations, understanding its broader biological impact is essential. Although caffeine cannot be considered an anticancer agent, its dual role in performance enhancement and health-related pathways highlights the need for integrative research bridging sports science and oncology.