Nutritional supplements to improve esports player performance: a systematic review of randomized controlled trials

Esports has become a globally popular competitive activity. The performance of esports athletes depends not only on daily skill training but also on cognitive function, reaction speed, and psychological mood. In recent years, nutritional supplements have attracted widespread attention as a potential adjunctive treatment. However, their actual effects lack systematic evaluation. Objective: The primary aim of this study is to comprehensively review existing evidence and assess the impact of nutritional supplements on the performance of esports athletes, including cognitive, psychological, and gaming aspects.

As of June 17, 2025, randomized controlled trials (RCTs) or randomized crossover trials investigating the effects of nutritional supplements on cognitive function, psychological mood, and competitive performance in esports players were retrieved from the PubMed, Scopus, Web of Science, and Embase databases. Two researchers independently extracted key information and data from the literature. The methodological quality of the included studies was assessed using the Physical Therapy Evidence Database (PEDro) scale.

A total of 13 randomized controlled trials were included, comprising 10 randomized crossover trials and 3 randomized controlled trials. The study population comprised 466 participants. The methodological quality of the studies, assessed by the PEDro scale (score range 6-10), was good to excellent. The studies included 18 nutritional supplement protocols, with 14 protocols involving pure caffeine or caffeine-containing supplements. Other protocols included active substances such as inositol-enhanced arginine silicate (ASI + I), γ-aminobutyric acid (GABA), and microalgae extracts. Based on existing evidence, some nutritional supplements are associated with three aspects of competitive performance among esports players: 1) Esports players demonstrate significant improvements in attention and executive function, which are closely related to gaming. 2) Improvements in esports players' psychological mood are manifested as increased vitality and reduced fatigue/negative emotions. 3) Improvements in gaming performance are primarily focused on shooting performance, such as increased shooting scores and accuracy, as well as reduced reaction times.

Specific nutritional supplements may improve esports players' cognitive function, psychological mood, and gaming performance.However, these findings represent preliminary evidence based on the heterogeneity of the included studies and raise concerns regarding the overall risk of bias in over half of the research. Furthermore, the small sample sizes and focus on amateur players limit the generalizability of the results. Consequently, caution is warranted when interpreting these findings.Future clinical studies are needed to standardize supplementation protocols, dosage, and measurement methods to confirm the benefits of nutritional supplements for esports players.