A single dose of cajuína does not improve leukocyte count, lipid peroxidation, and physical performance in runners: a randomized, crossover, double‑blind, placebo study.

Abstract

Purpose: To investigate the effects of a single dose of cajuína juice physical performance, leukocyte counts, and oxidative stress markers following a 10-km time trial in male runners.

Methods: A total of nine recreationally trained male runners (32 ± 9.2 years; 70.9 ± 8.1 kg, 1.71 ± 0.06 m, 3.9 ± 1.9 training sessions per week) were randomly assigned to receive either cajuína juice (containing approximately one gram of vitamin C) or a placebo (a similar drink containing 0 mg of vitamin C) two hours before exercise, with a one-week washout period between interventions. Blood samples were collected immediately before ingestion and post-exercise. Leukocyte counts, as well as malondialdehyde (MDA), uric acid, and albumin concentrations, were analyzed from the samples.

Results: Physical performance was not affected by cajuína intake (p > 0.05). Although a time effect (p = 0.01) was observed for MDA concentrations, no condition (p = 0.47) or interaction effects (p = 0.84) were revealed. Additionally, there were no effects of condition, time, and interaction for albumin (p = 0.83, p = 0.37, and p = 0.16, respectively) and uric acid (p = 0.64, p = 0.19, and p = 0.55, respectively) concentrations. No significant or positive changes in leukocyte counts were observed (p > 0.05).

Conclusion: The single-dose intake of cajuína (Anacardium occidentale L.) does not improve leukocyte count, lipid peroxidation, or physical performance in recreationally trained male runners subjected to a 10-km time trial.

Trial registration: The study was registered in the Brazilian Clinical Trials Registry (REBEC) under the following registration number: RBR-3cb6qtz. The study was prospectively registered on November 17, 2023.