Efeitos da ingestão de suco de uva tinto sobre o estresse oxidativo de corredores

Abstract

Purple grapes and their derivatives have a particular antioxidant and anti-inflammatory action due to their rich composition of polyphenols, which has been widely studied in the health field. However, to date, few studies have demonstrated the ergogenic capacity of purple grape juice in athletes. In this context, the present study investigated the effects of ingesting of purple grape juice on biomarkers of oxidative stress and physical performance in recreational runners. For this purpose, an experimental, randomized and controlled study was conducted with 53 recreational runners who were divided into two groups: an experimental group (n=30, 34.4±8.2 years) that ingested 10 mL/kg/day of whole purple grape juice and a control group (n=23, 36.0±7.9 years) that consumed an isocaloric, isoglycidic and isovolumetric carbohydrate drink daily for 28 days. The parameters evaluated were total antioxidant capacity - CAOT, superoxide dismutase enzyme (SOD), lipid peroxidation (malondialdehyde - MDA) and protein carbonylation, as blood biomarkers; exhaustion test, anaerobic threshold and aerobic capacity, to evaluate physical performance. Additionally, food consumption and body composition were evaluated; training loads in the season; psychometric behavior and sleep. The results showed that the time in the test until exhaustion was greater in the grape juice group, increasing from 61.9±28.7 to 72.8±36.0 minutes (↑ 17.1%), while the control group showed a slight increase from 61.9±23.8 to 64.5±22.5 minutes (↑7.3%). Analyzing the individual responses in time to exhaustion, 73.3% of the runners in the experimental group improved their running time, while the control group improved 39.1%. There was no significant improvement in antioxidant biomarkers, either between time points or between groups (CAOT: p = 0.12; SOD: p = 0.35). The protective effect of grape juice was observed clinically: the intervention group increased SOD by 8.0% and CAOT by 18.5%, while the control group increased SOD by 0.8% and reduced CAOT by 18.6%. For oxidative stress, similarly, there was no difference for lipid peroxidation (p = 0.76) and protein carbonylation (p = 0.69) when the groups were compared. Based on the findings, we can conclude that the ingestion of 10 mL/kg/day of whole purple grape juice for 28 days has ergogenic capacity by promoting improvement in physical performance, accompanied by clinical improvement in antioxidant activity.