Powergrape®, a whole grape extract, increases the antioxidant capacity in professional sportsmen during a competition period

During physical exercise, large amounts of oxygen are inhaled into the body increasing reactive oxygen species, free radicals generation. Even if professional sportsmen increase their antioxidant status by a regular physical training, during a competition period, this improvement is not sufficient to limit free radicals production and this could be detrimental to the body.

The aim of this work is to determine if the consumption of a grape extract – Powergrape® - is able to decrease oxidative stress generated in professional sportsmen during competition period. A randomized, double-blind, placebo controlled cross-over study was conducted on 20 volunteers. Plasma, urine biomarkers of oxidative stress and antioxidant capacity were determined after one month of supplementation (400mg/d). Performance was tested using the validated system Optojump®.

After one month of supplementation, plasma ORAC and FRAP values were increased significantly compared to the placebo (14966+/-335 vs. 14242+/-339µmol Teq/L respectively for ORAC values; 1053.7+/-31.5 vs. 993.7+/-26.7µmol Teq/L respectively for FRAP values; p<0.05). This improvement of plasma antioxidant capacity could be explained by significant increases of plasma vitamin E concentration and of GPx activity. Urinary isoprostanes were also decreased significantly (+7.8% vs. +56.7% for treated and placebo group respectively; p<0.05). Moreover, the performance (explosive power during or after the effort) of some sportsmen dependant on category was also increased significantly.

Consumption of a grape extract decreases oxidative stress induced by competition period and increases the antioxidant capacity in professional athletes. Moreover, in some sportsmen, Powergrape® increases the performance.

Acknowledgements: Thanks to Avantage Nutrition society and to the Laboratoire de Nutrition Humaine, INRA Clermont-Ferrand.