Six weeks of consuming a daily 450 mg dose of the extracts were associated with statistically significantly lower levels of malondialdehyde (MDA), a reactive carbonyl compound and a marker of oxidative stress, compared with placebo, according to findings published in the Journal of Dietary Supplements.
However, researchers from Isfahan University of Medical Sciences in Iran report that there were no changes in levels of markers of muscle damage.
The study supports an ever-growing body of science supporting the potential benefits of green tea (Camellia sinensis) and sour tea (Hibiscus sabdariffa L.), and the various flavonoids and polyphenols they contain.
The researchers recruited 54 male soccer to participate in their randomized, double-blind control trial. The men were randomly assigned to one of three groups: The first group received 450 mg/day of green tea extract; the second group received 450 mg/day of sour tea extract; and the third group received 450 mg/day of maltodextrin to act as controls.
Six weeks of supplementation resulted in significant reductions in MDA levels in both tea groups, compared with placebo, while the total antioxidant capacity of men significantly increased only in the sour tea group, compared to the other two groups.
On the other hand, not significant effects on muscle damage indices were observed, including aspartate aminotransferase, creatine kinase, lactate and dehydrogenase, said the researchers.
Source: Journal of Dietary Supplements
2017, Volume 14, Number 3, Pages 346-357
“The Effect of Green Tea and Sour Tea (Hibiscus sabdariffa L.) Supplementation on Oxidative Stress and Muscle Damage in Athletes”
Authors: A. Hadi et al.