Dietary phytochemical supplementation may improve muscle recovery from exercise. In this study, we investigated the effect of mate tea (MT) consumption – a phenol-rich beverage – on muscle strength and oxidative stress biomarkers after eccentric exercise. In a randomised, cross-over design, twelve men were assigned to drink either MT or water (control; CON) for 11 d. On the 8th day, subjects performed three sets of twenty maximal eccentric elbow flexion exercises. Maximal isometric elbow flexion force was measured before and at 0, 24, 48 and 72 h after exercise. Blood samples were obtained before and at 24, 48 and 72 h after exercise and analysed for total phenolics, GSH, GSSG, GSH:GSSG ratio and lipid hydroperoxides (LOOH). After eccentric exercise, muscle strength was significantly reduced over time, regardless of treatments. However, MT improved the rate of strength recovery by 8·6 % on the 1st day after exercise (P<0·05). Plasma concentration of total phenolic compounds was higher in MT than in CON at all time points (P<0·05) but decreased significantly at 72 h after exercise in both trials (P<0·05). Blood levels of GSH were significantly decreased at 48 and 72 h after exercise in CON (P<0·05) but did not change over time in MT. No significant changes were observed for GSSG, GSH:GSSG ratio and LOOH levels. MT intake did not influence muscle strength at all time points assessed but hastened the strength recovery over 24 h after exercise. MT also favoured the concentration of blood antioxidant compounds.

Mate (Ilex paraguariensis) is rich in polyphenolic compounds, which are thought to contribute to the health benefits of tea. Mate tea was administered orally to mice at a dose of 0·5, 1·0 or 2·0 g/kg for 60 d, and changes both in serum lipid concentration and fatty acid composition of liver and kidney were examined. The effects of mate tea on serum and tissue lipid peroxidation were assessed by the evaluation of thiobarbituric acid-reactive substances (TBARS). In tea-consuming mice, both MUFA (18 : 1n-9) and PUFA (18 : 2n-6 and 20 : 4n-6) were increased (P < 0·05) in the liver lipid (approximately 90 and 60 %, respectively), whereas only MUFA (approximately 20 %) were increased in the kidney lipid. The most altered PUFA class was n-6 PUFA, which increased by approximately 60–75 % (P < 0·05). This difference in the fatty acid profile in the liver is reflected in the increased PUFA:SFA ratio. Consistent with these results, mice fed with mate tea had much lower TBARS in the liver. No differences (P>0·05) were found in the levels of serum cholesterol, HDL-cholesterol and TAG under the conditions of the present study. These results suggest that treatment with mate tea was able to protect unsaturated fatty acids from oxidation and may have selective protective effects within the body, especially on the liver.