Vitamin E plays an important role in attenuating muscle damage caused by oxidative stress and inflammation. Despites of beneficial effects from antioxidant supplementation, effects of antioxidants on exercise-induced muscle damage are still unclear. The aim of this meta-analysis was to investigate the effects of dietary vitamin E supplementation on exercise-induced muscle damage, oxidative stress, and inflammation in randomized controlled trials (RCTs). The literature search was conducted through PubMed, Medline, Science Direct, Scopus, SPORTDiscuss, EBSCO, Google Scholar database up to February 2022. A total of 44 RCTs were selected, quality was assessed according to the Cochrane collaboration risk of bias tool (CCRBT), and they were analyzed by Revman 5.3. Dietary vitamin E supplementation had a protective effect on muscle damage represented by creatine kinase (CK; SMD -1.00, 95% CI: -1.95, -0.06) and lactate dehydrogenase (SMD -1.80, 95% CI: -3.21, -0.39). Muscle damage was more reduced when CK was measured immediately after exercise (SMD -1.89, 95% CI: -3.39, -0.39) and subjects were athletes (SMD -5.15, 95% CI: -9.92, -0.39). Especially vitamin E supplementation lower than 500 IU had more beneficial effects on exercise-induced muscle damage as measured by CK (SMD -1.94, 95% CI: -2.99, -0.89). In conclusion, dietary vitamin E supplementation lower than 500 IU could prevent exercise-induced muscle damage and had greater impact on athletes.
Keywords: exercise; inflammation; muscle damage; oxidative stress; vitamin E.