Systematic review and meta-analysis of antioxidants with or without exercise training improving muscle condition in older adults.

Oxidative stress and physical inactivity are regarded as important mechanisms contributing to muscle loss. However, the efficacy of antioxidants and their potential synergy with exercise training remain controversial for older population. The study aimed to evaluate the effects of antioxidants, either combined with or without exercise, on improving muscle strength, mass, and physical performance in older adults. We conducted a comprehensive search of the PubMed, MEDLINE, and Embase databases to identify randomized controlled trials (RCTs) on muscle condition in subjects aged 55 years or older. The search period covered from the inception of each database until June 10, 2024. A total of 39 RCTs involving 1714 participants were included. The meta-analysis presented that antioxidants alone could enhance muscle strength in 1 repetition maximum (RM) in leg press and physical function in the older population. Exercise alone could increase the walking distance of 6 min walk more than antioxidants alone. The combination of antioxidants and exercise further improved 1RM in leg press, usual walking speed and walking distance of 6 min walk compared to antioxidants alone. Additionally, this combination enhanced handgrip strength, 1RM in leg press and walking distance of 6 min walk more than exercise alone. This meta-analysis demonstrated that antioxidants alone had positive effects on muscle condition in older individuals. However, the combination of antioxidants and exercise was more effective than either intervention alone in improving muscle strength and physical function among the older adults.