Antioxidant-rich foods, antioxidant supplements, and sarcopenia in old-young adults ≥55 years old: A systematic review and meta-analysis of observational studies and randomized controlled trials

Sarcopenia is a disabling muscular multifactorial disease involving the oxidation process in old-young adults. We aimed to evaluate the relationship between antioxidant-rich foods (A-RF) and sarcopenia (muscle mass, strength, and function) based on observational studies (OS), and to assess the effectiveness of antioxidant interventions in ≥55-year-old adults via randomized controlled trials (RCTs). Moreover, to confirm if the OS results were in accordance with the RCTs results. We searched in the MEDLINE®/PubMed, Cochrane Library, and CINAHL databases from 2000 to 2020 about sarcopenia and specific nutrients/foods. The risk of bias was assessed and meta-analyses were performed using the Review Manager program. The systematic review included 28 studies (19 OS, 9 RCTs), whereas the meta-analysis included 4 RCTs. Results of the systematic review of OS revealed that higher A-RF consumption was associated with better sarcopenia outcomes. Results of the RCTs meta-analysis indicated that higher fruit/vegetable consumption, supplementation with magnesium, and vitamin E plus vitamin D and protein significantly reduced the time to complete 5 stands (mean difference; 95% CI; −1.11 s; 1.70, −0.51; p