Effect of nutritional supplementations on physical performance and muscle strength parameters in older people: A systematic review and meta-analysis

Malnutrition plays a role in the development of poor physical performance, frailty and sarcopenia. The use of nutritional supplementations for improving physical performance and muscle strength parameters in older people is unclear. We therefore aimed to summarize the effect of nutritional supplementations compared to placebo on physical performance (i.e. tests more investigating physical function, utilising aerobic capacity & muscle power) and muscle strength (i.e. tests depending on muscle power) outcomes in older people in randomized controlled trials (RCTs). A literature search in major databases was undertaken until the 01st September 2018. Eligible studies were RCTs investigating the effect of nutritional supplementations vs. placebo in older people (people having an age >60 years). Standardized mean differences (SMD) and 95% confidence intervals (CIs) were used through a random effect model. Over 4007 potentially eligible articles, 32 RCTs for a total of 4137 older participants (2097 treated and 2040 placebo) (mean age: 76.3 years; 65% females) were included. Compared to placebo, multi-nutrient supplementations significantly improved chair rise time (n = 3; SMD=-0.90; 95%CI: -1.46 to -0.33; I = 87%). Multi-nutrients significantly improved handgrip strength when compared to placebo (n = 6; 780 participants; SMD = 0.41; 95%CI: 0.06 to 0.76; I = 79%), as did nutritional supplementations including protein (n = 7; 535 participants; SMD = 0.24; 95%CI: 0.07 to 0.41; I = 16%).Nutritional supplementations also led to a significant improvement in chair rise time and in handgrip strength in participants affected by frailty/sarcopenia and in those affected by medical conditions. In conclusion, nutritional supplementation can improve a number of physical performance outcomes in older people, particularly when they include multi-nutrients and in people already affected by specific medical conditions, or by frailty/sarcopenia.