Nutritional Intervention Improves Muscle Mass and Physical Performance in the Elderly in the Community: A Systematic Review and Meta-Analysis.

Nutritional supplements have been extensively used as health interventions for the elderly. However, with the spread of COVID-19, no consensus exists on whether nutritional interventions could improve muscle mass and physical activity in community-dwelling older adults. To conduct a systematic review and meta-analysis to explore the effects of different nutritional interventions on muscle mass and physical performance in the elderly, we searched PubMed, Web of Science, Elsevier, and Cochrane databases from their founding dates to December 2023. The meta-analysis was performed using RevMan5.3 software. Only randomized controlled trials (RCTs) were considered, and the overall mean difference (MD) or standardized mean difference (SMD) with 95% confidence interval (CI) was calculated. There were 33 studies comprising 3579 elderly persons meeting the inclusion criteria. Comprehensive analysis suggested that the intervention effect of fat-free mass (FFM), appendix skeletal muscle mass (ASMM), handgrip strength (HGS), gait speed, and short physical performance battery (SPPB) score was higher in the nutritional supplement group than in the control group. The results of subgroup analysis demonstrated that protein supplementation (SMD = 0.82, p < 0.0001) had an optimal effect on ASMM (SMD = 0.89, p < 0.0001) and FFM (MD = 2.09, p < 0.0001) in the elderly. Vitamin D supplementation (SMD = 0.52, p < 0.0001) had a marginal effect on ASMM, and energy supplementation (SMD = 0.39, p = 0.0005) had the lowest effect. Moreover, nutritional interventions had the most significant impact on HGS (MD = 1.06, p < 0.0001) and TUG (MD = 0.14, p < 0.0001) in individuals aged 65-75 years old, with positive effects on FFM (MD = 1.62, p < 0.0001) and HGS (MD = 0.82, p < 0.0001) when compared to healthy elderly individuals, and had greater effect on ASMM (SMD = 0.69, p < 0.0001) than on the elderly with sarcopenia. Nutritional supplements can enhance muscle mass and physical performance in the elderly, while protein is recommended for muscle function. The golden period for implementing nutritional interventions to improve muscle function is before the age of 75 years. However, the impact of nutritional interventions varies with age and population. Given the limited evidence on nutritional interventions, more detailed and high-quality studies are highly warranted in the future.

Research on Knee Joint Load and Influencing Factors of Typical Tai Chi Movements.

Background: Tai chi is recognized worldwide for its rehabilitation abilities and healthcare benefits. However, in recent years, some movements associated with tai chi have been shown to damage the lower limb joints. The purpose of this study was to investigate and compare the effects of different movements, postures, center of mass (COM) movements, and range of knee movement of tai chi exercises on knee joint load. Methods: Fourteen professional tai chi practitioners in two postures (high and low) were enrolled to perform the following four typical tai chi movements: wild horse's mane (WHM), repulse monkey (RM), wave-hand in cloud (WHIC), and grasp the bird's tail (GBT). Kinematic and kinetics data were synchronously collected using the Vicon infrared high-speed motion capture system and a three-dimensional (3D) force measurement platform. Variance analysis and partial correlation analysis were performed to investigate factors influencing peak knee joint moment and vertical ground reaction force (VGRF). Results: The results showed that the peak knee extension and abduction moment were larger in WHM and RM than those in WHIC and GBT (p < 0.05). WHM was associated with greater rotation moment than the other typical movements (p < 0.05). VGRF and joint moment among different poses were significantly different. Low-pose tai chi typical movements were associated with greater VGRF, knee joint extension and abduction, and rotation moments than high-pose movements (p < 0.05). The anteroposterior and mediolateral COM displacements were strongly and positively associated with VGRF (p < 0.001), while the mediolateral COM displacement was negatively associated with knee extension moment (p < 0.001). The knee internal-external rotation ROM and anteroposterior and mediolateral COM displacements were positively associated with knee abduction moment (p < 0.01). Conclusion: For long-term tai chi exercises, choosing a suitable posture based on an individual exercise level and reasonable control of knee ROM and COM displacement can reduce the risk of knee injury during exercise.

The effectiveness of traditional Chinese medicine-based exercise on physical performance, balance and muscle strength among older adults: a systematic review with meta-analysis.

BACKGROUND: Traditional Chinese medicine (TCM) based exercises have been widely used in the prevention and treatment of balance, cardiopulmonary, and other related diseases in older adults. However, there seems to be no consensus on the improvement and comparison of physical performance, balance, and muscle strength in the elderly population. OBJECTIVES: To systematically examine the impact of different TCM-based exercises on physical performance, balance, and muscle strength outcomes in the elderly. METHODS: We searched PubMed, EMBASE, Scopus, and Cochrane Center, CNKI and Wan Fang between their date of inception and March 2021. This meta-analysis was performed using RevMan5.3 software. Only randomized controlled trials (RCT) or controlled clinical trials (CCT) were considered in TCM-based exercises (Tai Chi, Ba Duan Jin, Qigong). The overall mean difference (MD) or standardized mean difference (SMD), and its 95% confidence interval (CI) were calculated. MAIN RESULTS: A total of 27 studies with 2580 older adults met the inclusion criteria. The pooled analysis indicated that Tai Chi could be more effective in Times up and go (TUG) (MD = - 2.62, 95% CI - 4.00 to - 1.24, P = 0.0002), 5 times sit-stand (MD = - 1.89; 95%CI - 3.38 to - 0.40; P = 0.01), and handgrip strength outcomes (SMD = 0.69; 95%CI 0.52-0.86; P < 0.0001) compared to Ba Duan Jin and Qigong. The older adults performing Qigong could have a better benefit in Single-bed balance (SLB) with eyes closed compared to Tai Chi and Ba Duan Jin (MD = 3.42; 95%CI 1.55 to 5.29; P = 0.0003). Tai Chi also had benefits in terms of balance outcomes compared to those in the control group: Berg Balance scale (BBS) (MD = 1.41; 95% CI 0.03-2.85; P = 0.05), Functional reach test (FRT) (MD = 1.57; 95%CI 1.22-1.93; P < 0.0001). The Tai Chi study meta-analysis demonstrated significant effects on lower limb strength: knee extension (SMD = 0.56; 95%CI 0.26-0.86; P = 0.0003), ankle dorsiflexion (SMD = 0.67; 95%CI 0.02-1.31; P = 0.04) compared to the controls. CONCLUSION: This systematic review reveals that TCM-based exercises can effectively improve physical performance outcomes, balance outcomes, and muscle strength in the elderly population. While there is limited evidence on the efficacy of other TCM-based lifestyle interventions, more high-quality clinical trials on this topic are warranted.

Preservation of Cognitive Function by Lepidium meyenii (Maca) Is Associated with Improvement of Mitochondrial Activity and Upregulation of Autophagy-Related Proteins in Middle-Aged Mouse Cortex.

Maca has been used as a foodstuff and a traditional medicine in the Andean region for over 2,000 years. Recently the neuroprotective effects of maca also arouse interest of researchers. Decrease in mitochondrial function and decline in autophagy signaling may participate in the process of age-related cognitive decline. This study aimed to investigate if maca could improve cognitive function of middle-aged mice and if this effect was associated with improvement of mitochondrial activity and modulation of autophagy signaling in mouse cortex. Fourteen-month-old male ICR mice received maca powder administered by gavage for five weeks. Maca improved cognitive function, motor coordination, and endurance capacity in middle-aged mice, accompanied by increased mitochondrial respiratory function and upregulation of autophagy-related proteins in cortex. Our findings suggest that maca is a newly defined nutritional plant which can improve mitochondrial function and upregulate autophagy-related proteins and may be an effective functional food for slowing down age-related cognitive decline.