Sarcopenia prevention in older adults: Effectiveness and limitations of non-pharmacological interventions

Abstract

Sarcopenia is characterized by a decline in skeletal muscle mass, strength, and physical performance in older adults and is associated with reduced quality of life, an increased risk of requiring long-term care, and a significant economic burden on both patients and their families. In the context of global population aging, sarcopenia presents substantial health and social challenges. However, no effective pharmacological treatment has been established to date, and current management relies on non-pharmacological interventions. This review provides an overview of the most recent evidence on exercise, nutrition, and electrical muscle stimulation (EMS) as strategies to prevent the onset and progression of sarcopenia and discusses their effectiveness and limitations. Although the effectiveness of resistance training, alone or in combination with multicomponent exercise, has been demonstrated, the benefits of nutritional interventions and EMS remain limited. From a pathophysiological perspective, chronic inflammation has been identified as a key contributor to sarcopenia progression and is increasingly considered a potential therapeutic target. This review underscores the significance of a comprehensive intervention strategy tailored to the needs of the older population.

1. Introduction

Countries worldwide, including developed ones, are facing challenges of aging populations [1]. As life expectancy continues to increase, maintaining the health span of older adults has become both an individual concern and a critical national and societal issue, exemplified by labor force reduction and increasing social security burdens [2].

Skeletal muscle, which comprises approximately 40% of total body weight [3], plays a crucial role in locomotion, posture maintenance, and respiration and also serves as a key organ for energy metabolism [4]. Skeletal muscle is composed of multinucleated myofibers, which are broadly classified as slow-twitch (Type I) and fast-twitch (Type II_A, Type II_X, and intermediate hybrid fibers) fibers. Fast-twitch fibers are more susceptible to age-related atrophy, contributing to progressive decline in muscle strength and function observed in sarcopenia [5].

Sarcopenia is characterized by progressive and systemic loss of skeletal muscle mass (SMM) with aging, leading to an increased risk of falls, deterioration in the ability to perform daily activities, and a significant decline in quality of life [6]. Moreover, sarcopenia has been closely linked to increased mortality [7]. Currently, it is estimated that 10%–16% of the older population globally is affected by sarcopenia, underscoring the urgent need for developing preventative strategies and effective treatments [8].

The primary cause of sarcopenia is aging (primary sarcopenia), while secondary sarcopenia is associated with factors such as malnutrition and immobilization [9]. Extensive research has focused on non-pharmacological interventions, particularly exercise and nutritional therapy, to address these contributing factors [10]. Age-related hormonal imbalances and increased oxidative stress have been identified as key accelerators of muscle degeneration [11]. In addition to these interrelated risk factors, recent evidence has highlighted the significant role of chronic inflammation in the pathophysiology of sarcopenia. Chronic, low-grade inflammation suppresses muscle protein synthesis and promotes muscle atrophy [12].

This review provides an overview of the effectiveness of exercise, nutrition, and electrical muscle stimulation (EMS) in preventing sarcopenia, as well as the impact of chronic inflammation, particularly the relationship between periodontitis and sarcopenia. It also discusses future perspectives on comprehensive strategies for preventing sarcopenia in the aging population.

2. Sarcopenia and exercise

The consensus definition of sarcopenia is based on age-related loss of muscle mass, which is further characterized by a decline in muscle strength and physical performance [13]. Although institutions in Europe, Asia, and the United States have established different diagnostic criteria, they share common assessment components. Muscle strength is typically evaluated using grip strength (GS) and the chair stand test (CST), whereas muscle mass is assessed via appendicular SMM or whole-body SMM. Physical performance is commonly measured using gait speed, the Short Physical Performance Battery (SPPB), and the Timed Up and Go (TUG) test [[13], [14], [15]].

Immobilization is a key factor contributing to sarcopenia, underscoring the importance of exercise-based interventions [16]. Resistance training has been demonstrated to be an effective strategy for managing sarcopenia and is considered the first-line treatment [17]. The following section summarizes findings from systematic reviews and meta-analyses conducted over the past decade that examine the effectiveness of exercise interventions in individuals aged ≥ 60 years, primarily including those with sarcopenia or pre-sarcopenia.

2.1. Resistance training as an effective strategy for treatment and prevention of sarcopenia

Systematic reviews and meta-analyses targeting patients with pre-sarcopenia or sarcopenia have demonstrated that engaging in resistance training two to three times per week, over a mean duration of 23 weeks (range: 10–48 weeks), significantly improves muscle mass (ES = 0.29, P < 0.001), handgrip strength (ES = 0.51, P = 0.001), lower limb strength (ES = 0.93, P < 0.001), gait speed (ES = 0.75, P < 0.001), and overall functional performance (ES = 0.76, P < 0.001) in older adults [18].

Studies specifically targeting individuals diagnosed with sarcopenia have also been conducted. Zhang et al. [19] performed a meta-analysis of older patients with sarcopenia, with the intervention group engaging in exercise sessions one to eight times per week for 8–36 weeks. Exercise interventions significantly improved muscle mass, including skeletal muscle index (SMI) (standardized mean difference [SMD] = 0.37, P < 0.01) and appendicular muscle mass (SMD = 0.31, P < 0.01), as well as muscle strength, such as GS (SMD = 0.30, P < 0.01) and CST (SMD = 0.56, P < 0.01). Additionally, physical performance was significantly enhanced, as assessed via gait speed (SMD = 0.59, P < 0.01) and TUG performance (SMD = 0.74, P < 0.01).

Additional evidence suggests that resistance training may offer preventive benefits to broader older populations. A meta-analysis conducted by Mende et al. [20] evaluated the effects of progressive machine-based resistance training, performed two to three times per week over 12–25 weeks, in adults aged 80–92 years who were randomly selected from both community and institutional settings, despite sarcopenia diagnosis. Significant improvements in CST scores (SMD = −0.92, P < 0.00001) were observed in the intervention group, along with notable improvements in gait speed (SMD = 0.46, P < 0.0001), SPPB scores (SMD = 0.63, P < 0.01), and TUG performance (SMD = −0.62, P < 0.01). Although data on muscle mass were insufficient for the meta-analysis, several studies have reported that resistance training contributes to increased muscle mass. These findings suggest that machine-based resistance training is an effective intervention for preventing sarcopenia in both community and institutional settings.

Further research has examined the effectiveness of resistance training at different stages of sarcopenia progression. Resistance training has been reported to be an effective strategy for both pre-sarcopenia (preventive) and sarcopenia (therapeutic), contributing to improvements in muscle strength and physical performance. Specifically, resistance training in the early stages of sarcopenia is particularly beneficial for enhancing physical performance [18].

2.2. Aerobic exercise may enhance the effects of resistance training

Endurance training (aerobic exercise) is particularly effective for maintaining and improving maximal aerobic power. Aerobic exercise stimulates ATP production in the mitochondria of skeletal muscles, thereby enhancing aerobic capacity, improving metabolic regulation [21], and promoting cardiovascular function [22]. However, aerobic exercise alone does not significantly improve muscle strength compared to resistance training.

Wang et al. [23] conducted a meta-analysis involving 1252 older adults with sarcopenia aged 60–101 years and reported no statistically significant differences in exercise effects between the intervention and control groups for GS (mean difference [MD] = 0.83, P = 0.25) and knee extension (MD = 0.23, P = 0.12) when aerobic exercise was performed alone. Conversely, both resistance training and multicomponent exercise interventions, which combined aerobic and resistance training, led to a significant increase in muscle strength.

These findings indicate that while aerobic exercise alone has limited effectiveness in enhancing muscle strength, interventions that combine resistance training with aerobic exercise may be more beneficial.

2.3. Home-based training offers a safe and promising approach to sarcopenia treatment

Ensuring the safety and accessibility of exercise interventions is crucial for maintaining adherence. Home-based resistance exercises provide a convenient approach and can offer greater safety and ease of implementation than those provided by instrumented resistance exercises using gym equipment [24].

Elastic band training (EBT) has been proposed as a home-based training method. EBT maintains the benefits of strength training while offering higher self-perceived effectiveness than that with free-weight training [25]. Additionally, although excessive resistance training is associated with a significant risk of fractures, particularly in older adults with a history of osteoporosis, EBT offers the advantage of a lower risk of such injuries [26].

Tsai et al. [26] conducted a meta-analysis on the effectiveness of EBT in 231 older adults with sarcopenia, with a mean age of 68.7 years. Significant improvements in TUG (MD = −2.17 s, P < 0.00001), GS (MD = −0.04 m/s, P < 0.001), and appendicular SMI (MD = −0.14 kg, P = 0.01) were observed after a 12-week intervention. Despite limitations such as a small sample size and predominance of female participants, these findings indicate that EBT is a safe and effective training modality for enhancing physical performance and muscle mass.

The preventive potential of home-based resistance training has also been demonstrated in healthy older adults. Thiebaud et al. [27] systematically reviewed home-based resistance training programs targeting the lower body in healthy older individuals and reported modest but significant improvements, including an increase in knee extension strength of 3.1 kg and a reduction in TUG time of 0.4–1.3 s. The training program included the use of elastic bands, ankle weights, and bodyweight exercises. Furthermore, studies with higher levels of participant supervision have demonstrated greater improvements than studies with less supervision.

2.4. Summary and discussion

Both resistance training alone and multicomponent training, which includes resistance exercises, can significantly improve muscle strength, muscle mass, and physical performance. Notably, resistance training has demonstrated both therapeutic effects in sarcopenia and preventive benefits in pre-sarcopenia, highlighting the importance of incorporating resistance training programs into early intervention strategies.

Although aerobic exercise alone is unlikely to be an effective therapeutic intervention, it may enhance the effects of resistance training when these approaches are combined. In sarcopenia, Type II (fast-twitch) muscle fibers are more prone to atrophy than Type I (slow-twitch) fibers. Resistance training primarily targets fast-twitch fibers, whereas aerobic exercise predominantly engages slow-twitch fibers, which may explain its limited effectiveness in improving muscle strength and mass in patients with sarcopenia. Additionally, aerobic exercise improves the metabolic regulation of muscle and cardiovascular function, thereby activating the overall metabolism and potentially supporting the benefits of other interventions, including resistance training indirectly.

Home-based training is an effective approach to enhance muscle strength and physical performance while ensuring safety. However, some studies have suggested that the degree of improvement is modest. This could be attributed to the insufficient intensity of home-based training or the lack of supervision, which may reduce the motivation to progressively increase training intensity compared with supervised exercise programs. Currently, there is no consensus regarding the optimal intensity and frequency of exercise interventions, highlighting the need for further research in this area.

3. Sarcopenia and nutrition

Given that malnutrition is a key contributing factor in secondary sarcopenia, appropriate nutritional intake is crucial in sarcopenia interventions [8]. Studies have shown that individuals with sarcopenia exhibit a lower intake of both macronutrients (such as lipids and proteins) and micronutrients (including iron, phosphorus, potassium, and vitamin K) than healthy individuals [28]. Furthermore, age-related declines in dietary intake and anabolic resistance of skeletal muscles serve as significant barriers to the prevention and progression of sarcopenia [29].

3.1. Leucine- and beta-hydroxy-beta-methylbutyrate-containing supplementation may increase fat-free mass

Currently, a protein-rich diet is recommended as a nutritional intervention for individuals with sarcopenia. Among the effective supplementation strategies, the branched-chain amino acid leucine and its metabolite beta-hydroxy-beta-methylbutyrate (HMB) have been widely used [30]. Mechanistically, leucine promotes protein anabolism by activating the mechanistic target of rapamycin complex 1 (mTORC1), which simultaneously suppresses catabolic pathways by inhibiting autophagy, thereby contributing to muscle mass maintenance [30,31].

Systematic reviews and meta-analyses within the past decade examining the effectiveness of protein or amino acid interventions in individuals aged ≥ 60 years, including those with sarcopenia, have reported mixed findings. A meta-analysis [32] that included 1418 older adults who met at least one diagnostic criterion for sarcopenia or frailty found no significant effects of leucine supplementation alone on fat-free mass, GS, or leg press performance. However, when leucine was administered in combination with vitamin D, significant improvements were observed in GS (MD = 2.17 kg, P < 0.01) and gait speed (MD = 0.06 m/s, P < 0.01), suggesting the potential benefit of combined nutritional therapy. Conversely, Komar et al. [33] conducted a systematic review and meta-analysis involving 999 older individuals and found that leucine supplementation significantly increased lean body mass (MD = 0.99 kg, P = 0.0005), body weight (MD = 1.02 kg, P = 0.02), and body mass index (BMI) (MD = 0.33 kg/m², P = 0.001), particularly among participants with sarcopenia. However, they observed no significant effects on muscle strength, such as handgrip or knee extension strength. These findings suggest that while leucine-containing supplementation may be beneficial for increasing fat-free mass, particularly in sarcopenic individuals, its effect on muscle strength remains limited unless combined with other agents, such as vitamin D.

Focusing on the effects observed in healthy older adults, Wu et al. [34] investigated the effects of HMB in older adults aged ≥ 65 years, including predominantly healthy individuals. The meta-analysis included data from 287 participants with intervention periods ranging from 2 to 12 months and HMB dosages between 2 and 3 g/day. HMB supplementation significantly increased fat-free mass (SMD = 0.35, P = 0.004) in the intervention group, without altering body fat mass. However, the effects on muscle strength and physical performance were not significant, and the reported findings were inconsistent. Moreover, the collected data were deemed unsuitable for the meta-analysis. Notable limitations of the study were the predominance of healthy older adults in the sample population and the relatively small sample size. Xu et al. [35] conducted a meta-analysis evaluating the effects of amino acid or protein supplementation in older adults, including both healthy individuals and those with chronic conditions. Although the intervention significantly enhanced muscle protein synthesis (SMD = 1.08, P < 0.001), no significant improvements were observed in lean body mass (SMD = 0.18, P = 0.318) or leg lean mass (SMD = 0.006, P = 0.756), suggesting a dissociation between anabolic signaling and phenotypic muscle gains. A separate meta-analysis by Xu et al. [36], which focused specifically on leucine supplementation, analyzed data from 16 randomized controlled trials involving 999 older adults. The results showed modest increases in lean body mass (MD = 0.99 kg, P = 0.0005) and BMI (MD = 0.33 kg/m², P = 0.001); however, no significant improvements were found in muscle strength measures.

3.2. Vitamin D and omega-3 fatty acids may serve as adjunctive strategies for the prevention and treatment of sarcopenia

Vitamin D, a fat-soluble vitamin, plays a critical role in bone and muscle metabolism and suppresses myostatin, a negative regulator of muscle synthesis [37]. Omega-3 polyunsaturated fatty acids (omega-3 PUFAs) possess anti-inflammatory properties and have garnered attention for their potential in preventing and treating sarcopenia [38].

Evidence supporting the effectiveness of vitamin D as a monotherapy is limited, with most studies examining its use in combination with other nutritional interventions [39]. One such approach involves co-administration with leucine, as reported by Guo et al. [32], who demonstrated significant improvements in GS and gait speed in patients with sarcopenia treated with leucine and vitamin D. Furthermore, studies have explored the combined effects of whey protein and vitamin D. A meta-analysis by Nasimi et al. [40] compared whey protein supplementation alone to whey protein combined with vitamin D between individuals with and without sarcopenia, as well as between those with and without exercise intervention. Among the included randomized controlled trials, the whey protein and vitamin D combination group exhibited significant improvements in lean mass (SMD = 0.99, P = 0.03), muscle strength (SMD = 2.01, P < 0.001), and physical performance (SMD = 3.04, P < 0.001). Subgroup analysis excluding participants who underwent resistance training showed even greater improvements in muscle strength (SMD = 2.80, P < 0.01) and physical performance (SMD = 4.57, P < 0.001). However, in the subgroup analysis, including individuals who underwent resistance training, these effects were no longer statistically significant. The authors attributed this to the substantial effects of resistance training, which may have masked the effects of vitamin D supplementation.

Similarly, omega-3 fatty acids have been suggested as potential interventions for preventing and treating sarcopenia. A meta-analysis [38] involving 552 individuals aged 65–75 years, the majority of whom were healthy older adults without sarcopenia, demonstrated that daily intake of ≥ 2 g of omega-3 fatty acids resulted in increased muscle mass (SMD = 0.67, P < 0.05). Notably, among participants who continued supplementation for ≥ 24 weeks, gait speed also improved (SMD = 1.78, P < 0.05). However, a meta-analysis by Ma et al. [41], which included 2067 healthy older adults, reported no significant improvement in muscle mass following omega-3 fatty acid supplementation. Furthermore, no significant changes in gait speed were observed, although GS significantly increased in the intervention group (MD = 1.17 kg, P = 0.011). The omega-3 PUFA dosage across studies varied from 1.3 g to 4 g/day, with intervention durations ranging from 12 to 24 weeks, resulting in inconsistencies in dosage and duration. Moreover, a dose-response analysis was not performed.

Due to heterogeneity in study designs and inconsistent findings, the effectiveness of omega-3 fatty acids in sarcopenia management remains inconclusive. Further well-designed clinical trials with standardized dosages and intervention periods are required to establish their role in the prevention and treatment of sarcopenia.

3.3. Combining nutritional and exercise interventions may enhance treatment effectiveness beyond exercise alone

While the potential of nutritional interventions in sarcopenia treatment has been discussed, evidence indicates that their effectiveness is generally less consistent and more limited than that of exercise intervention. Consequently, combined exercise and nutritional therapy intervention has been explored as an alternative approach. Systematic reviews and meta-analyses focusing on healthy older adults or those with sarcopenia have reported additional benefits of protein or specific nutrient supplementation compared to those of resistance exercise alone [[42], [43], [44]].

Park et al. [45] conducted a meta-analysis examining the effectiveness of three interventions—nutritional therapy alone, exercise intervention alone, and a combined intervention—among 3063 older adults aged ≥ 60 years. The nutritional intervention consisted of protein-rich foods such as meat, milk, and protein supplements. Only the combined intervention significantly improved muscle quality, as assessed via SMI (MD = 0.20 kg/m², P < 0.05). Furthermore, physical performance, including gait speed (MD = 0.08 m/s, P < 0.001), improved in both the combined intervention and exercise-alone groups. Although SMI, GS, and gait speed improved more with the combined intervention than with exercise alone, these differences were not significant. In addition, muscle strength increased across all intervention groups, although the degree of improvement attributed to nutrition was relatively modest.

A meta-analysis by Antoniak et al. [46] examined the combined effects of vitamin D supplementation and exercise. This study included 729 older adults with a mean age of 78.2 years, who were categorized into two groups: one assessing the synergistic effects of vitamin D on exercise intervention and the other evaluating the impact of exercise intervention on vitamin D supplementation. Regarding the synergistic effect of vitamin D on exercise intervention, significant improvements were observed only in lower limb strength (SMD = 0.98, P < 0.00001), whereas other outcome measures showed positive trends but did not reach statistical significance. Conversely, the synergistic effect of exercise intervention and vitamin D supplementation led to significant improvements in lower limb strength (SMD = 2.69, P < 0.01), SPPB scores (MD = 1.09, P < 0.05), TUG performance (MD = −1.57 s, P = 0.001), and femoral neck bone mineral density (MD = 0.04 g/cm², P < 0.01). These findings highlight the effectiveness of resistance training as an intervention and suggest that the combination of vitamin D supplementation with exercise may be beneficial for specific aspects of sarcopenia, particularly lower limb strength.

3.4. Summary and discussion

Supplementation containing leucine and HMB may contribute to an increase in fat-free mass in healthy older adults; however, its effects on older individuals with sarcopenia or pre-sarcopenia appear to be limited.

When combined with leucine or whey protein, vitamin D has the potential to serve as an effective nutritional intervention for sarcopenia.

Although nutritional therapy alone may be a viable intervention for sarcopenia, conflicting findings have been reported, in part owing to the lack of consensus regarding appropriate dosage and intervention duration. Further research is required to establish standardized protocols.

Compared to nutritional therapy alone, the combined nutritional and exercise intervention has demonstrated significant improvements in muscle mass, strength, and physical performance. Furthermore, the combined approach tends to be more effective than exercise intervention alone.

4. Sarcopenia and EMS

So far, the effectiveness of exercise and nutritional interventions for sarcopenia has been discussed. However, these approaches may be less effective for older adults with limited mobility or anabolic resistance, necessitating alternative strategies. EMS induces muscle contraction through electrical stimulation and has garnered attention as a potential approach for maintaining muscle mass and function in older individuals with limited mobility [47].

EMS can be broadly classified into two types: whole-body EMS (WB-EMS), which simultaneously stimulates multiple major muscle groups, and local EMS, which is primarily used in orthopedic applications to target specific muscle groups using a single electrode. In particular, WB-EMS is advantageous owing to its ability to stimulate multiple muscle groups simultaneously, high time efficiency, and minimal joint load [48].

4.1. Physiological mechanisms of EMS

In vitro studies using myotube cultures have demonstrated that EMS partially mimics the effects of exercise training. Specifically, contraction-inducible cellular responses to electrical stimulation have been observed, including the upregulation and activation of AMPK, JNK, Akt, eNOS, GLUT4, and PGC1. Furthermore, electrical stimulation promotes GLUT4 translocation to the cell surface, suggesting an improvement in lipid-induced insulin resistance. Studies involving human participants have reported effects similar to those of exercise training. EMS increased muscle mass by approximately 10%–15% and improved muscle function by 10%–15% after 5–6 weeks of treatment. These findings suggest that EMS exerts effects at both microscopic (cellular) and macroscopic (human) levels, resembling those of exercise [49].

4.2. EMS as an effective alternative for older adults unable to perform exercises

Systematic reviews and meta-analyses published within the past decade evaluating the effects of EMS in adults aged ≥ 60 years, particularly those with or at risk of sarcopenia, identified only one relevant meta-analysis. This study, conducted by Zhong et al. [50], involved 508 sedentary older adults and demonstrated that EMS significantly increased muscle strength (MD = 1.68, P < 0.01). However, although improvements in muscle mass and physical performance were observed for some indices, the overall level of evidence was low. The interventions included both WB-EMS and local EMS, excluding applications to the abdominal and trunk muscles. One limitation of this study was its small sample size.

Focusing on the effects observed in healthy older adults, Oliveira et al. [51] conducted a meta-analysis that exclusively examined the effectiveness of WB-EMS. In a study involving 283 healthy older individuals aged 69–83 years, WB-EMS training alone resulted in significant improvements in the sarcopenia Z-score (SMD = 1.44, P < 0.01) and isometric strength of the leg extensors (SMD = 0.81, P < 0.01) in both mid-term and long-term interventions (2–6 months and ≥ 6 months, respectively). Additionally, long-term intervention significantly increased appendicular SMM (SMD = 0.69, P < 0.01). However, the study included reports with a low level of evidence; therefore, the effectiveness of EMS remains uncertain. Furthermore, WB-EMS did not demonstrate improvements comparable to those with exercise intervention.

These findings indicate that EMS, particularly WB-EMS, may serve as a feasible intervention for older individuals who are unable to undergo exercise programs. However, the number of studies remains limited, and the sample sizes and evidence levels are relatively small.

4.3. Limitations and potential risks of EMS

Importantly, EMS use is restricted in some cases. For instance, in Germany, WB-EMS is subject to regulatory limitations. Von Stengel et al. [52] proposed absolute contraindications for WB-EMS, including acute illnesses, bacterial infections, inflammatory conditions, electric implants or cardiac pacemakers, arrhythmias, untreated hypertension, atherosclerosis, arterial circulation disorders, neurological diseases, neuronal disorders, and epilepsy. Additionally, one of the reported adverse effects of EMS is rhabdomyolysis, a potentially fatal condition with subtle clinical symptoms. There are significant concerns regarding the potential risk of rhabdomyolysis as its incidence may be underreported because clinical presentation is often asymptomatic [53].

4.4. Summary and discussion

WB-EMS may significantly contribute to muscle strength improvement and serve as an effective intervention for preventing and treating sarcopenia in older adults who are unable to engage in exercise interventions. However, large-scale, high-quality randomized controlled trials are required to establish clear evidence of its effects on sarcopenia.

As WB-EMS is subject to regulatory restrictions in certain regions, careful consideration of usage conditions and potential adverse effects is necessary.

5. Sarcopenia and chronic inflammation

5.1. Effects of chronic inflammation on sarcopenia

Recent evidence indicates the crucial role of chronic inflammation in the onset and progression of sarcopenia. Unlike acute inflammation, which is a short-term protective response to injury or infection characterized by rapid onset and resolution, chronic inflammation persists over months to years at low levels. This persistent, low-grade inflammation, often referred to as inflammaging, is associated with aging and is characterized by elevated levels of inflammatory cytokines such as interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), and C-reactive protein (CRP). Inflammaging is a significant risk factor for age-related diseases, including sarcopenia, and is linked to muscle degradation through multiple pathways [54]. These inflammatory factors may induce mitochondrial dysfunction and increase oxidative stress, thereby accelerating muscle deterioration. In particular, chronic inflammation has been shown to activate the NF-κB signaling pathway, leading to enhanced proteolysis and reduced muscle protein synthesis [55].

Disruptions in gut microbial balance enhance intestinal permeability, allowing bacterial endotoxins to enter circulation and amplify systemic inflammatory responses. Modulating gut microbiota has been proposed as a potential strategy to reduce chronic inflammation and mitigate sarcopenia progression [54].

Studies have suggested that impaired oral health negatively affects sarcopenia in older individuals. Periodontitis, a chronic inflammatory disease, has been implicated in various systemic conditions, including metabolic disorders and musculoskeletal degeneration. Although direct evidence linking periodontitis and sarcopenia remains limited, shared inflammatory pathways suggest that periodontitis may contribute to sarcopenia progression.

This section reviews the latest evidence on the relationship among chronic inflammation, gut microbiota, and oral health, emphasizing their collective role in the development of sarcopenia. Understanding these interactions may help guide preventive strategies aimed at reducing systemic inflammation and preserving muscle function in older adults.

5.2. Epidemiological evidence on oral health and sarcopenia

5.2.1. Association between periodontitis and sarcopenia

Several epidemiological studies have investigated the association between periodontitis and sarcopenia. A cross-sectional study [56] conducted in the United States among adults aged 30–59 years examined the relationship between periodontitis severity, GS, and SMM index. This study reported that periodontitis was associated with decreased GS, but no significant correlation with SMM was found. This suggests that periodontitis primarily affects muscle function rather than muscle mass.

A previous study [57] demonstrated that tooth loss was not directly linked to sarcopenia but was significantly associated with impaired physical performance. Specifically, men with at least 10 missing teeth had a lower GS, whereas women had a slower walking speed. These findings indicate that the deterioration of oral health may contribute to functional decline rather than direct muscle wasting. Further, a recent study [58] demonstrated that poor oral health, particularly reduced number of teeth, was significantly associated with increased fracture risk in older adults. Although SMM (lean body mass) did not significantly correlate with fracture risk scores, tooth loss was associated with an increased risk of fractures; however, its direct link to muscle mass remains uncertain. This finding suggests a potential pathway connecting oral health deterioration, functional decline, and increased fracture risk, which are serious consequences of sarcopenia.

5.2.2. Role of oral frailty in musculoskeletal decline

Oral frailty, characterized by reduced chewing ability, dry mouth, and difficulty in swallowing, has been identified as a predictor of sarcopenia risk. A previous study [59] defined oral frailty as an intermediate stage between normal oral function and severe oral dysfunction. The study established the OF-5 criteria for diagnosing oral frailty based on the presence of at least two of the following five conditions: tooth loss, difficulty chewing, difficulty swallowing, dry mouth, and speech articulation issues. Their findings indicate that poor oral function increases the risk of sarcopenia. Furthermore, reduced chewing function may lead to inadequate protein intake, exacerbating muscle loss, whereas impaired speech may contribute to social isolation and accelerate the progression of sarcopenia.

5.3. Mechanistic pathways linking periodontitis and sarcopenia

5.3.1. Chronic inflammation and muscle wasting

Periodontitis induces chronic systemic inflammation through the persistent elevation of pro-inflammatory cytokines, including IL-6, TNF-α, and CRP, which may contribute to systemic inflammation. These cytokines play a pivotal role in muscle catabolism, leading to increased protein degradation and reduced muscle synthesis. An animal model study [60] demonstrated that experimental periodontitis exacerbated immobilization-induced muscle atrophy, highlighting the role of systemic inflammation in muscle deterioration.

5.3.2. Gut microbiota dysbiosis and metabolic dysfunction

Recent evidence suggests that oral pathogens, particularly Porphyromonas gingivalis (Pg), can alter gut microbiota composition and influence systemic metabolic health. Pg infection alters the gut microbiota, leading to metabolic dysfunction, which may contribute to muscle wasting rather than directly inducing it. An experimental study [61] found that Pg infection altered the gut microbiota composition, impaired glucose uptake in the skeletal muscle, and contributed to the metabolic dysfunction associated with sarcopenia in high-fat diet-fed mice. This mechanism may accelerate sarcopenia progression by disrupting energy metabolism and contributing to metabolic dysfunction, which, in turn, may influence muscle wasting.

5.4. Clinical implications and preventive strategies

Given the emerging evidence linking oral health to sarcopenia, integrating periodontal care with musculoskeletal health management may be beneficial [62]. The preventive strategies include the following: (1) early detection and treatment of periodontitis to reduce systemic inflammation; (2) nutritional interventions emphasizing protein intake and micronutrient support for muscle preservation; (3) exercise programs targeting strength and balance to counteract functional decline; and (4) microbiome-modulating therapies, including the use of probiotics, to mitigate the metabolic effects of oral pathogens.

5.5. Interventions to suppress chronic inflammation

The suppression of chronic inflammation is of paramount importance for preventing sarcopenia. Nutrients with anti-inflammatory properties, such as omega-3 fatty acids, polyphenols, and vitamin D, as well as moderate exercise, have been reported to be effective. Resistance training regulates muscle inflammatory responses and promotes the production of anti-inflammatory cytokines. Additionally, the intake of probiotics and prebiotics, which modulate the gut microbiota, may contribute to the suppression of inflammation.

5.6. Limitations of current evidence and future research directions

Several limitations should be acknowledged when interpreting the current evidence on chronic inflammation and sarcopenia. Many studies included in this review had relatively small sample sizes, particularly those examining the relationship between periodontitis and sarcopenia. Additionally, most epidemiological studies were cross-sectional in design, limiting the ability to establish causal relationships. The heterogeneity in diagnostic criteria for both sarcopenia and periodontitis across studies makes direct comparisons challenging.

Future research should focus on well-designed longitudinal studies with larger sample sizes to elucidate the temporal relationship between chronic inflammation and sarcopenia development. Interventional studies targeting inflammatory pathways, particularly through combined approaches that address multiple risk factors simultaneously, are needed. Furthermore, studies examining the effect of oral health interventions on sarcopenia prevention and treatment would provide valuable insights into the clinical applications of the relationship between oral health and muscle function.

6. Conclusions

This review provides an overview of the latest evidence on exercise, nutrition, and EMS, as well as the impact of chronic inflammation on preventing sarcopenia (Fig. 1). Among various strategies, resistance training and combined exercise interventions have been identified as the most effective approaches, with additional benefits observed when integrated with nutritional interventions. Furthermore, the suppression of chronic inflammation has been suggested to decelerate the progression of sarcopenia, underscoring the necessity of anti-inflammatory interventions. Moreover, modulation of gut microbiota may contribute to the regulation of systemic inflammation, highlighting the need for further research in this area. The implementation of personalized intervention strategies is imperative for extending the healthy lifespan of older adults.

Fig. 1.

Sarcopenia prevention in older adults: Latest evidence. Conceptual diagram summarizing the content of this paper, highlighting both non-pharmacological interventions for sarcopenia and the role of chronic inflammation in its development.

CRediT author statement

Doyoon Kim: Conceptualization, Writing-Original Draft. Satoru Morikawa: Conceptualization, Writing-Original Draft. Masashi Miyawaki: Writing-Original Draft, Writing-Review & Editing. Taneaki Nakagawa: Writing-Review & Editing. Sumito Ogawa: Writing-Review & Editing. Yoshitaka Kase: Conceptualization, Writing-Review & Editing.

Conflicts of interest

The authors declare no competing interests.