Current Opinion in Clinical Nutrition and Metabolic Care最新文献

Purpose of review: Skeletal muscle loss is a hallmark of aging, disease, and physical inactivity, with few effective treatments. Ketone bodies are lipid-derived molecules whose endogenous production is substantially amplified under conditions characterized by carbohydrate deprivation (e.g. fasting, a ketogenic diet). Orally ingested ketone supplements are now available that can rapidly induce a pronounced state of ketosis lasting hours without dietary carbohydrate restriction. Historically, ketone bodies have been hypothesized to spare muscle protein during starvation. Recently, their potential anabolic and anticatabolic effects on skeletal muscle have garnered renewed research and clinical interest. This review examines emerging evidence on ketone body administration and its influence on skeletal muscle protein turnover and related signaling, with consideration for therapeutic application in muscle wasting and rehabilitation.

Recent findings: Oral ketone supplementation has been shown to enhance postprandial muscle protein synthesis (MPS) in healthy young males. Under inflammatory catabolic conditions, ketone bodies may also promote a favorable net protein balance via suppression of muscle protein breakdown (MPB).

Summary: Ketone body administration may attenuate MPB and stimulate MPS, suggesting potential utility in counteracting muscle wasting. However, further studies are needed to elucidate underlying mechanisms and assess long-term effects on muscle mass and function in clinical settings.

Purpose of review: We discuss the premise and potential of multi-ingredient supplements (MIS) in the treatment of complex skeletal muscle (SkM) pathologies, and provide an updated review of literature on nutraceuticals in sarcopenia and sarcopenic obesity (SO) management, with an emphasis on single- vs. multi-ingredient protein-based formulations.

Recent findings: Several meta-analyses have confirmed the synergistic benefits of combining resistance training (RT) with dietary protein supplementation in older adults with sarcopenia or physical frailty, with a potential ceiling effect at 1.5-1.7 g PRO/kg BW/day.Single-ingredient supplements with proven synergism with RT and clinical relevance for sarcopenia treatment include the major milk proteins (whey and/or casein) and creatine monohydrate. Vitamin D 3 , calcium, and/or n -3 polyunsaturated fatty acids are also recommended for mitigating concurrent micronutrient deficiencies, bone loss, and inflammation. More evidence is needed to justify monotherapy with leucine or leucine metabolites over high-quality protein sources.RCTs have demonstrated superiority of whey-based MIS compared to isocaloric and isonitrogenous placebo for enhancing SkM growth in both younger and older persons, including obese and nonobese sarcopenic subgroups, as confirmed by in vivo body composition and/or biopsy sampling.Multi-ingredient formulations containing high-quality milk proteins, creatine monohydrate, vitamin D 3 , calcium, and n -3 polyunsaturated fatty acids may therefore be recommended in the multimodal treatment of sarcopenia and sarcopenic obesity.

Summary: Resistance training is the first-line treatment for musculoskeletal conditions and improves lean body mass, strength, and function in sarcopenia patients. Increased protein intake augments RT-induced muscle anabolism across clinical subpopulations, with recent evidence suggesting superiority of multi vs. single-ingredient protein-based supplements.

Purpose of review: This review aims to summarise recent findings on the effects of omega-3 fatty acids (FAs) on skeletal muscle vascular and metabolic health. We particularly focus on macrovascular (large blood vessel) outcomes, skeletal muscle microvascular (capillary) blood flow and skeletal muscle health and metabolism.

Recent findings: Recent meta-analysis and intervention studies suggest that omega-3 FAs improve macrovascular health outcomes in humans by enhancing endothelial function, reducing arterial stiffness and by increasing nitric oxide bioavailability. However, the benefits on macrovascular outcomes are more evident in clinical populations than in healthy individuals. In terms of dose, more than 1 g/day of omega-3 FA appear to be more beneficial than less than 1 g/day. In contrast to macrovascular outcomes, the effect of omega-3 FAs on skeletal muscle microvascular outcomes remains undetermined, demonstrating a significant gap in the field. In terms of skeletal muscle health and metabolism, omega-3 FAs improve muscle strength and ameliorate postprandial blood glucose levels in healthy individuals. The anti-inflammatory effects of omega-3 FAs also appear to benefit muscle health and metabolism.

Summary: Omega-3 FAs have a positive effect on macrovascular outcomes, muscle metabolism and health, specifically in clinical populations. The direct effects of omega-3 FAs on muscle microvascular outcomes in both healthy and clinical populations need to be determined.

Purpose of review: Despite long-standing evidence linking dietary fibre intake to improved glycaemic control and reduced chronic disease risk, most individuals fail to meet recommended intake levels. As interest grows in the gut microbiota's role in mediating fibre's health effects, this review evaluates recent human intervention trials to assess whether dietary fibre improves glucose homeostasis through microbiota-dependent mechanisms.

Recent findings: Nine recent randomised controlled trials (RCTs) have examined the effects of dietary fibre on glycaemic markers and gut microbiota, primarily in individuals at risk of or diagnosed with metabolic disease. Five studies reported improvements in glycaemic outcomes such as fasting glucose, insulin, or HOMA-IR. Microbial responses were inconsistent, with variable effects on diversity and composition. Notably, improvements in markers of gut barrier integrity and systemic inflammation were consistently observed in studies including these as mechanistic outcomes.

Summary: Although dietary fibre may enhance glycaemic control and modulate the gut microbiota, effects vary by fibre type, dose, population, and study design. Markers of gut barrier integrity and inflammation appear to be more reliable indicators of benefit compared with the assessments of gut microbial composition. Future trials should prioritise healthy populations to explore the potential of dietary fibre to maintain metabolic health.

Purpose of review: Malnutrition is common during critical illness and associated with worse outcomes. To identify high-risk patients and tailor management, it is important to evaluate patients' nutritional status.

Recent findings: Albumin, transthyretin, transferrin and retinol-binding protein (RBP) reflect the acute-phase in critical illness and are influenced to different degrees by various consequences of critical illness, including inflammation, fluid shifts and organ dysfunction. They should not be regarded as biomarkers of malnutrition. Similarly, total circulating lymphocyte count, insulin-like growth factor-1 and interleukin-6 associate with malnutrition but are not reliable laboratory biomarkers to assess nutritional status of critically ill patients.Nonlaboratory tools to evaluate nutritional status include ultrasound evaluation of skeletal muscle thickness and computed tomographic evaluation of paravertebral or limb fat to muscle ratio.Serial transthyretin, RBP and muscle imaging can be used to monitor changes in nutritional status over time.

Summary: Assessing nutritional status in critically ill patients is complex due to the influence of inflammation, fluid shifts, and organ dysfunction on traditional biomarkers. There is an urgent need for better tools to enable tailored personalized nutritional support.

Purpose of review: This narrative review aims to evaluate the current evidence on how intermittent fasting regimens - including alternate-day fasting (ADF) and time-restricted eating (TRE) - affect micronutrient intake in adults.

Recent findings: Several randomized controlled trials have reported reductions in the intake of key micronutrients such as calcium, magnesium, potassium, folate, vitamin C, and various B vitamins during ADF and TRE. These deficiencies are largely driven by lower total energy intake and reduced consumption of nutrient-dense foods on fasting days. While some studies found no significant differences in micronutrient adequacy between ADF/TRE and continuous energy restriction, others observed higher prevalence of inadequate micronutrient intake with intermittent fasting regimens. Dietary supplement use varied across studies and may help mitigate deficiency risks. Variations in study design, dietary adherence, dietary patterns, baseline nutritional status and nutritional advice appear to influence outcomes substantially.

Summary: Although intermittent fasting is an effective and flexible approach to weight management, it may compromise micronutrient intake if dietary quality is not prioritized. Emphasis should be placed on nutrient-dense food choices during eating windows. Dietary supplements may be necessary in restrictive or prolonged fasting regimens to prevent deficiencies and support overall metabolic health.

Purpose of review: Aging population rates are significantly increasing and improved quality of life during aging is a top priority. The decline in skeletal muscle mass and strength is a major concern with aging, as it impairs the ability to perform activities of daily living and significantly diminishes quality of life. Effective strategies to counteract this decline are necessary for supporting longevity and enhancing quality of life in older adults.

Recent findings: In addition to exercise and nutritional interventions, pharmaceutical compounds are routinely explored as a means of maintaining muscle size, strength and function during the aging process. The addition of exercise would offer greater effects, although combined evidence is lacking. In this review, we highlight several pharmacological compounds, including anabolic agents, caloric restriction mimetics, metformin, and rapamycin, targeted at skeletal muscle that may enhance the effect of exercise. These trials have demonstrated muscle retention and growth, as well as improved strength and functional outcomes.

Summary: Pharmacological therapy shows promise to improve skeletal muscle mass and function in older adults. The addition of exercise with these compounds would be expected to further enhance skeletal muscle adaptations and quality of life, especially in sarcopenic adults.

Purpose of review: Exercise profoundly alters immunological processes to improve overall health and immunity. The link between immune cell metabolism and function has prompted study of immune cell bioenergetics following acute exercise and the role of muscle-resident immune cells in training adaptations. This review highlights recent work in the area and discusses potential dietary approaches for boosting exercise-induced immunometabolic benefits.

Recent findings: Human studies highlight the ability of exercise to alter immune cell bioenergetics, with some also reporting accompanying changes in immune cell function. Rodent studies involving moderate exercise report improved innate and adaptive immune cell phenotypes that are accompanied by increased mitochondrial size and bioenergetic function. Various muscle resident immune cell subpopulations including macrophages, mast cells, and regulatory T cells also appear to be involved in the adaptive responses to exercise. Fasting, exogenous ketones, and mitochondrial enhancing compounds (e.g., sulforaphane, urolithin A) could theoretically potentiate the immunometabolic benefits of exercise based on their independent effects, but evidence for combined interventions is currently lacking.

Summary: Exercise and dietary manipulations that independently alter immunometabolic pathways could be combined to maximize associated health benefits. This may benefit those who cannot meet physical activity guidelines or want to maximize exercise adaptation.