Nutrition and sarcopenia: evidence for an interaction

Post-prandial tracer studies of protein and amino acid utilisation: what can they tell us about human amino acid and protein requirements?

Nitrogen balance (NB), the principal methodology used to derive recommendations for human protein and amino acid requirements, has been widely criticised, and calls for increased protein and amino acid requirement recommendations have been made, often on the basis of post-prandial amino acid tracer kinetic studies of muscle protein synthesis, or of amino acid oxidation. This narrative review considers our knowledge of the homeostatic regulation of the FFM throughout the diurnal cycle of feeding and fasting and what can and has been learnt from post-prandial amino acid tracer studies, about amino acid and protein requirements. Within the FFM, muscle mass in well fed weight-stable adults with healthy lifestyles appears fixed at a phenotypic level within a wide range of habitual protein intakes. However homoeostatic regulation occurs in response to variation in habitual protein intake, with adaptive changes in amino acid oxidation which influence the magnitude of diurnal losses and gains of body protein. Post-prandial indicator amino acid oxidation (IAAO) studies have been introduced as an alternative to NB and to the logistically complex 24 h [13C-1] amino acid balance studies, for assessment of protein and amino acid requirements. However, a detailed examination of IAAO studies shows both a lack of concern for homeostatic regulation of amino acid oxidation and  major flaws in their design and analytical interpretation, which seriously constrain their ability to provide reliable values. New ideas and a much more critical approach to existing work is needed if real progress is to be made in the area.

Identification of a leucine-mediated threshold effect governing macrophage mTOR signalling and cardiovascular risk

High protein intake is common in western societies and is often promoted as part of a healthy lifestyle; however, amino-acid-mediated mammalian target of rapamycin (mTOR) signalling in macrophages has been implicated in the pathogenesis of ischaemic cardiovascular disease. In a series of clinical studies on male and female participants ( NCT03946774 and NCT03994367 ) that involved graded amounts of protein ingestion together with detailed plasma amino acid analysis and human monocyte/macrophage experiments, we identify leucine as the key activator of mTOR signalling in macrophages. We describe a threshold effect of high protein intake and circulating leucine on monocytes/macrophages wherein only protein in excess of ∼25 g per meal induces mTOR activation and functional effects. By designing specific diets modified in protein and leucine content representative of the intake in the general population, we confirm this threshold effect in mouse models and find ingestion of protein in excess of ∼22% of dietary energy requirements drives atherosclerosis in male mice. These data demonstrate a mechanistic basis for the adverse impact of excessive dietary protein on cardiovascular risk.

Association between dietary antioxidant and fatty acids and low muscle mass in obese and non-obese community-dwelling older adults: An NHANES analysis

Sarcopenia increases disability, hospital stays, readmissions, and mortality in older adults. Antioxidative nutrients and fatty acids consumption may help maintain muscle mass by reducing oxidative stress. This study aims to assess the association between antioxidant and fatty acid intake and low muscle mass in community-dwelling older people. This retrospective analysis used data from the National Health and Nutrition Examination Survey from 1999 to 2004. Participants ≥ 60 years with information on muscle mass measured by Dual energy X-ray absorptiometry (DXA) were included. Appendicular skeletal muscle mass was assessed. Associations between antioxidants and fatty acids intake, and low muscle mass were evaluated using logistic regressions. 3648 (1748 men and 1900 women) were included. The prevalence of low muscle mass was 41% and 26% among men and women ≥ 75 years, and 45.2% and 28.4% among obese men and women. In obese males, a natural-log-unit increase of vitamin A (aOR = 0.806, 95% CI: 0.652-0.996), vitamin C (aOR = 0.878, 95% CI: 0.779-0.990), selenium intake (aOR = 0.716, 95% CI: 0.517-0.993), and higher saturated fatty acids (aOR = 0.956, 95% CI: 0.915-0.998) and monounsaturated fatty acids (aOR = 0.959, 95% CI: 0.925-0.994) intake were associated with decreased odds for low muscle mass. Among obese females, a natural-log-unit increase of vitamin E (P = .036), vitamin B12 (P = .014), total folate (P = .015), zinc (P = .005), and selenium intake (P = .018) were associated with increased odds of low muscle mass, whereas higher saturated fatty acids (P < .001), monounsaturated fatty acids (P = .001), and polyunsaturated fatty acids intake (P = .006) were associated with decreased odds for low muscle mass. Antioxidants (vitamin A, C, E, B6, B12, total folate, zinc, magnesium, selenium) intake does not consistently relate to low muscle mass across age and sex. Higher intake of saturated, monounsaturated, and polyunsaturated fatty acids are independently associated with reduced likelihood of low muscle mass in both obese older men and women.

Protein - a scoping review for Nordic Nutrition Recommendations 2023

Proteins are needed for providing essential amino acids, nitrogen, and fuel for the body's needs in all age groups. Proteins are especially required during active growth in pregnancy, lactation, childhood, and tissue growth in general. An adequate protein intake is needed in old adults to avoid premature muscle loss. According to the current dietary surveys, protein intake in the Nordic and Baltic countries varies from 15 to 19% of the total energy intake in adults. Comprehensive data regarding children and older adults are lacking. No good measure for protein status exists, and the estimation of physiological requirements is based on N-balance studies having some weaknesses. Protein quality is assessed by considering the protein digestibility of individual indispensable amino acids and their utilization (bioavailability), which is affected by food antinutrients and processing. The evidence regarding the association of protein intake per se with health outcomes is limited or suggestive. It is difficult to separate from the effect of other nutrients or ingredients in protein-rich foods. Proteins are widespread in foods, deriving from both animal and plant sources. Animal-sourced protein production puts more strain on the environment than plant-sourced proteins and contributes significantly to greenhouse gas emissions, thereby enhancing climate change. In Nordic and Baltic countries, consumption of animal-sourced proteins is relatively high. A shift toward more plant-based protein diets would be advisable for promoting a healthy and sustainable diet.

The role of nutrition in the prevention of sarcopenia

Sarcopenia is a common skeletal muscle disorder characterized by a loss of muscle mass and impaired muscle function that is associated with poor health outcomes. Although nutrition is considered an important factor in the etiology of sarcopenia, the preventive potential of diet, specifically the extent to which differences in habitual patterns of diet and/or nutrient intakes impact risk of its development, is poorly understood. This narrative review considered research evidence on dietary patterns and nutrient intakes in mid- (<60 y) and young-older (60-70 y) adulthood to evaluate how they relate to age-related changes in muscle mass and function. A key finding was that current evidence on adult diet and sarcopenia risk in older age is limited and fragmented, with different outcomes reported across studies (for example, lean mass, strength) and few reporting links to incident diagnosed sarcopenia. As these outcomes are not interchangeable, it challenges collation of the evidence, leaving many gaps in understanding. There is also limited information about adult (<70 y) diet and few longitudinal studies with repeated dietary assessments to enable definition of cumulative exposures across adulthood. However, despite these limitations, findings from studies of dietary patterns already provide reasonably consistent messages about the benefits of diets of higher quality in earlier adulthood for later physical performance, although whole-diet intervention trials are urgently needed to understand their potential. In comparison, there is little evidence of benefits of higher intakes of individual nutrients in earlier adulthood for later muscle mass and function. Although these gaps need to be addressed in future research, there may already be sufficient data to promote messages about diet quality more widely - that healthier diets of higher quality across adulthood, with known benefits for a range of health outcomes, are also linked to the effective preservation of muscle mass and function.

Physical Activity, Sedentary Behavior, Fruit and Vegetable Consumption, and Sarcopenia in Older Chinese Adults: A Cross-Sectional Study

PURPOSE

The purpose of this study was to investigate the association between moderate to vigorous physical activity (MVPA), sedentary behavior, fruit and vegetable intake, and the risk of sarcopenia among older Chinese adults.

METHODS

This cross-sectional study enrolled 5418 older Chinese adults who participated in the Study on Global Aging and Adult Health (SAGE). Participants reported information about their physical activity, sedentary behavior, and dietary habits (fruit and vegetable intake). Sarcopenia was defined as the presence of low skeletal muscle mass and either a slow gait speed or weak handgrip strength. A multiple logistic regression model was employed to determine the relationship between MVPA, sedentary behavior, fruit and vegetable intake, and the risk of sarcopenia.

RESULTS

Only 32.63% of participants met all three recommendations (for MVPA, sedentary behavior, and fruit and vegetable intake). Compared with meeting none of the recommendations, meeting all three recommendations was associated with a lower risk of sarcopenia (OR = 0.63, 95% CI = 0.41-0.98). Moreover, meeting the recommendation for sufficient fruit and vegetable intake (OR = 0.69, 95% CI = 0.58-0.83), MVPA and fruit/vegetable intake (OR = 0.67, 95% CI = 0.52-0.86), and sedentary behavior and fruit/vegetable intake (OR = 0.69, 95% CI = 0.48-0.98) was associated with a lower risk of sarcopenia.

CONCLUSION

Our findings indicate that in this large representative sample of older Chinese adults, meeting lifestyle recommendations for MVPA, sedentary behavior, and fruit and vegetable intake protected against sarcopenia.

Dietary patterns and sarcopenia in elderly adults: the Tianjin Chronic Low-grade Systemic Inflammation and Health (TCLSIH) study

Sarcopenia is a core contributor to several health consequences, including falls, fractures, physical limitations and disability. The pathophysiological processes of sarcopenia may be counteracted with the proper diet, delaying sarcopenia onset. Dietary pattern analysis is a whole diet approach used to investigate the relationship between diet and sarcopenia. Here, we aimed to investigate this relationship in an elderly Chinese population. A cross-sectional study with 2423 participants aged more than 60 years was performed. Sarcopenia was defined based on the guidelines of the Asian Working Group for Sarcopenia, composed of low muscle mass plus low grip strength and/or low gait speed. Dietary data were collected using a FFQ that included questions on 100 food items along with their specified serving sizes. Three dietary patterns were derived by factor analysis: sweet pattern, vegetable pattern and animal food pattern. The prevalence of sarcopenia was 16·1 %. The higher vegetable pattern score and animal food pattern score were related to lower prevalence of sarcopenia (P_trend = 0·006 and < 0·001, respectively); the multivariate-adjusted OR of the prevalence of sarcopenia in the highest v. lowest quartiles were 0·54 (95 % CI 0·34, 0·86) and 0·50 (95 % CI 0·33, 0·74), separately. The sweet pattern score was not significantly related to the prevalence of sarcopenia. The present study showed that vegetable pattern and animal food pattern were related to a lower prevalence of sarcopenia in Chinese older adults. Further studies are required to clarify these findings.

Associations of Dynapenic Obesity and Sarcopenic Obesity with the Risk of Complications in COVID-19

Ageing is associated with changes in body composition, such as low muscle mass (sarcopenia), decreased grip strength or physical function (dynapenia), and accumulation of fat mass. When the accumulation of fat mass synergistically accompanies low muscle mass or reduced grip strength, it results in sarcopenic obesity and dynapenic obesity, respectively. These types of obesity contribute to the increased risk of cardiovascular disease and mortality in the elderly, which could increase the damage caused by COVID-19. In this review, we associated factors that could generate a higher risk of COVID-19 complications in dynapenic obesity and sarcopenic obesity. For example, skeletal muscle regulates the expression of inflammatory cytokines and supports metabolic stress in pulmonary disease; hence, the presence of dynapenic obesity or sarcopenic obesity could be related to a poor prognosis in COVID-19 patients.

Increased Omega-3 Fatty Acid Intake Is Associated with Low Grip Strength in Elderly Korean Females

Omega-3 fatty acids, such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), have anti-inflammatory properties and have recently been considered essential factors for maintaining muscle health. This study aimed to investigate the relationship between omega-3 fatty acid intakes and sarcopenia by assessing grip strength in elderly Koreans who are at risk of sarcopenia. This study was conducted on 5529 individuals (2449 males and 3080 females) aged ≥65 years from the raw data of the Korea National Health and Nutrition Examination Survey 2015−2019. In this study, we analyzed the association between EPA and DHA intake, calculated from a 24-h recall method data, and grip strength, a diagnostic criterion for sarcopenia. The cut-off values for low grip strength were <26 kg for males and <18 kg for females, which were set for the Asian population. The results indicated that elderly females consuming EPA and DHA below the adequate intake (AI) had significantly lower grip strength (p < 0.0001) and, had a higher percentage contribution from carbohydrates, but a significantly lower percentage contribution from protein (p < 0.0001), compared to elderly females consuming EPA and DHA at or above the AI. In addition, after adjusting for confounding factors, the odds of low grip strength were 0.777 times lower among elderly females consuming EPA and DHA at or above the AI than those consuming EPA and DHA below the AI (95% confidence interval: 0.616−0.979, p = 0.0322). These results suggest that sufficient intake of EPA and DHA is pivotal to mitigate a reduction in grip strength and to improve the quality of nutrient intake among elderly females.

Various effects of nutritional status on clinical outcomes after intracerebral hemorrhage

Although the assessment of nutrition is essential for stroke patients, detailed associations between nutritional status at admission, subsequent complications, and clinical outcomes in patients with acute intracerebral hemorrhage (ICH) are unclear. We aimed to elucidate these associations using the Controlling Nutritional Status (CONUT) score. Consecutive patients with acute ICH were investigated. Nutritional status was evaluated using the CONUT score, calculated from the serum albumin level, lymphocyte count, and total cholesterol level. Subsequent complications, such as hemorrhage expansion (HE) during the acute stage and aspiration pneumonia during hospitalization, were evaluated. Poor outcome was defined as a modified Rankin Scale score of ≥ 3 at 3 months. Of the 721 patients, 49 had HE, 111 had aspiration pneumonia, and 409 had poor outcomes. Patients with HE had significantly lower total cholesterol levels than those without HE. Patients with aspiration pneumonia had significantly lower albumin levels, lower lymphocyte counts, and higher CONUT scores than those without aspiration pneumonia. Patients with poor outcomes had significantly lower albumin levels, lower lymphocyte counts, lower total cholesterol levels, and higher CONUT scores than those with good outcomes. Multivariable logistic analysis showed that higher CONUT scores were independently associated with poor outcome (odds ratio, 1.28; 95% confidence interval, 1.09-1.49; P = 0.002) after adjusting for baseline characteristics, HE, and aspiration pneumonia. Each component of CONUT was a useful predictor of subsequent complications. Malnutrition, determined using the CONUT score, was independently associated with poor outcomes in patients with ICH after adjusting for these complications.

The Inverse Association of Sarcopenia and Protein-Source Food and Vegetable Intakes in the Korean Elderly: The Korean Frailty and Aging Cohort Study

The aging population contributes to increasing economic and social burden worldwide. Sarcopenia, an age-related degenerative disease and progressive disorder, is characterized by a reduction in skeletal muscle mass and function. This study aims to assess the association between dietary factors and sarcopenia in the Korean elderly using nationwide data. A total of 801 subjects aged 70–84 years were included in this analysis. Subjects were divided into two groups: sarcopenic and nonsarcopenic groups according to the sarcopenia criteria established by the Asian Working Group for Sarcopenia. Nutrient and food intakes were assessed using a 24-h recall method. Logistic regression analysis was used to assess the association between sarcopenia and food group and nutrient intakes. In the multivariable models, the meat/fish/egg/legume food group, vegetable group, and total food intake were inversely associated with the prevalence of sarcopenia. The high intakes of energy, carbohydrate, protein, fiber, zinc, carotene, and vitamin B₆ were associated with the lower prevalence of sarcopenia. Therefore, consuming sufficient nutrients through various protein source foods and vegetables will help prevent sarcopenia in the Korean elderly.

Major dietary patterns in relation to muscle strength status among middle-aged people: A cross-sectional study within the RaNCD cohort

Grip strength in midlife can predict physical disability in senior years. Recent evidence shows the critical role of nutritional status on muscle function. We aimed to elucidate whether adherence to a particular dietary pattern would be associated with abnormal muscle strength among middle-aged people. In this cross-sectional study, a semiquantitative Food Frequency Questionnaire was used to assess the dietary intake of 2781 participants in the Ravansar Non-Communicable Chronic Disease (RaNCD) cohort. Major dietary patterns from 28 main food groups were extracted using principal component analysis. Binary logistic regression was used to determine the association between the tertiles of the major dietary patterns and muscle strength status. Two major dietary patterns were identified: the "mixed dietary pattern" that heavily loaded with fruits, vegetables, nuts, dairies, sweets, legumes, dried fruits, fish, red meat, butter, whole grains, natural juices, poultry, pickles, olive, industrial juice, egg, processed meat, and snacks and "unhealthy dietary pattern" that heavily loaded by fats, sugar, refined grains, soft drink, salt, organ meat, tea, and coffee. Adherence to the mixed dietary pattern (OR = 1.03, 95% CI = 0.8-1.33, P for trend = 0.77) and the unhealthy dietary pattern (OR = 1.01, 95% CI = 0.79-0.13, P for trend = 0.89) did not associate with abnormal muscle strength. This study suggests that the dietary pattern involving the consumption of healthy and unhealthy food does not have an effect on muscle strength in middle-aged adults.

Changes in Body Composition, Muscle Strength, and Fat Distribution Following Kidney Transplantation

RATIONALE AND OBJECTIVE

Low muscle mass relative to fat mass (relative sarcopenia) has been associated with mortality and disability but has not been examined following transplantation. We studied how measures of body composition change after receipt of a kidney allograft.

STUDY DESIGN

Prospective longitudinal cohort study.

SETTING AND PARTICIPANTS

60 kidney transplant recipients (ages 20-60 years) at the University of Pennsylvania.

EXPOSURE

Kidney transplantation.

OUTCOMES

DXA measures of fat mass index (FMI) and appendicular lean mass index (ALMI; representing muscle mass), CT measures of muscle density (low density represents increased intramuscular adipose tissue), dynamometer measures of leg muscle strength, and physical activity. ALMI relative to FMI (ALM_FMI) is an established index of relative sarcopenia.

ANALYTICAL APPROACH

Measures expressed as age, sex, and race-specific Z-scores for transplant recipients were compared to 327 healthy controls. Regression models were used to identify correlates of change in outcome Z-scores and compare transplant recipients to controls.

RESULTS

At transplantation, ALMI, ALMI_FMI, muscle strength and muscle density Z-scores were lower vs. controls (all p≤0.001). Transplant recipients received glucocorticoids throughout. The prevalence of obesity increased from 18 to 45%. Although ALMI increased following transplantation (p<0.001) and was comparable to controls from 6 months onward, gains were outpaced by increases in FMI, resulting in persistent ALMI_FMI deficits (mean Z-score -0.31 at 24 months, p=0.02 vs controls). Muscle density improved following transplantation despite gains in FMI (p = 0.02). Muscle strength relative to ALMI also improved (p = 0.04) but remained low compared with controls (p=0.01). Exercise increased in the early months following transplantation (p<0.05) but remained lower than controls (p=0.02).

LIMITATIONS

Lack of muscle biopsies precluded assessment of muscle histology and metabolism.

CONCLUSIONS

The two-year interval following kidney transplantation was characterized by gains in muscle mass and strength that were outpaced by gains in fat mass resulting in persistent relative sarcopenia.

Micronutrients and sarcopenia: current perspectives

Sarcopenia, a skeletal muscle disorder that is characterised by loss of muscle strength and mass, is common in older populations and associated with poorer health outcomes. Although the individual and economic costs of sarcopenia are widely recognised, current understanding of its pathophysiology is incomplete, limiting efforts to translate research evidence into effective preventive and treatment strategies. While nutrition is a key field of sarcopenia research, the role of differences in habitual diets, and the effectiveness of dietary change as a prevention or treatment strategy, is uncertain. There is a growing evidence base that links low micronutrient intakes to sarcopenia risk and/or its components (low muscle strength and mass, impaired physical performance), although there remain many gaps in understanding. There is some consistency in findings across studies highlighting potential roles for antioxidant nutrients, B vitamins and magnesium; however, the evidence is largely observational and from cross-sectional studies, often describing associations with different muscle outcomes. As low intakes of some micronutrients are common in older populations, there is a need for new research, particularly from well-characterised prospective cohorts, to improve the understanding of their role and importance in the aetiology of sarcopenia and to generate the evidence needed to inform dietary guidelines to promote muscle health.

Associations of sarcopenia components with physical activity and nutrition in Australian older adults performing exercise training

BACKGROUND

The risk of progressive declines in skeletal muscle mass and strength, termed sarcopenia, increases with age, physical inactivity and poor diet. The purpose of this study was to explore and compare associations of sarcopenia components with self-reported physical activity and nutrition in older adults participating in resistance training at Helsinki University Research [HUR] and conventional gyms for over a year, once a week, on average.

METHODS

The study looked at differences between HUR (n = 3) and conventional (n = 1) gyms. Muscle strength (via handgrip strength and chair stands), appendicular lean mass (ALM; via dual energy X-ray absorptiometry) and physical performance (via gait speed over a 4-m distance, short physical performance battery, timed up and go and 400-m walk tests) were evaluated in 80 community-dwelling older adults (mean ± SD 76.5 ± 6.5 years). Pearson correlations explored associations for sarcopenia components with self-reported physical activity (via Physical Activity Scale for the Elderly [PASE]) and nutrition (via Australian Eating Survey).

RESULTS

No differences in PASE and the Australian Recommended Food Score (ARFS) were observed between HUR and conventional gyms, however HUR gym participants had a significantly higher self-reported protein intake (108 ± 39 g vs 88 ± 27 g; p = 0.029) and a trend to have higher energy intake (9698 ± 3006 kJ vs 8266 ± 2904 kJ; p = 0.055). In both gym groups, gait speed was positively associated with self-reported physical activity (r = 0.275; p = 0.039 and r = 0.423; p = 0.044 for HUR and conventional gyms, respectively). ALM was positively associated with protein (p = 0.047, r = 0.418) and energy (p = 0.038, r = 0.435) intake in the conventional gym group. Similar associations were observed for ALM/h2 in the HUR group. None of the sarcopenia components were associated with ARFS in either gym group.

CONCLUSION

Older adults attending HUR and conventional gyms had similar self-reported function and nutrition (but not protein intake). Inadequate physical activity was associated with low gait speed and inadequate nutrition and low protein ingestion associated with low lean mas, even in older adults participating in exercise programs. Optimal physical activity and nutrition are important for maintaining muscle mass and function in older adults.

The prevalence of sarcopenia and relationships between dietary intake and muscle mass in head and neck cancer patients undergoing radiotherapy: A longitudinal study

PURPOSE

Our study aims to investigate dietary intake characteristics and their association with skeletal muscle mass in head and neck cancer patients treated with radiotherapy.

METHODS

From March 2017 to August 2018, patients with head and neck cancer who received radiotherapy at our affiliated hospital were enrolled. Dietary intake was assessed through 24-hr dietary recall and skeletal muscle mass was evaluated by bioelectrical impedance analysis at three-time points. Appendicular skeletal muscle mass was adjusted for height squared defined sarcopenia and correlated with dietary intake by generalized estimating equations (GEE).

RESULTS

This study sample comprised 287 patients [median age: 54 years; 187 (65.2%) men]. Median dietary intake at post-treatment was 14.95 kcal/kg/day energy and 0.63 g/kg/day protein. Skeletal muscle mass decreased significantly in all patients. The prevalence of sarcopenia increased from 24.4% before treatment to 46.7% at the end of treatment. Exploratory univariate GEE analysis revealed that radiotherapy time-point, male-gender, age ≥60 and decreased dietary energy intake significantly impacted on muscle loss represented by the appendicular skeletal muscle index. After controlling covariates, dietary energy intake was only positively associated with muscle loss in women (P = 0.013, 95% CI = 0.003-0.027) but not in men (P = 0.788, 95% CI = -0.007-0.009).

CONCLUSION

While the loss in skeletal muscle is more prevalent in men receiving radiotherapy, the effects of dietary energy intake were only associated with women. A prospective randomized clinical trial is required to identify the appropriate amount of dietary energy supplement by gender in cancer patients treated with radiotherapy.

Predictive Value of Serum Creatinine/Cystatin C in Acute Ischemic Stroke Patients under Nutritional Intervention

BACKGROUND AND PURPOSE

As a very common risk of adverse outcomes of the ischemic stroke patients, sarcopenia is associated with infectious complications and higher mortality. The goal of this retrospective study is to explore the predictive value of serum Cr/CysC ratio in acute ischemic stroke patients receiving nutritional intervention.

METHODS

We reviewed adult patients with AIS from December 2019 to February 2020. Patients with acute kidney injury were excluded and all patients received nutritional intervention during a 3-month follow-up period. We collected baseline data at admission including creatinine and cystatin C. The primary poor outcome was major disability (modified Rankin Scale score ≥ 4) at 3 months after AIS.

RESULTS

A total of 217 patients with AIS were identified for this study. Serum Cr/CysC ratio was significantly correlated with NIHSS at discharge, 1-month modified Rankin Scale score, and 3-month modified Rankin Scale score. During 3 months, 34 (15.70%) patients had a poor outcome after AIS and 11 (5.10%) patients died within 30 days. In multivariable logistic regression analyses, serum Cr/CysC ratio at admission was independently associated with 3-month poor outcomes (OR: 0.953, 95% CI: 0.921-0.986, p = .006) and 30-day mortality (OR: 0.953, 95% CI: 0.921-0.986, p = .006).

CONCLUSION

As a blood biochemical indexes reflecting the muscle mass and aiding in risk stratification, Cr/CysC ratio at admission could be used as a predictor of 30-day mortality and long-term poor prognosis in AIS patients.

Western dietary pattern is associated with higher risk of lower lean muscle mass in Korean postmenopausal women: data from the Korea National Health and Nutrition Examination Survey 2008-2011

BACKGROUND/OBJECTIVES

In a healthy person, from 35 years of age, there is an annual loss of muscle mass at the rate of 1–2% and is associated with a decline in the quality of life. This study aimed to identify the particular dietary patterns associated with the risk of lower lean muscle mass in Korean postmenopausal women.

SUBJECTS/METHODS

The Korea National Health and Nutrition Examination Survey (KNHANES) is a population-based, continuous cross-sectional annual survey. The participants of the KNHANES IV (2008–2009) and V (2010–2011) were considered for this study. The study sample consisted of 1548 postmenopausal women, aged 45–86 years. Lower lean muscle mass was defined as having appendicular skeletal muscle mass corrected for body weight less than 1 standard deviation of the young reference group aged 20 to 39 years in KNHANES IV and V. To identify the dietary pattern using factor analysis, 24-h recall data was used.

RESULTS

The prevalence of lower lean muscle mass was 31.3% in this study population. Four dietary patterns were identified by factor analysis; ‘Diverse’, ‘Western’, ‘Traditional’, and ‘Snacks and beverages’. The ‘Western’ pattern, highest factor loadings for flour and bread, potatoes, red meat, processed meat, eggs, and cheese, was significantly associated with a high (60%) risk of lower lean muscle mass (odds ratio [95% confidence interval] = 1.60 [1.07–2.39], P for trend = 0.01) after adjustments for potential covariates. The other 3 dietary patterns were not associated with lower lean muscle mass.

CONCLUSIONS

The study findings suggest that the ‘Western’ dietary pattern that includes flour and bread, potatoes, red meat, processed meat, eggs, and cheese, may be associated with a higher risk of lower lean muscle mass in Korean postmenopausal women.

Dietary protein and bone health: towards a synthesised view

The present paper reviews published literature on the relationship between dietary protein and bone health. It will include arguments both for and against the anabolic and catabolic effects of dietary protein on bone health. Adequate protein intake provides the amino acids used in building and maintaining bone tissue, as well as stimulating the action of insulin-like growth factor 1, which in turn promotes bone growth and increases calcium absorption. However, the metabolism of dietary sulphur amino acids, mainly from animal protein, can lead to increased physiological acidity, which may be detrimental for bone health in the long term. Similarly, cereal foods contain dietary phytate, which in turn contains phosphate. It is known that phosphate consumption can also lead to increased physiological acidity. Therefore, cereal products may produce as much acid as do animal proteins that contain sulphur amino acids. The overall effect of dietary protein on physiological acidity, and its consequent impact on bone health, is extremely complex and somewhat controversial. The consensus is now moving towards a synthesised approach. Particularly, how anabolic and catabolic mechanisms interact; as well as how the context of the whole diet and the type of protein consumed is important.

Nutrition and Muscle Strength, As the Key Component of Sarcopenia: An Overview of Current Evidence

Much has been achieved by recent research to increase understanding of the links between nutrition and muscle health. Focusing on muscle strength as the key component of sarcopenia, the aim of this overview was to evaluate its links to nutrition, both to variation in habitual diets in older populations, as well as considering supplementation effects in trials. A main message from the reviewed studies is that while many provide suggestive evidence of benefits of higher nutrient intakes and diets of higher quality, findings are inconsistent, and data on muscle strength are often lacking. To assess the potential of optimising diets as a strategy to promote and maintain muscle strength, gaps in current evidence need to be addressed. These include the need for (i) better understanding of individual differences in responsiveness to dietary change, and the need for targeted nutritional support; (ii) clearer distinction between protective and therapeutic actions of diet; and (iii) definition of the role of dietary patterns and their influence on muscle strength, to allow effects of changes in food consumption to be evaluated—particularly when combined with physical activity. Development of this evidence is needed to enable translation into appropriate dietary recommendations for older populations.

Nutritional strategies for maintaining muscle mass and strength from middle age to later life: A narrative review

Progressive age-related reductions in muscle mass and strength (sarcopenia) can cause substantial morbidity. This narrative review summarizes evidence of nutritional interventions for maintaining muscle mass and strength from midlife through old age. PubMed and Cochrane databases were searched to identify studies of dietary intake and nutritional interventions for sustaining muscle mass and strength. The benefits of progressive resistance training with and without dietary interventions are well documented. Protein and amino acid (particularly leucine) intake should be considered, and supplementation may be warranted for those not meeting recommended intakes. Vitamin D receptors are expressed in muscle tissue; meta-analyses have shown that vitamin D benefits muscle strength. Data suggest that milk and other dairy products containing different bioactive compounds (i.e. protein, leucine) can enhance muscle protein synthesis, particularly when combined with resistance exercise. Omega-3 s can improve muscle mass and strength by mediating cell signaling and inflammation-related oxidative damage; no studies were specifically conducted in sarcopenia. Low-dose antioxidants (e.g. vitamins C and E) can protect muscle tissue from oxidative damage, but relevant studies are limited. Magnesium is involved with muscle contraction processes, and data have shown benefits to muscle strength. Acidogenic diets increase muscle protein breakdown, which is exacerbated by aging. Alkalizing compounds (e.g. bicarbonates) can promote muscle strength. Small studies of probiotics and plant extracts have generated interest, but few large studies have been conducted. Based on available data, dietary and supplemental interventions may add to the benefits of exercise on muscle mass and strength; effects independent of exercise have not been consistently shown.

Dietary Oily Fish Intake and Frailty. A Population-Based Study in Frequent Fish Consumers Living in Rural Coastal Ecuador (the Atahualpa Project)

Oily fish are recommended as part of a healthy diet due to their high content of long-chain omega-3 polyunsaturated fatty acids (ω-3 PUFAs), proteins, and other nutrients. There is preliminary evidence of beneficial effects of ω-3 PUFAs in the prevention of sarcopenia (a major component of frailty). In this study, we aimed to assess the relationship between dietary oily fish intake and a measure of frailty - the Edmonton Frail Scale (EFS) score - in community-dwelling older adults living in rural coastal Ecuador. A total of 363 Atahualpa residents were enrolled. The mean fish servings per week were 8.8 ± 5.2 and mean EFS score was 5 ± 2.8 points. A linear regression model showed no association between the amount of oily fish intake and EFS scores. However, an interaction model, with participants stratified according to their median age and fish intake in quintiles, showed a significant effect for both variables on the EFS score (ß coefficient = 0.104; 95% C.I.: 0.003-0.206; p = 0.044). At the lowest quintile of fish intake, younger individuals have lower EFS scores than their older counterparts. As the consumption of oily fish increases, mean EFS scores margins were found to be progressively reduced in subjects aged 60-69 years but were largely unaffected in persons aged ≥70 years. It appears that oily fish intake has a positive effect on the frailty status of younger subjects but is superseded by the effects of age in the older population.

Milk and resistance exercise intervention to improve muscle function in community-dwelling older adults at risk of sarcopenia (MIlkMAN): protocol for a pilot study

INTRODUCTION

Sarcopenia is a progressive muscle disorder characterised by decline in skeletal muscle mass, strength and function leading to adverse health outcomes, including falls, frailty, poor quality of life and death. It occurs more commonly in older people and can be accelerated by poor diet and low physical activity. Intervention studies incorporating higher dietary protein intakes or protein supplementation combined with resistance exercise (RE) have been shown to limit muscle function decline. However, less is known about the role of whole foods in reducing the risk of sarcopenia. Milk is a source of high-quality nutrients, which may be beneficial for skeletal muscle. This pilot study examines the feasibility and acceptability of milk consumption with RE to improve muscle function in community-dwelling older adults at risk of sarcopenia.

METHODS AND ANALYSIS

30 older adults aged ≥65 years will be randomly allocated to three groups: 'whole milk+RE', 'skimmed milk+RE' or 'control drink+RE'. Assessments will take place in participants' homes, including screening (milk allergies, grip strength, walking speed), baseline and postintervention health and function. All participants will undertake a structured RE intervention twice a week for 6 weeks at a local gym, followed by the consumption of 500 mL of whole or skimmed milk (each ~20 g of protein) or an isocaloric control drink and another 500 mL at home. Participants' views about the study will be assessed using standardised open-ended questions. The primary outcomes include feasibility and acceptability of the intervention with recruitment, retention and intervention response rates. Analyses will include descriptive statistics, exploration of qualitative themes and intervention fidelity.

ETHICS AND DISSEMINATION

Outputs include pilot data to support funding applications; public involvement events; presentation at conferences and peer-reviewed publication.

TRIAL REGISTRATION NUMBER

ISRCTN13398279; Pre-results.

Dietary Patterns, Skeletal Muscle Health, and Sarcopenia in Older Adults

In recent decades, the significance of diet and dietary patterns (DPs) for skeletal muscle health has been gaining attention in ageing and nutritional research. Sarcopenia, a muscle disease characterised by low muscle strength, mass, and function is associated with an increased risk of functional decline, frailty, hospitalization, and death. The prevalence of sarcopenia increases with age and leads to high personal, social, and economic costs. Finding adequate nutritional measures to maintain muscle health, preserve function, and independence for the growing population of older adults would have important scientific and societal implications. Two main approaches have been employed to study the role of diet/DPs as a modifiable lifestyle factor in sarcopenia. An a priori or hypothesis-driven approach examines the adherence to pre-defined dietary indices such as the Mediterranean diet (MED) and Healthy Eating Index (HEI)—measures of diet quality—in relation to muscle health outcomes. A posteriori or data-driven approaches have used statistical tools—dimension reduction methods or clustering—to study DP-muscle health relationships. Both approaches recognise the importance of the whole diet and potential cumulative, synergistic, and antagonistic effects of foods and nutrients on ageing muscle. In this review, we have aimed to (i) summarise nutritional epidemiology evidence from four recent systematic reviews with updates from new primary studies about the role of DPs in muscle health, sarcopenia, and its components; (ii) hypothesise about the potential mechanisms of ‘myoprotective’ diets, with the MED as an example, and (iii) discuss the challenges facing nutritional epidemiology to produce the higher level evidence needed to understand the relationships between whole diets and healthy muscle ageing.

The application of stable-isotope tracers to study human musculoskeletal protein turnover: a tale of bag filling and bag enlargement

The nutritional regulation of protein and amino acid balance in human skeletal muscle carried out by the authors with Mike Rennie is reviewed in the context of a simple physiological model for the regulation of the maintenance and growth of skeletal muscle, the "Bag Theory". Beginning in London in the late 1970s the work has involved the use of stable isotopes to probe muscle protein synthesis and breakdown with two basic experimental models, primed-dose continuous tracer infusions combined with muscle biopsies and arterio-venous (A-V) studies across a limb, most often the leg, allowing both protein synthesis and breakdown as well as net balance to be measured. In this way, over a 30 year period, the way in which amino acids and insulin mediate the anabolic effect of a meal has been elaborated in great detail confirming the original concepts of bag filling within the muscle endomysial "bag", which is limited by the "bag" size unless bag enlargement occurs requiring new collagen synthesis. Finally we briefly review some new developments involving ² H₂ O labelling of muscle proteins.

Utilizing Dietary Nutrient Ratios in Nutritional Research: Expanding the Concept of Nutrient Ratios to Macronutrients

We recently showed that using micronutrient ratios in nutritional research might provide more insights into how diet affects metabolism and health outcomes, based on the notion that nutrients, unlike drugs, are not consumed one at a time and do not target a single metabolic pathway. In this paper, we present a concept of macronutrient ratios, including intra- and inter-macronutrient ratios. Macronutrient intakes from food only, from the What We Eat in America website (summarized National Health and Nutrition Examination Survey data) were transposed into Microsoft Excel to generate ratios. Overall, the dietary ratios of macronutrients may be more revealing and useful in epidemiology and in basic nutritional research than focusing on individual protein, fat, and carbohydrate intakes. While macronutrient ratios may be applied to all types of nutritional research, nutritional epidemiology, and, ultimately, dietary guidelines, the methodology required has not been established yet. In the meantime, intra- and inter-macronutrient ratios may serve as a measure of individual and total macronutrient quality.

Effects of dietary patterns and low protein intake on sarcopenia risk in the very old: The Newcastle 85+ study

Background

Sarcopenia, a progressive age-related loss of skeletal muscle mass and strength, leads to disability, falls, and hospitalisation. Individual variation in sarcopenia onset may be partly explained by lifestyle factors such as physical activity and diet. Healthy dietary patterns (DPs) have been linked to better physical functioning in older adults, but their role in sarcopenia in the very old (aged ≥85) is unknown.

Aims

To investigate the association between DPs and the risk of sarcopenia over 3 years, and to determine whether protein intake influences this relationship in community-dwelling older adults from the Newcastle 85 + Study.

Methods

The analytic sample consisted of 757 participants (61.2% women) who had dietary assessment at baseline. After two-step clustering with 30 food groups to derive DPs, we used logistic regression to determine the risk of prevalent and incident sarcopenia across DPs in all participants, and in those with low (<1 g/kg adjusted body weight/day [g/kg aBW/d]) and good protein intake (≥1 g/kg aBW/d).

Results

We identified three DPs (DP1: ‘Low Red Meat’, DP2: ‘Traditional British’ and DP3: ‘Low Butter’) that varied by unsaturated fat spreads/oils, butter, red meat, gravy and potato consumption. Compared with participants in DP3, those in DP2 had an increased risk of prevalent (OR = 2.42, 95% CI: 1.15–5.09, p = 0.02) but not 3-year incident sarcopenia (OR = 1.67, 0.59–4.67, p = 0.33) adjusted for socio-demographic, anthropometry, health and lifestyle factors. Furthermore, DP2 was associated with an increased risk of prevalent sarcopenia at baseline (OR = 2.14, 1.01–4.53, p = 0.05) and 3-year follow-up (OR = 5.45, 1.81–16.39, p = 0.003) after adjustment for key covariates in participants with good protein intake.

Conclusion

A DP high in foods characteristic of a traditional British diet (butter, red meat, gravy and potato) was associated with an increased risk of sarcopenia even when overall protein intake was good. The results need to be replicated in other cohorts of the very old to understand the role of DPs in sarcopenia onset and management.

Effect of combined fish oil & Curcumin on murine skeletal muscle morphology and stress response proteins during mechanical unloading

Skeletal muscle is a highly adaptable tissue capable of remodeling when dynamic stress is altered, including changes in mechanical loading and stretch. When muscle is subjected to an unloaded state (e.g., bedrest, immobilization, spaceflight) the resulting loss of muscle cross sectional area (CSA) impairs force production. In addition, muscle fiber-type shifts from slow to fast-twitch fibers. Unloading also results in a downregulation of heat shock proteins (e.g., HSP70) and anabolic signaling, which further exacerbate these morphological changes. Our lab recently showed reactive oxygen species (ROS) are causal in unloading-induced alterations in Akt and FoxO3a phosphorylation, muscle fiber atrophy, and fiber-type shift. Nutritional supplements such as fish oil and curcumin enhance anabolic signaling, glutathione levels, and heat shock proteins. We hypothesized that fish oil, rich in omega-3-fatty acids, combined with the polyphenol curcumin would enhance stress protective proteins and anabolic signaling in the rat soleus muscle, concomitant with synergistic protection of morphology. C57BL/6 mice were assigned to 3 groups (n = 6/group): ambulatory controls (CON), hindlimb unloading (HU), and hindlimb unloading with 5% fish oil, 1% curcumin in diet (FOC). FOC treatments began 10 days prior to HU and tissues were harvested following 7 days of HU. FOC mitigated the unloading induced decrease in CSA. FOC also enhanced abundance of HSP70 and anabolic signaling (Akt phosphorylation, p70S6K phosphorylation), while reducing Nox2, a source of oxidative stress. Therefore, we concluded that the combination of fish oil and curcumin prevents skeletal muscle atrophy due to a boost of heat shock proteins and anabolic signaling in an unloaded state.

The High Precision of Functional and Neuromuscular Measures to Classify Sarcopenia in Older Women

BACKGROUND AND PURPOSE

Previous literature suggests that reductions in appendicular skeletal mass (ASM) may have a greater detrimental effect than total lean body mass regarding the onset and progression of sarcopenia. Unfortunately, limited access to equipment that accurately determines ASM often leads to many individuals remaining undiagnosed and experiencing functional decline. Therefore, the purpose of this investigation was to determine the ability of functional and neuromuscular measures to identify ASM in older women.

METHODS

Forty-one (sarcopenic n = 15) older women underwent body composition analysis via dual-energy X-ray absorptiometry (DXA) and performed the following measures: bench press (BP) 1-repetition maximum strength (1RM), vertical jump height and power, handgrip strength, Timed Up and Go test, Berg Balance Scale testing, and bench press power testing at 20%, 40%, and 60% 1RM.

RESULTS AND DISCUSSION

Regression analyses revealed 3 significant models accounting for 93.8%, 91.1%, and 86.4% of the variance in DXA-derived ASM. Paired-samples t tests revealed no significant differences between model-derived and DXA-derived ASM for each model, and each model was significantly correlated to DXA-derived ASM (P < .001). In addition, each model revealed a strong ability to appropriately classify sarcopenia status, with the area under the curve values ranging from 0.86 to 0.93. The present data indicate that ASM can be determined with high precision by measuring outcome variables such as jump power, body weight, and grip strength in older women.

CONCLUSIONS

Therefore, the present models could be used to identify, screen, or classify older women as sarcopenic, ultimately allowing the implementation of interventions aimed at decreasing the difficulty of activities of daily living and increasing quality of life.

Improving the comprehension of sarcopenic state determinants: An multivariate approach involving hormonal, nutritional, lifestyle and genetic variables

It is known that sarcopenia is a multifaceted phenomenon, which involves genetic, nutritional, hormonal and living habits aspects. Then, an integrated analysis, as a multivariate approach, could improve the comprehension about the determinants of sarcopenic state in old adults. The present study aimed to investigate the interaction among serum vitamin D, daily caloric and protein intake, lifestyle habits, ACE I/D gene polymorphism and sarcopenic state in community-dwelling old adults. One hundred one community-dwelling old adults were clinically stratified as sarcopenic or non-sarcopenic. Serum vitamin D, daily caloric and protein intake, lifestyle habits (smoking, physical activity level and sedentary behavior) and ACE I/D gene polymorphism were recorded. A multivariate logistic regression technique was applied to investigate the interaction among the selected independent variables and the sarcopenic state. The independent variables age, smoking, serum Vitamin D and ACE I/D polymorphism achieved the statistical criteria to be inserted in the multivariate analysis. After a stepwise procedure from the multivariate logistic regression, the variables age, serum Vitamin D and ACE I/D polymorphism remained, together, in the final model. Sarcopenic state was significantly associated to older age, II-genotype and low serum Vitamin D in old adults from 60 years old.

Potential Roles of n-3 PUFAs during Skeletal Muscle Growth and Regeneration

Omega-3 polyunsaturated fatty acids (n-3 PUFAs), which are commonly found in fish oil supplements, are known to possess anti-inflammatory properties and more recently alter skeletal muscle function. In this review, we discuss novel findings related to how n-3 PUFAs modulate molecular signaling responsible for growth and hypertrophy as well as the activity of muscle stem cells. Muscle stem cells commonly known as satellite cells, are primarily responsible for driving the skeletal muscle repair process to potentially damaging stimuli, such as mechanical stress elicited by exercise contraction. To date, there is a paucity of human investigations related to the effects of n-3 PUFAs on satellite cell content and activity. Based on current in vitro investigations, this review focuses on novel mechanisms linking n-3 PUFA’s to satellite cell activity and how they may improve muscle repair. Understanding the role of n-3 PUFAs during muscle growth and regeneration in association with exercise could lead to the development of novel supplementation strategies that increase muscle mass and strength, therefore possibly reducing the burden of muscle wasting with age.

Nutrition in the Very Old

The population of older adults aged 85 years and over (the very old) is growing rapidly in many societies because of increases in life expectancy and reduced mortality at older ages. In 2016, 27.3 million very old adults were living in the European Union, and in the UK, 2.4% of the population (1.6 million) were aged 85 and over. Very old age is associated with increased risks of malnutrition, multimorbidity, and disability. Diet (nutrition) is a modifiable risk factor for multiple age-related conditions, including sarcopenia and functional decline. Dietary characteristics and nutrient intakes of the very old have been investigated in several European studies of ageing to better understand their nutritional requirements, which may differ from those in the young-old. However, there is a major gap in regard to evidence for the role of dietary patterns, protein, vitamin D and other nutrients for the maintenance of physical and cognitive functioning in later life. The Newcastle 85+ Study, UK and the Life and Living in Advanced Age, New Zealand are unique studies involving single birth cohorts which aim to assess health trajectories in very old adults and their biological, social and environmental influences, including nutrition. In this review, we have updated the latest findings in nutritional epidemiology with results from these studies, concentrating on the diet-physical functioning relationship.

The Importance of Assessing Nutritional Status to Ensure Optimal Recovery during the Chronic Phase of Stroke

Background

Despite evidence that many of the consequences of stroke that hinder recovery (i.e., obesity, muscle atrophy, and functional declines) have nutritionally modifiable behavior components, little attention has been focused on the significance of nutrition beyond the acute phase of stroke.

Objective

This literature review summarizes the evidence for and against the influence of nutrition on optimal recovery and rehabilitation in chronic (>6 months) stroke.

Results

The literature, which is mainly limited to cross-sectional studies, suggests that a suboptimal nutritional status, including an excess caloric intake, reduced protein intake, and micronutrient deficiencies, particularly the B-vitamins, vitamin D, and omega 3 fatty acids, may have deleterious effects on metabolic, physical, and psychological functioning in chronic stroke survivors.

Conclusions

Careful evaluation of dietary intake, especially among those with eating disabilities and preexisting malnutrition, may aid in the identification of individuals at increased nutritional risk through which early intervention may benefit recovery and rehabilitation and prevent further complications after stroke.

Does nutrition play a role in the prevention and management of sarcopenia?

There is a growing body of evidence that links nutrition to muscle mass, strength and function in older adults, suggesting that it has an important role to play both in the prevention and management of sarcopenia. This review summarises the discussions of a working group [ESCEO working group meeting 8th September 2016] that met to review current evidence and to consider its implications for preventive and treatment strategies. The review points to the importance of 'healthier' dietary patterns that are adequate in quality in older age, to ensure sufficient intakes of protein, vitamin D, antioxidant nutrients and long-chain polyunsaturated fatty acids. In particular, there is substantial evidence to support the roles of dietary protein and physical activity as key anabolic stimuli for muscle protein synthesis. However, much of the evidence is observational and from high-income countries. Further high-quality trials, particularly from more diverse populations, are needed to enable an understanding of dose and duration effects of individual nutrients on function, to elucidate mechanistic links, and to define optimal profiles and patterns of nutrient intake for older adults.

Dietary Protein in Older Adults: Adequate Daily Intake but Potential for Improved Distribution

Daily distribution of dietary protein may be important in protecting against sarcopenia, specifically in terms of per meal amounts relative to a proposed threshold for maximal response. The aims of this study were to determine total and per meal protein intake in older adults, as well as identifying associations with physical activity and sedentary behavior. Three-day food diaries recorded protein intake in 38 participants. Protein distribution, coefficient of variation (CV), and per meal amounts were calculated. Accelerometry was used to collect physical activity data as well as volume and patterns of sedentary time. Average intake was 1.14 g·kg-1·day-1. Distribution was uneven (CV = 0.67), and 79% of participants reported <0.4 g·kg-1 protein content in at least 2/3 daily meals. Protein intake was significantly correlated with step count (r = 0.439, p = 0.007) and negatively correlated with sedentary time (r = -0.456, p = 0.005) and Gini index G, which describes the pattern of accumulation of sedentary time (r = -0.421, p = 0.011). Total daily protein intake was sufficient; however, distribution did not align with the current literature; increasing protein intake may help to facilitate optimization of distribution. Associations between protein and other risk factors for sarcopenia may also inform protective strategies.

Fruit and Vegetable Intake and Hip Fracture Incidence in Older Men and Women: The CHANCES Project

The role of fruit and vegetable intake in relation to fracture prevention during adulthood and beyond is not adequately understood. We investigated the potential association between fruit and vegetable intake and hip fracture incidence in a large sample of older adults from Europe and the United States. A total of 142,018 individuals (116,509 women) aged ≥60 years, from five cohorts, were followed up prospectively for 1,911,482 person-years, accumulating 5552 hip fractures. Fruit and vegetable intake was assessed by validated, cohort-specific, food-frequency questionnaires (FFQ). Ηip fractures were ascertained through national patient registers or telephone interviews/questionnaires. Adjusted hazard ratios (HRs) derived by Cox proportional hazards regression were estimated for each cohort and subsequently pooled using random effects meta-analysis. Intake of ≤1 serving/day of fruit and vegetables combined was associated with 39% higher hip fracture risk (pooled adjusted HR, 1.39; 95% confidence interval [CI], 1.20 to 1.58) in comparison with moderate intake (>3 and ≤5 servings/day) (pfor heterogeneity  = 0.505), whereas higher intakes (>5 servings/day) were not associated with lower risk in comparison with the same reference. Associations were more evident among women. We concluded that a daily intake of 1 or <1 servings of fruits and vegetables was associated with increased hip fracture risk in relation to moderate daily intakes. Older adults with such low fruit and vegetable consumption may benefit from raising their intakes to moderate amounts in order to reduce their hip fracture risk. © 2016 American Society for Bone and Mineral Research.

Considering the benefits of egg consumption for older people at risk of sarcopenia

Sarcopenia is an important health issue for older people. It is closely linked with frailty and malnutrition and can significantly reduce both health and quality of life for those affected. Sarcopenic decline in muscle mass can start as early as the fourth and fifth decade of life, so the maintenance of muscle mass throughout adulthood, through regular physical activity and a balanced diet, should be an important consideration in reducing the risk of sarcopenia in older age. Maintaining regular exercise throughout older age remains key to the treatment of sarcopenia, as does an adequate intake of nutrients, including high-quality protein and vitamin D. A significant proportion of older people fail to meet the recommended requirements for protein; it has also been suggested that the requirements in existing recommendations could be higher. Evidence is emerging that an adequate intake of protein at each meal may be required to optimise muscle synthesis in older people. Eggs are an inexpensive, widely available and easily digestible source of high-quality protein and contain a significant proportion of leucine, an amino acid that is important for muscle synthesis, as well as many other nutrients of significance for older people, including vitamin D and omega-3 fatty acids. For many older people, eggs are a familiar and acceptable protein food at breakfast and other meals. Encouraging both those approaching older age and older people to include eggs more frequently, as part of a healthy, balanced diet and in addition to physical activity, could help them maintain their muscle strength and function, thereby preserving their functional capacity and reducing morbidity, mortality and healthcare costs associated with sarcopenia.

Sarcopenic obesity and complex interventions with nutrition and exercise in community-dwelling older persons--a narrative review

One of the many threats to independent life is the age-related loss of muscle mass and muscle function commonly referred to as sarcopenia. Another important health risk in old age leading to functional decline is obesity. Obesity prevalence in older persons is increasing, and like sarcopenia, severe obesity has been consistently associated with several negative health outcomes, disabilities, falls, and mobility limitations. Both sarcopenia and obesity pose a health risk for older persons per se, but in combination, they synergistically increase the risk for negative health outcomes and an earlier onset of disability. This combination of sarcopenia and obesity is commonly referred to as sarcopenic obesity. The present narrative review reports the current knowledge on the effects of complex interventions containing nutrition and exercise interventions in community-dwelling older persons with sarcopenic obesity. To date, several complex interventions with different outcomes have been conducted and have shown promise in counteracting either sarcopenia or obesity, but only a few studies have addressed the complex syndrome of sarcopenic obesity. Strong evidence exists on exercise interventions in sarcopenia, especially on strength training, and for obese older persons, strength exercise in combination with a dietary weight loss intervention demonstrated positive effects on muscle function and body fat. The differences in study protocols and target populations make it impossible at the moment to extract data for a meta-analysis or give state-of-the-art recommendations based on reliable evidence. A conclusion that can be drawn from this narrative review is that more exercise programs containing strength and aerobic exercise in combination with dietary interventions including a supervised weight loss program and/or protein supplements should be conducted in order to investigate possible positive effects on sarcopenic obesity.

Prevention and optimal management of sarcopenia: a review of combined exercise and nutrition interventions to improve muscle outcomes in older people

The growing recognition of sarcopenia, the age-related loss of skeletal muscle mass and function, has highlighted the need to understand more about its etiology. Declines in muscle mass and strength are expected aspects of aging, but there is significant variability between individuals in rates of loss. Although some of these differences can be explained by fixed factors, such as sex, much of the remaining variation is unexplained. This has led to increasing interest in the influence of adult lifestyle, particularly in the effects of modifiable factors such as physical activity and diet, and in identifying intervention opportunities both to prevent and manage sarcopenia. A number of trials have examined the separate effects of increased exercise or dietary supplementation on muscle mass and physical performance of older adults, but less is known about the extent to which benefits of exercise training could be enhanced when these interventions are combined. In a comprehensive review of the literature, we consider 17 studies of older adults (≥65 years) in which combined nutrition and exercise interventions were used to increase muscle strength and/or mass, and achieve improvements in physical performance. The studies were diverse in terms of the participants included (nutritional status, degree of physical frailty), supplementation strategies (differences in nutrients, doses), exercise training (type, frequency), as well as design (duration, setting). The main message is that enhanced benefits of exercise training, when combined with dietary supplementation, have been shown in some trials – indicating potential for future interventions, but that existing evidence is inconsistent. Further studies are needed, particularly of exercise training combined with dietary strategies that increase intakes of a range of nutrients, as well as bioactive non-nutrients, to provide the evidence on which public health and clinical recommendations can be based.

Associations between food and beverage groups and major diet-related chronic diseases: an exhaustive review of pooled/meta-analyses and systematic reviews

Associations between food and beverage groups and the risk of diet-related chronic disease (DRCD) have been the subject of intensive research in preventive nutrition. Pooled/meta-analyses and systematic reviews (PMASRs) aim to better characterize these associations. To date, however, there has been no attempt to synthesize all PMASRs that have assessed the relationship between food and beverage groups and DRCDs. The objectives of this review were to aggregate PMASRs to obtain an overview of the associations between food and beverage groups (n = 17) and DRCDs (n = 10) and to establish new directions for future research needs. The present review of 304 PMASRs published between 1950 and 2013 confirmed that plant food groups are more protective than animal food groups against DRCDs. Within plant food groups, grain products are more protective than fruits and vegetables. Among animal food groups, dairy/milk products have a neutral effect on the risk of DRCDs, while red/processed meats tend to increase the risk. Among beverages, tea was the most protective and soft drinks the least protective against DRCDs. For two of the DRCDs examined, sarcopenia and kidney disease, no PMASR was found. Overweight/obesity, type 2 diabetes, and various types of cardiovascular disease and cancer accounted for 289 of the PMASRs. There is a crucial need to further study the associations between food and beverage groups and mental health, skeletal health, digestive diseases, liver diseases, kidney diseases, obesity, and type 2 diabetes.

Diet and its relationship to sarcopenia in community dwelling Iranian elderly: a cross sectional study

OBJECTIVES

Sarcopenia is associated with frailty and disability among the elderly and imposes significant costs on health care systems. We tested whether adherence to a particular dietary pattern was associated with sarcopenia among the elderly in a district of Tehran, Iran.

METHODS

We used a semiquantitative Food Frequency Questionnaire to assess the dietary intake of 300 randomly-selected elderly men and women (at least 55 y old) living in the sixth district of Tehran; and the dietary patterns of the subjects were obtained using principal component analysis. We performed a logistic regression to measure the effect of adherence to each dietary pattern on the odds of sarcopenia.

RESULTS

Subjects in the highest tertile of the Mediterranean dietary pattern, characterized by a higher consumption of olive oil, fruits, vegetables, fish, and nuts, had a lower odds ratio for sarcopenia than those in the lowest tertile (OR = 0.42; 95% CI = 0.18-0.97; P for trend = 0.04). In contrast, adherence to the Western dietary pattern, characterized by a high consumption of sugar, soy, and fast foods, was not associated with sarcopenia (OR = 0.51; 95% CI = 0.21-1.24; P for trend = 0.13). Similarly, adherence to the Mixed dietary pattern, characterized by a high consumption of animal proteins, potatoes, and refined grains, did not affect the odds of sarcopenia (OR = 1.45; 95% CI = 0.66-3.19; P for trend = 0.95).

CONCLUSIONS

This study suggests that adherence to the Mediterranean diet is associated with lower odds of sarcopenia among the Iranian elderly.

Muscle changes in aging: understanding sarcopenia

Muscle physiology in the aging athlete is complex. Sarcopenia, the age-related decrease in lean muscle mass, can alter activity level and affect quality of life. This review addresses the microscopic and macroscopic changes in muscle with age, recognizes contributing factors including nutrition and changes in hormone levels, and identifies potential pharmacologic agents in clinical trial that may aid in the battle of this complex, costly, and disabling problem.

LEVEL OF EVIDENCE

Level 5.

Nutritional influences on age-related skeletal muscle loss

Age-related muscle loss impacts on whole-body metabolism and leads to frailty and sarcopenia, which are risk factors for fractures and mortality. Although nutrients are integral to muscle metabolism the relationship between nutrition and muscle loss has only been extensively investigated for protein and amino acids. The objective of the present paper is to describe other aspects of nutrition and their association with skeletal muscle mass. Mechanisms for muscle loss relate to imbalance in protein turnover with a number of anabolic pathways of which the mechanistic TOR pathway and the IGF-1–Akt–FoxO pathways are the most characterised. In terms of catabolism the ubiquitin proteasome system, apoptosis, autophagy, inflammation, oxidation and insulin resistance are among the major mechanisms proposed. The limited research associating vitamin D, alcohol, dietary acid–base load, dietary fat and anti-oxidant nutrients with age-related muscle loss is described. Vitamin D may be protective for muscle loss; a more alkalinogenic diet and diets higher in the anti-oxidant nutrients vitamin C and vitamin E may also prevent muscle loss. Although present recommendations for prevention of sarcopenia focus on protein, and to some extent on vitamin D, other aspects of the diet including fruits and vegetables should be considered. Clearly, more research into other aspects of nutrition and their role in prevention of muscle loss is required.