Optimal protein intake in the elderly

Possible Benefits of a Low Protein Diet in Older Patients With CKD at Risk of Malnutrition: A Pilot Randomized Controlled Trial

BACKGROUND

Current guidelines do not clarify whether older patients with advanced chronic kidney disease (CKD) may benefit of low protein (LP) diet if they are at risk of malnutrition. We compared the effects of normocalorie/normoprotein (NP) and normocalorie/LP diet on nutritional status and metabolic complications related to the progression of kidney damage in these patients.

METHODS

This pilot study had an open-label randomized-controlled design (ClinicalTrials.gov Id: NCT05015647). Thirty-five patients were treated for 6 months with two different diets (LP = 17) and (NP = 18). Malnutrition was assessed by the Malnutrition Inflammation Score and International Society of Renal Nutrition and Metabolism criteria. Renal function was assessed by creatinine and cystatin-C-based estimated glomerular filtration rate (eGFR).

RESULTS

At the end of the study, Malnutrition Inflammation Score was improved in both LP and NP groups (respectively: 3 ± 3 vs. 6 ± 1.5, p = 0.020 and 3 ± 2.5 vs. 6 ± 2, p = 0.012), prevalence of protein energy wasting syndrome decreased only in LP. LP group had higher eGFRcys-C (17 ± 6 vs. 12 ± 4 ml/min/1.73 m2; p < 0.05), lower serum urea (105 ± 65 vs. 138 ± 30 mg/dl; p < 0.05) and lower parathormone (68 ± 10 vs. 99 ± 61 ng/L; p < 0.05) than NP. Serum and urinary phosphorous did not change while fibroblast growth factor 23 (FGF23)-intact and FGF23 c-terminal increased in both groups [FGF23-intact in LP: 70 (48; 98) vs. 126 (90; 410) pg/ml, p < 0.01 and in NP: 86 (57; 194) vs. 143 (119; 186) pg/ml, p < 0.01; FGF23 c-terminal in LP: 77 (30.3; 112) vs. 111 (63; 384) RU/ml, p < 0.01 and in NP: 142 (56.6; 175) vs. 157 (76.7; 281) RU/ml, p < 0.01].

CONCLUSIONS

LP diet has a favorable impact on nutritional status as much as NP diet with possible greater benefits on the progression of kidney disease and some of its metabolic complications.

CLINICAL TRIAL REGISTRATION

https://clinicaltrials.gov/ct2/show/NCT05015647, identifier: NCT05015647.

Older American Women May Especially Benefit from Distributing and Consuming Protein for Decreasing Odds of Functional Limitations

OBJECTIVES

Protein is a key macronutrient for preserving physical function, but the role of protein intake on functional status may differ in men and women. We sought to examine the associations of daily protein intake and distribution on functional limitations in older American men and women.

DESIGN

Cross-sectional.

SETTING

Population-based survey.

PARTICIPANTS

The analytic sample included 3,976 men and 4,081 women aged ≥60-years from the 2007-2016 waves of the National Health and Nutrition Examination Survey.

MEASUREMENTS

Participants reported their ability to perform basic activities of daily living, instrumental activities of daily living, leisure and social activities, lower extremity mobility activities, and general physical tasks. Those reporting difficulty or an inability in completing such functional tasks were considered as having a functional limitation. Protein intake was determined with dietary recalls and participants revealed functional limitations. Protein recommendations of ≥0.80, ≥1.00, and ≥1.50 g/kg/day were used. Based on these cut-points, we also investigated distribution of protein across 4 eating occasions at ≥0.20, ≥0.25, and ≥0.38 g/kg/meal, respectively.

RESULTS

Older women meeting each recommendation had decreased odds for functional limitations: 0.55 (95% confidence interval (CI): 0.40-0.75) for ≥0.80 g/kg/day, 0.75 (CI: 0.58-0.97) for ≥1.00 g/kg/day, and 0.72 (CI: 0.55-0.94) for ≥1.5 g/kg/day. No significant associations were observed in older men. Further, older women with protein consumption ≥0.20 g/kg/meal had decreased odds for functional limitations: 0.24 (CI: 0.10-0.61) for 1 occasion, 0.20 (CI: 0.08-0.49) for 2 occasions, 0.16 (CI: 0.07-0.40) for 3 occasions, and 0.12 (CI: 0.04-0.32) for 4 occasions. A similar trend was observed for intake ≥0.25 g/kg/meal: 0.31 (CI: 0.16-0.62) for 2 occasions, 0.30 (CI: 0.14-0.61) for 3 occasions, and 0.31 (CI: 0.12-0.78) for 4 occasions. Women with 1 and 2 eating occasions at ≥0.38 g/kg/meal of protein had 0.66 (CI: 0.48-0.91) and 0.54 (CI: 0.37-0.79) decreased odds for functional limitations, respectively.

CONCLUSION

Trials that are powered to detect the effects of protein on functional status in women will help to establish causality.

Association Between Fish Consumption and Muscle Mass and Function in Middle-Age and Older Adults

Background: Sarcopenia, the age-related loss of skeletal muscle mass and function, represents a crucial risk factor for disability and mortality. Increasing intake of some nutrients, particularly protein and omega-3 fatty acids seems to be a promising strategy to augment muscle mass and function.

Objective: The purpose of this study was to assess the beneficial effects of fish consumption on muscle mass and function among middle-age and older adults.

Methods: Twenty-two adults aged 50–85 years participated in this study. Participants were asked to consume 150–170-g of fish for lunch twice a week for a 10-week period. During that period, participants were asked to maintain their normal diet and physical activity. Outcome measures included anthropometry, muscle mass, and muscle function. All these measures were assessed at baseline, week 5, and week 10. Repeated-measures analysis of variance was used to analyze statistical significance.

Results: Consuming fish twice a week for 10 weeks significantly increased the skeletal muscle mass and appendicular lean mass divided by height squared (ALM/h²) (p < 0.01). Handgrip strength and gait speed <0.8 m/s were also improved (p < 0.01) at week 10 compared with that at baseline.

Discussion: Consuming fish seems to improve muscle mass and function and may slow sarcopenia progression in middle-age and older adults.

Adding Flavours: Use of and Attitudes towards Sauces and Seasonings in a Sample of Community-Dwelling UK Older Adults

Adding flavours can encourage food intake in older adults for health benefits. The use and attitudes of 22 community-dwelling UK older adults (15 females, aged 65–83 years) towards foods and products that add flavour, e.g., sauces and seasonings, were investigated. Participants used foods/products to add flavour when cooking and eating from 0 to 17 times/day. Taste and flavour were important, and foods/products could add flavour, make foods more pleasant and did not cause discomfort. There were concerns, however, over the healthiness of some foods/products, while consuming a healthy diet and one’s health were important. Reasons for adding flavours largely centred around ‘meal enhancement’, reasons for not adding flavours focused on ‘the product itself’ and ‘characteristics of the meal’, but there was ‘variation’ and many ‘individual differences’. Our findings highlight the benefits of adding flavours for food intakes, particularly the use of naturally flavoursome foods, such as herbs, spices, onion and garlic.

Effect of Dietary Protein Intake on Bone Mineral Density and Fracture Incidence in Older Adults in the Health, Aging, and Body Composition Study

BACKGROUND

Dietary recommendations may underestimate the protein older adults need for optimal bone health. This study sought to determine associations of protein intake with bone mineral density (BMD) and fracture among community-dwelling White and Black older adults.

METHOD

Protein as a percentage of total energy intake (TEI) was assessed with a Food Frequency Questionnaire in 2160 older adults (73.5 ± 2.8 years; 51.5% women; 35.8% Black) in the Health, Aging, and Body Composition prospective cohort. Hip, femoral neck, and whole body BMD was assessed by dual-energy x-ray absorptiometry at baseline and 4 years, and lumbar trabecular, cortical, and integral BMD was assessed by computed tomography at baseline and 5 years. Fragility fractures over 5 years were adjudicated from self-report data collected every 6 months. Associations with tertiles of protein intake were assessed using analysis of covariance for BMD and multivariate Cox regression for fracture, adjusting for confounders.

RESULTS

Participants in the upper protein tertile (≥15% TEI) had 1.8%-6.0% higher mean hip and lumbar spine BMD compared to the lower protein tertile (<13% TEI; p < .05). Protein intake did not affect change in BMD at any site over the follow-up period. Participants in the upper protein tertile had a reduced risk of clinical vertebral fracture over 5 years of follow-up (hazard ratio: 0.36 [95% confidence interval: 0.14, 0.97] vs lower protein tertile, p = .04).

CONCLUSIONS

Older adults with higher protein intake (≥15% TEI) had higher BMD at the hip, whole body, and lumbar spine, and a lower risk of vertebral fracture.

Improved Healing after Non-Surgical Periodontal Therapy Is Associated with Higher Protein Intake in Patients Who Are Non-Smokers

The aim of this study was to determine whether a relationship between periodontal healing and protein intake exists in patients undergoing non-surgical treatment for periodontitis. Dietary protein intake was assessed using the 2005 Block food frequency questionnaire in patients with chronic generalized periodontitis undergoing scaling and root planing (n = 63 for non-smokers, n = 22 for smokers). Protein intake was correlated to post-treatment probing depth using multiple linear regression. Non-smoking patients who consumed ≥1 g protein/kg body weight/day had fewer sites with probing depth ≥ 4 mm after scaling and root planing compared to patients with intakes <1 g protein/kg body weight/day (11 ± 2 versus 16 ± 2, p = 0.05). This relationship was strengthened after controlling for baseline probing depth, hygienist and time between treatment and follow-up (10 ± 2 versus 16 ± 1, p = 0.018) and further strengthened after controlling for potential confounders including age, sex, body mass index, flossing frequency, and bleeding on probing (8 ± 2 versus 18 ± 2, p < 0.001). No associations were seen in patients who smoked. Consuming ≥1 g protein/kg body weight/day was associated with reductions in periodontal disease burden following scaling and root planing in patients who were non-smokers. Further studies are needed to differentiate between animal and plant proteins.

Effect of parenteral energy or amino acid doses on in-hospital mortality, among patients with aspiration pneumonia: a cohort medical claims database study

Background

This study examined the association between parenteral energy/amino acid doses and in-hospital mortality among inpatients on long-term nil per os (NPO) status, using a medical claims database in Japan.

Methods

Hospitalized patients with aspiration pneumonia, aged 65 and older, and on more than 7-day NPO status were identified in a medical claims database between January 2013 and December 2018. Using multivariate logistic regression and regression analyses, we examined the association between mean parenteral energy/amino acid doses and in-hospital mortality, and secondarily, the association between prognosis (in-hospital mortality, inability to receive full oral intake, readmission, and hospital stay length) and 4 groups of mean amino acid doses (no dose: 0 g/kg/day; very low dose: >0, ≤0.3 g/kg/day; low dose: >0.3, ≤0.6 g/kg/day; moderate dose: >0.6 g/kg/day).

Results

The analysis population included 20 457 inpatients (≥80 years: 78.3%). In total, 5 920 mortalities were recorded. Increased amino acid doses were significantly associated with reduced in-hospital mortality (p < .001). With a no dose reference level, the odds ratios (95% confidence interval) of in-hospital mortality adjusted for potential confounders were 0.78 (0.72–0.85), 0.74 (0.67–0.82), and 0.69 (0.59–0.81) for very low, low, and moderate amino acid doses, respectively. Additionally, patients prescribed amino acid dose levels more than 0.6 g/kg/day had shorter hospitalization periods than those prescribed none.

Conclusions

Increased amino acid doses were associated with reduced in-hospital mortality. Sufficient amino acid administration is recommended for patients with aspiration pneumonia requiring NPO status.

Sarcopenia; functional concerns, molecular mechanisms involved, and seafood as a nutritional intervention - review article

The fundamental basis for the human function is provided by skeletal muscle. Advancing age causes selective fiber atrophy, motor unit loss, and hybrid fiber formation resulting in hampered mass and strength, thus referred to as sarcopenia. Influence on the loss of independence of aged adults, contribute toward inclined healthcare costs conveys the injurious impact. The current understating of age-related skeletal muscle changes are addressed in this review, and further discusses mechanisms regulating protein turnover, although they do not completely define the process yet. Moreover, the reduced capacity of muscle regeneration due to impairment of satellite cell activation and proliferation with neuronal, immunological, hormonal factors were brought into the light of attention. Nevertheless, complete understating of sarcopenia requires disentangling it from disuse and disease. Nutritional intervention is considered a potentially preventable factor contributing to sarcopenia. Seafood is a crucial player in the fight against hunger and malnutrition, where it consists of macro and micronutrients. Hence, the review shed light on seafood as a nutritional intrusion in the treatment and prevention of sarcopenia. Understanding multiple factors will provide therapeutic targets in the prevention, treatment, and overcoming adverse effects of sarcopenia.

Approach to Obesity in the Older Population

Until recently, weight loss in older obese people was feared because of ensuing muscle loss and frailty. Facing overall increasing longevity, high rates of obesity in older individuals (age ≥ 65 years) and a growing recognition of the health and functional cost of the number of obesity years, abetted by evidence that intentional weight loss in older obese people is safe, this approach is gradually, but not unanimously, being replaced by more active principles. Lifestyle interventions that include reduced but sufficient energy intake, age-adequate protein and micronutrient intake, coupled with aerobic and resistance exercise tailored to personal limitations, can induce weight loss with improvement in frailty indices. Sustained weight loss at this age can prevent or ameliorate diabetes. More active steps are controversial. The use of weight loss medications, particularly glucagon-like peptide-1 analogs (liraglutide as the first example), provides an additional treatment tier. Its safety and cardiovascular health benefits have been convincingly shown in older obese patients with type 2 diabetes mellitus. In our opinion, this option should not be denied to obese individuals with prediabetes or other obesity-related comorbidities based on age. Finally, many reports now provide evidence that bariatric surgery can be safely performed in older people as the last treatment tier. Risk-benefit issues should be considered with extreme care and disclosed to candidates. The selection process requires good presurgical functional status, individualized consideration of the sequels of obesity, and reliance on centers that are highly experienced in the surgical procedure as well as short-term and long-term subsequent comprehensive care and support.

Protein quality of a probiotic beverage enriched with pea and rice protein

The aim of this study was to evaluate the effect of the fermentation of a probiotic beverage enriched with pea and rice proteins (PRF) on its protein quality. The protein quality was determined as the protein efficiency ratio (PER), net protein ratio (NPR), and the apparent (AD) and the true digestibility (TD) evaluated in vivo. The probiotic beverage was incorporated to a rat diet at a final concentration of 10% protein, for the evaluation of the PER, the NPR, the AD, and the TD. The protein digestibility amino acid score was also calculated. Results showed that the fermentation of beverage enriched with PRF had no effect on the TD but significantly increased the PER and the NPR (P ≤ 0.05) from 1.88 to 2.32 and from 1.66 to 2.30, respectively. Thus, the fermentation increased the protein quality of the PRF probiotic beverage. In addition, to determine if the beverage constitute in a good carrier matrix for the probiotics, the level of alive probiotics in the feces was evaluated and showed a concentration of 7.4 log CFU/g. PRACTICAL APPLICATION: Plant proteins are often of lower quality compared to animal proteins. Lactic acid fermentation of pea and rice protein has allowed to reach the same protein quality as casein. A plant-based fermented beverage with high protein quality and enriched with probiotics was developed.

Impact of preoperative nutritional support and rehabilitation therapy in patients undergoing pancreaticoduodenectomy

BACKGROUND

Sarcopenia is closely associated with morbidity after pancreatic surgery. We investigated the impact of preoperative nutritional support and rehabilitation on patients undergoing pancreaticoduodenectomy.

METHODS

This was a retrospective analysis of 101 patients who underwent pancreaticoduodenectomy. Skeletal muscle (SM) loss was defined using the SM index (cutoff level: 42 cm²/m² in men and 38 cm²/m² in women). A total of 33 and 30 patients received preoperative nutrition and prehabilitation, respectively. The neutrophil-to-lymphocyte ratio (NLR), Prognostic Nutritional Index (PNI), and modified Glasgow Prognostic Score (mGPS) values were calculated during the first visit and immediately before surgery.

RESULTS

SM loss was present in 65 of 101 patients and was significantly correlated with female sex, older age, lower body mass index, and low PNI. Preoperative nutritional support and prehabilitation prevented the decrease in PNI values in patients with SM loss. The NLR significantly improved in patients with SM loss who received nutritional support and prehabilitation. In patients with SM loss, the lack of preoperative nutrition and prehabilitation was an independent risk factor for postoperative pancreatic fistula.

CONCLUSIONS

Preoperative nutritional support and prehabilitation may reduce the incidence of pancreatic fistula in patients with SM loss and improve the surgical outcomes of patients undergoing pancreaticoduodenectomy.

Metabolic Evaluation of the Dietary Guidelines' Ounce Equivalents of Protein Food Sources in Young Adults: A Randomized Controlled Trial

BACKGROUND

The Dietary Guidelines for Americans (DGAs) published an "ounce equivalents" recommendation to help consumers meet protein requirements with a variety of protein food sources. However, the metabolic equivalency of these varied protein food sources has not been established.

OBJECTIVE

We have investigated the hypothesis that the anabolic responses to consumption of ounce equivalents of protein food sources would be directly related to the essential amino acid (EAA) content of the protein food source.

METHODS

Following 3 d of dietary control, a total of 56 healthy young adults underwent an 8.5-h metabolic study using stable isotope tracer methodology. The changes from baseline following consumption of 1 of 7 different protein food sources were compared with the baseline value for that individual (n = 8 per group).

RESULTS

Consumption of ounce equivalents of animal-based protein food sources (beef sirloin, pork loin, eggs) resulted in a greater gain in whole-body net protein balance above baseline than the ounce equivalents of plant-based protein food sources (tofu, kidney beans, peanut butter, mixed nuts; P < 0.01). The improvement in whole-body net protein balance was due to an increase in protein synthesis (P < 0.05) with all the animal protein sources, whereas the egg and pork groups also suppressed protein breakdown compared with the plant protein sources (P < 0.01). The magnitude of the whole-body net balance (anabolic) response was correlated with the EAA content of the protein food source (P < 0.001).

CONCLUSION

The "ounce equivalents" of protein food sources as expressed in the DGAs are not metabolically equivalent in young healthy individuals. The magnitude of anabolic response to dietary proteins should be considered as the DGAs develop approaches to establish healthy eating patterns.

Offspring migration and nutritional status of left-behind older adults in rural China

Improvements in nutritional status is a principal pathway to good health. This study examines the effect of migration of adult children on the nutrient intake of left-behind older adults in rural China. We use data from four waves (2004-2011) of the China Health and Nutrition Survey and utilize individual fixed effects methods to panel data. Results show that the migration of offspring is associated with significantly higher nutritional status of their left-behind parents, especially higher intake of proteins, carbohydrates, vitamins B1-B3, phosphorus, magnesium, iron, selenium, and copper. The intake of some of these nutrients is below recommended levels. The magnitude of the estimated effects vary between 4% and 24 %. Older adults who live with their grandchildren in rural households or have a low income benefit more from having adult child migrants in the household. The improvement of nutrition outcomes of left-behind older adults is mainly due to increased consumption of cereals, meat, eggs, and fish.

High Frequency Protein-Rich Meal Service to Promote Protein Distribution to Stimulate Muscle Function in Preoperative Patients

Apart from meeting daily protein requirements, an even distribution of protein consumption is proposed instrumental to optimizing protein muscle synthesis and preserving muscle mass. We assessed whether a high frequency protein-rich meal service for three weeks contributes to an even daily protein distribution and a higher muscle function in pre-operative patients. This study was a post-hoc analysis of a randomized controlled trial (RCT) in 102 patients. The intervention comprised six protein-rich dishes per day. Daily protein distribution was evaluated by a three-day food diary and muscle function by handgrip strength before and after the intervention. Protein intake was significantly higher in the intervention group at the in-between meals in the morning (7 ± 2 grams (g) vs. 2 ± 3 g, p < 0.05) and afternoon (8 ± 3 g vs. 2 ± 3 g, p < 0.05). Participants who consumed 20 g protein for at least two meals had a significantly higher handgrip strength compared to participants who did not. A high frequency protein-rich meal service is an effective strategy to optimize an even protein distribution across meals throughout the day. Home-delivered meal services can be optimized by offering more protein-rich options such as dairy or protein supplementation at breakfast, lunch and prior to sleep for a better protein distribution.

High protein diet improves the overall survival in older adults with advanced gastrointestinal cancer

BACKGROUND

High protein diet (HDP) promotes improvement of lean body mass in elderly without cancer; but the impact of high protein intake on muscle strength and mortality in cancer patients remains to be elucidated. This study evaluates the association between HPD on handgrip strength (HGS) and survival in older adults outpatients with advanced gastrointestinal cancer.

METHODS

Ninety-one patients with advanced gastrointestinal cancer (>65% tumor stage III-IV) undergoing radiotherapy, chemotherapy or surgery were enrolled. Upon first oncological visit, tumor stage was assessed by a physician. Then, a nutritionist or a dietitian measured the body mass index (BMI), HGS by means of a dynamometer, and dietary food intake by using 24h food recall. Patients were stratified in HPD (i.e, ≥1.5 g/kg/d) or low protein diet (LPD: <1.5 g/kg/d). Kaplan-Meier curve was used to assess the survival since the cancer diagnosis.

RESULTS

HPD was reported by approximately 30% of patients. Protein intake was significantly higher in HPD vs LPD patients (2.2 ± 0.8 vs. 0.8 ± 0.4 g/kg/d, respectively; p < 0.0001). No significant association was found between HPD and HGS, even after adjustment for physical activity, alcohol intake, smoking, sex, age, tumor stage, oncologic treatment and BMI (OR: 0.97 [95%CI: 0.88-1.08], p = 0.64), or for energy intake kcal/kg/day, leucine g/d and lipids g/d (OR: 0.93 [95%CI: 0.85-1.03, p = 0.19]. In addition, HPD group showed higher overall survival than LPD group (HPD: 14.7 vs. LPD: 7.3 months, p = 0.04).

CONCLUSION

HPD is not associated with better muscle function as measured by HGS, but with overall survival in older adults outpatients with advanced gastrointestinal cancer. HPD may represent a strategy to mitigate the cancer-induced mortality and should be further explored.

Immunological Endotyping of Chronic Critical Illness After Severe Sepsis

Improved management of severe sepsis has been one of the major health care accomplishments of the last two decades. Due to enhanced recognition and improved management of severe sepsis, in-hospital mortality has been reduced by up to 40%. With that good news, a new syndrome has unfortunately replaced in-hospital multi-organ failure and death. This syndrome of chronic critical illness (CCI) includes sepsis patients who survive the early "cytokine or genomic storm," but fail to fully recover, and progress into a persistent state of manageable organ injury requiring prolonged intensive care. These patients are commonly discharged to long-term care facilities where sepsis recidivism is high. As many as 33% of sepsis survivors develop CCI. CCI is the result, at least in part, of a maladaptive host response to chronic pattern-recognition receptor (PRR)-mediated processes. This maladaptive response results in dysregulated myelopoiesis, chronic inflammation, T-cell atrophy, T-cell exhaustion, and the expansion of suppressor cell functions. We have defined this panoply of host responses as a persistent inflammatory, immune suppressive and protein catabolic syndrome (PICS). Why is this important? We propose that PICS in survivors of critical illness is its own common, unique immunological endotype driven by the constant release of organ injury-associated, endogenous alarmins, and microbial products from secondary infections. While this syndrome can develop as a result of a diverse set of pathologies, it represents a shared outcome with a unique underlying pathobiological mechanism. Despite being a common outcome, there are no therapeutic interventions other than supportive therapies for this common disorder. Only through an improved understanding of the immunological endotype of PICS can rational therapeutic interventions be designed.

Evenness of dietary protein distribution is associated with higher muscle mass but not muscle strength or protein turnover in healthy adults: a systematic review

PURPOSE

Age-related decrease in muscle mass is, among several other factors, caused by suboptimal dietary protein intake. The protein intake of the general population has a skewed distribution towards the evening meal. However, it is hypothesised that an intake of protein with an even meal distribution leads to a more frequently maximised protein synthesis. This review investigates whether an even protein distribution is associated with preservation or gain in muscle mass, muscle strength, and protein turnover.

METHODS

Seven databases: PubMed, Web of Science, Google Scholar, CINAHL, Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, and Embase were searched. Studies included had a healthy population between 20 and 85 years of age, with a BMI between 18.5 and 30.0, investigated even vs. skewed protein distribution, and measured skeletal muscle relevant outcomes. Case studies and systematic reviews were excluded. Studies were appraised using the AXIS scale for observational studies and the PEDro scale for the remaining studies.

RESULTS

Fifteen studies met the eligibility criteria and were included. Three out of seven studies showed an association between even protein distribution and higher muscle mass. Two out of seven studies showed an association between greater muscle strength and an even protein distribution. Only one out of six studies found a positive association between protein synthesis and an even protein distribution.

CONCLUSION

Evidence indicated an association between muscle mass and an even protein intake. However, the evidence is currently insufficient to conclude whether an even protein intake is positively associated with muscle strength or protein turnover.

Milk proteins and their derived peptides on bone health: Biological functions, mechanisms, and prospects

Bone is a dynamic organ under constant metabolism (or remodeling), where a delicate balance between bone resorption and bone formation is maintained. Disruption of this coordinated bone remodeling results in bone diseases, such as osteoporosis, the most common bone disorder characterized by decreased bone mineral density and microarchitectural deterioration. Epidemiological and clinical evidence support that consumption of dairy products is beneficial for bone health; this benefit is often attributed to the presence of calcium, the physiological contributions of milk proteins on bone metabolism, however, are underestimated. Emerging evidence highlighted that not only milk proteins (including individual milk proteins) but also their derived peptides positively regulate bone remodeling and attenuate bone loss, via the regulation of cellular markers and signaling of osteoblasts and osteoclasts. This article aims to review current knowledge about the roles of milk proteins, with an emphasis on individual milk proteins, bioactive peptides derived from milk proteins, and effect of milk processing in particular fermentation, on bone metabolism, to highlight the potential uses of milk proteins in the prevention and treatment of osteoporosis, and, to discuss the knowledge gap and to recommend future research directions.

Potential Beneficial Effects of Dietary Protein Supplementation and Exercise on Functional Capacity in a Pilot Study of Individuals with Heart Failure with Preserved Ejection Fraction

Approximately half of heart failure patients in the US have heart failure with preserved ejection fraction (HFpEF). HFpEF impairs physical performance and thus reduces quality of life. Increasing dietary protein intake can increase lean body mass and physical performance in healthy elderly individuals, but the effect of a high-quality protein supplement, with or without a structured exercise program, has not been investigated in HFpEF patients. Twenty-three obese elderly HFpEF patients with grade 1 or 2 diastolic dysfunction were randomized into three groups: control, protein supplementation alone, and protein plus exercise. Protein supplementation involved providing sufficient whey protein so that total intake was 1.2 g protein/kg/day. The exercise intervention was 2 days of hydrotherapy and 1 day of gym sessions per week under supervision of a fitness expert. Physical parameters and functional tests were performed at baseline and at 12 weeks. Protein supplementation alone failed to improve physical performance. However, when combined with light exercise, there was significant improvement in some (6-minute walk, 10 m walking speed, quadriceps strength), but not all, physical function measurements. The results of this pilot study suggest that further exploration of potential interactive effects between protein supplementation and light exercise in individuals with HFpEF is warranted.

Factors associated with measures of sarcopenia in pre and postmenopausal women

BACKGROUND

Menopause associated low serum estradiol marks varieties of derangements in muscle mass and functions leading to sarcopenia. This cross-sectional study was carried out to examine the factors associated with measures of sarcopenia; skeletal muscle mass (SMM), muscle strength and physical performance (PP) in a group of premenopausal (PrMW) and postmenopausal women (PMW) selected from Sri Lanka.

METHODS

Randomly selected 184 PrMW and 166 PMW from Galle district, Sri Lanka were studied. SMM was measured with duel energy X ray absorptiometry and relative appendicular SMM index (RSMI; kg/m2) was calculated. Other measurements made include handgrip strength (HGS; kg) and gait speed (GS; m/s), anthropometric indices, consumption of macro and micronutrients, and pattern of physical activities (PA). A serum sample was analyzed for fasting insulin, serum estradiol and vitamin D. Variables which significantly correlated with RSMI, HGS and GS of PrMW and PMW were separately entered into multiple linear regression models to extract the associated factors.

RESULTS

Mean (SD) age of PrMW and PMW were 42.4 (6.0) and 55.8 (3.8) years respectively. In the regression analysis, RSMI in PrMW showed significant associations with body mass index (BMI), HGS, total-body-fat-mass (TBFM) and weight (adjusted R2 = 0.85) and in PMW with BMI, weight, TBFM, hip-circumference and fasting insulin (adjusted R2 = 0.80). BMI showed the strongest association with RSMI in both PrMW (r = 0.87, R2 = 0.76) and in PMW (r = 0.87, R2 = 0.76). HGS in PrMW showed significant associations with appendicular SMM (ASMM), total-body-bone-mineral-content, vigorous PA score, age and weight (adjusted R2 = 0.33) and in PMW with ASMM and height (adjusted R2 = 0.23). ASMM showed the strongest association with HGS in both PrMW (r = 0.44, R2 = 0.20) and PMW (r = 0.44, R2 = 0.20). GS in PrMW showed significant associations with height, BMI and energy consumption (adjusted R2 = 0.13) while in PMW, with carbohydrate consumption and total-body-bone-mineral-density (adjusted R2 = 0.09). While in PrMW, height showed the strongest association with GS (r = 0.28, R2 = 0.08) in PMW, it was carbohydrate consumption (r = 0.24, R2 = 0.06).

CONCLUSIONS

Factors that are associated with different measures of sarcopenia are not uniform and vary widely from anthropometry to nutrient intake indicating that these measures are somewhat independent and are governed by different factors.

The efficacy of essential amino acid supplementation for augmenting dietary protein intake in older adults: implications for skeletal muscle mass, strength and function

The primary aim of this review is to evaluate the efficacy of essential amino acid (EAA) supplementation as a strategy to increase dietary protein intake and improve muscle mass, strength and function in older adults. A sufficient daily protein intake is widely recognised to be fundamental for the successful management of sarcopenia in older undernourished adults. In practice, optimising protein intakes in older adults is complex, requiring consideration of the dose and amino acid composition (i.e. a complete EAA profile and abundant leucine content) of ingested protein on a per meal basis, alongside the age-related decline in appetite and the satiating properties of protein. Recent studies in older adults demonstrate that EAA-based supplements are non-satiating and can be administered alongside food to enhance the anabolic properties of a meal containing a suboptimal dose of protein; an effect magnified when combined with resistance exercise training. These findings support the notion that EAA supplementation could serve as an effective strategy to improve musculoskeletal health in older adults suffering from non-communicable diseases such as sarcopenia. Compliance is critical for the long-term success of complex interventions. Hence, aspects of palatability and desire to eat are important considerations regarding EAA supplementation. In conclusion, EAA-based supplements enriched with l-leucine offer an alternative strategy to whole protein sources to assist older adults in meeting protein recommendations. In practice, EAA supplements could be administered alongside meals of suboptimal protein content, or alternatively between meals on occasions when older adults achieve their per meal protein intake recommendations.

Nutrition and Weight Management in the Elderly

"Aging alters the way the body digests food, absorbs nutrients, and metabolizes energy. Changes in deglutition, digestion, and metabolism in this population are well described and may lead to alterations in oral intake, body composition, and overall health status. Elderly persons are at high risk for developing sarcopenia as well as sarcopenic obesity characterized by accelerated reduction in lean muscle mass and enhancement of body fat. Nutritional screening is important to identify high-risk individuals and facilitate care management planning. The most common assessment tool in elderly patients is the Mini Nutritional Assessment, which analyzes oral intake, health status, and anthropometrics."

The Anabolic Response to Dietary Protein Is Not Limited by the Maximal Stimulation of Protein Synthesis in Healthy Older Adults: A Randomized Crossover Trial

We have recently demonstrated in young adults that an anabolic response with mixed meal protein intake above ~35 g/meal, previously recognized as an "optimal" protein dose, was further stimulated. However, it is unknown if this applies to older adults. We therefore examined anabolic response to a mixed meal containing either 35 g (MOD, moderate amount of protein) or 70 g (HIGH, high amount of protein) in a randomized cross-over metabolic study in older adults (n = 8). Primed continuous infusions of L-[²H₅] phenylalanine and L-[²H₂]tyrosine were performed to determine whole-body protein kinetics and muscle protein fractional synthesis rate (MPS) in basal fasted and fed states. Whole-body protein kinetics (NB, net protein balance; PS, protein synthesis; PB, protein breakdown) and MPS was expressed as changes from the baseline post-absorptive state. Consistent with our previous findings in young adults, both feedings resulted in a positive NB, with HIGH being more positive than MOD. Furthermore, NB (expressed as g protein∙240 min) increased linearly with an increasing amount of protein intake, expressed relative to lean body mass. The positive NB was achieved due mainly to the suppression of PB in both MOD and to a greater extent HIGH, while PS was only increased in HIGH. Consistent with the whole-body data, MPS was significantly higher in HIGH than MOD. Plasma concentrations of essential amino acids and insulin were greater in HIGH vs. MOD. We conclude that in the context of mixed meals, whole-body anabolic response linearly increases with increasing protein intake primarily through the suppression of PB, and MPS was further stimulated with protein intake above the previously considered "optimal" protein dose in older adults.

Cachexia, muscle wasting, and frailty in cardiovascular disease

The last several years have seen increasing interest in understanding cachexia, muscle wasting, and physical frailty across the broad spectrum of patients with cardiovascular illnesses. This interest originally started in the field of heart failure, but has recently been extended to other areas such as atrial fibrillation, coronary artery disease, peripheral artery disease as well as to patients after cardiac surgery or transcatheter aortic valve implantation. Tissue wasting and frailty are prevalent among many of the affected patients. The ageing process itself and concomitant cardiovascular illness decrease lean mass while fat mass is relatively preserved, making elderly patients particularly prone to develop wasting syndromes and frailty. The aim of this review is to provide an overview of the available knowledge of body wasting and physical frailty in patients with cardiovascular illness, particularly focussing on patients with heart failure in whom most of the available data have been gathered. In addition, mechanisms of wasting and possible therapeutic targets are discussed.

The impact of Hayward green kiwifruit on dietary protein digestion and protein metabolism

Purpose

The purpose of the study was to determine if an actinidin protease aids gastric digestion and the protein anabolic response to dietary protein.

Methods

Hayward green kiwifruit (containing an actinidin protease) and Hort 16A gold kiwifruit (devoid of actinidin protease) were given in conjunction with a beef meal to healthy older subjects. Twelve healthy older males (N = 6) and females (N = 6) were studied with a randomized, double-blinded, crossover design to assess muscle and whole-body protein metabolism before and after ingestion of kiwifruit and 100 g of ground beef. Subjects consumed 2 of each variety of kiwifruit daily for 14 d prior to each metabolic study, and again during each study with beef intake.

Results

Hayward green kiwifruit consumption with beef resulted in a more rapid increase in peripheral plasma essential amino acid concentrations. There were significant time by kiwifruit intake interactions for plasma concentrations of EAAs, branched chain amino acids (BCAAs), and leucine (P < 0.01). However, there was no difference in the total amount of EAAs absorbed. As a result, there were no differences between kiwifruit in any of the measured parameters of protein kinetics.

Conclusion

Consumption of Hayward green kiwifruit, with a beef meal facilitates protein digestion and absorption of the constituent amino acids as compared to Hort 16A gold kiwifruit.

Clinical trial

NCT04356573, April 21, 2020 “retrospectively registered”.

A Call to Action: Now Is the Time to Screen Elderly and Treat Osteosarcopenia, a Position Paper of the Italian College of Academic Nutritionists MED/49 (ICAN-49)

Aging is a risk factor for the development of multiple chronic diseases, including cardiovascular disease, cancer and dementia. Life expectancy has increased in certain countries but this phenomenon is associated with a reduction of years of healthy life. Aging is associated with a number of physical and functional changes, especially sarcopenia. Sarcopenia is a clinical condition associated with a decrease in skeletal muscle and muscle strength, however, sarcopenia is a reversible condition. On the basis of the current scientific literature, sarcopenia could more appropriately capture an individual's vulnerability to negative health-related outcomes since it represents an early form of the chronic diseases. Recognition of this clinical condition can improve the management of older individuals in many different clinical settings. Despite the limitations of the indirect methods used to study body composition, the Italian College of the Academic Nutritionists ME/49 recommends that health authorities and health professionals around the world should make a greater effort to diagnose sarcopenia earlier and to manage it more effectively. In line with the development of cancer screening, the use of two diagnostic tools for sarcopenia (BIA and DXA) should be implemented.

Comparing supermarket loyalty card data with traditional diet survey data for understanding how protein is purchased and consumed in older adults for the UK, 2014-16

Background

Our ability to understand population-level dietary intake patterns is dependent on having access to high quality data. Diet surveys are common diet assessment methods, but can be limited by bias associated with under-reporting. Food purchases tracked using supermarket loyalty card records may supplement traditional surveys, however they are rarely available to academics and policy makers. The aim of our study is to explore population level patterns of protein purchasing and consumption in ageing adults (40 years onwards).

Methods

We used diet survey data from the National Diet and Nutrition Survey (2014–16) on food consumption, and loyalty card records on food purchases from a major high street supermarket retailer (2016–17) covering the UK. We computed the percentage of total energy derived from protein, protein intake per kg of body mass, and percentage of protein acquired by food type.

Results

We found that protein consumption (as the percentage of total energy purchased) increased between ages 40–65 years, and declined thereafter. In comparison, protein purchased in supermarkets was roughly 2–2.5 percentage points lower at each year of age. The proportion of adults meeting recommended levels of protein was lowest in age groups 55–69 and 70+. The time of protein consumption was skewed towards evening meals, with low intakes during breakfast or between main meals. Meat, fish and poultry dominated as sources of protein purchased and consumed, although adults also acquired a large share of their protein from dairy and bread, with little from plant protein.

Conclusions

Our study provides novel insights into how protein is purchased and consumed by ageing adults in the UK. Supermarket loyalty card data can reveal patterns of protein purchasing that when combined with traditional sources of dietary intake may enhance our understanding of dietary behaviours.

Whey protein ingestion in elderly diet and the association with physical, performance and clinical outcomes

Nutrition is critical to the health of the elderly, since most of them have a deficiency in key nutrient. The use of whey protein may be a food strategy to increase protein intake. The objective of this work was to evaluate the ingestion of whey protein for the elderly and the association with physical performance and clinical outcomes. A systematic review was conducted in order to find papers that shed some light in the correlation between whey protein and the elderly.

INCLUSION CRITERIA

population: elderly; intervention: use of whey protein when compared to control group; outcome: related to health, nutrition, or quality of life.

DATABASE

PubMed, with papers published in the last 5 years.

SEARCH STRATEGY

(elder OR senior OR elderly OR aging OR aged OR old OR older) AND (whey OR "whey protein"). 35 papers were selected of which 22 had a physical performance outcome and 13 had clinical outcomes. Studies indicate that whey protein supplements promote protein synthesis in the elderly, improving muscle performance and aerobic capacity, protecting against sarcopenia and reducing the risk for falls. In the papers studied, the age group considered to be elderly was ≥65 years in 27 papers and ≥60 years in the other 8 papers. Whey protein also appears to contribute to improved health, recovery from disease, prevention of cardiovascular and metabolic risks, and hepatic steatosis complications. Data suggest that whey protein supplements may be promising for the health improvement of the elderly.

Protein Requirements during Hypocaloric Nutrition for the Older Patient With Critical Illness and Obesity: An Approach to Clinical Practice

Current guidelines recommend a hypocaloric, high protein nutrition regimen for patients with obesity and critical illness. The impact of advancing age presents with unique challenges in which a greater protein intake is required to overcome the anabolic resistance associated with aging in the face of presumed decreased renal function. The primary objective of this review is to provide an overview of the impact of obesity and advancing age on protein requirements for patients with critical illness and review the scientific evidence supporting the rationale for hypocaloric, high protein nutrition for this subpopulation, as well as provide some practical suggestions for their clinical management.

Nutrition and Sarcopenia-What Do We Know?

Muscle health is important for the functionality and independence of older adults, and certain nutrients as well as dietary patterns have been shown to offer protective effects against declines in strength and function associated with aging. In this paper, micronutrients, macronutrients, and food groups have been reviewed, along with their studied effects on the prevalence and incidence of sarcopenia, as well as their ability to preserve muscle mass and optimize physical performance. Randomized controlled trials appear to suggest a critical role for dietary intake of protein in preventing sarcopenia and muscle loss, although the optimal dose and type of protein is unknown. There are some promising data regarding the role of vitamin D and sarcopenia, but it is unclear whether the dose, frequency of dose, or length of treatment impacts the efficacy of vitamin D on improving muscle mass or function. Selenium, magnesium, and omega 3 fatty acids have been studied as supplements in clinical trials and in the diet, and they appear to demonstrate a potential association with physical activity and muscle performance in older individuals. Following the Mediterranean diet and higher consumption of fruits and vegetables have been associated with improved physical performance and protection against muscle wasting, sarcopenia, and frailty.

Protein Requirements of Elderly Chinese Adults Are Higher than Current Recommendations

BACKGROUND

Due to a lack of research data on the protein requirements of the elderly in China, the estimated average requirement (EAR) and the recommended nutrient intake (RNI) of protein in the elderly remain the same as those in young and middle-aged people at 0.98 g/(kg·d).

OBJECTIVE

The objective of this study was to determine the protein requirements of healthy Chinese adults >65y old through use of the indicator amino acid oxidation (IAAO) method.

METHODS

Seven healthy adult men and 7 healthy adult women participated in the study, with protein intakes ranging from 0.3 to 1.8 g/(kg·d). The diets were isocaloric and provided energy at a 1.5 resting energy expenditure. Protein was given based on the lactalbumin. Phenylalanine and tyrosine were added to protein doses of 0.3-1.5 g/kg according to the highest dose of protein content [1.8 g/(kg·d)]. Phenylalanine and tyrosine concentrations were kept constant at each protein dose. The mean protein requirement was determined by applying a nonlinear mixed-effects model analysis to the F13CO2, which identified a breakpoint in F13CO2 in response to graded amounts of protein. This trial was registered with the Chinese clinical trial registry as ChiCTR-BOC-17010930.

RESULTS

Protein EAR and RNI for healthy elderly Chinese adults were determined to be 0.91 and 1.17 g/(kg·d), respectively, based on the indicator amino acid oxidation technique.

CONCLUSIONS

The estimates of protein requirements for Chinese adults >65 y in the present study are 3.4% and 19.4% higher than the current estimated requirements, 0.88 g/(kg·d) for EAR and 0.98 g/(kg·d) for RNI.

Nutrition interventions to treat low muscle mass in cancer

Many patients with cancer experience poor nutritional status, which detrimentally impacts clinical outcomes. Poor nutritional status in cancer is primarily manifested by severe muscle mass (MM) depletion, which may occur at any stage (from curative to palliative) and often co-exists with obesity. The objective of this article was to discuss gaps and opportunities related to the role of nutrition in preventing and reversing low MM in cancer. It also provides a narrative review of relevant nutritional interventions for patients capable of oral intake. The impact of nutrition interventions to prevent/treat low MM in cancer is not well understood, potentially due to the limited number of studies and of clinically viable, accurate body composition assessment tools. Additionally, the type of study designs, inclusion criteria, length of intervention, and choice of nutritional strategies have not been optimal, likely underestimating the anabolic potential of nutrition interventions. Nutrition studies are also often of short duration, and interventions that adapt to the metabolic and behavioural changes during the clinical journey are needed. We discuss energy requirements (25-30 kcal/kg/day) and interventions of protein (1.0-1.5 g/kg/day), branched-chain amino acids (leucine: 2-4 g/day), β-hydroxy β-methylbutyrate (3 g/day), glutamine (0.3 g/kg/day), carnitine (4-6 g/day), creatine (5 g/day), fish oil/eicosapentanoic acid (2.0-2.2 g/day EPA and 1.5 g/day DHA), vitamin/minerals (e.g. vitamin D: 600-800 international units per day), and multimodal approaches (nutrition, exercise, and pharmaceutical) to countermeasure low MM in cancer. Although the evidence is variable by modality type, interventions were generally not specifically studied in the context of cancer. Understanding patients' nutritional requirements could lead to targeted prescriptions to prevent or attenuate low MM in cancer, with the overall aim of minimizing muscle loss during anti-cancer therapy and maximizing muscle anabolism during recovery. It is anticipated that this will, in turn, improve overall health and prognostication including tolerance to treatment and survival. However, oncology-specific interventions with more robust study designs are needed to facilitate these goals.

Protein-Related Dietary Parameters and Frailty Status in Older Community-Dwellers across Different Frailty Instruments

The present study investigated the associations between frailty status and (a) daily protein intake, (b) daily body weight-adjusted protein intake, (c) branched-chain amino acid (BCAA) consumption, (d) evenness of protein distribution across main meals, (e) number of daily meals providing at least 30 g of protein, and (f) number of daily meals providing at least 0.4 g protein/kg of body weight in community-dwelling older adults. The relationship between frailty status and protein-related dietary parameters was explored across different frailty assessment tools. Two hundred older adults were enrolled in the study. Participant frailty status was determined according to a modified Fried’s frailty phenotype (mFP), the FRAIL scale, and the Study of Osteoporotic Fracture (SOF) index. Diet was assessed by 24-h dietary recall, while diet composition was estimated using a nutritional software. A frailty instrument-dependent relationship was observed between frailty status and protein-related dietary parameters. Protein consumption was associated with frailty status only in participants identified as frail according to the mFP. In addition, protein and BCAA intake was found to be greater in robust and pre-frail participants relative to their frail counterparts. Our findings suggest that the association between frailty and protein-related dietary parameters is tool dependent. Specifically, protein and BCAA consumption appears to be lower only in older adults identified as frail by the mFP.

Effects of Bromelain and Double Emulsion on the Physicochemical Properties of Pork Loin

Our aim was to investigate the effects of bromelain embedded in double emulsion (DE) on physicochemical properties of pork loin. We evaluated DE characteristics such as size, zeta potential, and microscopy after fabrication. We marinated meat with distilled water (DW), 1% (w/v) bromelain solution, blank DE, and 1% (w/v) bromelain loaded in double emulsion (DE E) for 0, 24, 48, and 72 h at 4°C, and prepared raw meat for control. The marinated samples were assessed for color, water holding capacity, cooking loss, moisture content, pH, protein solubility, Warner-Bratzler shear force (WBSF) and gel electrophoresis. The droplet size of 1% (w/v) bromelain embedded in DE was increased compared with blank DE (p<0.05) and values of zeta potential decreased. The increase in lightness and color difference range of the DE-treated group was lower than that of the DW-treated group (p<0.05). Moreover, treatment by immersion in 1% (w/v) DE E resulted in the highest water holding capacity values (p<0.05) and lower cooking loss values than water base treatment (p<0.05). Results for myofibrillar protein solubility and WBSF showed a similar trend. 1% (w/v) DE E showed degradation of myosin heavy chain after 48 h in sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Thus, bromelain-loaded DE is useful for controlling and handling enzyme activity in food industry.

Exercise Countermeasures to Neuromuscular Deconditioning in Spaceflight

The mechanical unloading of spaceflight elicits a host of physiological adaptations including reductions in muscle mass, muscle strength, and muscle function and alterations in central interpretation of visual, vestibular, and proprioceptive information. Upon return to a terrestrial, gravitational environment, these result in reduced function and performance, the potential consequences of which will be exacerbated during exploration missions to austere and distant destinations such as the moon and Mars. Exercise is a potent countermeasure to unloading-induced physiological maladaptations and has been employed since the early days of spaceflight. In-flight exercise hardware has evolved from rudimentary and largely ineffective devices to the current suite onboard the International Space Station (ISS) comprised of a cycle ergometer, treadmill, and resistance exercise device; these contemporary devices have either fully protected or significantly attenuated neuromuscular degradation in spaceflight. However, unlike current microgravity operations on the ISS, future exploration missions will include surface operations in partial gravity environments, which will require greater physiological capacity and work output of their crews. For these flights, it is critical to identify physiological thresholds below which task performance will be impaired and to develop exercise countermeasures-both pre- and in-flight-to ensure that crewmembers are able to safely and effectively complete physically demanding mission objectives. © 2020 American Physiological Society. Compr Physiol 10:171-196, 2020.

Controversy in Nutrition Recommendations for Short Bowel Syndrome: How Type of SBS Impacts Response

PURPOSE OF REVIEW

This review examines the current recommendations for dietary management of patients living with short bowel syndrome (SBS) and outlines the need for future research to provide optimal care for this unique group of patients.

RECENT FINDINGS

Providers caring for patients with SBS lack sufficient data to help guide recommendations regarding diet. The majority of studies are conducted at a single medical institution on a small number of anatomically diverse patients. Multi-center studies would allow for inclusion of a larger number of patients and may lead to more individualized dietary recommendations. Patients with short bowel syndrome should be evaluated on an individual basis by a multidisciplinary team including physicians, dieticians, pharmacists, and nurses specializing in the care of these complex patients. Tailoring both medical and nutritional therapy will help realize the overarching goal for these patients of maintaining adequate nutrition with diet and medications, and achieving independence from parenteral support.

The relationships between sarcopenic skeletal muscle loss during ageing and macronutrient metabolism, obesity and onset of diabetes

Skeletal muscle is integral to the metabolism and utilisation of macronutrients; however, substantial muscle loss and morphological changes occur with ageing. These are associated with loss of muscle function and accelerate rapidly from the age of 60 years, leading to the conditions of sarcopenia and frailty. As the relationship between muscle ageing and macronutrient metabolism and utilisation has seen limited research to date, this review focuses on the interactions between skeletal muscle changes during ageing, metabolism and utilisation of fat, carbohydrates and overall energy expenditure.Skeletal muscle contributes less to resting energy expenditure during ageing, potentially contributing to onset of obesity from middle age. Age-related changes to skeletal muscle lead to glucose dysregulation, with consequent reduction in glycaemic control, increased insulin resistance and ultimately onset of type-2 diabetes. Recent studies indicate that high total fat and SFA intake are detrimental to skeletal muscle, while higher intakes of PUFA are protective. Age-associated changes in skeletal muscle may also reduce total fatty acid utilisation.In conclusion, further research is needed to understand the relationships between macronutrient metabolism and utilisation and age-related changes to skeletal muscle. No dietary recommendations exist specifically for skeletal muscle health during ageing, but we advise individuals to follow healthy eating guidelines, by consuming sufficient protein, fruit and vegetables, and limited SFA and to maintain physically active lifestyles. Clinicians responsible for managing type-2 diabetes need to be aware of growing evidence relating age-related skeletal muscle changes to diabetes onset and progression.

Daily Protein Intake and Distribution of Daily Protein Consumed Decreases Odds for Functional Disability in Older Americans

Objective: We sought to determine whether daily protein intake and protein distribution across eating occasions were associated with functional disability in a national sample of older Americans. Methods: Data from 8,070 adults aged ≥60 years from the 2007-2016 waves of the National Health and Nutrition Examination Survey were included. Protein intake and functional capacity was self-reported. A daily protein recommendation of ≥1.0 g/kg/day was utilized. The daily protein recommendation was then spread-out across four meals, whereby a ≥0.25 g/kg/meal threshold was used. Results: Those meeting the daily protein recommendation had 0.78 (95% confidence interval [CI] = [0.65, 0.93]) decreased odds for functional disability. Persons meeting the protein intake threshold per eating occasion for one, two, three, and four occasions had 0.60 (CI = [0.38, 0.95]), 0.48 (CI = [0.30, 0.77]), 0.47 (CI = [0.29, 0.77]), and 0.39 (CI = [0.20, 0.75]) decreased odds for functional disability, respectively. Discussion: Protein consumption seems to be important for preserving function in older Americans.

Vegetable but not animal protein intake is associated to a better physical performance: a study on a general population sample of adults

Background

The research was conducted in the frame of a population-based, case control study, called Genes Environment Interaction in Respiratory Disease.

Objective

To assess the association between protein intake and physical performance in a general population sample.

Design

Researchers investigated the association between the participants’ dietary information and their physical performance using the 6-min walking test and the distance walked in metres (6MWD) as main outcome measure. Information on dietary intake was collected using the validated European Investigation into Cancer and Nutrition food frequency questionnaires (FFQs). Then, daily intake of energy and macronutrients was estimated by means of the NAF software (nutritional analysis of FFQ). Linear regression models were used to evaluate the associations between vegetable, animal and total protein intakes and the 6MWD. The models were adjusted for socio-demographic features, total fats and available carbohydrate intakes.

Results

The participants were 223 subjects (57% females) aged between 23 and 68 years. Their mean vegetable and animal proteins intake for gram/kg of body weight/day were, respectively, 0.4 and 0.7. After adjusting for all the potential confounders, there was a significant increase of 20.0 (95% CI 0.8; 39.2) m in the distance walked for an increase in 10 g/day of vegetable proteins and non-significant variations of −1.8 (95% CI −9.3; 5.7) m for an increase in 10 g/day of animal proteins and of 0.5 (95% CI −6.8; 7.7) for an increase in 10 g/day of total proteins.

Discussion and conclusions

Our result suggests a positive role of vegetable proteins on physical performance. Whether this result is related to the high protein intake itself or may be a consequence of the other properties of plant-based foods deserves further investigation.

Prospective Associations of Diet Quality With Incident Frailty in Older Adults: The Health, Aging, and Body Composition Study

OBJECTIVE

To examine associations of diet quality indicators with 4-year incidence of frailty in community-dwelling older adults.

DESIGN

Prospective cohort study.

SETTING

Health, Aging, and Body Composition Study, United States.

PARTICIPANTS

Community-dwelling men and women, aged 70 to 81 years in 1998 to 1999 (first follow-up, present study's baseline; n = 2154).

MEASUREMENTS

At first follow-up, dietary intake over the preceding year was assessed with a food frequency questionnaire. Indicators of diet quality include the Healthy Eating Index (categorized as poor, medium, and good), energy intake, and protein intake (a priori adjusted for energy intake using the nutrient residual model). Frailty status was determined using Fried's five-component frailty phenotype and categorized into "robust" (0 components present), "pre-frailty" (1 - 2 components present), or "frail" (3-5 components present). Cox proportional hazards analysis was used to examine associations of the diet quality indicators with 4-year incidence of (1) frailty and (2) pre-frailty or frailty. Competing risk analysis was used to examine associations with frailty by accounting for competing risks of death.

RESULTS

During the 4-year follow-up, 277 of the 2154 participants, robust or pre-frail at baseline, developed frailty, and 629 of the 1020 participants, robust at baseline, developed pre-frailty or frailty. Among the robust and pre-frail, after adjustment for confounders including energy intake, those consuming poor- and medium-quality diets had a higher frailty incidence than those consuming good-quality diets (hazard ratio [HR] = 1.92 [95% confidence interval {CI} = 1.17-3.17] and HR = 1.40 [95% CI = 0.99-1.98], respectively). No associations for energy or protein intake were observed. Competing risk analyses yielded similar results. Among the robust, those with lower vegetable protein intake had a higher "pre-frailty or frailty" incidence (per -10 g/d: HR = 1.20; 95% CI = 1.04-1.39). No other associations were observed.

CONCLUSION

Poorer overall diet quality and lower vegetable protein intake may increase the risk of becoming frail in old age. We found no association for intakes of energy, total protein, or animal protein. J Am Geriatr Soc 67:1835-1842, 2019.

Nutritional Strategies to Combat Type 2 Diabetes in Aging Adults: The Importance of Protein

The prevalence of pre-diabetes (PD) and type II diabetes (T2D) has risen dramatically in recent years affecting an estimated 422 million adults worldwide. The risk of T2D increases with age, with the sharpest rise in diagnosis occurring after age 40. With age, there is also a progressive decline in muscle mass starting after the age of 30. The decline in muscle mass and function due to aging is termed sarcopenia and immediately precedes the sharp rise in T2D. The purpose of the current review is to discuss the role of protein to attenuate declines in muscle mass and insulin sensitivity to prevent T2D and sarcopenia in aging adults. The current recommended dietary allowance for protein consumption is set at 0.8 g/kg/day and is based on dated studies on young healthy men and may not be sufficient for older adults. Protein consumption upwards of 1.0-1.5 g/kg/day in older adults is able to induce improvements in glycemic control and muscle mass. Obesity, particularly central or visceral obesity is a major risk factor in the development of PD and T2D. However, the tissue composition of weight loss in older adults includes both lean body mass and fat mass and therefore may have adverse metabolic consequences in older adults who are already at a high risk of lean body mass loss. High protein diets have the ability to increase weight loss while preserving lean body mass therefore inducing "high-quality weight loss," which provides favorable metabolic changes in older adults. High protein diets also induce beneficial outcomes on glycemic markers due to satiety, lowered post-prandial glucose response, increased thermogenesis, and the ability to decrease rates of muscle protein breakdown (MPB). The consumption of dairy specific protein consumption has also been shown to improve insulin sensitivity by improving body composition, enhancing insulin release, accelerating fat oxidation, and stimulating rates of muscle protein synthesis (MPS) in older adults. Exercise, specifically resistance training, also works synergistically to attenuate the progression of PD and T2D by further stimulating rates of MPS thereby increasing muscle mass and inducing favorable changes in glycemic control independent of lean body mass increases.

Effect of whey protein supplementation combined with resistance training on body composition, muscular strength, functional capacity, and plasma-metabolism biomarkers in older women with sarcopenic obesity: A randomized, double-blind, placebo-controlled trial

BACKGROUNDS & AIMS

Obesity and sarcopenia are independent illnesses associated with contemporary dietary and physical activity behaviors, aggravated by aging. Their coexistence is termed sarcopenic obesity (SO). Hence, increasing protein intake and resistance training (RT) are interventions that could counteract these illnesses. The objective of this investigation was to analyze the effects of whey protein (WP) supplementation associated with RT on body composition, muscular strength, functional capacity, and plasma-metabolism biomarkers in older women with SO.

METHODS

Twenty six sarcopenic (appendicular lean soft tissue ALST < 15.02 kg) obese (body fat mass ≥ 35%) older women were randomly assigned to receive daily, either 35 g of WP (WP group) or placebo (PLA group), combined with supervised RT (8 exercises, 3 × 8-12 rep, 3 times a week), during a 12-week protocol. Blood samples, blood pressure, dietary intake, functional capacity tests, the one repetition maximum (1RM) test, and body composition were assessed before and after the intervention period. Two-way analysis of variance for repeated measures was applied for comparisons.

RESULTS

The WP group presented greater (P < 0.05) increases in ALST (WP = 6.0% vs. PLA = 2.5%) and decreases in (P < 0.05) total (-3.3% vs. -0.3%) and trunk fat mass (WP = -5.1% vs. PLA = -1.1) and IL-6 (WP = -34.6% vs. PLA = 9.3%) compared with the PLA group. Both groups demonstrated improved (P < 0.05) scores for muscular strength, waist-hip ratio, functional capacity, and other plasma-metabolism biomarkers without significant differences between conditions.

CONCLUSION

Whey protein combined with RT increased ALST, and decreased total and trunk fat mass, improving sarcopenia and decreasing SO in older women, with a limited impact on inflammation. Registered under ClinicalTrials.gov Identifier n° NCT03752359.

Dietary strategies for mitigating osteosarcopenia in older adults: a narrative review

The synchronic loss of bone mineral density and decrease in muscle mass, strength, and function defines the scenario of osteosarcopenia, which is associated with an increased risk of falls and fractures in older adults. An important role in preventing muscle and bone loss is played by nutritional factors, in particular the intake of proteins, calcium, magnesium and vitamin D. This review summarizes the available literature concerning the influence of protein intake and supplementation (vitamin D, Ca, Mg, branched-chain amino acids) on the decline of musculoskeletal integrity in healthy older adults. Furthermore, in this paper, we attempted to give some suggestions to build up adequate nutritional and dietary strategies against the age-related loss of muscle and bone mass.

Effects of higher habitual protein intake on resistance-training-induced changes in body composition and muscular strength in untrained older women: A clinical trial study

BACKGROUND

Aging is accompanied by progressive and accentuated decline in muscular strength and skeletal muscle mass, affecting health and functional autonomy. Both resistance training (RT) and diet are strategies that may contribute to improvement in the health of the elderly.

AIM

The purpose of this study was to evaluate the effects of higher habitual protein intake on RT-induced changes in body composition and strength in untrained postmenopausal women.

METHODS

Seventy older women were submitted to an RT program. Body composition, muscular strength, and dietary intake (24 h dietary recall) were performed pre- and post-intervention. To verify different intervention effects according to protein intake of the participants, the sample was separated into tertiles according to protein intake: low, moderate, and high protein intake.

RESULTS

A time vs. group interaction ( p < 0.05) was observed, with high protein intake presenting greater increases compared with low protein intake, for skeletal muscle mass (5.3% vs. 1.3%), lower limb lean soft tissue (4.9% vs. 1.4%), upper lean soft tissue (4.9% vs. 1.2%), preacher curl (24% vs. 15.2%), and total strength (16.4% vs. 11.7%). A time vs. group interaction ( p < 0.05) was observed, with high protein intake presenting greater increases compared with moderate protein intake, for skeletal muscle mass (5.3% vs. 3.2%). In all groups, a main effect of time ( p < 0.05) was observed for knee extension and chest press.

CONCLUSIONS

We conclude that intake of >1.0 g/kg/day of protein promotes gains in skeletal muscle mass and muscular strength after RT in untrained older women.