Prevalence of protein intake below recommended in community-dwelling older adults: a meta-analysis across cohorts from the PROMISS consortium

Study Protocol for a Randomized Controlled Trial Investigating the Effects of the Daily Consumption of Ruminant Milk on Digestive Comfort and Nutrition in Older Women: The YUMMI Study

BACKGROUND

Age-related changes can lead to dietary insufficiency in older adults. The inclusion of high-quality, nutrient-dense foods such as ruminant milks can significantly improve health outcomes. However, many older adults worldwide do not meet daily milk intake recommendations because of digestive discomfort and health concerns. Ovine and caprine milks are increasingly popular for their perceived digestive and nutritional benefits. While preclinical studies suggest differences in milk digestion, human studies investigating acute postprandial responses remain inconclusive, and the impacts of sustained milk consumption remain uncertain.

OBJECTIVES

Hence, we present a randomized controlled trial investigating how the sustained consumption of bovine, caprine, or ovine milk influences digestion, nutrition, and metabolism in older women.

METHODS

A total of 165 healthy older women were randomized to receive bovine, caprine, or ovine milk, or no milk, twice daily for 12 weeks. The primary outcome is the impact of milk consumption on digestive comfort assessed via the Gastrointestinal Syndrome Rating Scale (GSRS). Secondary outcomes include changes in nutrient intake, plasma amino acid and lipid appearance, bowel habits, the gut microbiota, cardiometabolic health, physical function, physical activity, sleep, mood, sensory perception, and emotional response.

CONCLUSIONS

The findings could inform dietary recommendations for older women and facilitate the development of targeted functional food products.

The role of nutrient sensing dysregulation in anorexia of ageing: The little we know and the much we don't

The age-related decline in appetite and food intake - termed "anorexia of ageing" - is implicated in undernutrition in later life and hence provides a public health challenge for our ageing population. Eating behaviour is controlled, in part, by homeostatic mechanisms which sense nutrient status and provide feedback to appetite control regions of the brain. Such feedback signals, propagated by episodic gut hormones, are dysregulated in some older adults. The secretory responses of appetite-related gut hormones to feeding are amplified, inducing a more anorexigenic signal which is associated with reduced appetite and food intake. Such an augmented response would indicate an increase in gut sensitivity to nutrients. Consequently, this review explores the role of gastrointestinal tract nutrient sensing in age-related appetite dysregulation. We review and synthesise evidence for age-related alterations in nutrient sensing which may explain the observed hormonal dysregulation. Drawing on what is known regarding elements of nutrient sensing pathways in animal models, in other tissues of the body, and in certain models of disease, we identify potential causal mechanisms including alterations in enteroendocrine cell number and distribution, dysregulation of cell signalling pathways, and changes in the gut milieu. From identified gaps in evidence, we highlight interesting and important avenues for future research.

Nutrition in the prevention and treatment of skeletal muscle ageing and sarcopenia: a single nutrient, a whole food and a whole diet approach

Loss of skeletal muscle strength and mass (sarcopenia) is common in older adults and associated with an increased risk of disability, frailty and premature death. Finding cost-effective prevention and treatment strategies for sarcopenia for the growing ageing population is therefore of great public health interest. Although nutrition is considered an important factor in the aetiology of sarcopenia, its potential for sarcopenia prevention and/or treatment is still being evaluated. Nutrition research for sarcopenia utilises three main approaches to understand muscle-nutrition relationships, evaluating: single nutrients, whole foods and whole diet effects - both alone or combined with exercise. Applying these approaches, we summarise recent evidence from qualitative and quantitative syntheses of findings from observational and intervention studies of healthy older adults, and those with sarcopenia. We consider protein supplements, whole foods (fruits and vegetables) and the Mediterranean diet as exemplars. There is some evidence of beneficial effects of protein supplementation ≥ 0·8 g/kg body weight/d on muscle mass when combined with exercise training in intervention studies of healthy and sarcopenic older adults. In contrast, evidence for effects on muscle function (strength and physical performance) is inconclusive. There is reasonably consistent epidemiological evidence suggesting benefits of higher fruits and vegetables consumption for better physical performance. Similarly, higher adherence to the Mediterranean diet is associated with beneficial effects on muscle function in observational studies. However, intervention studies are lacking. This review discusses how current evidence may inform the development of preventive and intervention strategies for optimal muscle ageing and nutritional public policy aimed at combatting sarcopenia.

Plant protein, fibre and physical activity solutions to address poor appetite and prevent undernutrition in older adults: study protocol for the APPETITE randomised controlled trial

Reduced appetite with ageing is a key factor that may increase risk of undernutrition. The objective of this study is to determine the impact of innovative plant protein fibre (PPF) products within a personalised optimised diet (PD), a physical activity (PA) programme, and their combination on appetite, and other nutritional, functional and clinical outcomes in community-dwelling older adults in a multi-country randomised controlled intervention trial. One hundred and eighty community-dwelling adults (approximately sixty per trial centre in Germany, Ireland and Italy) aged 65 years and over will be recruited to participate in a 12-week, parallel-group, controlled trial. Participants will be randomised into one of four groups: 1, PD (incorporating two PPF products): 2, PA; 3, PD + PA; and 4, no intervention (control). The primary outcome is appetite measured by visual analogue scales and energy intake from an ad libitum test meal. Secondary outcomes include fasting and postprandial appetite-related gut hormones, Simplified Nutritional Appetite Questionnaire score, body composition, cardiorespiratory fitness, muscle strength, physical function and PA. In addition, self-efficacy, cognitive status, dietary restraint, depressive symptoms and compliance and acceptability of the intervention will be assessed. Metabolomic profiles, RMR, muscle motor unit properties and gut microbiome will also be assessed to explore potential underlying mechanisms. This multi-centre randomised controlled trial will advance knowledge on how PD (incorporating PPF products), PA and their combination influence appetite, nutritional status and related health outcomes in community-dwelling older adults and contribute to the prevention of undernutrition. Trial registration: Clinical Trials.gov Registry NCT05608707 (registered on 2 November 2022). Protocol Version: NCT05608707 Version 4 (registered on 29 September 2023).

Appetite, food intake, and gut hormone responses to glycomacropeptide protein ingestion in older adults: A feasibility, acceptability, and pilot study

Glycomacropeptide (GMP) has a unique amino acid profile which may make less satiating than other dietary proteins. This study assessed the feasibility and likely acceptability of a leucine-enriched GMP drink and determined appetite response in older adults (OA). Thirteen OA (11f; 70 ± 4 years) were recruited for sensory assessments of a leucine-enriched GMP drink when mixed with water and with fruit smoothie, compared with whey protein isolate (WHEY). Participants also partook in a single focus group exploring acceptability to protein and supplementation. Separately, a counterbalanced, double-blind study with twelve OA (8f; 69 ± 3 years) was conducted to determine appetite and gut hormone responses. Fasting subjective appetite was recorded using visual analogue scales and a fasted venous blood sample was collected (to measures acyl-ghrelin, PYY, GLP-1, and CCK) before participants consumed either: GMP protein (27g + 3g leucine, 350 mL water), WHEY (30g, 350 mL water), or water. Participants rested for 240 min, with appetite measures and blood sampling throughout. An ad libitum pasta-based meal was then consumed. Sensory testing revealed low pleasantness rating for GMP in water vs. WHEY (16 ± 14 vs 31 ± 24, p = 0.016). GMP addition to smoothie reduced pleasantness (26 ± 21 vs. 61 ± 29, p = 0.009) and worsened the aroma (46 ± 15 vs. 69 ± 28, p = 0.014). The focus group revealed uncertainty of protein needs and a scepticism of supplements, with preference for food. Gut hormone response did not differ between GMP and WHEY (nAUC for all gut hormones p > 0.05). There was no difference between conditions for lunch ad libitum intake (549 ± 171 kcal, 512 ± 238 kcal, 460 ± 199 kcal for GMP, WHEY, and water, p = 0.175), or for subjective appetite response. Leucine-enriched GMP was not less satiating than WHEY, and low palatability and scepticism of supplements question the likely acceptability of GMP supplementation. Providing trusted nutritional advice and food enrichment/fortification may be preferred strategies for increasing protein intake in OA.

Meeting the global protein supply requirements of a growing and ageing population

Human dietary patterns are a major cause of environmental transformation, with agriculture occupying ~ 50% of global land space, while food production itself is responsible for ~ 30% of all greenhouse gas emissions and 70% of freshwater use. Furthermore, the global population is also growing, such that by 2050, it is estimated to exceed ~ 9 billion. While most of this expansion in population is expected to occur in developing countries, in high-income countries there are also predicted changes in demographics, with major increases in the number of older people. There is a growing consensus that older people have a greater requirement for protein. With a larger and older population, global needs for protein are set to increase. This paper summarises the conclusions from a Rank Prize funded colloquium evaluating novel strategies to meet this increasing global protein need.

Nutritional Considerations in Hip and Knee Arthroplasty: A Critical Analysis of Current Evidence

» Initial screening for malnutrition can be initiated with a fibrinogen-albumin ratio threshold <11.7.» Protein supplementation to goal (1.2-1.9 g/kg), along with essential amino acid augmented with beta-hydroxy-beta-methylbutyrate and resistance training have shown benefit, especially in sarcopenic patients.» Omega-3 and omega-6 polyunsaturated fatty acid supplementation has a strong antioxidant role and gain of muscle mass.» Supplementation with adenosine triphosphate and magnesium sulfate provides an avenue to decrease postoperative pain and opioid consumption.» Motivational interviewing and multidisciplinary teams to achieve preoperative weight loss >20 lbs in morbidly obese patients can decrease complication rates.

Distribution of daily protein intake and appendicular skeletal muscle mass in healthy free-living Chinese older adults

AIMS

Evidence regarding impact of protein intake distribution on skeletal muscle mass in older adults is limited and inconsistent. This study aims to investigate the relationship of evenness of dietary protein distribution and number of meals exceeding a threshold with appendicular skeletal muscle mass (ASM) in healthy and free-living Chinese older adults.

METHODS

Repeated measured data of 5689 adult participants aged ≥ 60 years from the China Health and Nutrition Survey (CHNS) 2015 and 2018 waves were analyzed. Mixed-effects linear regression model was performed to examine the relationship between coefficient of variance (CV) of protein intake across meals, number of meals ≥ 0.4 g protein/kg BW and ASM, respectively. Analyses were conducted separately for male and female.

RESULTS

The average CV of protein intake in each wave was in the range of 0.34-0.35. More than 40% male and female participants in each wave had no meal reaching 0.4 g protein/kg BW. Female participants in the highest quartile of protein intake CV had significantly lower ASM (β = -0.18, 95%CI = -0.32, -0.04) compared with those in the lowest quartile, after adjustment for multiple confounders. Significant negative trends were observed across dietary protein CV quartiles with ASM both in male (P trend = 0.043) and female (P trend = 0.007). Significant positive association between number of meals exceeding 0.4 g protein /kg BW and relative ASM were observed in females (2 meals vs. 0 meal: β = 0.003, 95%CI = 0.0007,0.006;≥3 meals vs. 0 meal: β = 0.008, 95%CI = 0.003,0.013), after adjusting for multiple covariates.

CONCLUSIONS

A more even-distributed protein intake pattern and more meals reaching protein intake threshold were respectively associated with higher appendicular skeletal muscle mass in healthy and free-living older Chinese adults. Prospective studies and intervention trials are needed to confirm these cross-sectional findings.

Dietary protein and amino acid intakes for mitigating sarcopenia in humans

Adult humans generally experience a 0.5-1%/year loss in whole-body skeletal muscle mass and a reduction of muscle strength by 1.5-5%/year beginning at the age of 50 years. This results in sarcopenia (aging-related progressive losses of skeletal muscle mass and strength) that affects 10-16% of adults aged ≥ 60 years worldwide. Concentrations of some amino acids (AAs) such as branched-chain AAs, arginine, glutamine, glycine, and serine are reduced in the plasma of older than young adults likely due to insufficient protein intake, reduced protein digestibility, and increased AA catabolism by the portal-drained viscera. Acute, short-term, or long-term administration of some of these AAs or a mixture of proteinogenic AAs can enhance blood flow to skeletal muscle, activate the mechanistic target of rapamycin cell signaling pathway for the initiation of muscle protein synthesis, and modulate the metabolic activity of the muscle. In addition, some AA metabolites such as taurine, β-alanine, carnosine, and creatine have similar physiological effects on improving muscle mass and function in older adults. Long-term adequate intakes of protein and the AA metabolites can aid in mitigating sarcopenia in elderly adults. Appropriate combinations of animal- and plant-sourced foods are most desirable to maintain proper dietary AA balance.

Effects of Kt/Vurea on outcomes according to age in patients on maintenance hemodialysis

Background

The guidelines recommended target and minimum single-pool Kt/Vurea are 1.4 and 1.2, respectively, in hemodialysis patients. However, the optimal hemodialysis dose remains controversial. We investigated the effects of Kt/Vurea on patient outcomes according to age, with a focus on older patients.

Methods

This study used the hemodialysis quality assessment program and claims datasets. Patients were divided into four subgroups according to age (<65, 65-74, 75-84, and ≥85 years). Each group was divided into three subgroups according to Kt/Vurea : reference (ref) (1.2 ≤ Kt/Vurea ≤ 1.4), low (< 1.2), and high (> 1.4).

Results

The low, ref, and high Kt/Vurea groups included 1668, 8156, and 16 546 (< 65 years); 474, 3058, and 7646 (65-74 years); 225, 1362, and 4194 (75-84 years); and 14, 126, and 455 (≥85 years) patients, respectively. The low Kt/Vurea group had higher mortality rates than the ref Kt/Vurea group irrespective of age [adjusted hazard ratio (aHR), 95% confidence interval (CI): 1.23, 1.11-1.36; 1.14, 1.00-1.30; 1.28, 1.09-1.52; and 2.10, 1.16-3.98, in patients aged <65, 65-74, 75-84, and ≥85 years, respectively]. The high Kt/Vurea group had lower mortality rates than the ref Kt/Vurea group in patients aged <65 and 65-74 years (aHR, 95% Cl: 0.87, 0.82-0.92 and 0.93, 0.87-0.99 in patients aged <65 and 65-74 years, respectively).

Conclusions

These results support the current recommendations of a minimum Kt/Vurea of 1.2 even in patients age ≥85 years. In young patients, Kt/Vurea above the recommended threshold can be beneficial for survival.

Evidence for protein leverage on total energy intake, but not body mass index, in a large cohort of older adults

BACKGROUND

Protein leverage (PL) is the phenomenon of consuming food until absolute intake of protein approaches a 'target value', such that total energy intake (TEI) varies passively with the ratio of protein: non-protein energy (fat + carbohydrate) in the diet. The PL hypothesis (PLH) suggests that the dilution of protein in energy-dense foods, particularly those rich in carbohydrates and fats, combines with protein leverage to contribute to the global obesity epidemic. Evidence for PL has been reported in younger adults, children and adolescents. This study aimed to test for PL and the protein leverage hypothesis (PLH) in a cohort of older adults.

METHODS

We conducted a retrospective analysis of dietary intake in a cohort of 1699 community-dwelling older adults aged 67-84 years from the NuAge cohort. We computed TEI and the energy contribution (EC) from each macronutrient. The strength of leverage of macronutrients was assessed through power functions ( TEI = μ * EC L ). Body mass index (BMI) was calculated, and mixture models were fitted to predict TEI and BMI from macronutrients' ECs.

RESULTS

In this cohort of older adults, 53% of individuals had obesity and 1.5% had severe cases. The mean TEI was 7673 kJ and macronutrients' ECs were 50.4%, 33.2% and 16.4%, respectively for carbohydrates, fat, and protein. There was a strong negative association (L = -0.37; p < 0.001) between the protein EC and TEI. Each percent of energy intake from protein reduced TEI by 77 kJ on average, ceteris paribus. However, BMI was unassociated with TEI in this cohort.

CONCLUSIONS

Findings indicate clear evidence for PL on TEI, but not on BMI, likely because of aging, body composition, sarcopenia, or protein wasting.

Mobility and strength training with and without protein supplements for pre-frail or frail older adults with low protein intake: the Maximising Mobility and Strength Training (MMoST) feasibility randomised controlled trial protocol

Background Frailty is a common syndrome affecting older people and puts them at risk of hospitalisation, needing care or death. First signs of frailty include reduced muscle strength and mobility decline. A key cause of mobility decline as we age is sarcopenia (age related reduction in muscle strength and mass). Poor nutrition contributes to sarcopenia. A shortfall in protein is associated with reduced muscle mass and strength. This may be due to inadequate intake but also because older people have higher protein needs, especially those with multimorbidity. We need to develop effective treatment to reduce or slow the onset of frailty and mobility decline. Exercise is a recommended treatment. Protein supplements to address the shortfall in protein have the potential to enhance the benefit of regular exercise in frail or pre-frail older adults. This has yet to be definitively demonstrated. Aim To establish the feasibility of conducting an RCT evaluating mobility and strength training with or without protein supplements for people over 60 years old who are frail or pre-frail with a low protein intake. Methods A multicentre, parallel, 2-group, feasibility RCT. Participants (recruitment target = 50) with problems walking, low protein intake and classified as frail or pre-frail will be recruited from four NHS Physiotherapy community services. Participants will be randomised (secure computer-generated: 1:1) to receive 24 weeks of mobility and strength training (delivered in 16 group sessions plus home exercises) or 24 weeks of mobility and strength training with daily protein supplements. Primary feasibility objectives are to estimate 1) ability to screen and recruit eligible participants, 2) intervention fidelity, adherence, and tolerance and 3) retention of participants at follow up. Secondary objectives are to 1) test data collection procedures, 2) assess data completeness and 3) confirm sample size calculation for a definitive RCT. Registration ISRCTN Registry (ISRCTN30405954; 18/10/2022).

A narrative review investigating the potential effect of lubrication as a mitigation strategy for whey protein-associated mouthdrying

Whey is consumed by active adults to aid muscle recovery and growth, the general population as a nutritious convenient food, and by older adults to prevent sarcopenia due to its high leucine content. However, whey protein has poor consumer acceptance in this latter demographic, partially due to mouthdrying. This is thought to result from electrostatic interactions between whey and salivary proteins, mucoadhesion to the oral mucosa, and the inherent astringency of acidity. Previous unsuccessful mitigation strategies include viscosity, sweetness and fat manipulation. This literature review reveals support for increasing lubrication to reduce mouthdrying. However, of the 50 papers reviewed, none have proposed a method by which whey protein could be modified as an ingredient to reduce mouthdrying in whey-fortified products. This review recommends the use of modern technologies to increase lubrication as a novel mitigation strategy to reduce mouthdrying, with the potential to increase consumer acceptance.

The Importance of Dietary Protein Quality in Mid- to High-Income Countries

In wealthy countries, the protein intake of adults is usually considered to be adequate, and considerations of protein quality are often deemed irrelevant. The objective was to examine dietary protein intakes of adults in developed countries in the context of dietary protein quality. An analysis of NHANES population data on actual protein intakes in the United States (a developed country) demonstrated that for a dietary Digestible Indispensable Amino Acid Score (DIAAS) of 100%, 11% of the adult (19-50 y) population had habitual protein intakes below the Estimated Average Requirement (EAR) and 22% below the Recommended Dietary Allowance. The percentage of the population with utilizable protein intakes potentially falling below the EAR increased as the assumed DIAAS declined. Analysis of the NHANES data and several other datasets also indicated that total protein intakes can be limiting or close to limiting for the elderly and some vegetarians and vegans. Here, lower dietary protein quality can potentially lead to inadequate utilizable protein intakes. For many people in specific physiological states (e.g., weight loss, endurance sports, resistance exercise) attempting to meet higher dietary protein targets often with accompanying lowered energy intakes, low dietary protein quality can lead to protein calories expressed as a proportion of total calories, falling outside what may be acceptable limits (maximum of 30% protein calories from total calories). In general, individuals within the adult population may be susceptible to macronutrient imbalance (whenever total protein intakes are high, daily energy intakes low) and for diets with lower protein quality (DIAAS <100%). Our analysis shows that dietary protein quality is relevant in mid- to high-income countries.

Animal and vegetable protein intake and malnutrition in older adults: a multicohort study

OBJECTIVES

Malnutrition is a global concern in older adults, as it negatively affects morbidity and mortality. While higher animal protein intake may help prevent and treat malnutrition, it might also increase the risk of chronic diseases and death. Conversely, vegetable protein intake might have a lower anabolic effect and not be as effective to improve nutritional status. We studied whether animal and vegetable protein intake are associated with changes in nutritional status in older adults.

DESIGN

We used pooled data from two Spanish cohorts: the Seniors-ENRICA 1 and Seniors-ENRICA 2.

SETTINGS AND PARTICIPANTS

2,965 community-dwelling adults aged 62-92 years.

MEASUREMENTS

Protein intake was estimated at baseline via an electronic, validated diet history. Nutritional status was assessed at baseline and after 2.6 years with the GLIM (Global Leadership Initiative on Malnutrition) phenotypic criteria: weight loss, low body mass index, and reduced muscle mass. The odds of improvements in nutritional status were assessed with logistic regression models, extensively adjusted for potential confounders.

RESULTS

Higher animal and vegetable protein intake were associated with improvements in nutritional status [odds ratios (95% confidence intervals) per 0.25 g/kg/day were 1.15 (1.00, 1.32) and 1.77 (1.35, 2.32), respectively]. Cereal protein intake drove most of the latter association [2.07 (1.44, 2.98)]. Replacing 0.25 g/kg/day of total animal protein, meat, or fish protein (but not dairy or egg protein) with vegetable protein was associated with improvements in nutritional status [1.54 (1.13, 2.09), 1.70 (1.20, 2.41), and 1.77 (1.18, 2.64), respectively].

CONCLUSIONS

Higher animal and, especially, vegetable protein intake were associated with improvements in nutritional status in older adults. Replacing total animal protein, meat, or fish protein with vegetable protein may help improve malnutrition.

Prevalence and Trends of Weakness Among Middle-Aged and Older Adults in the United States

ABSTRACT

McGrath, R, FitzSimmons, S, Andrew, S, Black, K, Bradley, A, Christensen, BK, Collins, K, Klawitter, L, Kieser, J, Langford, M, Orr, M, and Hackney, KJ. Prevalence and trends of weakness among middle-aged and older adults in the United States. J Strength Cond Res 37(12): 2484-2490, 2023-Muscle weakness, which is often determined with low handgrip strength (HGS), is associated with several adverse health conditions; however, the prevalence and trends of weakness in the United States is not well-understood. We sought to estimate the prevalence and trends of weakness in Americans aged at least 50 years. The total unweighted analytic sample included 22,895 Americans from the 2006-2016 waves of the Health and Retirement Study. Handgrip strength was measured with a handgrip dynamometer. Men with weakness were below at least one of the absolute or normalized (body mass, body mass index) cut points: <35.5 kg, <0.45 kg/kg, <1.05 kg/kg/m 2 . The presence of any weakness in women was also identified as being below one of the absolute or normalized HGS cut points: <20.0 kg, <0.34 kg/kg, or <0.79 kg/kg/m 2 . There was an increasing trend in the prevalence of any weakness over time ( p < 0.001). The prevalence of weakness was 45.1% (95% confidence interval [CI]: 44.0-46.0) in the 2006-2008 waves and 52.6% (CI: 51.5-53.7) in the 2014-2016 waves. Weakness prevalence was higher for older (≥65 years) Americans (64.2%; CI: 62.8-65.5) compared with middle-aged (50-64 years) Americans (42.2%; CI: 40.6-43.8) in the 2014-2016 waves. Moreover, the prevalence of weakness in the 2014-2016 waves was generally higher in women (54.5%; CI: 53.1-55.9) than in men (50.4%; CI: 48.7-52.0). Differences existed in weakness prevalence across races and ethnicities. The findings from our investigation suggest that the prevalence of weakness is overall pronounced and increasing in Americans. Efforts for mitigating and better operationalizing weakness will elevate in importance as our older American population grows.

Vegan diet: nutritional components, implementation, and effects on adults' health

Vegan diet has emerged as a popular dietary choice for people worldwide in recent times, due to concerns such as health issues, animal rights and welfare, and the sustainability of the environment. The purpose of this literature review was to explain how a vegan diet may affect the health of adults and to point out beneficial components found in it as well as any difficulties associated with its implementation. Evidence supports that a vegan diet can reduce the risk of chronic diseases, such as type 2 diabetes, hypertension, and certain types of cancer. A well-planned vegan diet must include adequate calories and nutrients, as well as the necessary supplements, such as vitamin B12, vitamin D and EPA/DHA. Given the current growing interest in plant-based diets among the general population, it is crucial to understand both the barriers, risks, and benefits of the vegan diet among physicians, policy makers, and the general population.

The Health, Aging, and Body Composition (Health ABC) Study-Ground-Breaking Science for 25 Years and Counting

BACKGROUND

The Health, Aging, and Body Composition Study is a longitudinal cohort study that started just over 25 years ago. This ground-breaking study tested specific hypotheses about the importance of weight, body composition, and weight-related health conditions for incident functional limitation in older adults.

METHODS

Narrative review with analysis of ancillary studies, career awards, publications, and citations.

RESULTS

Key findings of the study demonstrated the importance of body composition as a whole, both fat and lean mass, in the disablement pathway. The quality of the muscle in terms of its strength and its composition was found to be a critical feature in defining sarcopenia. Dietary patterns and especially protein intake, social factors, and cognition were found to be critical elements for functional limitation and disability. The study is highly cited and its assessments have been widely adopted in both observational studies and clinical trials. Its impact continues as a platform for collaboration and career development.

CONCLUSIONS

The Health ABC provides a knowledge base for the prevention of disability and promotion of mobility in older adults.

Plasma Levels of Branched Chain Amino Acids, Incident Hip Fractures, and Bone Mineral Density of the Hip and Spine

OBJECTIVE

Branched chain amino acids (BCAA) are building blocks for protein, an essential component of bone. However, the association of plasma levels of BCAA with fractures in populations outside of Hong Kong or with hip fractures in particular is not known. The purpose of these analyses was to determine the relationship of BCAA including valine, leucine, and isoleucine and total BCAA (SD of the sum of Z-scores for each BCAA) with incident hip fractures and bone mineral density (BMD) of the hip and lumbar spine in older African American and Caucasian men and women in the Cardiovascular Health Study.

DESIGN

Longitudinal analyses of association of plasma levels of BCAA with incident hip fractures and cross-sectional BMD of the hip and lumbar spine from the Cardiovascular Health Study.

SETTING

Community.

PARTICIPANTS

A total of 1850 men (38% of cohort) and women; mean age 73 years.

MAIN OUTCOME MEASURES

Incident hip fractures and cross-sectional BMD of the total hip, femoral neck, and lumbar spine.

RESULTS

In fully adjusted models, over 12 years of follow-up, we observed no significant association between incident hip fracture and plasma values of valine, leucine, isoleucine, or total BCAA per 1 SD higher of each BCAA. Plasma values of leucine but not valine, isoleucine, or total BCAA, were positively and significantly associated with BMD of the total hip (P = .03) and femoral neck (P = .02), but not the lumbar spine (P = .07).

CONCLUSIONS

Plasma levels of the BCAA leucine may be associated with higher BMD in older men and women. However, given the lack of significant association with hip fracture risk, further information is needed to determine whether BCAAs would be novel targets for osteoporosis therapies.

The feasibility of a 6-month dietary intervention aiming to increase protein intake among community-dwelling older adults with low habitual protein intake: A secondary analysis of the PROMISS randomised controlled trial

BACKGROUND

The PROMISS randomised controlled trial showed that personalised dietary advice increased protein intake and improved 400-m walk time and leg strength among community-dwelling older adults with a low habitual protein intake. This secondary analysis describes and further evaluates the methods and feasibility of the model used to carry out dietary intervention in the PROMISS randomised controlled trial.

METHODS

In total, 185 participants (≥65 years, 54% women) with a habitual low protein intake (<1.0 g/kg adjusted body weight/day) in Finland and the Netherlands received personalised dietary advice and complimentary protein-enriched food products for 6 months with two main objectives: (1) to increase protein intake to ≥1.2 g/kg adjusted body weight/day (energy-neutral) and (2) to include each day a 'high-protein meal' containing ≥ 30-35 g of protein. The feasibility of the model was evaluated by the adoption of the advice, feedback from the participants, and practical experiences by the nutritionists.

RESULTS

In all, 174 participants (93.5%) completed the intervention. At the 6-month follow-up, 41.8% reached both main objectives of the advice. The participants' general rating for the dietary advice was 8.6 (SD 1.0) (on a scale of 1-10; 10 indicating very good). Sticking to the advice was (very) easy for 79.2% of the participants. The nutritionists perceived the model feasible for the participants except for those with low food intake.

CONCLUSIONS

The methods used in this model are mainly feasible, well-received and effective in increasing protein intake among community-dwelling older adults with low habitual protein intake.

Protein intake and bone health: an umbrella review of systematic reviews for the evidence-based guideline of the German Nutrition Society

This umbrella review aimed at assessing whether a protein intake exceeding the current recommendation for younger (0.8 g/kg body weight [BW]/day) and older (1.0 g/kg BW/day) adults affects bone mineral density and fracture risk. Moreover, the effect of animal or plant protein was evaluated. A systematic literature search was conducted in PubMed, Embase, and Cochrane Database of Systematic Reviews for systematic reviews (SRs) with or without meta-analysis of prospective studies published between 11/2008 and 08/2021. Methodological quality, outcome-specific certainty of evidence, and overall certainty of evidence of the retrieved SRs were assessed using established tools and predefined criteria. Eleven SRs of randomized controlled trials (RCTs) and/or cohort studies were included. In SRs of cohort studies and RCTs, protein intake/kg BW/day ranged between 0.21-0.95 g (low intake) and > 1.24 g (high intake), respectively, and between 0.67-1.1 g (control groups) and 1.01-1.69 g (intervention groups), respectively. The vast majority of outcome-specific certainty of evidence was rated "low" or "very low." The overall certainty of evidence for an association (cohort studies) or effect (RCTs) of total, animal or plant protein intake on each of the investigated outcomes was rated "insufficient," with the exception of possible evidence for a reduced hip fracture risk by high vs. low protein intake. Since protein intakes in low/control and high/intervention groups were very heterogeneous and with low certainty of evidence, it remains unclear whether a dose above the current recommendation or type of protein intake (animal or plant protein) affects bone health overall. However, there is possible evidence for reduced hip fracture risk with high versus low protein intake.

Risk of Sarcopenia and Associated Factors in Older Adults with Type 2 Diabetes: An Exploratory Cross-Sectional Study

BACKGROUND

Evidence on the risk of sarcopenia and associated factors in older adults with type 2 diabetes (T2D) is lacking. We evaluate (1) the proportion of patients at risk of sarcopenia in older adults with T2D; and (2) the factors associated with the risk of sarcopenia.

METHODS

We conducted a cross-sectional study on T2D patients over 65 years referred to our outpatient clinic and who carried out the yearly complication assessment visit. Eligible patients were administered questionnaires during phone interviews for the risk evaluation of sarcopenia (SARC-F), the risk evaluation of malnutrition (Mini Nutritional Assessment Short Form (MNA^®-SF)), the adherence to the Mediterranean diet (MEDI-quest), and the evaluation of physical activity (the International Physical Activity Questionnaire short form).

RESULTS

A total of 138 patients were included in the study, and 12 patients (8.7% (95% CI 4.6-14.7)) were at risk of sarcopenia. The mean SARC-F score was significantly higher in women compared with men (2.1 ± 1.8 vs. 0.9 ± 1.4, respectively; p < 0.001). The majority of patients identified at risk of sarcopenia compared with those not at risk were women (75% vs. 30%, respectively; p = 0.003), had a higher proportion of neuropathy (50% vs. 19%, respectively; p = 0.027), a lower mean MNA^®-SF score (11.6 ± 1.5 vs. 13.0 ± 1.4, respectively; p = 0.001), a lower mean MEDI-quest score (5.2 ± 1.5 vs. 5.9 ± 1, respectively; p = 0.037), and were more inactive (92% vs. 61%, respectively; p = 0.032).

CONCLUSIONS

In a sample of older adults with T2D, the risk of sarcopenia was identified in 8.7% (95% CI: 4.6-14.7) of the sample, and the main factors associated were female gender, neuropathy, a lower MNA^®-SF score, low adherence to the Mediterranean diet, and low physical activity.

Nutrition Education Improves Intakes of Protein, Polyunsaturated Fatty Acids, and Vitamins C and E in Community-Dwelling Older Adults

This study investigated the effect of nutrition education program on protein and nutrient intake, physical performance, and health-related quality of life (HRQoL) in community-dwelling older adults (≥65 years). The participants were randomized in clusters to intervention (IG, n = 51) and control (CG, n = 45) groups. Those in IG took part in the Eating for Strong Aging education program consisting of nutrition education in peer groups, written materials, and personal advice. Nutrient intake was assessed with 3-day food diaries, physical performance with Short Physical Performance Battery (SPPB) and HRQoL with 15-D-QoL instrument. Total of 89 participants completed the study. The mean age was 76 years (IG) and 74 years (CG). At three months, the mean change in protein intake was 0.10 g/adjusted bodyweight (ABW) kg/d in the IG, and -0.07 g/ABW kg/d in the CG (p = 0.024). Intakes of polyunsaturated fatty acids and vitamins C and E increased in the IG compared to the CG (p < 0.05). Changes in SPPB or total HRQoL scores between the IG and the CG did not differ. HRQoL dimension mobility improved in the IG compared to the CG (p = 0.035). In conclusion, the Eating for Strong Aging educational program improved nutrition and may be beneficial for mobility-related QoL.

"Diet for the prevention and management of sarcopenia"

Sarcopenia is a geriatric condition characterized by a progressive loss of skeletal muscle mass and strength, with an increased risk of adverse health outcomes (e.g., falls, disability, institutionalization, reduced quality of life, mortality). Pharmacological remedies are currently unavailable for preventing the development of sarcopenia, halting its progression, or impeding its negative health outcomes. The most effective strategies to contrast sarcopenia rely on the adoption of healthier lifestyle behaviors, including adherence to high-quality diets and regular physical activity. In this review, the role of nutrition in the prevention and management of sarcopenia is summarized. Special attention is given to current "blockbuster" dietary regimes and agents used to counteract age-related muscle wasting, together with their putative mechanisms of action. Issues related to the design and implementation of effective nutritional strategies are discussed, with a focus on unanswered questions on the most appropriate timing of nutritional interventions to preserve muscle health and function into old age. A brief description is also provided on new technologies that can facilitate the development and implementation of personalized nutrition plans to contrast sarcopenia.

Dietary protein requirements and recommendations for healthy older adults: a critical narrative review of the scientific evidence

Adequate protein intake is essential for the maintenance of whole-body protein mass. Different methodological approaches are used to substantiate the evidence for the current protein recommendations, and it is continuously debated whether older adults require more protein to counteract the age-dependent loss of muscle mass, sarcopenia. Thus, the purpose of this critical narrative review is to outline and discuss differences in the approaches and methodologies assessing the protein requirements and, hence, resulting in controversies in current protein recommendations for healthy older adults. Through a literature search, this narrative review first summarises the historical development of the Food and Agriculture Organization/World Health Organization/United Nations University setting of protein requirements and recommendations for healthy older adults. Hereafter, we describe the various types of studies (epidemiological studies and protein turnover kinetic measurements) and applied methodological approaches founding the basis and the different recommendations with focus on healthy older adults. Finally, we discuss important factors to be considered in future studies to obtain evidence for international agreement on protein requirements and recommendations for healthy older adults. We conclude by proposing future directions to determine 'true' protein requirements and recommendations for healthy older adults.

Dietary Protein Intake and Physical Function in Māori and Non-Māori Adults of Advanced Age in New Zealand: LiLACS NZ

The population of older adults is growing exponentially. Research shows that current protein intake recommendations are unlikely to meet the ageing requirements and may be linked to reduced physical function. Ensuring optimal function levels is crucial for independence and quality of life in older age. This study aims to quantify the protein intake in those over 90 years of age and determine the association between historical protein intake (2011) and subsequent physical function at ten years follow-up (2021). Eighty-one participants (23 Māori and 54 non-Māori) undertook dietary assessment 24 h multiple-pass recall (MPR) and a standardised health and social questionnaire with physical assessment in 2011 and 2021. Intake24, a virtual 24 h MPR, was utilised to analyse dietary intake. Functional status was measured using the Nottingham Extended Activities of Daily Living Scale (NEADL), and physical performance was the Short Physical Performance Battery (SPPB). Māori men and women consumed less protein (g/day) in 2021 than in 2011 (P = 0.043 in men), but weight-adjusted protein intake in Māori participants over the ten years was not significantly reduced. Both non-Māori men and women consumed significantly less protein (g/day) between 2011 and 2021 (p = 0.006 and p = 0.001, respectively), which was also significant when protein intake was adjusted for weight in non-Māori women (p = 0.01). Weight-adjusted protein intake in 2011 was independently associated with functional status (NEADL score) in 2021 (p =< 0.001). There was no association between past protein intake and SPPB score (p = 0.993). Animal protein was replaced with plant-based protein over time. In conclusion, a reduction in protein intake was seen in all participants. The independent association between past protein intake and future functional status supports recommendations to keep protein intake high in advanced age.

Sarcopenia: prevalence and its main risk factors in older women

Introduction: Sarcopenia is a major public health concern. It is defined as a progressive and gen­eralized skeletal muscle disorder that is associated with an increased likelihood of falls, fractures, physical disability, and ultimately, premature death.   Objective: The aim of the study was to assess the prevalence and determine the role of physical activity, nutrient intake, and selected risk factors for the development of sarcopenia in older women.   Methods: The study involved 302 women aged ≥65 years (mean age: 72.1± 5.9 years). Bioelectrical impedance analysis of body composition, static muscle strength measurements, Timed Up and Go test, and the assessment of current physical activity using accelerometers were performed. Diets were assessed using the 24-h recall method from two non-consecutive days. The energy and nutrient content of diets was calculated using the computer program DIETA 6.   Results: Sarcopenia was present in 28.8% of the women studied. The most important factor in the decrease in the risk of sarcopenia was protein intake ≥ 0.9 g/kg b.m. (OR=0.08;p<0.001), and physical activity ≥ 4000 steps/day. However, these results were not statistically significant (OR=0.58; p=0.08). Furthermore, the risk of developing sarcopenia increased as BMI (OR=1.36; p<0.001) or percent of body fat (OR=1.29; p<0.001) increased.

High Protein Intake at Lunch Is Negatively Associated with Blood Pressure in Community-Dwelling Older Adults: A Cross-Sectional Study

BACKGROUND

The present study was conducted to explore the association between protein intake across the main meals and hypertension (HTN)-related parameters in community-dwelling Brazilian older adults.

METHODS

Brazilian community-dwelling older adults were recruited in a senior center. Dietary habits were assessed through 24 h recall. Protein intake was classified as high and low according to median and recommended dietary allowance values. Absolute and body weight (BW)-adjusted protein consumption levels were quantified and analyzed according to ingestion across the main meals. Systolic (SBP) and diastolic blood pressure (DBP) were measured using an oscilometric monitor. Participants were categorized as hypertensive according to physician diagnosis or the detection of high SBP and/or DBP values.

RESULTS

One hundred ninety-seven older adults were enrolled in the present study. Protein intake at lunch was independently and negatively associated with SBP. Furthermore, a lower prevalence of HTN (diagnosed by a physician) was observed in participants with higher intakes of protein. These results remained significant after adjustment for many covariates. However, significance was lost when kilocalories and micronutrients were included in the model.

CONCLUSIONS

Findings of the present study indicate that protein intake at lunch was independently and negatively associated with systolic BP in community-dwelling older adults.

Validation of the German version of the Protein Screener 55

BACKGROUND/OBJECTIVES

The Protein Screener 55 + (Pro55 + ) is a brief food questionnaire to screen older community-dwelling adults for low protein intake. The result is the predicted probability of protein intake <1.0 g/kg adjusted body weight (aBW)/d ranging from 0-1. For purposes of cross-cultural validation, we translated the Pro55+ into German and tested its discriminative accuracy in detecting low protein intake of older community-dwelling people in Germany.

SUBJECTS/METHODS

After translation and pilot-testing, the Pro55+ and the reference standard (3-day dietary record) were completed by 144 participants (81.6 ± 3.9 years, 61.8% female). Discriminative properties were tested by receiver operating characteristic curves and by calculating sensitivity and specificity for different cut-offs of predicted probability (>0.3/>0.5/>0.7) using <1.0 or <0.8 g/kg aBW/d to define low protein intake.

RESULTS

Protein intake was <1.0 g/kg aBW/d in 39.6% of the sample and <0.8 g/kg aBW/d in 17.4%. Area under the curve was 62.0% (95%CI 52.6-71.5) and 68.8% (58.1-79.4), respectively. Specificity was 82-90% using probability cut-offs of 0.5 and 0.7 for both protein thresholds. Sensitivity was poor for protein threshold of 1.0 g/kg aBW/d regardless of the used probability cut-offs. For protein threshold of <0.8 g/kg aBW/d, sensitivity was 88.0% (71.8-96.9) using a probability cut-off of 0.09.

CONCLUSION

The overall discriminative accuracy of the German Pro55+ to identify older community-dwelling people with low protein intake was poor. However, applying different probability cut-offs allows increasing specificity and sensitivity for 0.8 g/kg aBW/d to levels justifying the use for certain purposes e.g. excluding individuals with adequate protein intake. Further validation is needed.

Alternative dietary protein sources to support healthy and active skeletal muscle aging

To mitigate the age-related decline in skeletal muscle quantity and quality, and the associated negative health outcomes, it has been proposed that dietary protein recommendations for older adults should be increased alongside an active lifestyle and/or structured exercise training. Concomitantly, there are growing environmental concerns associated with the production of animal-based dietary protein sources. The question therefore arises as to where this dietary protein required for meeting the protein demands of the rapidly aging global population should (or could) be obtained. Various non-animal-derived protein sources possess favorable sustainability credentials, though much less is known (compared with animal-derived proteins) about their ability to influence muscle anabolism. It is also likely that the anabolic potential of various alternative protein sources varies markedly, with the majority of options remaining to be investigated. The purpose of this review was to thoroughly assess the current evidence base for the utility of alternative protein sources (plants, fungi, insects, algae, and lab-grown "meat") to support muscle anabolism in (active) older adults. The solid existing data portfolio requires considerable expansion to encompass the strategic evaluation of the various types of dietary protein sources. Such data will ultimately be necessary to support desirable alterations and refinements in nutritional guidelines to support healthy and active aging, while concomitantly securing a sustainable food future.

Effect of personalized dietary advice to increase protein intake on food consumption and the environmental impact of the diet in community-dwelling older adults: results from the PROMISS trial

PURPOSE

Diet modelling studies suggest that increasing protein intake with no consideration for sustainability results in a higher environmental impact on the diet. To better understand the impact in real life, the aim of this study was to assess the effect of dietary advice to increase protein intake on food consumption and the environmental impact of the diet in community-dwelling older adults.

METHODS

Food consumption and environmental impact were analyzed among 124 Dutch older adults with lower habitual protein intake (< 1.0 g/kg adjusted body weight/day) participating in the six-month PROMISS trial. Dietary intake data from three 24-h dietary recalls, aided by food diaries, and results from life cycle assessments were used to examine the differences in changes in food consumption and environmental impact between those who received dietary advice to isocalorically increase protein intake to ≥ 1.2 g/kg aBW/d (Protein + ; n = 84) and those who did not receive dietary advice (Control; n = 40).

RESULTS

Compared to the Control, Protein + increased protein intake from animal-based food products (11.0 g protein/d, 95% CI 6.6-15.4, p < 0.001), plant-based food products (2.1 g protein/d, 95% CI 0.2-4.0, p = 0.031) and protein-enriched food products provided during the trial (18 g protein/d, 95% CI 14.5-21.6, p < 0.001) at the 6-month follow-up. Diet-associated greenhouse gas emissions increased by 16% (p < 0.001), land use by 19% (p < 0.001), terrestrial acidification by 20% (p = 0.01), and marine eutrophication by 16% (p = 0.035) in Protein + compared to the Control.

CONCLUSION

This study found that dietary advice increased protein intake, favoring animal-based protein, and increased the environmental impact of the diet in older adults.

TRIAL REGISTRATION

ClinicalTrials.gov. NCT03712306. October 2018.

Promoting Protein Intake in an Ageing Population: Product Design Implications for Protein Fortification

Protein is a macronutrient of interest for an ageing population and intake requirements increase with age. Accordingly, protein is often fortified into products for older adults to help alleviate malnutrition and impede sarcopenia. However, more emphasis needs to be placed upon designing protein-fortified products to ensure suitability for older adults. This study involved a two-stage approach: (1) an initial review of products commonly fortified with protein and (2) two questionnaires for younger and older adults (n = 73; 18-30; 65+) to investigate optimal portion sizes (drinks and cakes) as well as attitudes, consumption habits and preferences towards protein fortification. The initial literature and market review demonstrated protein-fortified products are typically in liquid or snack format; however, there is considerable variability in terms of product types, serving size and protein sources. There were no age-related differences found for ideal cakes portion size whereas there were for liquids. Older adults are typically not consuming protein-fortified products; therefore, more importance should be placed on the consumption moment (breakfast or as snacks between meals) and on cereals, pasta, porridge, cakes, and biscuits. Older adults need increased awareness of, and more education on, the benefits of protein consumption, coupled with products tailored and designed to encourage intake.

Determinants of muscle density and clinical outcomes: Findings from the Hertfordshire Cohort Study

PURPOSE

The age-related loss of skeletal muscle mass and strength is associated with adverse health outcomes. However, to date, peripheral quantitative computed tomography (pQCT)-derived muscle density has been little studied. We used a well characterised cohort of older adults to identify lifestyle and anthropometric determinants of pQCT-derived muscle density measured 11 years later, and to report relationships between pQCT-derived muscle density with history of falls and prevalent fractures.

METHODS

A lifestyle questionnaire was administered to 197 men and 178 women, aged 59-70 at baseline. After a median of 11.5 (IQR 10.9, 12.3) years, pQCT (Stratec XCT2000) of the radius and tibia was performed to measure forearm muscle density (FMD) and calf muscle density (CMD). Presence of falls and fractures since the age of 45 were determined through participant recall; vertebral fractures were also ascertained through vertebral fracture assessment using iDXA. Total hip BMD (TH aBMD) was assessed using DXA. Baseline characteristics in relation to muscle density at follow-up were examined using linear regression; associations between muscle density and prior falls and fractures were investigated using logistic regression. All analyses were adjusted for sex and age.

RESULTS

Mean (SD) age at muscle density measurement was 76.3 (2.6) years. Mean (SD) FMD was 79.9 (3.1) and 77.2 (3.2) among males and females, respectively; CMD was 80.7 (2.6) and 78.5 (2.6) among males and females, respectively. Significant sex-differences in muscle density were observed at each site (p < 0.001). Female sex, lower weight, and lower body mass index were associated (p < 0.05) with both lower FMD and CMD. Additional correlates of lower CMD included older age and shorter stature. Lifestyle measures were not associated with muscle density in this cohort. Lower FMD was related to increased risk of previous fracture (odds ratio (95 % CI) per SD lower FMD: 1.42 (1.07, 1.89), p = 0.015) but not after adjustment for TH aBMD (p > 0.08). No significant relationships were seen between muscle density and falls.

CONCLUSION

Female sex, older age, and lower BMI were associated with subsequent lower muscle density in older community-dwelling adults. Lower FMD was related to increased risk of previous fracture. Changes in muscle density over time might precede adverse outcomes such as falls and fractures and may be a long-term predictor of frailty. It could be also suggested that muscle density could be a more clinically meaningful surrogate of functional decline and disability than muscle size or mass, but more studies are needed to support this notion.

Protein intake and physical function in older adults: A systematic review and meta-analysis

BACKGROUND

The present study explored cross-sectional and longitudinal associations between protein intake and physical function in older adults.

METHODS

We conducted a systematic review and meta-analysis of cross-sectional and longitudinal studies that investigated the association between protein intake and measures of physical function in older adults. Cross-sectional, case-control, and longitudinal cohort studies that investigated the association between protein intake and physical function as a primary or secondary outcome in people aged 60 + years were included. Studies published in languages other than English, Italian, Portuguese, or Spanish were excluded. Studies were retrieved from MEDLINE, SCOPUS, EMBASE, CINAHL, AgeLine, and Food Science Source databases through January 31, 2022. A pooled effect size was calculated based on standard mean differences (SMD), MD, log odds ratio (OR) and Z-score..

RESULTS

Twenty-two cross-sectional studies examined a total of 11,332 community-dwellers, hospitalized older adults, and elite senior athletes with a mean age of approximately 75 years. The pooled analysis indicated that a protein intake higher than the recommended dietary allowance (RDA) was significantly associated with higher Short Physical Performance Battery (SPPB) scores (SMD: 0.63, 95% CI: 0.27, 0.99, P-value: 0.0006), faster walking speed, greater lower-limb (SMD: 0.22, 95% CI: 0.04, 0.40, P-value: 0.02) and isometric handgrip strength (Z-score: 0.087, 95% CI: 0.046-0.128, P-value: 0.0001), and better balance (SMD: 0.33, 95% CI: 0.05, 0.62, P-value: 0.02). Nine longitudinal studies investigated 12,424 community-dwelling and native older adults with a mean age of approximately 85 years. A protein intake higher than the current RDA was not associated with lower decline in either isometric handgrip strength (logOR: 0.99, 95% CI: 0.97-1.02, P-value= 0.67) or walking speed (logOR: 0.92, 95% CI: 0.77-1.10, P-value= 0.35).

CONCLUSIONS

A protein intake higher than the RDA is cross-sectionally associated with better physical performance and greater muscle strength in older adults. However, a high consumption of proteins does not seem to prevent physical function decline over time.

Protein Intake and Oral Health in Older Adults-A Narrative Review

Oral health is vital to general health and well-being for all ages, and as with other chronic conditions, oral health problems increase with age. There is a bi-directional link between nutrition and oral health, in that nutrition affects the health of oral tissues and saliva, and the health of the mouth may affect the foods consumed. Evidence suggests that a healthy diet generally has a positive impact on oral health in older adults. Although studies examining the direct link between oral health and protein intake in older adults are limited, some have explored the relationship via malnutrition, which is also prevalent among older adults. Protein-energy malnutrition (PEM) may be associated with poor oral health, dental caries, enamel hypoplasia, and salivary gland atrophy. This narrative review presents the theoretical evidence on the impact of dietary protein and amino acid composition on oral health, and their combined impact on overall health in older adults.

Nutritional intake and malnutrition in institutionalised and non-institutionalised older adults

Malnutrition (synonym: undernutrition) is prevalent among older adults, which may be partly related to changes in dietary intake, but evidence on the link between malnutrition and diet is scarce. The aims of this study were to estimate the association between energy/nutrients intake and malnutrition, and to characterise nutritional inadequacy in institutionalised and non-institutionalised older adults. A national survey was conducted including a Portuguese representative sample of nursing home (NH) residents (n 563) and community-dwellers (n 837) aged ≥ 65 years. Data included socio-demographic characteristics, self-reported health, loneliness feelings, nutritional status (Mini Nutritional Assessment^®) and dietary intake (two non-consecutive 24-h recalls). A higher energy intake was associated with lower odds of malnutrition risk (being 'at risk of malnutrition' or 'malnourished') in both settings, but only significant among NH residents after adjusting for confounders (NH: OR = 0·66, 95 % CI 0·50, 0·86; community: OR = 0·64, 95 % CI 0·37, 1·10). The intake of carbohydrates, fat, fibre, vitamin C, Na, K and Mg was inversely associated with malnutrition risk in NH residents, and protein, fat, vitamin B₆, folates, Na, K, Ca and Mg intake in community-dwellers. After additional adjustment for total energy, only Na and Mg intake of community-dwellers remained significantly associated. The prevalence of inadequate nutrient intake was generally higher for the malnutrition risk group, which was particularly evident among community-dwellers. The effect of dietary intake on nutritional status seems more dependent on total energy and carbohydrates intake in institutionalised elders, whereas among community-dwellers protein and some micronutrients appear to have a greater impact.

Does Internet Use Connect Us to a Healthy Diet? Evidence from Rural China

Dietary patterns in China have changed dramatically over the past few decades as the Internet has become rapidly available. Based on data from the China Health and Nutrition Survey (2006–2011), we use a two-way fixed effects model and an instrumental variable approach to determine the impact of Internet use on the dietary quality of rural residents. The results indicate that Internet use could significantly improve the dietary quality of Chinese rural residents, with an increase of about 10.4% in the China Food Pagoda Score (CFPS), mainly due to the increase in the dietary quality score for five food groups: fruits, meats, eggs, oil, and salt. We also found that Internet use significantly increased the consumption amounts of milk and its products (4 g), fruits (31 g), eggs (8 g), and vegetables (34 g), while also decreasing the intake of salts (2 g) and oil (6 g). A possible mechanism is that Internet use improves the dietary knowledge of rural residents, thus optimizing their dietary structure. Moreover, the effect of the Internet was greater among females and those who prepare food for a family. Rural residents without a college degree enjoyed more benefits. In summary, governments should further promote Internet penetration in rural areas for health purposes.

Role of muscle-targeted nutritional therapy: new data

PURPOSE OF REVIEW

To provide an updated overview of recent efficacy data on the use of muscle-targeted nutritional therapy, which should consider the optimization of protein and essential amino acids intakes, possibly in combination with supplementation with vitamin D (correction of deficiency/insufficiency status) and v-3 fatty acids.

RECENT FINDINGS

Intervention studies conducted in the last years in different healthcare settings and heterogeneous patient populations support the use of muscle-targeted oral nutritional supplementation to improve muscle mass, function and physical performance in patients with sarcopenia. Higher efficacy is likely to be achieved in combination with individually tailored resistance exercise training programs and when nutritional therapy and the provision of specific nutrients result in an adequate protein-calorie balance. However, not only a reactive but also a pro-active application of this therapy could be proposed as evidence exists on the maintenance of or improvement in the same outcome variables in patients at risk of losing skeletal muscle mass.

SUMMARY

Based on available efficacy data, both a reactive and pro-active use of muscle-targeted nutritional therapy are promising and should be proposed. However, future research should be directed toward the management of patient populations characterized by substantial muscle wasting, as these have been frequently excluded from previous trials, perhaps to avoid confounding.

Increases in protein intake, protein distribution score, and micronutrient intakes in older adults in response to a whole food-based dietary intervention

BACKGROUND

Changes in nutrient intakes and protein distribution were analyzed in response to a whole food-based dietary intervention targeting high-protein meals in older adults.

METHODS

Community-dwelling older adults (n = 56; M/F, 28/28; age, 69.3 ± 4.0 years) completed a 12-week intervention after randomization to exercise only (EX, n = 19), nutrition only (NUTR, n = 16), or nutrition plus exercise (NUTR + EX, n = 21). NUTR and NUTR + EX followed a dietary intervention targeting ~ 0.4 g/kg of protein at each of breakfast, lunch and dinner.

RESULTS

Relative protein intake increased in NUTR (0.99 ± 0.34 to 1.43 ± 0.39 g/kg, P < 0.001) and NUTR + EX (0.90 ± 0.20 to 1.57 ± 0.49 g/kg, P < 0.001). Intakes of cholesterol, B vitamins, selenium and iodine were increased in both NUTR and NUTR + EX (P < 0.05 for all).

CONCLUSION

This dietary intervention was effective at increasing daily protein intake and achieving an even distribution pattern. Changes in micronutrient intake were marked, and reflect the increase in consumption of animal-derived protein-rich food sources.

Disparities in Nutritional Adequacy of Diets between Different Socioeconomic Groups of Finnish Adults

Information on dietary adequacy is needed to assess food and nutrition security in a modern society, especially in the transition towards climate-friendly food systems. In this study, differences in the nutritional adequacy of diets among Finnish adults were evaluated in population groups of different education, income and urbanisation levels. The study used data from the FinDiet 2017 Survey (n = 1655, 18-74 years). Modelled usual intakes of foods and nutrients were evaluated relative to food-based dietary guidelines issued by the National Nutrition Council of Finland (FNNC) and with respect to nutrient adequacy following the Nordic Nutrition Recommendations and FNNC. For about half of the nutrients studied, intakes were found to be adequate. Intakes of protein, fat, saturated fatty acids and salt were estimated to be high. By contrast, inadequate intakes were seen in folate and vitamins A, D, B1, B2 and C in almost all groups studied. Groups with a higher education and income, groups that lived in urban areas and, in particular, women adhered more closely to recommended food consumption and nutrient intakes than others. However, major challenges posed by the Finnish diet are common to all groups studied, and only certain dietary features evaluated in view of nutritional adequacy are associated with socioeconomic differences.

Perspective: Vegan Diets for Older Adults? A Perspective On the Potential Impact On Muscle Mass and Strength

Consumers are increasingly encouraged to consume more plant-based foods and lower their consumption of foods from animal origin. Concurrently, older adults are recommended to consume an adequate amount of high-quality dietary protein for the prevention of age-related muscle loss. In the current Perspective article, we discuss why it may not be preferred to consume a vegan diet at an older age. Our perspective is based on the proposed lower bioavailability and functionality of proteins in a vegan diet due to the matrix of the whole-food protein sources, the lower essential amino acid (EAA) content, and specific EAA deficiencies in proteins derived from plant-based foods. We propose that a vegan diet increases the risk of an inadequate protein intake at an older age and that current strategies to improve the anabolic properties of plant-based foods are not feasible for many older adults. We provide recommendations for further research to substantiate the remaining knowledge gaps regarding the consequences of a vegan diet on skeletal muscle mass and strength at an older age.

The Acute Effects of Breakfast Drinks with Varying Protein and Energy Contents on Appetite and Free-Living Energy Intake in UK Older Adults

Proposed strategies for preventing protein deficiencies in older patients include increasing protein intake at breakfast. However, protein is highly satiating and the effects of very high protein intakes at breakfast on subsequent appetite and free-living energy intake (EI) in older adults are unclear. This study compared the acute effects of two breakfast drinks varying in protein and energy contents on appetite and free-living EI in healthy older adults using a randomized 2 × 2 crossover design. Participants (n = 48 (20 men, 28 women); mean ± SD age: 69 ± 3 years; BMI: 22.2 ± 2.0 kg·m⁻²; fat-free mass: 45.5 ± 8.0 kg) consumed two drinks for breakfast (high-protein (30.4 ± 5.3 g), low-energy (211.2 ± 37.1 kcal) content (HPLE) and very high-protein (61.8 ± 9.9 g), fed to energy requirements (428.0 ± 68.9 kcal) (VHPER)) one week apart. Appetite perceptions were assessed for 3 h post-drink and free-living EI was measured for the remainder of the day. Appetite was lower in VHPER than HPLE from 30 min onwards (p < 0.01). Free-living energy and protein intake did not differ between conditions (p = 0.814). However, 24 h EI (breakfast drink intake + free-living intake) was greater in VHPER than HPLE (1937 ± 568 kcal vs. 1705 ± 490 kcal; p = 0.001), as was 24 h protein intake (123.0 ± 26.0 g vs. 88.6 ± 20.9 g; p < 0.001). Consuming a very high-protein breakfast drink acutely suppressed appetite more than a low-energy, high-protein drink in older adults, though free-living EI was unaffected. The long-term effects of adopting such a breakfast strategy in older adults at high risk of energy and protein malnutrition warrants exploration.

Low awareness of community-dwelling older adults on the importance of dietary protein: new insights from four qualitative studies

Meeting the recommended daily protein intake can be a challenge for community-dwelling older adults (CDOA). In order to understand why, we studied attitudes towards protein-rich products and healthy eating in general; identified needs and preferences, barriers and promotors and knowledge regarding dietary behaviour and implementation of high protein products. Attitudes towards protein-rich products and healthy eating were evaluated in focus groups (study 1, n 17). To gain insights in the needs and preferences of older adults with regard to meals and meal products (study 2, n 30), visual information on eating behaviour was assessed using photovoicing and verified in post-photovoice interviews. In studies 3 and 4, semi-structured interviews were conducted to identify protein consumption-related barriers, opportunities (n 20) and knowledge and communication channels (n 40), respectively. Risk of low protein intake was assessed using ProteinScreener55+ (Pro55+) in studies 2–4 (n 90). Focus groups showed that participants were unaware of potential inadequate dietary protein. Photovoicing showed that sixteen of thirty participants mainly consumed traditional Dutch products. In post-photovoice interviews, participants indicated that they were satisfied with their current eating behaviour. Barriers for adequate use of protein-rich products were ‘lack of knowledge’, ‘resistance to change habits’ and ‘no urge to receive dietary advice’. Promotors were ‘trust in professionals’ and ‘product offers’. Sixty-two percent had a low risk of low protein intake. CDOA feel low urgency to increase protein intake, possibly linked to low knowledge levels. A challenge for professionals would be to motivate older adults to change their eating pattern, to optimise protein intake.

Effectiveness of a Per-Meal Protein Prescription and Nutrition Education with versus without Diet Coaching on Dietary Protein Intake and Muscle Health in Middle-Aged Women

Sufficient dietary protein intake is vital to maintaining muscle health with aging. Yet protein intake among adults is often inadequate. This study's main objective was to examine the impact of nutrition education (NE) and a per-meal protein prescription (PRx) with versus without diet coaching on protein intake. A secondary objective examined its effects on muscle health. Participants included 53 women, age 45-64 years. All participants received NE and PRx; those randomized to coached-group received 10-weeks of diet coaching. Assessments included: protein intake at baseline, weeks 4 and 12 and muscle health (muscle mass, grip strength, five-chair rise test, 4 mgait speed test). The Chi-square test examined percentages of participants meeting PRx between groups. Repeated measures analysis of variance assessed within group and intervention effects on protein intake and muscle health parameters. Protein intake (g/kg body weight) increased (p < 0.001): not-coached (n = 28) 0.8 ± 0.2 to 1.2 ± 0.3 and coached (n = 25) 1.0 ± 0.2 to 1.4 ± 0.3 with no significant difference between groups. A greater percentage of coached-group participants met (p = 0.04) breakfast (72%) and met (p < 0.001) three-meal (76%) PRx versus not-coached participants (25% and 53%, respectively). Participants in both groups exhibited significantly (p < 0.001) improved times for the five-chair rise test and 4 mgait speed test. Diet coaching in conjunction with a PRx and NE should be considered to assist individuals in improving protein intake through self-selection of protein-rich foods.

Independent Determinants of Appetite Impairment among Patients with Stage 3 or Higher Chronic Kidney Disease: A Prospective Study

Protein-energy wasting (PEW) is an important complication resulting from chronic kidney disease (CKD). Appetite impairment contributes significantly to PEW in these patients, but risk factors associated with having appetite impairment in patients with CKD remain elusive. Patients with an estimated glomerular filtration rate <60 mL/min/1.73 m² for ≥2 times at least three months apart were prospectively enrolled during 2017, with their demographic features, comorbidities, anthropometric parameters, physical and performance indices, functional status, frailty, sensory organ integrity, and laboratory data collected. Their appetite status was measured using the Council on Nutrition Appetite Questionnaire (CNAQ). We examined independent determinants of appetite impairment in these CKD patients using multiple regression analyses. Among 78 patients with CKD, 42.3% had CNAQ-identified impaired appetite. Those with an impaired appetite also had poorer physical performance, a higher degree of functional impairment, higher frail severities, lower serum sodium levels, less intact oral cavity, and a trend toward having less intact nasal structures than those without. Multiple regression analyses revealed that a higher frail severity, in the forms of increasing Study of Osteoporotic Fractures (SOF) scores (odds ratio (OR), 2.74; 95% confidence interval (CI), 1.15–6.57) and a less intact nasal structure (OR, 0.96; 95% CI, 0.92–0.995) were associated with a higher probability of having an impaired appetite, while higher serum sodium (OR, 0.76; 95% CI, 0.6–0.97) correlated with a lower probability. Based on our findings, in patients with CKD, the severity of frailty, serum sodium, and nasal structural integrity might modify appetite status. Therapies targeting these factors might be beneficial for appetite restoration in patients with CKD.

Malnutrition in Older Adults-Recent Advances and Remaining Challenges

Malnutrition in older adults has been recognised as a challenging health concern associated with not only increased mortality and morbidity, but also with physical decline, which has wide ranging acute implications for activities of daily living and quality of life in general. Malnutrition is common and may also contribute to the development of the geriatric syndromes in older adults. Malnutrition in the old is reflected by either involuntary weight loss or low body mass index, but hidden deficiencies such as micronutrient deficiencies are more difficult to assess and therefore frequently overlooked in the community-dwelling old. In developed countries, the most cited cause of malnutrition is disease, as both acute and chronic disorders have the potential to result in or aggravate malnutrition. Therefore, as higher age is one risk factor for developing disease, older adults have the highest risk of being at nutritional risk or becoming malnourished. However, the aetiology of malnutrition is complex and multifactorial, and the development of malnutrition in the old is most likely also facilitated by ageing processes. This comprehensive narrative review summarizes current evidence on the prevalence and determinants of malnutrition in old adults spanning from age-related changes to disease-associated risk factors, and outlines remaining challenges in the understanding, identification as well as treatment of malnutrition, which in some cases may include targeted supplementation of macro- and/or micronutrients, when diet alone is not sufficient to meet age-specific requirements.

Low protein intake, physical activity, and physical function in European and North American community-dwelling older adults: a pooled analysis of four longitudinal aging cohorts

BACKGROUND

Dietary protein may slow the decline in muscle mass and function with aging, making it a sensible candidate to prevent or modulate disability progression. At present, studies providing reliable estimates of the association between protein intake and physical function, and its interaction with physical activity (PA), in community-dwelling older adults are lacking.

OBJECTIVES

We investigated the longitudinal relation between protein intake and physical function, and the interaction with PA.

METHODS

We undertook a pooled analysis of individual participant data from cohorts in the PROMISS (PRevention Of Malnutrition In Senior Subjects in the European Union) consortium (the Health Aging and Body Composition Study, Quebec Longitudinal Study on Nutrition and Successful Aging, Longitudinal Aging Study Amsterdam, and Newcastle 85+) in which 5725 community-dwelling older adults were followed up to 8.5 y. The relation between protein intake and walking speed was determined using joint models (linear mixed-effects and Cox proportional hazards models) and the relation with mobility limitation was investigated using multistate models.

RESULTS

Higher protein intake was modestly protective of decline in walking speed in a dose-dependent manner [e.g., protein intake ≥1.2 compared with 0.8 g/kg adjusted body weight (aBW)/d: β = 0.024, 95% CI: 0.009, 0.032 SD/y], with no clear indication of interaction with PA. Participants with protein intake ≥0.8 g/kg aBW/d had also a lower likelihood of incident mobility limitation, which was observed for each level of PA. This association seemed to be dose-dependent for difficulty walking but not for difficulty climbing stairs. No associations between protein intake and other mobility limitations transitions were observed.

CONCLUSIONS

Higher daily protein intake can reduce physical function decline not only in older adults with protein intake below the current RDA of 0.8 g/kg BW/d, but also in those with a protein intake that is already considered sufficient. This dose-dependent association was observed for each level of PA, suggesting no clear synergistic association between protein intake and PA in relation to physical function.