Animal protein intake is inversely associated with mortality in older adults: the InCHIANTI study

Associations of serum albumin and dietary protein intake with all-cause mortality in community-dwelling older adults at risk of sarcopenia

Objective

The Asian Working Group for Sarcopenia 2019 consensus emphasized nutritional assessment and intervention for community-dwelling older people with sarcopenia status. This study aimed to examine the association of serum albumin and dietary protein intake (DPI) with all-cause mortality among older adults at risk of sarcopenia.

Methods

We enrolled 1763 older adults at risk of sarcopenia in the Chinese Longitudinal Healthy Longevity Survey (2012-2018) using calf circumference and handgrip strength. Serum albumin concentrations were measured using bromocresol green methods, and DPI frequency was evaluated using a semi-quantitative questionnaire at baseline. Cox proportional hazards models were used to explore the association of serum albumin and DPI with all-cause mortality.

Results

During 5606.3 person-years of follow-up (median: 3.28 years), 802 older people died. After adjusting for socio-demographics, health behaviors, and clinical characteristics, we observed an inverse linear association between serum albumin and all-cause mortality (Pnon-linear = 0.429). Participants with low albumin levels (<40.0 g/L) had a 43 % higher risk of mortality than their counterparts (hazard ratio (HR) = 1.43, 95 % confidence interval (CI) = 1.22-1.66). There was no significant association between DPI and mortality (Ps > 0.05). Moreover, the association between low albumin and all-cause mortality remained significant in the lower DPI subgroup (HR = 1.47, 95 % CI = 1.18-1.85), but was not significant in the high DPI subgroup (HR = 1.15, 95 % CI = 0.92-1.39).

Conclusions

Serum albumin levels are inversely associated with all-cause mortality in community-based older adults at risk of sarcopenia. Sufficient dietary protein consumption may attenuate the effect of low serum albumin on increased mortality and potential mechanisms for the interaction warrant further exploration.

Accelerated Aging Induced by an Unhealthy High-Fat Diet: Initial Evidence for the Role of Nrf2 Deficiency and Impaired Stress Resilience in Cellular Senescence

High-fat diets (HFDs) have pervaded modern dietary habits, characterized by their excessive saturated fat content and low nutritional value. Epidemiological studies have compellingly linked HFD consumption to obesity and the development of type 2 diabetes mellitus. Moreover, the synergistic interplay of HFD, obesity, and diabetes expedites the aging process and prematurely fosters age-related diseases. However, the underlying mechanisms driving these associations remain enigmatic. One of the most conspicuous hallmarks of aging is the accumulation of highly inflammatory senescent cells, with mounting evidence implicating increased cellular senescence in the pathogenesis of age-related diseases. Our hypothesis posits that HFD consumption amplifies senescence burden across multiple organs. To scrutinize this hypothesis, we subjected mice to a 6-month HFD regimen, assessing senescence biomarker expression in the liver, white adipose tissue, and the brain. Aging is intrinsically linked to impaired cellular stress resilience, driven by dysfunction in Nrf2-mediated cytoprotective pathways that safeguard cells against oxidative stress-induced senescence. To ascertain whether Nrf2-mediated pathways shield against senescence induction in response to HFD consumption, we explored senescence burden in a novel model of aging: Nrf2-deficient (Nrf2+/-) mice, emulating the aging phenotype. Our initial findings unveiled significant Nrf2 dysfunction in Nrf2+/- mice, mirroring aging-related alterations. HFD led to substantial obesity, hyperglycemia, and impaired insulin sensitivity in both Nrf2+/- and Nrf2+/+ mice. In control mice, HFD primarily heightened senescence burden in white adipose tissue, evidenced by increased Cdkn2a senescence biomarker expression. In Nrf2+/- mice, HFD elicited a significant surge in senescence burden across the liver, white adipose tissue, and the brain. We postulate that HFD-induced augmentation of senescence burden may be a pivotal contributor to accelerated organismal aging and the premature onset of age-related diseases.

Plant proteins: are they a good alternative to animal proteins in older people?

PURPOSE OF REVIEW

This review provides the latest insight into the impact of consuming plant-based protein for older people.

RECENT FINDINGS

According to the latest data, a healthy diet rich in plant-based-protein-rich-food could promote healthy aging. This health effect is partly because of the amino acid composition of proteins, as well as to the important constituents such as fiber and bioactive compounds found in the matrix. Furthermore, even though animal protein is more effective at stimulating muscle protein synthesis, a high consumption of plant protein (beyond 31 g/day) appears to enhance physical performance and reduce the risk of frailty in older individuals.

SUMMARY

Recent literature highlights numerous health benefits for older people associated with a substantial intake of plant-based vs. animal-based protein, both in preventing and mitigating chronic age-related diseases and reducing the risk of all-cause mortality. However, a high intake of plant-based protein-rich products could pose risks of malnutrition and fiber-related intestinal intolerances. Further research is needed to assess the risk-benefit ratio of a high consumption of plant proteins in older individuals before we can make robust recommendations on how far animal proteins can be healthfully replaced with plant proteins.

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.

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.

Amino acids and cancer: potential for therapies?

PURPOSE OF REVIEW

Cancer patients may have a variety of disorders associated with systemic inflammation caused by disease progression. Consequently, we have protein hypercatabolism. In view of this, protein and amino acid adequacy should be considered in relation to nutritional behavior. Therefore, this review aims to evaluate the influence of protein and amino acids in the nutritional therapy of cancer.

RECENT FINDINGS

Diets with adequate protein levels appear to be beneficial in the treatment of cancer; guidelines suggest consumption of greater than 1.0-1.5 g/kg body weight/day. In patients diagnosed with malnutrition, sarcopenia, or cachexia, it is recommended to use the maximum amount of protein (1.5 g/kg of weight/day) to adapt the diet. In addition, based on the evidence found, there is no consensus on the dose and effects in cancer patients of amino acids such as branched-chain amino acids, glutamine, arginine, and creatine.

SUMMARY

When evaluating the components of the diet of cancer patients, the protein recommendation should be greater than 1.0-1.5 g/kg of weight/day, with a distribution between animal and vegetable proteins. We found little evidence demonstrating clinical benefits regarding individual or combined amino acid supplementation. Still, it is unclear how the use, dose, and specificity for different types of cancer should be prescribed or at what stage of treatment amino acids should be prescribed.

Improving Cognitive Function with Nutritional Supplements in Aging: A Comprehensive Narrative Review of Clinical Studies Investigating the Effects of Vitamins, Minerals, Antioxidants, and Other Dietary Supplements

Cognitive impairment and dementia are burgeoning public health concerns, especially given the increasing longevity of the global population. These conditions not only affect the quality of life of individuals and their families, but also pose significant economic burdens on healthcare systems. In this context, our comprehensive narrative review critically examines the role of nutritional supplements in mitigating cognitive decline. Amidst growing interest in non-pharmacological interventions for cognitive enhancement, this review delves into the efficacy of vitamins, minerals, antioxidants, and other dietary supplements. Through a systematic evaluation of randomized controlled trials, observational studies, and meta-analysis, this review focuses on outcomes such as memory enhancement, attention improvement, executive function support, and neuroprotection. The findings suggest a complex interplay between nutritional supplementation and cognitive health, with some supplements showing promising results and others displaying limited or context-dependent effectiveness. The review highlights the importance of dosage, bioavailability, and individual differences in response to supplementation. Additionally, it addresses safety concerns and potential interactions with conventional treatments. By providing a clear overview of current scientific knowledge, this review aims to guide healthcare professionals and researchers in making informed decisions about the use of nutritional supplements for cognitive health.

Pflanzliche Ernährung und ausreichende Proteinzufuhr für ein gesundes Altern

Da die zunehmend ungesunde Ernährungs- und Lebensweise westlicher Industrienationen zur steigenden Prävalenz ernährungsbedingter, chronischer Erkrankungen beitragen, rückt eine pflanzenbasierte Ernährung (PBE) immer mehr in den Fokus der Forschung. Insgesamt ist eine PBE mit vorteilhaften Effekten auf die kardiovaskuläre und metabole Gesundheit assoziiert. Dies wird auf die höhere Nährstoffdichte und reduzierte Proteinzufuhr zurückgeführt, die sich auch günstig auf das Mortalitätsrisiko auszuwirken scheint. Unklar ist allerdings, wie günstig sich eine PBE im höheren Lebensalter auswirkt, da longitudinale Daten speziell für die ältere Generation fehlen. Außerdem besteht im Alter (> 65 Jahre) ein Proteinmehrbedarf, sodass aufgrund der geringeren Proteindichte und Proteinqualität einer PBE Bedenken bez. einer adäquaten Proteinversorgung bestehen. Sehr restriktive Ernährungsweisen werden aufgrund des zu erwartenden Protein- und Nährstoffmangels insbesondere im höheren Lebensalter nicht empfohlen.

Friend or Foe? The Role of Animal-Source Foods in Healthy and Environmentally Sustainable Diets

Scientific and political discussions around the role of animal-source foods (ASFs) in healthy and environmentally sustainable diets are often polarizing. To bring clarity to this important topic, we critically reviewed the evidence on the health and environmental benefits and risks of ASFs, focusing on primary trade-offs and tensions, and summarized the evidence on alternative proteins and protein-rich foods. ASFs are rich in bioavailable nutrients commonly lacking globally and can make important contributions to food and nutrition security. Many populations in Sub-Saharan Africa and South Asia could benefit from increased consumption of ASFs through improved nutrient intakes and reduced undernutrition. Where consumption is high, processed meat should be limited, and red meat and saturated fat should be moderated to lower noncommunicable disease risk-this could also have cobenefits for environmental sustainability. ASF production generally has a large environmental impact; yet, when produced at the appropriate scale and in accordance with local ecosystems and contexts, ASFs can play an important role in circular and diverse agroecosystems that, in certain circumstances, can help restore biodiversity and degraded land and mitigate greenhouse gas emissions from food production. The amount and type of ASF that is healthy and environmentally sustainable will depend on the local context and health priorities and will change over time as populations develop, nutritional concerns evolve, and alternative foods from new technologies become more available and acceptable. Efforts by governments and civil society organizations to increase or decrease ASF consumption should be considered in light of the nutritional and environmental needs and risks in the local context and, importantly, integrally involve the local stakeholders impacted by any changes. Policies, programs, and incentives are needed to ensure best practices in production, curb excess consumption where high, and sustainably increase consumption where low.

Barriers to and Facilitators of the Consumption of Animal-Based Protein-Rich Foods in Older Adults: Re-Analysis with a Focus on Sustainability

Older adults may gain health benefits from the consumption of animal-based protein-rich foods, but environmental pressures suggest advocating some meat and dairy foods over others, and understanding the barriers and facilitators for consuming these different foods would be of value. Existing data on the barriers to and facilitators of the consumption of meat and dairy products were re-analysed for differing effects for white, red, and processed meat consumption and for yoghurt, soft cheese, and hard cheese consumption. White meat consumption was associated with fewer concerns over spoilage and waste and stronger perceptions that meat is convenient (smallest Beta = 0.135, p = 0.01), while red and processed meat consumption were positively associated with liking /taste, appearance, and convenience (smallest Beta = 0.117, p = 0.03). Yoghurt and soft cheese consumption were positively associated with liking/taste and medical concerns, and fewer concerns over ability and habit (smallest Beta = -0.111, p = 0.05), while hard cheese consumption was only associated with liking/taste (Beta = 0.153, p = 0.01). Taken together, these data suggest that enhancing or promoting the enjoyment, taste, visual appeal, and ease-of-consumption of the more sustainable meat and dairy options may be of value in encouraging the consumption of these foods in older adults.

Reply to Grant, W.B. Comment on "Coelho-Junior et al. Protein Intake and Frailty in Older Adults: A Systematic Review and Meta-Analysis of Observational Studies. Nutrients 2022, 14, 2767"

We recently conducted a systematic review and meta-analysis to assess the association between protein consumption and frailty in older adults [...].

High protein diet in digestive cancers

PURPOSE OF REVIEW

Recent advances in the nutritional management of patients with digestive cancers suggest that modulation of protein intake may significantly contribute to achieve nutritional and clinical benefits. By reviewing the available evidence, a quantitatively and qualitatively optimal protein intake could be derived.

RECENT FINDINGS

High protein diets (i.e., 1-1.5 g/kg body weight/day) appear key to maintain the adequate nutritional status, and may also contribute to achieve clinical benefits. This target appears particularly relevant in patients with digestive cancers at risk or already malnourished, or in older patients. During active cancer treatments, protein intake should be closer to the upper limit of the recommended intake. Also, high protein intake should be maintained beyond the periods of catabolic crisis associated with active treatments. In contrast with general reasoning, animal proteins should represent the majority of the recommended intake. Based on the available evidence, the intake of no specific amino acid can be strongly recommended to enhance anabolic potentials or the immune modulating effects of high protein diets.

SUMMARY

High protein intake, mostly based on animal proteins, should be recommended to patients with digestive cancers. However, this target should be translated into clinical prescription after considering the clinical and metabolic needs of the patients. The quest for the optimal protein intake of patients with cancer at different time points of their clinical journey is still open.