Musculoskeletal disorders and age-related musculoskeletal decline are major contributors to the burden of ill health seen in older subjects. Despite this increased burden, these chronic disorders of old age receive a relatively small proportion of national research funds. Much has been learned about fundamental processes involved in ageing from basic science research and this is leading to identification of key pathways that mediate ageing which may help the search for interventions to reduce age-related musculoskeletal decline. This short review will focus on the role of reactive oxygen species in age-related skeletal muscle decline and on the implications of this work for potential nutritional interventions in sarcopenia. The key physiological role of reactive oxygen species is now known to be in mediating redox signalling in muscle and other tissues and ageing leads to disruption of such pathways. In muscle, this is reflected in an age-related attenuation of specific adaptations and responses to contractile activity that impacts the ability of skeletal muscle from ageing individuals to respond to exercise. These pathways provides potential targets for identification of logical interventions that may help maintain muscle mass and function during ageing.

The relationship between nutrition and ageing is complex. The metabolism and synthesis of micronutrients within the gut microbiome can influence human health but is challenging to study. Furthermore, studying ageing in humans is time-consuming and difficult to control for environmental factors. Studies in model organisms can guide research efforts in this area. This review describes how the nematode Caenorhabditis elegans can be used to study how bacteria and diet influence ageing and inform follow-on studies in humans. It is known that certain bacteria accelerate ageing in C. elegans. This age-accelerating effect is prevented by inhibiting folate synthesis within the bacteria, and we propose that in the human microbiome, certain bacteria also accelerate ageing in a way that can be modulated by interfering with bacterial folate synthesis. Bacterial-derived folates do not promote ageing themselves; rather, ageing is accelerated by bacteria in some way, either through secondary metabolites or other bacterial activity, which is dependent on bacterial folate synthesis. In humans, it may be possible to inhibit bacterial folate synthesis in the human gut while maintaining healthy folate status in the body via food and supplementation. The supplement form of folic acid has a common breakdown product that can be used by bacteria to increase folate synthesis. Thus, supplementation with folic acid may not be good for health in certain circumstances such as in older people or those with an excess of proteobacteria in their microbiome. For these groups, alternative supplement strategies may be a safer way to ensure adequate folate levels.

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 ≥0.8g/kg body weight/day 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.

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).

Deficiency of vitamin B12 (B12 or cobalamin), an essential water-soluble vitamin, leads to neurological damage, which can be irreversible and anaemia, and is sometimes associated with chronic disorders such as osteoporosis and cardiovascular diseases. Clinical tests to detect B12 deficiency lack specificity and sensitivity. Delays in detecting B12 deficiency pose a major threat because the progressive decline in organ functions may go unnoticed until the damage is advanced or irreversible. Here, using targeted unbiased metabolomic profiling in the sera of subjects with low B12 levels v control individuals, we set out to identify biomarker(s) of B12 insufficiency. Metabolomic profiling identified seventy-seven metabolites, and partial least squares discriminant analysis and hierarchical clustering analysis showed a differential abundance of taurine, xanthine, hypoxanthine, chenodeoxycholic acid, neopterin and glycocholic acid in subjects with low B12 levels. Random forest multivariate analysis identified a taurine/chenodeoxycholic acid ratio, with an AUC score of 1, to be the best biomarker to predict low B12 levels. Mechanistic studies using a mouse model of B12 deficiency showed that B12 deficiency reshaped the transcriptomic and metabolomic landscape of the cell, identifying a downregulation of methionine, taurine, urea cycle and nucleotide metabolism and an upregulation of Krebs cycle. Thus, we propose taurine/chenodeoxycholic acid ratio in serum as a potential biomarker of low B12 levels in humans and elucidate using a mouse model of cellular metabolic pathways regulated by B12 deficiency.

The aim of this study is to investigate whether 25-hydroxyvitamin D (25(OH)D) is associated with periodontitis and tooth loss in older adults. A total of 2346 adults underwent a detailed dental examination as part of the health assessment of a national population study – The Irish Longitudinal Study of Ageing. 25(OH)D analysis was performed on frozen non-fasting total plasma using LC-MS. The analysis included both multiple logistic regression and multinominal logistic regression to investigate associations between 25(OH)D concentration, periodontitis and tooth loss, adjusting for a range of potential confounders. Results of the analysis found the mean age of participants was 65·3 years (sd 8·2) and 55·3 % of the group were female. Based on the quintile of 25(OH)D concentration, participants in the lowest v. highest quintile had an OR of 1·57 (95 % CI 1·16, 2·13; P < 0·01) of having periodontitis in the fully adjusted model. For tooth loss, participants in the lowest v. highest quintile of 25(OH)D had a RRR of 1·55 (95 % CI 1·12, 2·13; P < 0·01) to have 1–19 teeth and a RRR of 1·96 (95 % CI 1·20, 3·21; P < 0·01) to be edentulous, relative to those with ≥ 20 teeth in the fully adjusted models. These findings demonstrate that in this cross-sectional study of older men and women from Ireland, 25(OH)D concentration was associated with both periodontitis and tooth loss, independent of other risk factors.

Loneliness and social isolation among older adults are emerging public health concerns. Older adults from ethnic minority communities or with immigration backgrounds may be particularly vulnerable when encountering loneliness and social isolation due to the double jeopardy of their old age and minority status. The goal of this study is to conduct a scoping review of published journal articles on ethnic minority/immigrant older adults' loneliness and social isolation experiences to show the extent, range and nature of empirical studies in this area across several high-income countries (i.e. European countries, United States of America (USA), Canada, Australia and New Zealand). This review uses Arksey and O'Malley's five-state framework, a well-established scoping review method. We identify and analyse 76 articles published between 1983 and 2021. This evidence base is largely US-focused (54%) with the vast majority (76%) having a quantitative design. We summarise and map factors of loneliness and social isolation into a multi-dimensional socio-ecological model. By doing so, we show how ethnicity/immigration-specific factors and general factors intersect in multiple dimensions across places and time, shaping ethnic minority/immigrant older adults' heterogeneous experiences of loneliness and social isolation. Several critical gaps that should be at the forefront of future research are highlighted and discussed.

Multimorbidity, the existence of two or more concurrent chronic conditions in a single individual, represents a major global health challenge. The Nutrition Society’s 2023 Winter Conference at the Royal Society, London focused on the topic of ‘Diet and lifestyle strategies for prevention and management of multimorbidity’, with symposia designed to explore pathways for prevention of multimorbidity across the lifecourse, the role of ageing, the gut-brain-heart connection and lifestyle strategies for prevention and management of multimorbidity. It also considered machine learning and precision nutrition approaches for addressing research challenges in multimorbidity. The opening plenary lecture discussed advancing diet and lifestyle research to address the increasing burden and complexity of multimorbidity. The two-day programme concluded with a plenary which addressed the key dietary risk factors and policies in multimorbidity prevention.

An increasing body of evidence has emerged suggesting that lifestyle behaviours, including diet quality, may be an important modifiable risk factor for mental health disorders. The Mediterranean diet (MedDiet), which is often heralded as an anti-inflammatory diet, has been widely investigated and promoted as one of the ‘healthiest’ dietary patterns for reducing chronic disease risk and promoting healthy ageing(1). Greater adherence to a MedDiet and/or anti-inflammatory diet is inversely associated with the risk of depression or depressive symptoms in younger and middle-aged adults(2). However, these findings have been inconsistent, particularly in older adults. We therefore explored the independent associations between adherence to a MedDiet and severity of symptoms related to depression, anxiety and stress in community-dwelling older adults from Australia. We conducted a cross-sectional study of older Australians aged ≥ 60 years. Older adults who were permanent residents of Australia, free from dementia or cognitive decline and could independently complete an anonymous online survey in English were invited to participate. A 75-item self-administered questionnaire was used to assess the relationship between adherence to a MedDiet and severity of symptoms related to depression, anxiety, and stress. MedDiet adherence was assessed using the Mediterranean Diet Adherence Screener (MEDAS)(3) and the Depression, Anxiety and Stress Scale (DASS-21)(4) was used to assess the severity of negative emotional symptoms. Multivariable linear regression analysis (and 95% CI) was used to investigate the independent association between adherence to a MedDiet and severity of symptoms related depression, anxiety and stress using one unadjusted and six adjusted predictor models. A total of n = 294 participants were included in the final analyses (70.4 ± 6.2 years; Females, n = 201; Males, n = 91; n = 2 unspecified). Adherence to a MedDiet was inversely associated with severity of anxiety symptoms (β = −0.118; CI: −0.761, −0.012; P = 0.043) independent of age, gender, BMI, physical activity, sleep, cognitive risk and ability to perform activities of daily living. Furthermore, MedDiet adherence was inversely associated with symptoms of stress (β = −0.151; CI: −0.680, −0.073; P = 0.015) independent of age, gender, BMI, physical activity and sleep. However, no relationship between MedDiet adherence and depressive symptoms was observed. We showed that adherence to a MedDiet is inversely associated with severity of symptoms related to anxiety and stress but not for depression. Exploration of these findings using longitudinal analyses and robust clinical trials are needed to better elucidate these findings in older adults.

As the global population continues to age, strategies that promote health and wellbeing among older adults are urgently required. This demographic faces an increasing burden of chronic diseases linked to inflammation(1), often associated with diets that are energy dense and nutrient poor(2). Importantly, the impact of these conditions can be minimised by adopting an anti-inflammatory dietary pattern, such as the Mediterranean diet(3). While there are numerous predictors of behaviour and an individual’s capacity for behaviour change, nutrition knowledge is a fundamental influencer of eating behaviours(4). However, knowledge of anti-inflammatory diets generally and the Mediterranean diet specifically is lacking among older adults(5), highlighting the need for effective educational programs targeting this group. Digital health technologies have the potential to provide cost-effective and accessible nutrition education, however, few technologies have been developed to meet older adults unique needs and preferences. To address this gap, this study aimed to explore the specific needs and design preferences of older adults for an online nutrition education resource. A total of 20 adults aged 55 years and older participated in one of four 2-hour participatory design workshops, where prompted discussion questions were used to explore their use of technology and scope their needs and preferences for an online nutrition education resource. All participants were regularly using a range of different devices (e.g., smartphones, tablets, and computers) and reported being comfortable doing so. Participants wanted a website that could be accessed across devices (i.e., desktop and mobile friendly) that provided practical nutrition advice, recipes, and information on the link between diet and disease. A number of design principles were identified as essential to optimise the user experience, including large and simple fonts, use of dark type on a light background, and clear categories for easy navigation. To enhance engagement, participants sought a personalised resource that could be adjusted to suit their needs, provided up-to-date information, and allowed for easy content sharing with others, such as by exporting information as a PDF. Participatory design methods offer new knowledge for developing and refining existing and future digital health technologies that are appropriate and useful for the target audience. Specifically, the older adult participants were motivated to access a user-friendly web-based nutrition resource provided it was able to be personalised to their health and nutrition needs, offered practical solutions such as adaptations to portion size or in relation to cost, and was easily shareable with others. Given the limited availability of online, self-directed and evidence-based nutrition education resources for older adults, these findings provide valuable insights to shape digital health resources that cater to the needs and preferences of this population and have the potential to support healthy eating habits and contribute to reducing diet-related chronic disease burden.

A narrative of decline dominates the ageing process in the Global North. At the same time, older people have shared more positive stories of ageing, particularly with respect to their leisure practices. I explore this tension by drawing on an interview-based study with people playing walking football in the United Kingdom. My contention is that older people express multiple meanings of ageing that disturb deficit-focused cultural scripts of later-life, albeit in ways that can be fraught with tensions and contradictions. First, I explore how older people cultivate an alternate identity departing from assumptions of loneliness and degradation, with walking football providing an opportunity to develop friendships and a sense of belonging. Second, older people emphasise their own (good) health and the embodied demands of walking football, yet in doing so, can reinforce ageist discourses by distinguishing themselves from the inactive and isolated (older) other. Third, older people reflect on their current and future involvement in walking football in positive ways. However, through attending to the temporal character of their experiences, I show how, whilst older people express a desire to continue participation, this is threatened by the realities of their ageing bodies in ways that align with deficit framings of later-life. I conclude by calling for recognising the multiplicity of older people's experiences and exercising caution about reproducing over-simplistic and sweeping celebrations of ageing.

To examine the combined effects of ageing and bilingualism in language processing, we tested young and older mono- and bilingual speakers in L1 comprehension and production. In Experiment 1, bilinguals were slower to detect words than monolinguals in sentences with a low-constraint context, but not when a high-constraint context was provided. Older adults tended to outperform younger adults in high-constraint sentences. In Experiment 2, older speakers were slower than younger speakers to produce small-scope prepositional phrases (e.g., ‘the cone above the grape), suggesting more extensive planning. Bilingual disadvantages were observed in larger-scope complex phrases (e.g., ‘the cone and the pink grape’). Individual differences in language proficiency did not modulate the effects. The results support bilingual disadvantages in syntactic processing and age-preserved syntax, alongside semantic processing unaffected by either bilingualism or age. We found no interactions between age and bilingualism, suggesting that these two factors independently impact language processing.

Although evidence on aspects of individual ageing of LGBTQI (lesbian, gay, bisexual, transgender, queer and/or intersex) people is mounting, there is a poor understanding of the macro aspects of population ageing within the LGBTQI population itself. This paper seeks to address this lacuna through an examination of structural and numerical ageing of the Australian LGBQ population. Drawing upon new data sources, alongside recent advances in demographic modelling, we utilised a modified multi-state cohort-component projection model to produce estimates and projections of the ageing of the Australian LGBQ population from 2016 to 2041. Our results indicate that the LGBQ population is significantly younger than the heterosexual population and is ageing structurally (in relative terms) at a slower rate. However, the LGBQ population is ageing considerably faster numerically (in absolute percentage growth terms) relative to the heterosexual population. We show the LGBQ population aged 65+ is projected to grow between 150 and 170 per cent between 2016 and 2041, under relatively conservative assumptions. This strong numerical ageing counters traditional assumptions about ageing of the LGBQ population and provides data to improve visibility of this population and to ameliorate future planning for health, care and social service provision that is appropriate and well-funded. The methods and materials we develop in this paper provide new opportunities for other countries to improve planning for LGBQ populations similarly.

Globally, we are currently facing a rapid demographic shift leading to an increase in the proportion of older adults within the population. This raises concerns about the potential increase in age-related diseases and their impact on our ability to provide adequate health and end-of-life care. To apply appropriate interventions, understanding the changes that happen with ageing becomes essential. Ageing is often accompanied by a decrease in appetite and physical activity, which may lead to malnutrition, resulting in decreased muscle mass, physical capabilities and independence. To preserve muscle mass, older adults are advised to increase protein intake and physical activity. However, protein’s high satiating effect may cause reduced energy intake. Physical activity is also advised to maintain or enhance older adult’s appetite. This review paper aims to discuss appetite-related changes that occur with ageing and their consequences. In particular, it will focus on investigating the relationship between protein intake and physical activity and their impact on appetite and energy intake in the ageing population. Recent studies suggest that physical activity might contribute to maintaining or enhancing appetite in older adults. Nevertheless, establishing a definitive consensus on the satiating effect of protein in ageing remains a work in progress, despite some promising results in the existing literature.