The Physiological Effects of Amino Acids Arginine and Citrulline: Is There a Basis for Development of a Beverage to Promote Endurance Performance? A Narrative Review of Orally Administered Supplements

Nutritional and ergogenic aid supplementation is prevalent within athletic or general fitness populations, and is only continuing to gain momentum. Taken in isolation or as a combination, amino acid (AA) supplementation has the potential to increase endurance performance among other benefits. L-Arginine (L-Arg) and L-Citrulline (L-Cit) are two AAs proposed to increase endothelial nitric oxide (NO) synthesis, with potential additional physiological benefits, and therefore may contribute to enhanced performance outcomes such as increased power output, or time to exhaustion. However, the appropriate dose for promoting physiological and performance benefits of these AAs, and their potential synergistic effects remains to be determined. Therefore, the aim of this review was to evaluate the varied concentrations used in the current literature, assess the effects of L-Arg and L-Cit in combination on physiological responses and endurance performance, and consider if there is a fundamental basis for providing these supplements in the form of a beverage. A total of six studies were considered eligible for the review which utilized a range of 3–8 g of the AA constituents. The findings support the notion that supplementing with a combination of L-Arg and L-Cit may increase NO production, enhance vasodilation, and therefore increase performance capacity in athletes. A beverage as a carrier for the two AAs is worth considering; however, there remains limited research assessing these outcomes across a consistent range of concentrations in order to see their full potential

Risk of Social Isolation as a Contributing Factor to Diet Quality in Community-Dwelling Older Persons Living in the Australian Capital Territory—A Pilot Study

Objectives: Social isolation is recognised as a risk factor in the inflammatory process. This study explored the association between social isolation and the Dietary Inflammatory Index (DII) in community-dwelling older persons. Methods: This cross-sectional pilot study recruited 107 community-dwelling people aged over 55 years living in the Australian Capital Territory. Participants completed an extensive food frequency questionnaire and provided anthropometric and sociodemographic data. Social isolation was evaluated using the Lubben Social Network Scale (LSNS). Diet quality was assessed using DII. Results: Average age was 70.1 (±8.61) years and 62.8% were female. The average DII score was −1.10 (±1.21), indicating an anti-inflammatory diet. Higher LSNS was associated with lower DII (b (95% CI) = −0.041 (−0.066, −0.17); p < 0.01) and was positively influenced by the number of people in household (b (95% CI) = 5.731 (2.336, 9.127); p = 0.001). Conclusion: Increased risk of social isolation was associated with an increased tendency towards a more inflammatory diet. Reducing social isolation may decrease the inflammatory component of dietary intake for older persons living independently in the community

Prickly Pear Cacti (Opuntia spp.) Cladodes as a Functional Ingredient for Hyperglycemia Management: A Brief Narrative Review

The worldwide prevalence of obesity is increasing along with its comorbidities, including type 2 diabetes mellitus (T2DM). From a pathophysiological perspective, T2DM arises as a consequence of insulin resistance and pancreatic β-cell dysfunction, which together induce chronic hyperglycemia. The pharmacological treatment of T2DM specifically focuses on its management, rather than remission, with a lack of pharmacological agents to prevent the onset of the disease. Considering the role of unhealthy dietary patterns on the development of T2DM, identifying novel food ingredients and bioactive substances may provide new avenues by which to address the T2DM epidemic. In this brief review, we have summarized the latest findings on the consumption of the prickly pear (PP; Opuntia spp.) cladode as a potential nutritional tool for the management of hyperglycemia. The consumption of prickly pear cladodes was reported to exert hypoglycemic effects, making it a potential cost-effective nutritional intervention for the management of T2DM. Several studies have demonstrated that the consumption of prickly pear cladodes and the related products reduced post-prandial glucose levels. The cladodes’ high fiber content may be implicated in improving glycemic control, by affecting glucose absorption and effectively slowing its release into the blood circulation. Given these potential hypoglycemic effects, prickly pear cladodes may represent a potential functional food ingredient to improve glycemic control and counter the negative metabolic effects of the modern Western diet. Nonetheless, in consideration of the lack of evidence on the chronic effects of the prickly pear cladode, future research aimed at evaluating its long-term effects on glycemic control is warranted

Association between lipids and apolipoproteins on type 2 diabetes risk; moderating effects of gender and polymorphisms; the ATTICA study

Background and Aims Type 2 diabetes mellitus (T2DM) is a condition defined by hyperglycaemia, but also often presents with dyslipidaemia and suppressed HDL cholesterol. Mendelian randomization studies have suggested a causal link between low HDL cholesterol and T2DM. However, influences of gender, polymorphisms and lifestyle, all known to influence HDL cholesterol, have not been fully explored in a prospective cohort. Methods and Results In 2001-2002, a random sample of 1514 males (18-87 years old) and 1528 females (18-89 years old) were recruited in the ATTICA study. The 10-year follow-up (2011-2012) included 1485 participants. Lipids and lipoproteins levels, glucose and insulin levels were measured together with apolipoprotein A1 (apoA1) 75 G/A genotype, which is known to influence HDL-cholesterol. In total, 12.9% of the study sample developed T2DM within the 10-year follow-up period. In multivariable models, for each mg/dL increase in apoA1 levels in males, 10-year T2DM risk decreased 1.02%; while every unit increase in apoB/LDL-cholesterol ratio increased risk 4-fold. Finally, for every unit increase in triglycerides/apoA1 ratio, the risk increased 85%. HOMA-IR independently predicted T2DM 10-year incidence only for carriers of GG polymorphism (all, p0.05). Conclusion ApoA1 was associated with decreased T2DM risk and TG/ApoA1 and apoB/LDL were associated with increased risk of T2DM, only in males. ApoA1 polymorphism, which is associated with lower HDL cholesterol, influenced the predictive effects of HOMA-IR on T2DM incidence, which appeared to be moderated by physical activity, suggesting potential scope for more targeted preventative strategies

The Effects of Green Tea Amino Acid L-Theanine Consumption on the Ability to Manage Stress and Anxiety Levels:a Systematic Review

The green tea amino acid, L-theanine (L-THE) is associated with several health benefits, including improvements in mood, cognition and a reduction of stress and anxiety-like symptoms. This systematic review evaluated the effect of pure L-THE intake, in the form of orally administered nutritional supplements, on stress responses and anxiety levels in human randomised controlled trials. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist, 9 peer-reviewed journal articles were identified where L-THE as a supplement was compared to a control. Our findings suggest that supplementation of 200–400 mg/day of L-THE may assist in the reduction of stress and anxiety in people exposed to stressful conditions. Despite this finding, longer-term and larger cohort clinical studies, including those where L-THE is incorporated into the diet regularly, are needed to clinically justify the use of L-THE as a therapeutic agent to reduce stress and anxiety in people exposed to stressful conditions

An Exploratory Study of Nutrition Knowledge and Challenges Faced by Informal Carers of Community-Dwelling People with Dementia: Online Survey and Thematic Analysis

Nutrition knowledge is a primary factor influencing food choices and the ability to identify nutritional risk for carers of people with dementia. Acquiring nutrition knowledge helps carers monitor changes in food intake and micronutrient intake, and whether a healthy and balanced diet is being consumed. This study aimed to assess the nutrition knowledge of carers in the Australian community and their experiences with nutrition education. Using a mixed-methods approach, the nutrition knowledge of informal carers was assessed using the revised General Nutrition Knowledge Questionnaire (AUS-R-NKQ), and interviews of informal carers were used to explore the perspectives in a sub-sample. A total of 57 carers (44 females; mean age of 63.0 ± 13.1) completed the survey, and 11 carers participated in follow-up interviews. The total sample scored 22.9 (±4.57) out of 38 on the AUS-R-NKQ, suggesting basic nutrition knowledge. The interviewed carers acknowledged the importance of healthy nutrition but viewed the provision of a healthy diet for a person with dementia as challenging. In both the survey and interviews, carers reported limited use and availability of dementia-specific nutrition resources. Carers were unsatisfied with the advice and number of referrals provided to improve the nutrition of the person with dementia and desired less confusing nutrition education materials adapted to their level of knowledge. The present study highlights the need for informal carers to be supported to acquire adequate nutrition knowledge

Immersive virtual reality in the promotion of health and well-being for people in residential aged care without cognitive impairment: A scoping review

Objective Sustaining the health and well-being of older people living in residential aged care (RAC) requires new means of providing safe and stimulating recreational and therapeutic programs such as using virtual reality (VR). The aim of the scoping review was to investigate the utility of immersive VR interventions using head-mounted display technology to promote the health and well-being of people without cognitive impairment living in RAC. Method The following databases were searched from inception until January 2024: PubMed, PsycINFO, Scopus, Cochrane and CINAHL. The eligibility criteria were quantitative, qualitative or mixed methods studies published in English, conducted in RAC, using VR with head-mounted display with people without cognitive impairment. Results Of the 274 articles identified, 9 articles with a total of 310 residents and 50 staff met the inclusion criteria. Seven factors to either impede or enable the use of VR with head-mounted displays in RAC were: residents’ agency; the nature of the VR experience; the content of the experience; the ease of use and comfort of the technology; the role of RAC staff; and the role of residents’ family members. Conclusion Immersive VR has potential as a tool to promote the health and well-being of people without cognitive impairment living in RAC. Small sample sizes, variations in study design, and selection bias mean that generalisability of the results is limited. Further research is recommended to inform the design and implementation of immersive VR programs tailored specifically for this population

Hostile personality as a risk factor for hyperglycemia and obesity in adult populations:a systematic review

PURPOSE: Several studies have already provided valuable insights into the physiological and genetic causes of hyperglycemia and obesity. Concurrently, personality traits, such as hostility, have been suggested to have an impact on health and illness (i.e., self-reported general health, coronary artery disease, and overall mortality). The present systematic review investigated possible effects of hostility upon metabolic markers, such as high plasma glucose level and obesity among adults. We also attempted to reveal current gaps in knowledge and provide insights for future directions. METHODS: This systematic review was performed following the PRISMA 2009 guidelines to examine current evidence arising from observational studies regarding the potential impact of hostile behavior on hyperglycemia and obesity among adults. Of the initial 139 articles, 13 studies were included. RESULTS: The evidence supports an association between pre-diabetes and obesity with a hostile temperament in certain populations. The relationship between hostility and hyperglycemia was most common in African American women, in women with a family history of diabetes, in unmarried individuals, in White men, as well as in middle-aged and older people. Regarding obesity, high body mass index (BMI) was associated with a hostile personality, particularly among men. However, the paths by which hostile temperament affects glucose levels and BMI, as well as potential mediating and moderating mechanisms, are not entirely understood. CONCLUSIONS: There is a need for research to enhance the understanding of biological, psychological and social factors related to hostility with a view to prevention and effective intervention