Peptides and aging: Their role in anorexia and memory

Association between malnutrition and cognitive frailty in older adults: A systematic review and meta-analysis

BACKGROUND

To systematically assess the association between cognitive frailty (CF) and malnutrition in older adults.

METHODS

8 databases were retrieved up until April 2023 by two reviewers in dependently, and meta-analysis was performed by Stata 16.0 software.

RESULTS

A total of 19 studies were meta-analyzed to assess the relationship between CF and malnutrition in older adults. The pooled prevalence of CF from 17 studies was 23 %, and the pooled prevalence of malnutrition among patients with CF from 12 studies was 57 %. Data from 13 studies on the association between CF and malnutrition unveiled a high risk of CF in older adults with malnutrition (OR = 3.77, 95 % CI: 2.49-5.69).

CONCLUSION

The prevalence of malnutrition is high in older adults with CF, and there is a significant delve into targeted treatment and preventive measures to ameliorate the quality of life of older adults.

Anorexia of Aging: Metabolic Changes and Biomarker Discovery

The age-associated decrease in appetite and food intake is referred to as "anorexia of aging". Older adults with anorexia show changes in the quantity/quality of energy supplied to the organism which eventually may cause a mismatch between ingested calories and physiological energy demands. Therefore, a state of malnutrition and impaired metabolism may ensue which renders older people more vulnerable to stressors and more prone to incur negative health outcomes. These latter cover a wide range of conditions including sarcopenia, low engagement in physical activity, and more severe consequences such as disability, loss of independence, hospitalization, nursing home placement, and mortality. Malnutrition has been recognized by the European Society of Clinical Nutrition (ESPEN) among the chief risk factors for the development of frailty. Frailty refers to a state of increased vulnerability to stressors stemming from reduced physiologic reserve, and according to ESPEN, is also nutrition-based. Alike frailty, anorexia is highly prevalent among older adults, and its multifactorial nature includes metabolic changes that develop in older age and possibly underly the condition. Circulating factors, including hormones (eg, cholecystokinin, ghrelin, leptin, and inflammatory and microbial mediators of gut dysbiosis), have been proposed as biomarkers for this condition to support early identification and develop personalized nutritional interventions. Additional studies are needed to untangle the interrelationship between gut microbiota and appetite regulation in older adults operating through brain-gut crosstalk. Furthermore, the contribution of the genetic background to appetite regulation and specific nutritional needs warrants investigation. Here, we provide an overview on anorexia of aging in the context of age-related metabolic changes. A special focus is placed on candidate biomarkers that may be used to assist in the early identification of anorexia of aging and in the development of personalized nutritional counseling.

Understanding the appetite modulation pathways: The role of the FFA1 and FFA4 receptors

Pharmaconutrition is an area of current interest, especially concerning the advances in the pharmacology of nutrient-sensing receptors, as have been accomplished in the last 20 years. The family of free fatty acid (FFA) receptors is composed of four members, sequentially named as FFA1 to FFA4, which are activated by the short to long-chain fatty acids. The affinity of the FFA1 and FFA4 receptors for the omega-3 polyunsaturated fatty acids prompted pre-clinical and clinical investigations regarding their involvement in metabolic diseases. The main studies have been focused on the receptors' expression analyses, the featuring of knockout mice, and the assessment of selective synthetic ligands. These clearly have indicated a relevant role for FFA1 and FFA4 in the peripheral and central circuits for the regulation of energetic metabolism. This review article aimed to discuss the relevance of the FFA1 and FFA4 receptors in appetite-related complications, mainly related to obesity, cancer cachexia, and anorexia in the elderly, emphasizing whether their pharmacological modulation might be useful for the management of these disorders.

Frailty, Cognitive Decline, Neurodegenerative Diseases and Nutrition Interventions

Currently the human population is aging faster. This leads to higher dependency rates and the transformation of health and social care to adapt to this aged population. Among the changes developed by this population is frailty. It is defined as a clinically detectable syndrome, related to the aging of multiple physiological systems, which prompts a situation of vulnerability. The etiology of frailty seems to be multifactorial and its pathophysiology is influenced by the interaction of numerous factors. Morley et al. propose four main mechanisms triggering the frailty: atherosclerosis, sarcopenia, cognitive deterioration and malnutrition, with their respective metabolic alterations. Malnutrition is associated with cognitive impairment or functional loss, but it is also known that an inadequate nutritional status predisposes to cognitive frailty. Additionally, nutritional factors that may influence vascular risk factors will potentially have an effect on dementia decline among patients with cognitive frailty. This review aims to describe the nutritional factors that have been researched so far which may lead to the development of frailty, and especially cognitive decline.

Anorexia of Aging - An Updated Short Review

The anorexia of aging affects approximately a quarter of older people and is a major contributor to the development of under-nutrition and many other adverse health outcomes in older people. Despite the high prevalence, the anorexia of aging is frequently overlooked by clinicians and, of even more concern, it is commonly accepted as inevitable and a part of 'normal' aging. Early identification of risk coupled with efforts to mitigate these risks through appropriate interventions might stem the deleterious consequences of the anorexia of aging. This review aims to provide an update on the current knowledge base whilst making some practical suggestions that may be of use in clinical practice. Interventions such as exercise and good nutrition remain the preferred treatment while pharmacological options, whilst they continue to be trialed, are not currently recommended for routine clinical use.

Anorexia of ageing: a key component in the pathogenesis of both sarcopenia and cachexia

The anorexia of aging was first recognized as a physiological syndrome 30 years ago. Its major causes are an alteration in fundal compliance with an increase in antral stretch and enhanced cholecystokinin activity leading to increased satiation.This anorexia leads to weight loss in aging persons and is one of the component causes of the aging related sarcopenia. This physiological anorexia also increases the risk of more severe anorexia when an older person has an increase in inflammatory cytokines such as occurs when they have an illness. This results in an increase in the anorexia due to cachexia in older persons.

The relevance of nutrition for the concept of cognitive frailty

PURPOSE OF REVIEW

Physical and cognitive frailty are interrelated and synergistic syndromes more frequently seen in old age, which represent intermediate stages between aging successfully and disability. Poor nutrition is a fundamental determinant for both conditions, while various dietary components are proposed to prevent and/or improve them. This updated review discusses the possible influence of nutritional factors on cognitive frailty and its potential mediators.

RECENT FINDINGS

Oxidative stress, low-grade systemic inflammation, neuroinflammation, and altered autophagy, all associated with obesity, metabolic syndrome and insulin resistance, are proposed mechanisms to explain the influence of nutrition on cognitive health. Even if no single food or supplement has definitively demonstrated to affect physical frailty and cognitive impairment, combining various dietary and lifestyle components in the Mediterranean dietary pattern has shown benefit.

SUMMARY

Cognitive frailty is a potential useful construct for the early detection of cognitive impairment and physical frailty, in order to implement timely interventions. Validation of this construct is eagerly needed. Nutritional status is a fundamental part of physical frailty, and potentially important in the prevention of cognitive decline. Identifying and treating protein/calorie and individual nutrients insufficiency is mandatory in all older adults. Conversely, overeating in middle age has been associated with cognitive decline in older age. A lifelong balance diet, such as the Mediterranean diet, combined with regular physical and mental exercise, is perhaps the best preventive strategy against cognitive decline in old age.

Anorexia of aging and its role for frailty

PURPOSE OF REVIEW

The purpose of this review is to examine the concept of anorexia of aging, including its complex pathophysiology and the multifaceted interventions required to prevent adverse health consequences from this geriatric syndrome.

RECENT FINDINGS

Anorexia of aging is extremely common, occurring in up to 30% of elderly individuals; however, this diagnosis is frequently missed or erroneously attributed to a normal part of the aging process. With aging, impairments in smell and taste can limit the desire to eat. Alterations in stress hormones and inflammatory mediators can lead to excess catabolism, cachexia, and reduced appetite. In addition, mood disorders, such as anxiety and depression, are powerful inhibitors of appetite. Anorexia of aging, with its negative consequences on weight and muscle mass, is a risk factor for the development of frailty and is important to screen for, as early intervention is key to reversing this debilitating condition.

SUMMARY

Anorexia of aging is a complex geriatric syndrome and a direct risk factor for frailty and thus should not be accepted as normal consequence of aging. Early diagnosis and formulating a plan for targeted interventions is critical to prevent disability and preserve function in elderly patients.

Two cases of food aversion with semantic dementia

Accounts of altered eating behavior in semantic dementia generally emphasize gluttony and abnormal food preferences. Here we describe two female patients with no past history of eating disorders who developed early prominent aversion to food in the context of an otherwise typical semantic dementia syndrome. One patient (aged 57) presented features in line with anorexia nervosa while the second patient (aged 58) presented with a syndrome more suggestive of bulimia nervosa. These cases add to the growing spectrum of apparently dichotomous behavior patterns in the frontotemporal dementias and illustrate a potentially under-recognized cause of eating disorders presenting in later life.