Oxidative stress, frailty and cognitive decline

Health-related and socio-demographic factors associated with frailty in the elderly: a systematic literature review

Frailty is a syndrome that leads to practical harm in the lives of elders, since it is related to increased risk of dependency, falls, hospitalization, institutionalization, and death. The objective of this systematic review was to identify the socio-demographic, psycho-behavioral, health-related, nutritional, and lifestyle factors associated with frailty in the elderly. A total of 4,183 studies published from 2001 to 2013 were detected in the databases, and 182 complete articles were selected. After a comprehensive reading and application of selection criteria, 35 eligible articles remained for analysis. The main factors associated with frailty were: age, female gender, black race/color, schooling, income, cardiovascular diseases, number of comorbidities/diseases, functional incapacity, poor self-rated health, depressive symptoms, cognitive function, body mass index, smoking, and alcohol use. Knowledge of the complexity of determinants of frailty can assist the formulation of measures for prevention and early intervention, thereby contributing to better quality of life for the elderly.

Association between endothelial dysfunction and frailty: the Toledo Study for Healthy Aging

Cardiovascular disease (CVD), both clinical and subclinical, has been proposed as one of the mechanisms underlying frailty. However, there is no evidence addressing the relationship between the earliest stage of CVD (endothelial dysfunction) and frailty. The goal of the study was to analyze the association between endothelial dysfunction, evaluated by asymmetric dimethylarginine (ADMA) levels, and frailty. We used data from the Toledo Study for Healthy Aging, a prospective Spanish cohort study. Biological samples were obtained and ADMA levels were determined using an enzyme immunoassay method. Logistic regression was used to estimate the odds ratio (OR) and 95 % confidence intervals of frailty associated with ADMA. Adjustments were made for age, gender, cardiovascular risk factors, and presence of atherosclerotic disease (assessed by ankle–brachial index; ABI). One thousand two hundred eighty-seven community-dwelling elderly were included. One hundred seven (8.3 %) were identified as frail, 542 (42.1 %) as pre-frail, and 638 (49.6 %) as non-frail. ADMAvalues were higher in frail subjects than in non-frail ones. In addition, an interaction between the presence of atherosclerotic disease and ADMA on the odds of frailty (p=0.045) was detected. After adjustments for age, classical cardiovascular risk factors, and ABI, the risk of frailty was associated with increasing levels of ADMA in subjects without atherosclerotic disease [OR for 1 standard deviation increase in ADMA=1.14 (1.01–1.28), p=0.032] but not in those with atherosclerotic disease. In our study, endothelial dysfunction, assessed by ADMA levels, is associated with frailty. These findings provide additional support for a relevant role of vascular system since its earliest stage in frailty.

Cognition and nutrition

PURPOSE OF REVIEW

Aging is associated with a decline in cognition. This review examines the available data on the effects of nutrition on cognitive impairment. It also explores the mechanism(s) by which food may enhance memory.

RECENT FINDINGS

An increasing body of evidence has supported the role of the Mediterranean diet and extra-virgin olive oil in protecting cognition. A number of nutritional formulations to improve deteriorating memory are being studied. Undernutrition is associated with cognitive decline. Hyperglycemia and hypertriglyceridemia cause cognitive impairment.

SUMMARY

There are increasing data to support the role of nutrition in maintaining cognition.

Frailty and cognitive impairment--a review of the evidence and causal mechanisms

Incidence rates of cognitive impairment and dementia are rising with the ageing population. Meanwhile, the limited success of current treatments has led to a search for early markers of dementia which could predict future progression or improve quality of life for those already suffering from the disease. One focus has been on the correlation between physical and cognitive measures with an increasing interest in the association between frailty and cognitive decline. Frailty is an age-related syndrome described as the decreased ability of an organism to respond to stressors. A number of epidemiological studies have reported that frailty increases the risk of future cognitive decline and that cognitive impairment increases the risk of frailty suggesting that cognition and frailty interact within a cycle of decline associated with ageing. This paper reviews the evidence for an association between frailty and cognitive impairment and outlines some of the mechanisms that potentially underpin this relationship from brain neuropathology and hormonal dysregulation to cardiovascular risk and psychological factors.

How to design nutritional intervention trials to slow cognitive decline in apparently healthy populations and apply for efficacy claims: a statement from the International Academy on Nutrition and Aging Task Force

Interventions are crucial as they offer simple and inexpensive public health solutions that will be useful over the long term use. A Task Force on designing trials of nutritional interventions to slow cognitive decline in older adults was held in Toulouse in September 2012. The aim of the Task Force was to bring together leading experts from academia, the food industry and regulatory agencies to determine the best trial designs that would enable us to reach our goal of maintaining or improving cognitive function in apparently healthy aging people. An associated challenge for this Task Force was to determine the type of trials required by the Public Food Agencies for assessing the impact of nutritional compounds in comparison to well established requirements for drug trials. Although the required quality of the study design, rationale and statistical analysis remains the same, the studies designed to show reduction of cognitive decline require a long duration and the objectives of this task force was to determine best design for these trials. Two specific needs were identified to support trials of nutritional interventions: 1- Risk- reduction strategies are needed to tackle the growing burden of cognitive decline that may lead to dementia, 2- Innovative study designs are needed to improve the quality of these studies.

Musculoskeletal frailty: a geriatric syndrome at the core of fracture occurrence in older age

A progressive decline in physiologic reserves inevitably occurs with ageing. Frailty results from reaching a threshold of decline across multiple organ systems. By consequence, frail elderly experience an excess vulnerability to stressors and are at high risk for functional deficits and comorbid disorders, possibly leading to institutionalization, hospitalization and death. The phenotype of frailty is referred to as the frailty syndrome and is widely recognized in geriatric medical practice. Although frailty affects both musculoskeletal and nonmusculoskeletal systems, sarcopenia, which is defined as age-related loss of muscle mass and strength, constitutes one of the main determinants of fracture risk in older age and one of the main components of the clinical frailty syndrome. As a result, operational definitions of frailty and therapeutic strategies in older patients tend to focus on the consequences of sarcopenia.

The neuroprotective potential of phenolic-enriched fractions from four Juniperus species found in Portugal

The increase in population lifespan has enhanced the incidence of neurodegenerative diseases, for which there is, as yet, no cure. We aimed to chemically characterize phenolic-enriched fractions (PEFs) from four wild Juniperus sp. found in Portugal (Juniperus navicularis, Juniperus oxycedrus badia, Juniperus phoenicea and Juniperus turbinata) and address their potential as sources of natural products for treatment of neurodegenerative diseases. Leaves from the four Juniperus sp. evaluated contained a range of phenolic components which differed quantitatively between the species. The PEFs obtained were rich sources of phenolic compounds, exhibited acetylcholinesterase (AChE) inhibitory activity and also displayed effective intracellular radical scavenging properties in neurons submitted to oxidative injury but showed a different order of effectiveness compared to AChE inhibition. These properties made them good candidates for testing in a neurodegeneration cell model. Pre-incubation with J. oxycedrus badia PEF for 24h protected neurons from injury in the neurodegeneration cell model.