Long-Chain Omega-3 Fatty Acid Intake Is Associated with Age but not Cognitive Performance in an Older Australian Sample.

BACKGROUND: Long-chain omega-3 polyunsaturated fatty acids (LCn-3 PUFA) are essential nutrients and may be capable of delaying age-related cognitive decline. However, previous studies indicate that Australians are not meeting recommendations for LCn-3 PUFA intake. The current study therefore examined LCn-3 PUFA intake in an older Australia sample, as well as associations between LCn-3 PUFA intake and cognitive function. METHODS: Cross-sectional data were collected from 90 adults aged 50 to 80 years. LCn-3 PUFA intake was assessed using a food frequency questionnaire and red blood cell fatty acid profiles were used to calculate the Omega-3 Index (RBC n-3 index). Cognitive function was measured using Addenbrooke's Cognitive Examination-III. RESULTS: Positive associations were observed between age and RBC n-3 index (b=0.06, 95% CI: 0.01 - 0.10, P=0.01), and age and LCn-3 PUFA intake from fish oil capsules (b=17.5, 95% CI: 2.4 - 32.5 mg/day, P=0.02). When adjusting for LCn-3 PUFA from fish oil capsules, the association between age and RBC n-3 index was no longer significant. No associations were observed between LCn-3 PUFA intake and cognitive function. CONCLUSION: LCn-3 PUFA and fish oil consumption increased with age in this sample of older Australians, particularly due to supplement intake. However, LCn-3 PUFA intake was not associated with cognitive function.

Salivary levels of alpha-amylase are associated with neurobehavioral alertness during extended wakefulness, but not simulated night-shift work.

Sleep loss is one of the most common causes of accidents and errors in operational environments. Currently, no single method satisfies all of the requisite criteria of an effective system for assessing the risk of injury prior to safety being compromised. Research has concentrated towards the development of a biomarker for individualized assessment of sleepiness-related deficits in neurobehavioral alertness, with salivary alpha-amylase (sAA) recently reported as a potential biomarker during acute total sleep deprivation. The present study extends on previous research by investigating the association between sAA and neurobehavioral alertness during simulated night-shift work, during individuals are required to work at night when biological processes are strongly promoting sleep and sleep during the day when endogenous processes are promoting wakefulness. In a laboratory-controlled environment, 10 healthy non-shift working males aged 24.7 ±â€¯5.3 years (mean ±â€¯SD) underwent four consecutive nights of simulated night-shift work. Between 17:30-04:30 h participants provided saliva samples and completed a 3 min psychomotor vigilance test (PVT-B), 40 min simulated driving task, and 3 min digit symbol substitution test (DSST). Higher sAA levels were associated with faster response speed on the PVT-B, reduced lane variability on the simulated driving task, and improved information processing speed on the DSST during the first night-shift. There were no associations between sAA levels and performance outcomes during subsequent night-shifts. Findings indicate that the usability of sAA to assess the risk of neurobehavioral deficits during shift-work operations is limited. However, the robust circadian rhythm exhibited by sAA during the protocol of circadian misalignment suggests that sAA could serve as a potential circadian marker.

Nuts and Cardiovascular Disease Prevention.

PURPOSE OF REVIEW: We review recent epidemiological and clinical studies investigating the consumption of tree nuts and peanuts and cardiovascular disease (CVD) mortality as well as CVD risk factors. RECENT FINDINGS: A greater consumption of tree nuts and peanuts is associated with a reduced risk of CVD mortality, as well as lower CVD events. Furthermore, risk factors associated with the development of CVD such as dyslipidemia, impaired vascular function, and hypertension are improved with regular tree nut and peanut consumption through a range of mechanism associated with their nutrient-rich profiles. There is weak inconsistent evidence for an effect of nut consumption on inflammation. There is emerging evidence that consuming tree nuts reduces the incidence of non-alcoholic fatty liver disease (NAFLD) and promotes diversity of gut microbiota, which in turn may improve CVD outcomes. Evidence for CVD prevention is strong for some varieties of tree nuts, particularly walnuts, and length of supplementation and dose are important factors for consideration with recommendations.

Validation and reproducibility of an Australian caffeine food frequency questionnaire.

The aim of this study was to measure validity and reproducibility of a caffeine food frequency questionnaire (C-FFQ) developed for the Australian population. The C-FFQ was designed to assess average daily caffeine consumption using four categories of food and beverages including; energy drinks; soft drinks/soda; coffee and tea and chocolate (food and drink). Participants completed a seven-day food diary immediately followed by the C-FFQ on two consecutive days. The questionnaire was first piloted in 20 adults, and then, a validity/reproducibility study was conducted (n = 90 adults). The C-FFQ showed moderate correlations (r = .60), fair agreement (mean difference 63 mg) and reasonable quintile rankings indicating fair to moderate agreement with the seven-day food diary. To test reproducibility, the C-FFQ was compared to itself and showed strong correlations (r = .90), good quintile rankings and strong kappa values (κ = 0.65), indicating strong reproducibility. The C-FFQ shows adequate validity and reproducibility and will aid researchers in Australia to quantify caffeine consumption.

Omega-3 fatty acids as an adjunct for periodontal therapy-a review.

OBJECTIVES: The aim of this article is to present an overview of omega-3 fatty acids, their anti-inflammatory properties and potential use as an adjunct for periodontal therapy. MATERIALS AND METHODS: A general literature search was conducted to provide an overview of omega-3 fatty acids, their metabolism and anti-inflammatory properties. A more specific literature search of PubMed and EMBASE was conducted to identify articles dealing studies investigating the effects of omega-3 fatty acids in the treatment of periodontitis in animals and humans and included cross-sectional, longitudinal and intervention designs. RESULTS: To date, there is good emerging evidence that dietary supplementation with fish oil may be of some benefit and this is enhanced if combined with aspirin. All clinical intervention studies to date have been on small sample sizes, and this indicates there is need for larger and more robust clinical trials to verify these initial findings. CONCLUSIONS: Dietary supplementation with fish oil could be a cost-effective adjunctive therapy to the management of periodontal disease. CLINICAL RELEVANCE: The host modulatory properties of omega-3 fatty acids warrant further assessment of their use as an adjunct in the management of periodontitis.

Adiposity is related to decrements in cardiorespiratory fitness in obese and normal-weight children.

BACKGROUND: Obese children are typically less physically active than their normal-weight peers and are often assumed to be 'unfit'. OBJECTIVE: Investigate the relationships between adiposity, physical activity levels and cardiorespiratory fitness (CRF) in obese and normal-weight children. A secondary aim was to examine obese/normal-weight differences in CRF. METHODS: Obese (N = 107) and normal-weight (N = 132) 10-13-year-olds participated. Fat-free mass (FFM), percent fat, physical activity and peak oxygen uptake (VO2peak ) were assessed. Analyses were adjusted for socioeconomic status (SES). RESULTS: Higher percent fat was inversely associated with VO2peak normalized for mass (r = -0.780, P < 0.001) even after controlling for physical activity (r = -0.673, P < 0.001). While higher percent fat was also inversely associated with VO2peak normalized for FFM, this was only significant in males (r = -0.247, P = 0.004) and did not persist after controlling for physical activity (r = -0.059 P = 0.526). Compared with normal-weight children, obese children had higher absolute VO2peak , lower VO2peak corrected for mass (P ≤ 0.009) and lower VO2peak corrected for FFM (P = 0.041) that did not persist after controlling for SES (P = 0.086). CONCLUSION: Obesity-related inefficiencies in CRF were evident. Higher adiposity was associated with poorer CRF relative to mass, irrespective of physical activity levels. However, low physical activity levels may be responsible for associations between adiposity and CRF relative to FFM seen in boys, indicating the importance of encouraging physical activity.

Weighing up the evidence -- a systematic review of measures used for the sensation of breathlessness in obesity.

Breathlessness on exertion is common in people with obesity. Assessments of breathlessness may include sensation (intensity, sensory quality or unpleasantness) and/ or the behavioral/emotional consequences of the sensation (respiratory-related functional impairment, disability or quality of life). This systematic review of primary studies published since 2005 evaluated how has the sensation of breathlessness been assessed in adults with increased adiposity. A total of 41 articles were retained from the systematic search strategy resulting in 20 instruments. The Modified Borg Scale (perceived exertion-intensity), the Medical Research Council (MRC) Scale and Baseline Dyspnea Index (BDI; both assess respiratory-related functional impairment) were, respectively, the most frequently reported instruments. Few instruments had been tested for reliability and validity in people with increased adiposity. Visual Analog Scale, Modified Borg Scale, descriptors of sensory quality, MRC and BDI can be recommended as instruments based on their psychometric properties (reliability (correlations >0.8) and concurrent validity (correlation with severity of airways obstruction and walking distance)). A greater number of instruments were identified that assessed the consequences of the breathlessness rather than breathlessness as a sensation. If sensation drives behavior, comprehensive data on the sensation of breathlessness might assist in understanding the behavioral consequences of interventions.

Day-to-day physical functioning and disability in obese 10- to 13-year-olds.

UNLABELLED: What is already known about this subject? Compared with their healthy-weight peers, children with obesity have; impaired physical health-related quality of life reduced physical activity levels reduced capacity to perform certain weight-bearing tasks in field-based fitness tests What this study adds? First investigation of obesity-related disability in children using the International Classification for Functioning, Disability and Health framework for Children and Youth. Obesity in children appears to be associated with disability impacting basic locomotor skills and physical health-related quality of life. Children's participation in key life areas related to physical functioning appears to be minimally impacted by obesity. OBJECTIVE: The aim of this study was to investigate whether obesity is related to impaired day-to-day physical functioning and disability in children. METHODS: An observational case-control study was conducted in three Australian states. Obese (n = 107) and healthy-weight (n = 132) 10- to 13-year-olds (132 male, 107 female) were recruited via media advertisements. Assessment of body composition (dual energy X-ray absorptiometry), locomotor capacity (six-minute walk test [6MWT], timed up and down stairs test [TUDS] and timed up and go [TUG]) and child-reported physical health-related quality of life (HRQoL) were undertaken. Participants wore an accelerometer for 8 days and completed two use-of-time telephone interviews to assess participation in key life areas. RESULTS: Compared with their healthy-weight counterparts, obese children had lower physical HRQoL scores (P < 0.01) and reduced locomotor capacity (TUDS z-score, TUG and 6MWT; P < 0.01). Higher percent body fat was significantly related to lower physical HRQoL scores (r = -0.48, P < 0.01), slower performance times for the TUDS and TUG (r = 0.59 and 0.26 respectively, P < 0.01), shorter 6MWT distances (r = -0.51, P < 0.01) and reduced time spent in community participation activities (r = -0.23, P < 0.01). CONCLUSIONS: As anticipated, obesity appears to undermine physical functioning in children, including the capacity to perform basic locomotor skills yet, unexpectedly, participation in key life areas related to physical functioning appeared largely unaffected.

Obesity: the new childhood disability?

This review addresses the impact of obesity on paediatric physical functioning utilizing the World Health Organization International Classification of Functioning, Disability and Health Framework (ICF). The ICF encompasses functioning (as it relates to all body functions and structures), activities (undertaking a particular task) and participation (in a life situation) with disability referring to impairments in body functions/structures, activity restrictions or participation limitations. Electronic databases were searched for peer-reviewed studies published in English prior to May 2009 that examined aspects of physical functioning in children (≤18 years). Eligible studies (N = 104) were ranked by design and synthesized descriptively. Childhood obesity was found to be associated with deficits in function, including impaired cardiorespiratory fitness and performance of motor tasks; and there was some limited evidence of increased musculoskeletal pain and decrements in muscle strength, gait and balance. Health-related quality of life and the subset of physical functioning was inversely related to weight status. However, studies investigating impacts of obesity on wider activity and participation were lacking. Further research utilizing the ICF is required to identify and better characterize the effects of paediatric obesity on physical function, activity and participation, thereby improving targets for intervention to reduce disability in this population.

Acute resveratrol supplementation improves flow-mediated dilatation in overweight/obese individuals with mildly elevated blood pressure.

BACKGROUND AND AIMS: Flow-mediated dilatation of the brachial artery (FMD) is a biomarker of endothelial function and cardiovascular health. Impaired FMD is associated with several cardiovascular risk factors including hypertension and obesity. Various food ingredients such as polyphenols have been shown to improve FMD. We investigated whether consuming resveratrol, a polyphenol found in red wine, can enhance FMD acutely and whether there is a dose-response relationship for this effect. METHODS AND RESULTS: 19 overweight/obese (BMI 25-35 kg m(-2)) men or post-menopausal women with untreated borderline hypertension (systolic BP: 130-160 mmHg or diastolic BP: 85-100 mmHg) consumed three doses of resveratrol (resVida™ 30, 90 and 270 mg) and a placebo at weekly intervals in a double-blind, randomized crossover comparison. One hour after consumption of the supplement, plasma resveratrol and FMD were measured. Data were analyzed by linear regression versus log(10) dose of resveratrol. 14 men and 5 women (age 55 ± 2 years, BMI 28.7 ± 0.5 kg m(-2), BP 141 ± 2/89 ± 1 mmHg) completed this study. There was a significant dose effect of resveratrol on plasma resveratrol concentration (P < 0.001) and on FMD (P < 0.01), which increased from 4.1 ± 0.8% (placebo) to 7.7 ± 1.5% after 270 mg resveratrol. FMD was also linearly related to log(10) plasma resveratrol concentration (P < 0.01). CONCLUSION: Acute resveratrol consumption increased plasma resveratrol concentrations and FMD in a dose-related manner. This effect may contribute to the purported cardiovascular health benefits of grapes and red wine.

Dose-related effects of flavanol-rich cocoa on blood pressure.

Consumption of flavanol-containing cocoa products has been shown to lower blood pressure (BP), but the minimum dose required to reduce BP is not known. This study aimed to examine the effect of three different doses of cocoa flavanols (CF) on 24-h mean arterial BP. Twenty four hour ambulatory BP (24-ABP) monitoring was performed in 32 men and 20 postmenopausal women with untreated mild hypertension (seated clinic BP >130/85 and <160/100 mm Hg). Participants were randomized and instructed to consume daily a reconstituted cocoa beverage containing 33, 372, 712 or 1052 mg day(-1) of CF for 6 weeks in a double-blind, parallel comparison. Seated clinic BP and 24-h ABP were measured at 0, 3 and 6 weeks. Seated clinic BP did not change during the study period. There were significant reductions in 24-h systolic (5.3+/-5.1 mm Hg; P=0.001), diastolic (3+/-3.2 mm Hg; P=0.002) and mean arterial BP (3.8+/-3.2 mm Hg; P=0.0004) at the 1052 mg day(-1) CF only. No reduction in BP was seen at any other dose. No evidence of dose-response was seen in this experiment. The highest dose of 1052 mg CF per day was found to significantly lower BP. These results support previous evidence for CF to lower BP, however more research is needed to establish the most effective dose and food matrix.

Health-related quality of life in obese children and adolescents.

OBJECTIVE: This review addresses the effect of overweight and obese weight status on pediatric health-related quality of life (HRQOL). METHOD: Web of Science, Medline, CINAHL, Cochrane Library, EMBASE, AMED and PubMed were searched for peer-reviewed studies in English reporting HRQOL and weight status in youth (<21 years), published before March 2008. RESULTS: Twenty-eight articles were identified. Regression of HRQOL against body mass index (BMI) using pooled data from 13 studies utilizing the Pediatric Quality of Life Inventory identified an inverse relationship between BMI and pediatric HRQOL (r=-0.7, P=0.008), with impairments in physical and social functioning consistently reported. HRQOL seemed to improve with weight loss, but randomized controlled trials were few and lacked long-term follow-up. CONCLUSIONS: Little is known about the factors associated with reduced HRQOL among overweight or obese youth, although gender, age and obesity-related co-morbidities may play a role. Few studies have examined the differences in HRQOL between community and treatment-seeking samples. Pooled regressions suggest pediatric self-reported HRQOL can be predicted from parent proxy reports, although parents of obese youths tend to perceive worse HRQOL than children do about themselves. Thus, future research should include both pediatric and parent proxy perspectives.

Effect of cocoa flavanols and exercise on cardiometabolic risk factors in overweight and obese subjects.

OBJECTIVE: Impaired endothelial function in obesity may reduce blood flow to sites of metabolism, contributing to impaired fat oxidation and insulin resistance. This study investigated the effects of cocoa flavanols and regular exercise, interventions known to improve endothelial function, on cardiometabolic function and body composition in obese individuals. DESIGN: Overweight and obese adults were randomly assigned to high-flavanol cocoa (HF, 902 mg flavanols), HF and exercise, low-flavanol cocoa (LF, 36 mg flavanols), or LF and exercise for 12 weeks (exercise duration was 3 x 45 min per week at 75% of age-predicted maximum heart rate). Body composition was assessed by dual-energy X-ray absorptiometry at 0 and 12 weeks. Brachial artery flow-mediated dilatation (FMD), supine blood pressure (BP) and fasting plasma insulin, and glucose levels were assessed at 0, 6 and 12 weeks, respectively. Insulin sensitivity/resistance was determined using the modified homeostasis model assessment of insulin resistance (HOMA2). RESULTS: A total of 49 subjects (M=18; F=31) completed the intervention. Baseline averages were as follows: body mass index=33.5 kg/m(2); BP=123/76 mm Hg; HOMA2=2.4; FMD=4.3%; rate of fat oxidation during exercise=0.34 g min(-1); abdominal fat=45.7% of total abdominal mass. Compared to LF, HF increased FMD acutely (2 h post-dose) by 2.4% (P<0.01) and chronically (over 12 weeks; P<0.01) by 1.6% and reduced insulin resistance by 0.31% (P<0.05), diastolic BP by 1.6 mm Hg and mean arterial BP by 1.2 mm Hg (P<0.05), independent of exercise. Regular exercise increased fat oxidation during exercise by 0.10 g min(-1) (P<0.01) and reduced abdominal fat by 0.92% (P<0.05). CONCLUSION: Although HF consumption was shown to improve endothelial function, it did not enhance the effects of exercise on body fat and fat metabolism in obese subjects. However, it may be useful for reducing cardiometabolic risk factors in this population.

T-cell receptor variable gene products and early HIV-1 infection.

To assess the hypothesis that the human immunodeficiency virus (HIV) might mimic major histocompatibility complex (MHC) allodeterminants and interact with T-cell receptors (TCRs) of alloreactive T-cells, we have done a preliminary analysis of the range of alpha beta TCR gene products in 16 HIV-1-seropositive individuals with normal CD4 counts and in 16 healthy HIV-1-negative controls. Using a panel of monoclonal antibodies with a two-colour direct immunofluorescence method, we found a significant increase in the expression of the V beta 5.3 subfamily in the HIV-positive patient group compared with controls (p less than 0.01). Selected increase in expression of V beta sequences has been described in various autoimmune conditions and our findings raise the possibility that the immunopathological damage from HIV infection may be due to the induction of autoreactivity. If HIV does mimic MHC II, the normal immune response to the virus could represent an autoimmune process similar to graft-versus-host disease.