Effects of dairy products naturally enriched with cis-9,trans-11 conjugated linoleic acid on the blood lipid profile in healthy middle-aged men

Background: Interest in the development of dairy products naturally enriched in conjugated linoleic acid (CLA) exists. However, feeding regimens that enhance the CLA content of milk also increase concentrations of trans-18:1 fatty acids. The implications for human health are not yet known. Objective: This study investigated the effects of consuming dairy products naturally enriched in cis-9,trans-11 CLA (and trans-11 18:1) on the blood lipid profile, the atherogenicity of LDL, and markers of inflammation and insulin resistance in healthy middle-aged men. Design: Healthy middle-aged men (n = 32) consumed ultra-heat-treated milk, butter, and cheese that provided 0.151 g/d (control) or 1.421 g/d (modified) cis-9,trans-11 CLA for 6 wk. This was followed by a 7-wk washout and a crossover to the other treatment. Results: Consumption of dairy products enriched with cis-9,trans-11 CLA and trans-11 18:1 did not significantly affect body weight, inflammatory markers, insulin, glucose, triacylglycerols, or total, LDL, and HDL cholesterol but resulted in a small increase in the ratio of LDL to HDL cholesterol. The modified dairy products changed LDL fatty acid composition but had no significant effect on LDL particle size or the susceptibility of LDL to oxidation. Overall, increased consumption of full-fat dairy products and naturally derived trans fatty acids did not cause significant changes in cardiovascular disease risk variables, as may be expected on the basis of current health recommendations. Conclusion: Dairy products naturally enriched with cis-9,trans-11 CLA and trans-11 18: 1 do not appear to have a significant effect on the blood lipid profile.

Relation between the fatty acid composition of peripheral blood mononuclear cells and measures of immune cell function in health free-living subjects aged 25-72 y

Background: There is little information about the relation between the fatty acid composition of human immune cells and the function of those cells over the habitual range of fatty acid intakes. Objective: The objective of the study was to determine the relation between the fatty acid composition of human peripheral blood mononuclear cell (PBMC) phospholipids and the functions of human immune cells. Design: One hundred fifty healthy adult subjects provided a fasting blood sample. The phagocytic and oxidative burst activities of monocytes and neutrophils were measured in whole blood. PBMCs were isolated and used to measure lymphocyte proliferation in response to the T cell mitogen concanavalin A and the production of cytokines in response to concanavalin A or bacterial lipopolysaccharide. The fatty acid composition of plasma and PBMC phospholipids was determined. Results: Wide variations in fatty acid composition of PBMC phospholipids and immune cell functions were identified among the subjects. The proportions of total Polyunsaturated fatty acids (PUFAs), of total n-6 and n-3 PUFAs, and of several individual PUFAs in PBMC phospholipids were positively correlated with phagocytosis by neutrophils and monocytes, neutrophil oxidative burst, lymphocyte proliferation, and interferon gamma production. The ratios of saturated fatty acids to PUFAs and of n-6 to n-3 PUFAs were negatively correlated with these same immune functions. The relation of PBMC fatty acid composition to monocyte oxidative burst was the reverse of its relation to monocyte phagocytosis and neutrophil oxidative burst. Conclusion: Variations in the fatty acid composition of PBMC phospholipids account for some of the variability in immune cell functions among healthy adults.

Exaggerated postprandial lipaemia and lower post-heparin lipoprotein lipase activity in middle-aged men

An exaggerated postprandial lipaemic response is thought to play a central role in the development of an atherogenic lipoprotein phenotype, a recognized lipid risk factor for coronary heart disease. A small number of limited studies have compared postprandial lipaemia in subjects of varying age, but have not investigated mechanisms underlying age-associated changes in postprandial lipaemia. In order to test the hypothesis that impaired lipaemia in older subjects is associated with loss of insulin sensitivity, the present study compared the postprandial lipaemic and hormone responses for 9 h following a standard mixed meal in normolipidaemic healthy young and middle-aged men. Lipoprotein lipase (LPL) and hepatic lipase (HL) activities were determined in post-heparin plasma 9 h postprandially and on another occasion under fasting conditions. Postprandial plasma glucose (P < 0.02), retinyl ester (indirect marker for chylomicron particles; P < 0.005) and triacylglycerol (TAG)-rich lipoprotein (density < 1.006 g/ml fraction of plasma) TAG (P < 0.05) and retinyl ester (P < 0.005) responses were higher in middle-aged men, whereas plasma insulin responses were lower in this group (P < 0.001). Fasting and 9 h postprandial LPL and HL activities were also significantly lower in the middle-aged men compared with the young men (P < 0.006). In conclusion, the higher incremental postprandial TAG response in middle-aged men than young men was attributed to the accumulation of dietary-derived TAG-rich lipoproteins (density < 1.006 g/ml fraction of plasma) and occurred in the absence of marked differences in fasting TAG levels between the two groups. Fasting and postprandial LPL and HL activities were markedly lower in middle-aged men, but lack of statistical associations between measures of insulin response and post-heparin lipase activities, as well as between insulin and measures of postprandial lipaemia, suggest that this lower activity cannot be attributed to lack of sensitivity of lipases to activation by insulin. Alternatively, post-heparin lipase activities may not be good markers for the insulin-sensitive component of lipase that is activated postprandially.

Do expert drivers have a reduced illusion of superiority?

It is well established that people tend to rate themselves as better than average across many domains. To maintain these illusions, it is suggested that people distort feedback about their own and others' performance. This study examined expert/novice differences in self-ratings when people compared themselves with others of the same level of expertise and background as themselves. Given that a key expert characteristic is increased self-monitoring, we predicted that experts in a domain may have a reduced illusion of superiority because they are more aware of their actual ability. We compared expert police drivers with novice police drivers and found that this prediction was not supported. Expert police drivers rated themselves as superior to equally qualified drivers, to the same degree as novices, Cohen's d = .03 ns. Despite their extensive additional training and experience, experts still appear to be as susceptible to illusions of superiority Lis everyone else. (C) 2004 Elsevier Ltd. All rights reserved.

Does anticipation training affect drivers' risk taking?

Skill and risk taking are argued to be independent and to require different remedial programs. However, it is possible to contend that skill-based training could be associated with an increase, a decrease, or no change in risk taking behavior. In 3 experiments, the authors examined the influence of a skill-based training program (hazard perception) on the risk taking behavior of car drivers (using video-based driving simulations). Experiment 1 demonstrated a decrease in risk taking for novice drivers. In Experiment 2, the authors examined the possibilities that the skills training might operate through either a nonspecific reduction in risk taking or a specific improvement in hazard perception. Evidence supported the latter. These findings were replicated in a more ecological context in Experiment 3, which compared advanced and nonadvanced police drivers.

Drivers' ratings of different components of their own driving skill: a greater illusion of superiority for skills that relate to accident involvement

Different components of driving skill relate to accident involvement in different ways. For instance, while hazard-perception skill has been found to predict accident involvement, vehicle-control skill has not. We found that drivers rated themselves superior to both their peers and the average driver on 18 components of driving skill (N = 181 respondents). These biases were greater for hazard-perception skills than for either vehicle-control skills or driving skill in general. Also, ratings of hazard-perception skill related to self-perceived safety after overall skill was controlled for. We suggest that although drivers appear to appreciate the role of hazard perception in safe driving, any safety benefit to be derived from this appreciation may be undermined by drivers' inflated opinions of their own hazard-perception skill. We also tested the relationship between illusory beliefs about driving skill and risk taking and looked at ways of manipulating drivers' illusory beliefs.

A behavioral comparison between motorcyclists and a matched group of non-motorcycling car drivers: factors influencing accident risk

Motorcyclists and a matched group of non-motorcycling car drivers were assessed on behavioral measures known to relate to accident involvement. Using a range of laboratory measures, we found that motorcyclists chose faster speeds than the car drivers, overtook more, and pulled into smaller gaps in traffic, though they did not travel any closer to the vehicle in front. The speed and following distance findings were replicated by two further studies involving unobtrusive roadside observation. We suggest that the increased risk-taking behavior of motorcyclists was only likely to account for a small proportion of the difference in accident risk between motorcyclists and car drivers. A second group of motorcyclists was asked to complete the simulator tests as if driving a car. They did not differ from the non-motorcycling car drivers on the risk-taking measures but were better at hazard perception. There were also no differences for sensation seeking, mild social deviance, and attitudes to riding/driving, indicating that the risk-taking tendencies of motorcyclists did not transfer beyond motorcycling, while their hazard perception skill did. (C) 2002 Elsevier Science Ltd. All rights reserved.

Obesity and health in Europeans aged 50 years and older

Background: Obesity is increasing globally across all population groups. Limited data are available on how obesity patterns differ across countries. Objective: To document the prevalence of obesity and related health conditions for Europeans aged 50 years and older, and to estimate the association between obesity and health outcomes across 10 European countries. Methods: Data were obtained from the 2004 Survey of Health, Ageing and Retirement in Europe, a cross-national survey of 22 777 Continental Europeans over the age of 50 years. The health outcomes included self-reported health, disability, doctor-diagnosed chronic health conditions and depression. Multivariate regression analysis was used to predict health outcomes across weight classes (defined by body mass index [BMI] from self-reported weight and height) in the pooled sample and individually in each country. Results: The prevalence of obesity (BMI >= 30) ranged from 12.8% in Sweden to 20.2% in Spain for men and from 12.3% in Switzerland to 25.6% in Spain for women. Adjusting for compositional differences across countries changed little in the observed large heterogeneity in obesity rates throughout Europe. Compared with normal weight individuals, men and women with greater BMI had significantly higher risks for all chronic health conditions examined except heart disease in overweight men. Depression was linked to obesity in women only. Particularly pronounced risks of impaired health and chronic health conditions were found among severely obese people. The effects of obesity on health did not vary significantly across countries. Conclusions: Cross-country differences in the prevalence of obesity in older Europeans are substantial and exceed socio-demographic differentials in excessive body weight. Obesity is associated with significantly poorer health outcomes among Europeans aged 50 years and over, with effects similar across countries. Large heterogeneity in obesity throughout Europe should be investigated further to identify areas for effective public policy. (C) 2007 Published by Elsevier Ltd on behalf of The Royal Institute of Public Health.

Global pollinator declines: trends, impacts and drivers

Pollinators are a key component of global biodiversity, providing vital ecosystem services to crops and wild plants. There is clear evidence of recent declines in both wild and domesticated pollinators, and parallel declines in the plants that rely upon them. Here we describe the nature and extent of reported declines, and review the potential drivers of pollinator loss, including habitat loss and fragmentation, agrochemicals, pathogens, alien species, climate change and the interactions between them. Pollinator declines can result in loss of pollination services which have important negative ecological and economic impacts that could significantly affect themaintenance of wild plant diversity, wider ecosystemstability, crop production, food security and human welfare.