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Title:
Limited effect of dietary saturated fat on plasma saturated fat in the context of a low carbohydrate diet
Authors:
Forsythe, Cassandra E.; Phinney, Stephen D.; Feinman, Richard D.; Volk, Brittanie M.; Freidenreich, Daniel; Quann, Erin; Ballard, Kevin; Puglisi, Michael J.; Maresh, Carl M.; Kraemer, William J.; Bibus, Douglas M.; Fernandez, Maria Luz; Volek, Jeff S.
Abstract:
We recently showed that a hypocaloric carbohydrate restricted diet (CRD) had two striking effects: (1) a reduction in plasma saturated fatty acids (SFA) despite higher intake than a low fat diet, and (2) a decrease in inflammation despite a significant increase in arachidonic acid (ARA). Here we extend these findings in 8 weight stable men who were fed two 6-week CRD (12%en carbohydrate) varying in quality of fat. One CRD emphasized SFA (CRD-SFA, 86 g/d SFA) and the other, unsaturated fat (CRD-UFA, 47 g SFA/d). All foods were provided to subjects. Both CRD decreased serum triacylglycerol (TAG) and insulin, and increased LDL-C particle size. The CRD-UFA significantly decreased plasma TAG SFA (27.48 ± 2.89 mol%) compared to baseline (31.06 ± 4.26 mol%). Plasma TAG SFA, however, remained unchanged in the CRD-SFA (33.14 ± 3.49 mol%) despite a doubling in SFA intake. Both CRD significantly reduced plasma palmitoleic acid (16:1n-7) indicating decreased de novo lipogenesis. CRD-SFA significantly increased plasma phospholipid ARA content, while CRD-UFA significantly increased EPA and DHA. Urine 8-iso PGF(2α), a free radical-catalyzed product of ARA, was significantly lower than baseline following CRD-UFA (-32%). There was a significant inverse correlation between changes in urine 8-iso PGF(2α) and PL ARA on both CRD (r = -0.82 CRD-SFA; r = -0.62 CRD-UFA). These findings are consistent with the concept that dietary saturated fat is efficiently metabolized in the presence of low carbohydrate, and that a CRD results in better preservation of plasma ARA.
Published:
2010-10
Title:
Mitochondrial dysfunction in obesity.
Authors:
Bournat, Juan C; Brown, Chester W
Abstract:
PURPOSE OF REVIEW The review highlights recent findings regarding the functions of mitochondria in adipocytes, providing an understanding of their central roles in regulating substrate metabolism, energy expenditure, disposal of reactive oxygen species (ROS), and in the pathophysiology of obesity and insulin resistance, as well as roles in the mechanisms that affect adipogenesis and mature adipocyte function. RECENT FINDINGS Nutrient excess leads to mitochondrial dysfunction, which in turn leads to obesity-related pathologies, in part due to the harmful effects of ROS. The recent recognition of 'ectopic' brown adipose in humans suggests that this tissue may play an underappreciated role in the control of energy expenditure. Transcription factors, PGC-1alpha and PRDM16, which regulate brown adipogenesis, and members of the TGF-beta superfamily that modulate this process may be important new targets for antiobesity drugs. SUMMARY Mitochondria play central roles in ATP production, energy expenditure, and disposal of ROS. Excessive energy substrates lead to mitochondrial dysfunction with consequential effects on lipid and glucose metabolism. Adipocytes help to maintain the appropriate balance between energy storage and expenditure and maintaining this balance requires normal mitochondrial function. Many adipokines, including members of the TGF-beta superfamily, and transcriptional coactivators, PGC-1alpha and PRDM16, are important regulators of this process.
Published:
2010-10
Title:
Pivotal advance: The pattern recognition receptor ligands lipopolysaccharide and polyinosine-polycytidylic acid stimulate factor B synthesis by the macrophage through distinct but overlapping mechanisms
Authors:
Kaczorowski, David J.; Afrazi, Amin; Scott, Melanie J.; Kwak, Joon H.; Gill, Roop; Edmonds, Rebecca D.; Liu, Yujian; Fan, Jie; Billiar, Timothy R.
Abstract:
TLRs and complement are critical to the host response in sepsis, trauma, and ischemia/reperfusion. We hypothesize that TLR stimulation leads to synthesis and release of complement components by macrophages, an important source of extrahepatic complement. RAW264.7 macrophages or peritoneal macrophages from WT and TLR4-, TLR3-, TRIF-, or MyD88-deficient mice were cultured under standard conditions. In some experiments, cells were pretreated with inhibitors of MAPKs or a NF-κB inhibitor. Cells were stimulated with TLR ligands at known stimulatory concentrations. Intratracheal and i.p. injections were also performed in mice. RT-PCR, Western blotting, and immunocytochemistry were used for analysis. Using a RT-PCR-based panel, we demonstrate that of 18 complement components tested, factor B of the alternative pathway is the most robustly up-regulated complement component in macrophages in response to LPS. This up-regulation results in release of factor B into the media. Up-regulation of factor B by LPS is dependent on TLR4, TRIF, JNK, and NF-κB. A screen of other TLR ligands demonstrated that stimulation with poly I:C (dsRNA analog) also results in up-regulation of factor B, which is dependent on JNK and NF-κB but independent of TLR3 and TRIF. Up-regulation of factor B is also observed after intratracheal and i.p. injection of LPS or poly I:C in vivo. PRR stimulation profoundly influences production and release of factor B by macrophages. Understanding the mechanisms of PRR-mediated complement production may lead to strategies aimed at preventing tissue damage in diverse settings, including sepsis, trauma, and ischemia/reperfusion.
Published:
2010-10
Title:
Polycystic ovary syndrome in the pediatric population
Authors:
Bremer, Andrew A
Abstract:
Polycystic ovary syndrome (PCOS) is a common disorder characterized by hyperandrogenism and disordered gonadotropin secretion, often associated with insulin resistance. The syndrome, which modulates both hormonal and metabolic processes, is the most common endocrinopathy in reproductive-age women and increases a woman's risk of infertility, endometrial pathology, and cardiometabolic disease. As it is currently defined, PCOS most likely encompasses several distinct diseases with similar clinical phenotypes but different underlying pathophysiological processes. However, hyperandrogenism remains the syndrome's clinical hallmark. The clinical manifestations of PCOS often emerge during childhood or in the peripubertal years, suggesting that the syndrome is influenced by fetal programming and/or early postnatal events. However, given that the full clinical spectrum of PCOS does not typically appear until puberty, a "two-hit" hypothesis has been proposed: (1) a girl develops hyperandrogenism via one or more of many different potential mechanisms; (2) the preexisting hyperandrogenism subsequently disturbs the hypothalamic–pituitary–ovarian axis, resulting in ovulatory dysfunction and sustained hyperandrogenism. No consensus guidelines exist regarding the diagnosis and management of PCOS in the pediatric population; however, because the syndrome is a diagnosis of exclusion, the clinical evaluation of girls suspected of having PCOS is aimed at excluding other causes of androgen excess and menstrual dysfunction. For the syndrome's management, emphasis is placed on lifestyle and symptom-directed treatment.
Published:
2010-10
Title:
Saturated fat and cardiometabolic risk factors, coronary heart disease, stroke, and diabetes: a fresh look at the evidence
Authors:
Micha, Renata; Mozaffarian, Dariush
Abstract:
Dietary and policy recommendations frequently focus on reducing saturated fatty acid consumption for improving cardiometabolic health, based largely on ecologic and animal studies. Recent advances in nutritional science now allow assessment of critical questions about health effects of saturated fatty acids (SFA). We reviewed the evidence from randomized controlled trials (RCTs) of lipid and non-lipid risk factors, prospective cohort studies of disease endpoints, and RCTs of disease endpoints for cardiometabolic effects of SFA consumption in humans, including whether effects vary depending on specific SFA chain-length; on the replacement nutrient; or on disease outcomes evaluated. Compared with carbohydrate, the TC:HDL-C ratio is nonsignificantly affected by consumption of myristic or palmitic acid, is nonsignificantly decreased by stearic acid, and is significantly decreased by lauric acid. However, insufficient evidence exists for different chain-length-specific effects on other risk pathways or, more importantly, disease endpoints. Based on consistent evidence from human studies, replacing SFA with polyunsaturated fat modestly lowers coronary heart disease risk, with ~10% risk reduction for a 5% energy substitution; whereas replacing SFA with carbohydrate has no benefit and replacing SFA with monounsaturated fat has uncertain effects. Evidence for the effects of SFA consumption on vascular function, insulin resistance, diabetes, and stroke is mixed, with many studies showing no clear effects, highlighting a need for further investigation of these endpoints. Public health emphasis on reducing SFA consumption without considering the replacement nutrient or, more importantly, the many other food-based risk factors for cardiometabolic disease is unlikely to produce substantial intended benefits.
Published:
2010-10
Title:
Saturated fat and cardiometabolic risk factors, coronary heart disease, stroke, and diabetes: a fresh look at the evidence. [Review]
Authors:
Micha, Renata; Mozaffarian, Dariush
Abstract:
Dietary and policy recommendations frequently focus on reducing saturated fatty acid consumption for improving cardiometabolic health, based largely on ecologic and animal studies. Recent advances in nutritional science now allow assessment of critical questions about health effects of saturated fatty acids (SFA). We reviewed the evidence from randomized controlled trials (RCTs) of lipid and non-lipid risk factors, prospective cohort studies of disease endpoints, and RCTs of disease endpoints for cardiometabolic effects of SFA consumption in humans, including whether effects vary depending on specific SFA chain-length; on the replacement nutrient; or on disease outcomes evaluated. Compared with carbohydrate, the TC:HDL-C ratio is nonsignificantly affected by consumption of myristic or palmitic acid, is nonsignificantly decreased by stearic acid, and is significantly decreased by lauric acid. However, insufficient evidence exists for different chain-length-specific effects on other risk pathways or, more importantly, disease endpoints. Based on consistent evidence from human studies, replacing SFA with polyunsaturated fat modestly lowers coronary heart disease risk, with ~10% risk reduction for a 5% energy substitution; whereas replacing SFA with carbohydrate has no benefit and replacing SFA with monounsaturated fat has uncertain effects. Evidence for the effects of SFA consumption on vascular function, insulin resistance, diabetes, and stroke is mixed, with many studies showing no clear effects, highlighting a need for further investigation of these endpoints. Public health emphasis on reducing SFA consumption without considering the replacement nutrient or, more importantly, the many other food-based risk factors for cardiometabolic disease is unlikely to produce substantial intended benefits.
Published:
2010-10
Title:
The pros and cons of phytoestrogens
Authors:
Patisaul, Heather B.; Jefferson, Wendy
Abstract:
Phytoestrogens are plant derived compounds found in a wide variety of foods, most notably soy. A litany of health benefits including a lowered risk of osteoporosis, heart disease, breast cancer, and menopausal symptoms, are frequently attributed to phytoestrogens but many are also considered endocrine disruptors, indicating that they have the potential to cause adverse health effects as well. Consequently, the question of whether or not phytoestrogens are beneficial or harmful to human health remains unresolved. The answer is likely complex and may depend on age, health status, and even the presence or absence of specific gut microflora. Clarity on this issue is needed because global consumption is rapidly increasing. Phytoestrogens are present in numerous dietary supplements and widely marketed as a natural alternative to estrogen replacement therapy. Soy infant formula now constitutes up to a third of the US market, and soy protein is now added to many processed foods. As weak estrogen agonists/antagonists with molecular and cellular properties similar to synthetic endocrine disruptors such as Bisphenol A (BPA), the phytoestrogens provide a useful model to comprehensively investigate the biological impact of endocrine disruptors in general. This review weighs the evidence for and against the purported health benefits and adverse effects of phytoestrogens.
Published:
2010-10
Title:
A low-fat, high-complex carbohydrate diet supplemented with long-chain (n-3) fatty acids alters the postprandial lipoprotein profile in patients with metabolic syndrome
Authors:
Jimenez-Gomez, Yolanda; Marin, Carmen; Peerez-Martinez, Pablo; Hartwich, Jadwiga; Malczewska-Malec, Malgorzata; Golabek, Iwona; Kiec-Wilk, Beata; Cruz-Teno, Cristina; Rodriguez, Fernando; Gomez, Purificacion; Gomez-Luna, Maria J.; Defoort, Catherine; Gibney, Michael J.; Perez-Jimenez, Francisco; Roche, Helen M.; Lopez-Miranda, Jose
Abstract:
Dietary fat intake plays a critical role in the development of metabolic syndrome (MetS). This study addressed the hypothesis that dietary fat quantity and quality may differentially modulate postprandial lipoprotein metabolism in MetS patients. A multi-center, parallel, randomized, controlled trial conducted within the LIPGENE study randomly assigned MetS patients to 1 of 4 diets: high-SFA [HSFA; 38% energy (E) from fat, 16% E as SFA], high-monounsaturated fatty acid [HMUFA; 38% E from fat, 20% E as MUFA], and 2 low-fat, high-complex carbohydrate [LFHCC; 28% E from fat] diets supplemented with 1.24 g/d of long-chain (LC) (n-3) PUFA (ratio 1.4 eicosapentaenoic acid:1 docosahexaenoic acid) or placebo (1.24 g/d of high-oleic sunflower-seed oil) for 12 wk each. A fat challenge with the same fat composition as the diets was conducted pre- and postintervention. Postprandial total cholesterol, triglycerides (TG), apolipoprotein (apo) B, apo B-48, apo A-I, LDL-cholesterol, HDL-cholesterol and cholesterol, TG, retinyl palmitate, and apo B in TG-rich lipoproteins (TRL; large and small) were determined pre- and postintervention. Postintervention, postprandial TG (P < 0.001) and large TRL-TG (P = 0.009) clearance began earlier and was faster in the HMUFA group compared with the HSFA and LFHCC groups. The LFHCC (n-3) group had a lower postprandial TG concentration (P < 0.001) than the other diet groups. Consuming the LFHCC diet increased the TG (P = 0.04), large TRL-TG (P = 0.01), TRL-cholesterol (P
Published:
2010-09
Title:
A novel pre-clinical in vivo mouse model for malignant brain tumor growth and invasion
Authors:
Shelton, Laura M.; Mukherjee, Purna; Huysentruyt, Leanne C.; Urits, Ivan; Rosenberg, Joshua A.; Seyfried, Thomas N.
Abstract:
Glioblastoma multiforme (GBM) is a rapidly progressive disease of morbidity and mortality and is the most common form of primary brain cancer in adults. Lack of appropriate in vivo models has been a major roadblock to developing effective therapies for GBM. A new highly invasive in vivo GBM model is described that was derived from a spontaneous brain tumor (VM-M3) in the VM mouse strain. Highly invasive tumor cells could be identified histologically on the hemisphere contralateral to the hemisphere implanted with tumor cells or tissue. Tumor cells were highly expressive for the chemokine receptor CXCR4 and the proliferation marker Ki-67 and could be identified invading through the pia mater, the vascular system, the ventricular system, around neurons, and over white matter tracts including the corpus callosum. In addition, the brain tumor cells were labeled with the firefly luciferase gene, allowing for non-invasive detection and quantitation through bioluminescent imaging. The VM-M3 tumor has a short incubation time with mortality occurring in 100% of the animals within approximately 15 days. The VM-M3 brain tumor model therefore can be used in a pre-clinical setting for the rapid evaluation of novel anti-invasive therapies.
Published:
2010-09
Title:
Approach to the patient with an adrenal incidentaloma
Authors:
Nieman, Lynnette K
Abstract:
Unsuspected adrenal masses, or incidentalomas, are increasingly found with the widespread use of thoracic and abdominal imaging. These masses may be hormonally active or nonfunctional and malignant or benign. Clinicians must determine the nature of the mass to decide what treatment, if any, is needed. Measurement of precontrast Hounsfield units (HU) and contrast washout on computed tomography scan provide useful diagnostic information. All patients should undergo biochemical testing for pheochromocytoma, either with plasma or urinary catecholamine measurements. This is particularly important before surgical resection, which is routinely recommended for masses larger than 4 cm in diameter without a clear-cut diagnosis and for others with hormonal secretion or ominous imaging characteristics. Hypertensive patients should undergo biochemical testing for hyperaldosteronism. Patients with features consistent with Cushing's syndrome, such as glucose intolerance, weight gain, and unexplained osteopenia, should be evaluated for cortisol excess. Here, the dexamethasone suppression test and late-night salivary cortisol may be preferred over measurement of urine cortisol. The ability of surgical resection to reverse features of mild hypercortisolism is not well established. For masses that appear to be benign (50%), small (
Published:
2010-09
Title:
Effective small group learning: AMEE Guide No. 48
Authors:
Edmunds, Sarah; Brown, George
Abstract:
The objective of this educational guide is to outline the major facets of effective small group learning, particularly applied to medicine. These are discussion skills, methods, the roles and responsibilities of tutors and students, the dynamics of groups and the effects of individuals. It is argued that the bases of effective small group learning are discussion skills such as listening, questioning and responding. These skills are the platform for the methods of facilitating discussion and thinking. The facilitating methods strengthen the generic methods, such as tutorials, seminars and electronic tutorials. However, the success of these methods is dependent in part upon the roles and responsibilities taken by students and tutors and the consequent group dynamic. The group dynamic can be adversely affected by individuals. Evaluation of the processes of small group learning can provide diagnoses of the behaviour of difficult individuals. More importantly, studies of the processes can help to develop more effective small group learning.
Published:
2010-09
Title:
Electroconvulsive Therapy Stimulus Parameters: Rethinking Dosage
Authors:
Peterchev, Angel V.; Rosa, Moacyr A.; Deng, Zhi-De; Prudic, Joan; Lisanby, Sarah H.
Abstract:
In this paper we review the parameters that define the ECT electrical stimulus and discuss their biophysical roles. We also present the summary metrics of charge and energy that are conventionally used to describe the dose of ECT and the rules commonly deployed to individualize the dose for each patient. We then highlight the limitations of these summary metrics and dosing rules in that they do not adequately capture the roles of the distinct stimulus parameters. Specifically, there is strong theoretical and empirical evidence that stimulus parameters (pulse amplitude, shape, and width, and train frequency, directionality, polarity, and duration) exert unique neurobiological effects that are important for understanding ECT outcomes. Consideration of the distinct stimulus parameters, in conjunction with electrode placement, is central to further optimization of ECT dosing paradigms to improve the risk/benefit ratio. Indeed, manipulation of specific parameters, such as reduction of pulse width and increase in number of pulses, has already resulted in dramatic reduction of adverse side effects, while maintaining efficacy. Furthermore, the manipulation of other parameters, such as current amplitude, which are commonly held at fixed, high values, might be productively examined as additional means of targeting and individualizing the stimulus, potentially reducing side effects. We recommend that ECT dose be defined using all stimulus parameters rather than a summary metric. All stimulus parameters should be noted in treatment records and published reports. To enable research on optimization of dosing paradigms, we suggest that ECT devices provide capabilities to adjust and display all stimulus parameters.
Published:
2010-09
Title:
Is Malnutrition Associated with Crowding in Permanent Dentition?
Authors:
Thomaz, Erika B. A. F.; Cangussu, Maria Cristina T.; da Silva, Antônio Augusto M.; Assis, Ana Marlúcia O.
Abstract:
Evidence suggests that energy-protein malnutrition is associated with impaired growth and development of facial bones. The objective of this study was to investigate the association between nutritional status and reduced space for dental eruption (crowding) in permanent dentition. A cross-sectional study with probabilistic sampling design was used. We evaluated 2,060 students aged 12 to 15 years enrolled in schools in the northeast of Brazil. Crowding was defined according to World Health Organization (WHO) as misalignment of teeth due to lack of space for them to erupt in the correct position. Nutritional status was evaluated by means of body mass index and height-for-age, using the WHO’s reference curves. Parents and adolescents responded to a questionnaire about demographic, socioeconomic, biological and behavioral characteristics. The associations were estimated by odds ratio (OR) in multivariate logistic regression analysis (alpha = 0.05). Confounding and effect-modification were taken into account. An association between low height-for-age (z-score
Published:
2010-09
Title:
Serum Concentrations of Vitamin B12 and Folate in British Male Omnivores, Vegetarians and Vegans: Results From a Cross-Sectional Analysis of the EPIC-Oxford Cohort Study
Authors:
Am, Gilsing; Fl, Crowe; Z, Lloyd-Wright; Ta, Sanders; Pn, Appleby; Ne, Allen; Tj, Key
Abstract:
Vegans have lower vitamin B12 concentrations, but higher folate concentrations, than vegetarians and omnivores. Half of the vegans were categorized as vitamin B12 deficient and would be expected to have a higher risk of developing clinical symptoms related to vitamin B12 deficiency.
Published:
2010-09
Title:
The effect of a high-fat meal on postprandial arterial stiffness in men with obesity and type 2 diabetes
Authors:
Phillips, L. K.; Peake, J. M.; Zhang, X.; Hickman, I. J.; Kolade, O.; Sacre, J. W.; Huang, B. E.; Simpson, P.; Li, S. H.; Whitehead, J. P.; Sharman, J. E.; Martin, J. H.; Prins, J. B.
Abstract:
CONCLUSIONS: Obesity is associated with an attenuated overall postprandial decrease in AIx. Subjects with T2DM have a preserved, but significantly prolonged, reduction in AIx after a high-fat meal. The correlation between AIx and triglycerides suggests that postprandial dysmetabolism may impact on vascular dynamics. The markedly different response observed in the obese subjects compared with those with T2DM was unexpected and warrants additional evaluation.
Published:
2010-09
Title:
[Influence of vegetarian diet on serum values of homocysteine and total antioxidant status in children]
Authors:
Chełchowska, Magdalena; Ambroszkiewicz, Jadwiga; Klemarczyk, Witold; Gajewska, Joanna; Ołtarzewski, Mariusz; Laskowska-Klita, Teresa
Abstract:
The vegetarian diet may play a preventive role in the development of chronic diseases such as coronary heart and cardiovascular disease. However increase of homocysteine (Hcy) concentration in peoples avoiding animal products may contribute to an increased atherosclerotic risk in these subjects. Recent evidence has suggested that role of hyperhomocysteinemia in atherogenesis is associated with process of autooxidation, which can promote the production of hydroxyl radicals, resulting in oxidative modification of low density lipoprotein and endothelium injury. The oxidant-antioxidant imbalance depends not only on the amount of enhanced free oxygen species but also insufficiency of antioxidant defence system. Total antioxidant status (TAS) expresses capacity for scavenging of free radicals minimizes oxidative damage. The aim of this study was to asses concentrations of homocysteine and total antioxidant status in serum of children on vegetarian and omnivorous diet. We also studied levels of vitamin A (retinol) and vitamin E (alpha-tocopherol) particular components of TAS. MATERIAL AND METHODS: The study included 35 children, aged 5-16 who had been referred to Institute of Mother and Child for dietary consultation. From those, 17 were lacto-ovo-vegetarians and 18 omnivores. Dietary constituents were analyzed using the nutritional programme Dietetyk2 and completed with supplementation data. Concentration of homocysteine was estimated in serum with fluorescence polarization immunoassay and TAS by colorimetric method. Levels of vitamin A and E were determined using high-pressure liquid chromatography (HPLC). RESULTS: The mean concentration of homocysteine was similar in both studied groups (vegetarians: 6.13 +/- 1.01 micromol/l vs. omnivores: 5.45 +/- 0.98 micromol/l). In vegetarian children serum level of TAS was significantly lower (1.21 +/- 0.06 mmol/I) as compared to those in non-vegetarian ones (1.30 +/- 0.05 mmol/l, p < 0.0001), but remained within the physiological range (1.16-1.40 mmol/l). The mean concentrations of vitamins A and E in serum of vegetarians were lower than observed in omnivores group, but only in case of alpha-tocopherol the difference was statistically significant (vegetarians: 15.58 +/- 4.12 vs. omnivores: 18.41 +/- 3.10; p
Published:
2010-09
Title:
n-6 Fatty acids and cardiovascular health: a review of the evidence for dietary intake recommendations. [Review] [110 refs]
Authors:
Czernichow, Sebastien; Thomas, Daniel; Bruckert, Eric
Abstract:
n-6 PUFA are well known for their critical role in many physiological functions and seem to reduce risks of CHD. However, some argue that excessive consumption of n-6 PUFA may lead to adverse effects on health and therefore recommend reducing dietary n-6 PUFA intake or fixing an upper limit. In this context, the present work aimed to review evidence on the link between n-6 PUFA and risks of CVD. Epidemiological studies show that n-6 PUFA dietary intake significantly lowers blood LDL-cholesterol levels. In addition, n-6 PUFA intake does not increase several CVD risk factors such as blood pressure, inflammatory markers, haemostatic parameters and obesity. Data from prospective cohort and interventional studies converge towards a specific protective role of dietary n-6 PUFA intake, in particular linoleic acid, against CVD. n-6 PUFA benefits are even increased when SFA intake is also reduced. In regards to studies examined in this narrative review, recommendation for n-6 PUFA intake above 5 %, and ideally about 10 %, of total energy appears justified. [References: 110]
Published:
2010-09
Title:
A multicomponent intervention reduces body weight and cardiovascular risk at a GEICO corporate site
Authors:
Ferdowsian, Hope R.; Barnard, Neal D.; Hoover, Valerie J.; Katcher, Heather I.; Levin, Susan M.; Green, Amber A.; Cohen, Joshua L.
Abstract:
PURPOSE: To determine whether a multicomponent nutrition intervention program at a corporate site reduces body weight and improves other cardiovascular risk factors in overweight individuals. DESIGN: Prospective clinical intervention study. SUBJECTS/SETTING: Employees of the Government Employees Insurance Company (GEICO) (N = 113), aged 21 to 65 years, with a body mass index > or =25 kg/m(2) and/or previous diagnosis of type 2 diabetes. INTERVENTION: A 22-week intervention including a low-fat, vegan diet. MEASURES: Changes in body weight, anthropometric measures, blood pressure, lipid profile, and dietary intake. ANALYSIS: Multivariate analyses of variance were calculated for clinical and nutrient measures, followed by univariate analyses of variance, to determine the significance of differences between groups in changes over time. RESULTS: Intervention-group participants experienced greater weight changes compared with control-group participants (mean, -5.1 [SE, .6] kg vs. + .1 [SE, .6] kg, p < .0001), as well as greater changes in waist circumference (mean, -4.7 [SE, .6] cm vs. + .8 [SE, .6] cm, p < .0001) and waistratiohip ratio (mean, -.006 [SE, .003] vs. + .014 [SE, .005], p = .0007). Weight loss of 5% of body weight was more frequently observed in the intervention group (48.5%) compared with the control group (11.1%) (chi(2)[1, N = 113] = 16.99, p
Published:
2010-08
Title:
A rapid direct solvent extraction method for the extraction of 2-dodecylcyclobutanone from irradiated ground beef patties using acetonitrile
Authors:
Hijaz, Faraj; Kumar, Amit; Smith, J. Scott
Abstract:
The amount of irradiated beef in the U.S. market is growing, and a reliable, rapid method is needed to detect irradiated beef and quantify the irradiation dose. The official analytical method (BS EN 1785 2003) that has been adopted by the European Union is time consuming. The objective of this study was to develop a rapid method for the analysis of 2-dodecylcyclobutanone (2-DCB) in irradiated beef. A 5 g sample of commercially irradiated ground beef patty (90/10) was extracted with n-hexane using a Soxhlet apparatus or with acetonitrile via direct solvent extraction. The Soxhlet hexane extract was evaporated to dryness, and the sample was dissolved in a mixture of ethyl acetate and acetonitrile (1:1). The defatted extract was purified with a 1 g silica cartridge. Another 5 g aliquot of the same patty was mixed with 50 mL acetonitrile and either blended for 1 min with a hand blender or crushed for 10 min with a glass rod. The extraction procedure was repeated 3 times, and the acetonitrile was collected and evaporated to dryness. Eluants from both methods were concentrated under nitrogen and injected into a gas chromatography-mass spectrometry. The 2-DCB concentration in the commercial samples was 0.031 +/- 0.0026 ppm (n = 5) for the Soxhlet method and 0.031 +/- 0.0025 ppm (n = 10) for direct solvent extraction. Recovery of 2-DCB from spiked beef samples in the direct solvent extraction method was 93.2 +/- 9.0% (n = 7). This study showed that the direct solvent extraction method is simple and as efficient and reproducible as the Soxhlet method.
Published:
2010-08
Title:
Anticonvulsant and proconvulsant actions of 2-deoxy-D-glucose
Authors:
Gasior, Maciej; Yankura, Jessica; Hartman, Adam L.; French, Amy; Rogawski, Michael A.
Abstract:
PURPOSE: 2-Deoxy-D-glucose (2-DG), a glucose analog that accumulates in cells and interferes with carbohydrate metabolism by inhibiting glycolytic enzymes, has anticonvulsant actions. Recognizing that severe glucose deprivation can induce seizures, we sought to determine whether acute treatment with 2-DG can promote seizure susceptibility by assessing its effects on seizure threshold. For comparison, we studied 3-methyl-glucose (3-MG), which like 2-DG accumulates in cells and reduces glucose uptake, but does not inhibit glycolysis. METHODS: Mice were treated with 2-DG or 3-MG and the seizure threshold determined in the 6-Hz test, the mouse electroshock seizure threshold (MEST) test, and the intravenous pentylenetetrazol (i.v. PTZ) or kainic acid (i.v. KA) seizure threshold tests. 2-DG was also tested in fully amygdala-kindled rats. RESULTS: 2-DG (125-500 mg/kg, i.p., 30 min before testing) significantly elevated the seizure threshold in the 6-Hz seizure test. 2-DG (250-500 mg/kg) decreased the threshold in the MEST and i.v. PTZ and i.v. KA tests. 3-MG had no effect on seizure threshold in the 6-Hz test but, like 2-DG, decreased seizure threshold in the i.v. PTZ test. 2-DG (250 and 500 mg/kg, i.p., 30 min before testing) had no effect on amygdala-kindled seizures. CONCLUSIONS: Although 2-DG protects against seizures in the 6-Hz seizure test, it promotes seizures in some other models. The proconvulsant action may relate to reduced glucose uptake, whereas the anticonvulsant action may require inhibition of glycolysis and shunting of glucose metabolism through the pentose phosphate pathway.
Published:
2010-08
Title:
Cardiovascular disease risk factors and dietary habits of farmers from Crete 45 years after the first description of the Mediterranean diet
Authors:
Vardavas, Constantine I.; Linardakis, Manolis K.; Hatzis, Christos M.; Saris, Wim H. M.; Kafatos, Anthony G.
Abstract:
CONCLUSION: The population's lack of adherence to the Mediterranean diet, have led to the fact that currently farmers from Crete are likely to be at a higher risk for developing CVD in comparison with earlier generations.
Published:
2010-08
Title:
Effects of ingesting protein in combination with carbohydrate during exercise on endurance performance: a systematic review with meta-analysis
Authors:
Stearns, Rebecca L.; Emmanuel, Holly; Volek, Jeff S.; Casa, Douglas J.
Abstract:
Coingestion of protein with carbohydrate has been shown to enhance muscle recovery, particularly after intense bouts of exercise. However, performance benefits of ingesting a protein-carbohydrate drink during exercise remains unclear. Therefore, we used a systematic review with meta-analysis to examine the influence of protein ingestion during exercise on subsequent endurance performance. Eleven qualifying studies were included that contained 3 time-trial and 8 time-to-exhaustion cycling protocols. Only 3 of these studies controlled for caloric content and contained an isocaloric trial. Of the 11, 4 reported significant differences between a control and protein trial; however, none of these were isocaloric studies. The 3 time-trial protocols showed no significant improvement with protein. The meta-analysis of the time-trial studies revealed no significant overall effect (p = 0.73), whereas meta-analysis of time-to-exhaustion studies revealed a significant effect (p = 0.008). Of the time-to-exhaustion trials, the isocaloric studies found no significant effect (p = 0.71), whereas the isocarbohydrate studies revealed a significant effect (p = 0.05). The average percent improvement with ingestion of protein was 9.0%. The isocarbohydrate studies reported an improvement of 10.5%, whereas the isocaloric studies revealed a 3.4% improvement. We conclude that compared to carbohydrate alone, coingestion of protein and carbohydrate during exercise demonstrated an ergogenic effect on endurance performance when assessed by time to exhaustion and also where supplements were matched for carbohydrate (isocarbohydrate). Thus, the ergogenic effect of protein seen in isocarbohydrate studies may be because of a generic effect of adding calories (fuel) as opposed to a unique benefit of protein. Further research is warranted before a clear conclusion can be drawn.
Published:
2010-08
Title:
Efficacy and Safety of a High Protein, Low Carbohydrate Diet for Weight Loss in Severely Obese Adolescents
Authors:
Krebs, Nancy F.; Gao, Dexiang; Gralla, Jane; Collins, Juliet S.; Johnson, Susan L.
Abstract:
Objective To evaluate the efficacy and safety of a carbohydrate restricted versus a low fat diet on weight loss, metabolic markers, body composition, and cardiac function tests in severely obese adolescents. Study design Subjects were randomized to one of two diets: a high protein, low carbohydrate (20 g/day) diet (HPLC) or low fat (30% of calories) (LF) regimen for 13 weeks; close monitoring was maintained to evaluate safety. After the intervention, no clinical contact was made until follow-up measurements were obtained at 24 and 36 weeks from baseline. The primary outcome was change in BMI-Z-score at 13, 24, and 36 weeks. Results Forty-six subjects (24 HPLC, 22 in LF) initiated and 33 subjects completed the intervention; follow-up data were available on approximately half of the subjects. Significant reduction in BMI-Z-score (BMI-Z) was achieved in both groups during intervention, and was significantly greater for the HPLC group (p=0.03). Both groups maintained significant BMI-Z reduction at follow-up; changes were not significantly different between groups. Loss of lean body mass was not spared in the HPLC group. No serious adverse effects were observed related to metabolic profiles, cardiac function, or subjective complaints. Conclusions The HPLC diet is a safe and effective option for medically supervised weight loss in severely obese adolescents.
Published:
2010-08
Title:
Familiarity Breeds Respect: Attitudes of Medical Students Towards Psychiatry Following a Clinical Attachment
Authors:
Lampe, Lisa; Coulston, Carissa; Walter, Garry; Malhi, Gin
Abstract:
Objective: The aim of this paper was to examine the influence of a clinical attachment in psychiatry on medical students’ attitudes to psychiatry as a specialty and potential career. Method: Medical students at Sydney Medical School were surveyed following an 8-week clinical attachment in psychiatry. Secondary analyses sought to identify associations with variables such as age, gender and level of clinical experience as a medical student. Results: Following a clinical attachment in psychiatry, 80% of students rated their attitude to psychiatry as more positive. Approximately 32% rated themselves as likely or very likely to choose a career in psychiatry. No differences were seen with respect to gender, age or stage of training. The quality of the teaching, enthusiasm of the clinical teachers, the holistic approach and scientific basis of psychiatry were cited by students as factors influencing attitudes. Conclusions: The clinical rotation in psychiatry is a significant factor influencing medical student attitudes towards psychiatry.
Published:
2010-08
Title:
Fueling the vegetarian (vegan) athlete
Authors:
Fuhrman, Joel; Ferreri, Deana M.
Abstract:
Vegetarian diets are associated with several health benefits, but whether a vegetarian or vegan diet is beneficial for athletic performance has not yet been defined. Based on the evidence in the literature that diets high in unrefined plant foods are associated with beneficial effects on overall health, lifespan, immune function, and cardiovascular health, such diets likely would promote improved athletic performance as well. In this article, we review the state of the literature on vegetarian diets and athletic performance, discuss prevention of potential micronutrient deficiencies that may occur in the vegan athlete, and provide strategies on meeting the enhanced caloric and protein needs of an athlete with a plant-based diet.
Published:
2010-08
Title:
Lymphatic Lipid Transport: Sewer or Subway?
Authors:
Dixon, J. Brandon
Abstract:
The lymphatics began receiving attention in the scientific community as early as 1622, when Gasparo Aselli noted the appearance of milky white vessels in the mesentery of a well-fed dog. Since this time, the lymphatic system has been historically regarded as the sewer of the vasculature, passively draining fluid and proteins from the interstitial spaces (along with lipid from the gut) into the blood. Recent reports, however, suggest that the lymphatic role in lipid transport is an active and intricate process and when lymphatic function is compromised, there are systemic consequences to lipid metabolism and transport. This review highlights these recent findings and suggests future directions for understanding the interplay between lymphatic and lipid biology in health and disease.
Published:
2010-08
Title:
Maximal strength training improves cycling economy in competitive cyclists
Authors:
Sunde, Arnstein; Støren, Oyvind; Bjerkaas, Marius; Larsen, Morten H.; Hoff, Jan; Helgerud, Jan
Abstract:
The purpose of the present study was to investigate the effect of maximal strength training on cycling economy (CE) at 70% of maximal oxygen consumption (Vo2max), work efficiency in cycling at 70% Vo2max, and time to exhaustion at maximal aerobic power. Responses in 1 repetition maximum (1RM) and rate of force development (RFD) in half-squats, Vo2max, CE, work efficiency, and time to exhaustion at maximal aerobic power were examined. Sixteen competitive road cyclists (12 men and 4 women) were randomly assigned into either an intervention or a control group. Thirteen (10 men and 3 women) cyclists completed the study. The intervention group (7 men and 1 woman) performed half-squats, 4 sets of 4 repetitions maximum, 3 times per week for 8 weeks, as a supplement to their normal endurance training. The control group continued their normal endurance training during the same period. The intervention manifested significant (p < 0.05) improvements in 1RM (14.2%), RFD (16.7%), CE (4.8%), work efficiency (4.7%), and time to exhaustion at pre-intervention maximal aerobic power (17.2%). No changes were found in Vo2max or body weight. The control group exhibited an improvement in work efficiency (1.4%), but this improvement was significantly (p
Published:
2010-08
Title:
Metabolic profiling strategy for discovery of nutritional biomarkers: proline betaine as a marker of citrus consumption
Authors:
Heinzmann, Silke S.; Brown, Ian J.; Chan, Queenie; Bictash, Magda; Dumas, Marc-Emmanuel; Kochhar, Sunil; Stamler, Jeremiah; Holmes, Elaine; Elliott, Paul; Nicholson, Jeremy K.
Abstract:
BACKGROUND: New food biomarkers are needed to objectively evaluate the effect of diet on health and to check adherence to dietary recommendations and healthy eating patterns. OBJECTIVE: We developed a strategy for food biomarker discovery, which combined nutritional intervention with metabolic phenotyping and biomarker validation in a large-scale epidemiologic study. DESIGN: We administered a standardized diet to 8 individuals and established a putative urinary biomarker of fruit consumption by using (1)H nuclear magnetic resonance (NMR) spectroscopic profiling. The origin of the biomarker was confirmed by using targeted NMR spectroscopy of various fruit. Excretion kinetics of the biomarker were measured. The biomarker was validated by using urinary NMR spectra from UK participants of the INTERMAP (International Collaborative Study of Macronutrients, Micronutrients, and Blood Pressure) (n = 499) in which citrus consumption was ascertained from four 24-h dietary recalls per person. Finally, dietary patterns of citrus consumers (n = 787) and nonconsumers (n = 1211) were compared. RESULTS: We identified proline betaine as a putative biomarker of citrus consumption. High concentrations were observed only in citrus fruit. Most proline betaine was excreted < or =14 h after a first-order excretion profile. Biomarker validation in the epidemiologic data showed a sensitivity of 86.3% for elevated proline betaine excretion in participants who reported citrus consumption and a specificity of 90.6% (P
Published:
2010-08
Title:
Milk-derived proteins and minerals alter serum osteocalcin in prepubertal boys after 7 days
Authors:
Mark, Alicja Budek; Hoppe, Camilla; Michaelsen, Kim F.; Mølgaard, Christian
Abstract:
We have previously shown that at equal protein content, milk, but not meat, decreased bone turnover in boys. This suggested that milk-derived components are important for bone metabolism. In the present study, we hypothesized that milk-derived proteins (whey and casein) affect bone turnover during growth depending on the content of milk minerals (calcium and phosphorus). This was a randomized, parallel, double-blind study. Eight-year-old boys (n = 57) received 1 of 4 milk drinks: whey protein with low or high content of minerals, or casein protein with low or high content of minerals. The amount of whey and casein was identical to their content in 1.5 L of milk. We measured serum osteocalcin (sOC), bone-specific alkaline phosphatase, and C-terminal telopeptides of type I collagen (immunoassay) and estimated dietary intake (3-day weighed food record) at baseline and after 7 days. Only sOC was significantly affected by the treatments (P < .05). There was a significant interaction between milk-derived proteins and minerals with regard to sOC (P = .01). The intake of milk drinks containing whey increased sOC at the low content of minerals, whereas it decreased sOC at the high content of minerals (P
Published:
2010-08
Title:
Multifactorial lifestyle interventions in the primary and secondary prevention of cardiovascular disease and type 2 diabetes mellitus - A systematic review of randomized controlled trials
Authors:
Angermayr, Lucia; Melchart, Dieter; Linde, Klaus
Abstract:
This systematic review aims to summarize the available randomized trials of multifactorial lifestyle interventions in the primary and secondary prevention of coronary heart disease and type 2 diabetes mellitus. Randomized trials investigating the effects of lifestyle interventions including the elements of diet, physical activity, and stress management in people at increased risk for or with manifest coronary heart disease or type 2 diabetes mellitus were searched for in five electronic database and by citation tracking. Quality was assessed using the Cochrane Collaboration's risk of bias tool. Exploratory effect size calculations were performed for a variety of laboratory and clinical outcome measures. Twenty-five trials including a total of 7,703 participants met the inclusion criteria. Fifteen trials were in patients with coronary heart disease, seven in patients with type 2 diabetes mellitus, and three on primary prevention. The interventions varied greatly regarding concept, intensity, and providers. Compared to participants in "usual care" control groups, there were no consistent effects on lipid levels and blood pressure and small effects on body mass index and glycated hemoglobin (HbA1c). Composite cardiac event rates were significantly less in the intervention groups of the few trials reporting these outcomes. Mortality was also lower in the intervention groups, but the difference was not statistically significant, and confidence intervals were wide. The evidence base for multifactorial lifestyle interventions is weak. Effects on surrogate measures seemminor, but there may be clinically relevant effects on major clinical endpoints. © The Society of Behavioral Medicine 2010.
Published:
2010-08
Title:
Prepartum dietary energy source fed to beef cows: I. Effects on pre- and postpartum cow performance
Authors:
Radunz, A E; Fluharty, F L; Day, M L; Zerby, H N; Loerch, S C
Abstract:
Mature Angus-cross beef cows (n = 144) were used to determine effects of late gestation dietary energy source on pre- and postpartum cow performance in a complete randomized block design experiment. Cows were adapted to diets starting at 167 +/- 9 d of gestation and fed until 1 wk before expected calving date. Cows were fed 1 of 3 dietary energy sources: grass hay (HY), corn (CN), or dried distillers grains (DDGS). Cows allotted to HY were allowed ad libitum access to round-bale grass hay, and average hay disappearance was 12.4 kg/d. Limit-fed corn and DDGS diets contained 5.3 kg of whole-shelled corn or 4.1 kg of DDGS, respectively, plus 2.1 kg of hay, and 1.0 kg of supplement to meet cow nutritional needs during late gestation and to allow for an energy intake similar to HY. Every 21 d, BW, BCS, and ultrasound measurement of backfat between the 12th and 13th ribs were collected. At 210 d in gestation, jugular blood samples were collected from cows at 0, 3, 6, and 9 h postfeeding and were analyzed for glucose, insulin, NEFA, and blood urea N (BUN) concentrations. After parturition, cows were fed a common diet and managed similarly. Milk production was determined by weigh-suckle-weigh procedure on d 31, 100, and 176 postpartum. Cows fed DDGS during late gestation gained more (P = 0.04) BW than cows fed HY or CN; however, no difference in BCS change was detected (P = 0.28) among treatments. Plasma glucose concentrations were similar among treatments (P = 0.64), whereas insulin concentrations at 3 h postfeeding were greater (P = 0.002) for cows fed DDGS than those fed HY or CN. Plasma BUN concentrations were greater (P < or = 0.02) for cows fed DDGS vs. CN or HY up to 6 h postfeeding. Birth weight was greater (P or = 0.51), or milk composition (P > or = 0.39). Maternal dietary energy source in late gestation did not affect pre- or postpartum cow performance, but did change plasma hormones and metabolites during gestation. Heavier birth weights in calves from cows fed CN or DDGS indicate the changes in maternal metabolism affected energy partitioning of nutrients to the fetus and subsequent fetal growth.
Published:
2010-08
Title:
Seizure tests distinguish intermittent fasting from the ketogenic diet
Authors:
Hartman, Adam L.; Zheng, Xiangrong; Bergbower, Emily; Kennedy, Michiko; Hardwick, J. Marie
Abstract:
PURPOSE: Calorie restriction can be anticonvulsant in animal models. The ketogenic diet was designed to mimic calorie restriction and has been assumed to work by the same mechanisms. We challenged this assumption by profiling the effects of these dietary regimens in mice subjected to a battery of acute seizure tests. METHODS: Juvenile male NIH Swiss mice received ketogenic diet or a normal diet fed in restricted quantities (continuously or intermittently) for ∼12 days, starting at 3-4 weeks of age. Seizures were induced by the 6 Hz test, kainic acid, maximal electroshock, or pentylenetetrazol. RESULTS: The ketogenic and calorie-restricted diets often had opposite effects depending on the seizure test. The ketogenic diet protected from 6 Hz-induced seizures, whereas calorie restriction (daily and intermittent) increased seizure activity. Conversely, calorie restriction protected juvenile mice against seizures induced by kainic acid, whereas the ketogenic diet failed to protect. Intermittent caloric restriction worsened seizures induced by maximal electroshock but had no effect on those induced by pentylenetetrazol. DISCUSSION: In contrast to a longstanding hypothesis, calorie restriction and the ketogenic diet differ in their acute seizure test profiles, suggesting that they have different underlying anticonvulsant mechanisms. These findings highlight the importance of the 6 Hz test and its ability to reflect the benefits of ketosis and fat consumption.
Published:
2010-08
Title:
Television and video game exposure and the development of attention problems
Authors:
Swing, Edward L.; Gentile, Douglas A.; Anderson, Craig A.; Walsh, David A.
Abstract:
OBJECTIVES: Television viewing has been associated with greater subsequent attention problems in children. Few studies have examined the possibility of a similar association between video games and attention problems, and none of these has used a longitudinal design. METHODS: A sample of 1323 middle childhood participants were assessed during a 13-month period by parent- and child-reported television and video game exposure as well as teacher-reported attention problems. Another sample of 210 late adolescent/early adult participants provided self-reports of television exposure, video game exposure, and attention problems. RESULTS: Exposure to television and video games was associated with greater attention problems. The association of television and video games to attention problems in the middle childhood sample remained significant when earlier attention problems and gender were statistically controlled. The associations of screen media and attention problems were similar across media type (television or video games) and age (middle childhood or late adolescent/early adult). CONCLUSIONS: Viewing television and playing video games each are associated with increased subsequent attention problems in childhood. It seems that a similar association among television, video games, and attention problems exists in late adolescence and early adulthood. Research on potential risk factors for attention problems should be expanded to include video games in addition to television.
Published:
2010-08
Title:
A consensus on criteria for cure of acromegaly
Authors:
Giustina, A; Chanson, P; Bronstein, M D; Klibanski, A; Lamberts, S; Casanueva, F F; Trainer, P; Ghigo, E; Ho, K; Melmed, S
Abstract:
The Acromegaly Consensus Group met in April 2009 to revisit the guidelines on criteria for cure as defined in 2000. Participants included 74 neurosurgeons and endocrinologists with extensive experience of treating acromegaly. EVIDENCE/CONSENSUS PROCESS: Relevant assays, biochemical measures, clinical outcomes, and definition of disease control were discussed, based on the available published evidence, and the strength of consensus statements was rated. Criteria to define active acromegaly and disease control were agreed, and several significant changes were made to the 2000 guidelines. Appropriate methods of measuring and achieving disease control were summarized.
Published:
2010-07
Title:
Dietary intake is associated with phthalate body burden in a nationally representative sample
Authors:
Colacino JA; Harris TR; Schecter A
Abstract:
Background: Phthalates are compounds that are used in a wide range of consumer products. However, the contribution of dietary intake to phthalate exposure has not been well defined. Objective: The objective of this study was to assess the contribution of different food types to phthalate exposure. Phthalates are chemicals of concern because of the high levels measured in people and the environment, as well as the demonstrated toxicity in animal studies and limited epidemiological studies. Previous research, although limited, has suggested that phthalates contaminate food in various countries. Methods: We conducted an exploratory analysis of data collected as part of the 2003-2004 National Health and Nutrition Examination Survey (NHANES). Associations between dietary intake (assessed by a 24-hr dietary recall) for a range of food types (meat, poultry, fish, fruit, vegetable, and dairy) and phthalate metabolites measured in urine were analyzed using multiple linear regression modeling. Results: We found that metabolites of di-(2-ethylhexyl) phthalate (DEHP) and high-molecularweight phthalate metabolites were associated with the consumption of poultry. Monoethyl phthalate, the metabolite of diethyl phthalate (DEP), was associated with vegetable consumption, specifically tomato and potato consumption. Discussion: These results, combined with results from previous studies, suggest that diet is an important route of intake for phthalates. Further research is needed to determine the sources of food contamination with these toxic chemicals and to describe the levels of contamination of U.S. food in a large, representative U.S. sample.
Published:
2010-07
Title:
Differential impact of milk fatty acid profiles on cardiovascular risk biomarkers in healthy men and women
Authors:
Malpuech-Brugere, C.; Mouriot, J.; Boue-Vaysse, C.; Combe, N.; Peyraud, J.-L.; LeRuyet, P.; Chesneau, G.; Morio, B.; Chardigny, J.-M.
Abstract:
CONCLUSIONS: Different milk fat profiles can change cardiovascular plasma parameters in human healthy volunteers. A limited increase of the R-TFA/SFA ratio in dairy products is associated with an improvement in some cardiovascular risk factors. However, a further increase in R-TFA/SFA ratio has no additional benefit.
Published:
2010-07
Title:
Leptin is associated with the size of the apolipoprotein(a) particle in African tribal populations living on fish or vegetarian diet
Authors:
Winnicki, Mikolaj; Puato, Massimo; Somers, Virend K.; Zambon, Alberto; Marcovina, Santica M.; Rattazzi, Marcello; Phillips, Bradley G.; Pauletto, Paolo
Abstract:
OBJECTIVE: Apolipoprotein(a) [or apo(a)] isoform size, which is strongly genetically determined, showed significant association with the cardiovascular risk. Subjects on a fish diet have lower lipoprotein(a) levels, larger apo(a) isoform sizes and lower leptin levels than their vegetarian diet counterparts. We hypothesized that leptin may contribute to a potential association between the type of diet and the size of apo(a) isoforms. METHODS: Anthropometric data, dietary nutrients, lipoprotein profile, plasma leptin levels, and apo(a) isoforms were evaluated in two related homogenous African tribal populations of Tanzania, one on a primarily freshwater fish diet (n=278), and the other on a vegetarian diet (n=326). RESULTS: We observed a strong negative association between leptin levels and size of each of the apo(a) isoforms in both fish and vegetable diet groups, and in both genders. However, leptin was not associated with levels of lipoprotein(a). In multivariate analysis, a strong and independent association between leptin and size of apo(a) isoforms was observed. The size of apo(a) isoforms was strongly associated with high and low leptin states. Subjects with low leptins had 30% larger sizes of apo(a) isoforms than their high leptin counterparts. CONCLUSIONS: High leptin subjects have smaller, potentially more atherogenic, apo(a) isoform sizes than low leptin ones. We suggest that omega-3 rich diet can influence the levels of apo(a) and/or Lp(a) even though they are mainly genetically determined. These findings may have implications for understanding the interaction between leptin and cardiovascular risk.
Published:
2010-07
Title:
Structure-function relationships in feedback regulation of energy fluxes in vivo in health and disease: mitochondrial interactosome
Authors:
Saks, Valdur; Guzun, Rita; Timohhina, Natalja; Tepp, Kersti; Varikmaa, Minna; Monge, Claire; Beraud, Nathalie; Kaambre, Tuuli; Kuznetsov, Andrey; Kadaja, Lumme; Eimre, Margus; Seppet, Enn
Abstract:
The aim of this review is to analyze the results of experimental research of mechanisms of regulation of mitochondrial respiration in cardiac and skeletal muscle cells in vivo obtained by using the permeabilized cell technique. Such an analysis in the framework of Molecular Systems Bioenergetics shows that the mechanisms of regulation of energy fluxes depend on the structural organization of the cells and interaction of mitochondria with cytoskeletal elements. Two types of cells of cardiac phenotype with very different structures were analyzed: adult cardiomyocytes and continuously dividing cancerous HL-1 cells. In cardiomyocytes mitochondria are arranged very regularly, and show rapid configuration changes of inner membrane but no fusion or fission, diffusion of ADP and ATP is restricted mostly at the level of mitochondrial outer membrane due to an interaction of heterodimeric tubulin with voltage dependent anion channel, VDAC. VDAC with associated tubulin forms a supercomplex, Mitochondrial Interactosome, with mitochondrial creatine kinase, MtCK, which is structurally and functionally coupled to ATP synthasome. Due to selectively limited permeability of VDAC for adenine nucleotides, mitochondrial respiration rate depends almost linearly upon the changes of cytoplasmic ADP concentration in their physiological range. Functional coupling of MtCK with ATP synthasome amplifies this signal by recycling adenine nucleotides in mitochondria coupled to effective phosphocreatine synthesis. In cancerous HL-1 cells this complex is significantly modified: tubulin is replaced by hexokinase and MtCK is lacking, resulting in direct utilization of mitochondrial ATP for glycolytic lactate production and in this way contributing in the mechanism of the Warburg effect. Systemic analysis of changes in the integrated system of energy metabolism is also helpful for better understanding of pathogenesis of many other diseases.
Published:
2010-07
Title:
A high-protein low-fat diet is more effective in improving blood pressure and triglycerides in calorie-restricted obese individuals with newly diagnosed type 2 diabetes
Authors:
Papakonstantinou, E.; Triantafillidou, D.; Panagiotakos, D. B.; Koutsovasilis, A.; Saliaris, M.; Manolis, A.; Melidonis, A.; Zampelas, A.
Abstract:
CONCLUSIONS: A protein to fat ratio of 1.5 in diets significantly improves blood pressure and TG concentrations in obese individuals with DM2.
Published:
2010-06
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