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Title:
Diet and lifestyle of the Sami of southern Lapland in the 1930s--1950s and today.
Authors:
Nilsson, Lena Maria; Dahlgren, Lars; Johansson, Ingegerd; Brustad, Magritt; Sjolander, Per; Van Guelpen, Bethany
Abstract:
OBJECTIVES: To describe the lifestyle of the Sami of southern Lapland 50 to 70 years ago in relation to the present-day Sami and non-Sami populations and, thereby, to provide a basis for future studies of culturally related determinants of health and illness. STUDY DESIGN: A qualitative analysis, and a quantitative comparison of Sami and non-Sami groups. METHODS: Semi-structured interviews were conducted with 20 elderly Sami concerning their parents' lifestyle and diet 50 to 70 years ago. Questionnaire data from 81 reindeer-herding Sami, 226 non-reindeer-herding Sami and 1,842 sex-, age- and geographically matched non-Sami from the population-based Vasterbotten Intervention Project were analysed by non-parametric tests and partial least squares methodology. RESULTS: Surprisingly, fatty fish may have been more important than reindeer meat for the Sami of southern Lapland in the 1930s to 1950s, and it is still consumed more frequently by reindeer-herding Sami than nonreindeer-herding Sami and non-Sami. Other dietary characteristics of the historical Sami and present-day reindeer-herding Sami were higher intakes of fat, blood and boiled coffee, and lower intakes of bread, fibre and cultivated vegetables, compared with present-day non-Sami. Physical activity was also a part of the daily life of the Sami to a greater extent in the 1930s to 1950s than today. Sami men often worked far from home, while the women were responsible for fishing, farming, gardening (which was introduced in the 1930-1950 period), as well as housework and childcare. CONCLUSIONS: For studies investigating characteristic lifestyle elements of specific ethnic groups, the elements of greatest acknowledged cultural importance today (in this case reindeer meat) may not be of the most objective importance traditionally.
Published:
2011-06
Title:
Diet induced epigenetic changes and their implications for health
Authors:
Mckay, J. A.; Mathers, J. C.
Abstract:
Dietary exposures can have consequences for health years or decades later and this raises questions about the mechanisms through which such exposures are 'remembered' and how they result in altered disease risk. There is growing evidence that epigenetic mechanisms may mediate the effects of nutrition and may be causal for the development of common complex (or chronic) diseases. Epigenetics encompasses changes to marks on the genome (and associated cellular machinery) that are copied from one cell generation to the next, which may alter gene expression, but which do not involve changes in the primary DNA sequence. These include three distinct, but closely inter-acting, mechanisms including DNA methylation, histone modifications and non-coding microRNAs (miRNA) which, together, are responsible for regulating gene expression not only during cellular differentiation in embryonic and foetal development but also throughout the life-course. This review summarizes the growing evidence that numerous dietary factors, including micronutrients and non-nutrient dietary components such as genistein and polyphenols, can modify epigenetic marks. In some cases, for example, effects of altered dietary supply of methyl donors on DNA methylation, there are plausible explanations for the observed epigenetic changes, but to a large extent, the mechanisms responsible for diet-epigenome-health relationships remain to be discovered. In addition, relatively little is known about which epigenomic marks are most labile in response to dietary exposures. Given the plasticity of epigenetic marks and their responsiveness to dietary factors, there is potential for the development of epigenetic marks as biomarkers of health for use in intervention studies. © 2011 The Authors. Acta Physiologica © 2011 Scandinavian Physiological Society.
Published:
2011-06
Title:
Diets of modern hunter-gatherers vary substantially in their carbohydrate content depending on ecoenvironments: results from an ethnographic analysis
Authors:
Ströhle, Alexander; Hahn, Andreas
Abstract:
In the past, attempts have been made to estimate the carbohydrate contents of preagricultural human diets. Those estimations have primarily been based on interpretations of ethnographic data of modern hunter-gatherers. In this study, it was hypothesized that diets of modern hunter-gatherers vary in their carbohydrate content depending on ecoenvironments. Thus, using data of plant-to-animal subsistence ratios, we calculated the carbohydrate intake (percentage of the total energy) in 229 hunter-gatherer diets throughout the world and determined how differences in ecological environments altered carbohydrate intake. We found a wide range of carbohydrate intake (≈3%-50% of the total energy intake; median and mode, 16%-22% of the total energy). Hunter-gatherer diets were characterized by an identical carbohydrate intake (30%-35% of the total energy) over a wide range of latitude intervals (11°-40° north or south of the equator). However, with increasing latitude intervals from 41° to greater than 60°, carbohydrate intake decreased markedly from approximately equal to 20% to 9% or less of the total energy. Hunter-gatherers living in desert and tropical grasslands consumed the most carbohydrates (≈29%-34% of the total energy). Diets of hunter-gatherers living in northern areas (tundra and northern coniferous forest) contained a very low carbohydrate content (≤15% of the total energy). In conclusion, diets of hunter-gatherers showed substantial variation in their carbohydrate content. Independent of the local environment, however, the range of energy intake from carbohydrates in the diets of most hunter-gatherer societies was markedly different (lower) from the amounts currently recommended for healthy humans.
Published:
2011-06
Title:
Effect of 1 Week of Sleep Restriction on Testosterone Levels in Young Healthy Men
Authors:
Leproult, Rachel
Abstract:
CONTEXT: High on-treatment platelet reactivity is associated with atherothrombotic events following coronary stent implantation. OBJECTIVE: To evaluate the capability of multiple platelet function tests to predict clinical outcome. DESIGN, SETTING, AND PATIENTS: Prospective, observational, single-center cohort study of 1069 consecutive patients taking clopidogrel undergoing elective coronary stent implantation between December 2005 and December 2007. On-treatment platelet reactivity was measured in parallel by light transmittance aggregometry, VerifyNow P2Y12 and Plateletworks assays, and the IMPACT-R and the platelet function analysis system (PFA-100) (with the Dade PFA collagen/adenosine diphosphate [ADP] cartridge and Innovance PFA P2Y). Cut-off values for high on-treatment platelet reactivity were established by receiver operating characteristic curve analysis. MAIN OUTCOME MEASUREMENT: The primary end point was defined as a composite of all-cause death, nonfatal acute myocardial infarction, stent thrombosis, and ischemic stroke. The primary safety end point included TIMI (Thrombolysis In Myocardial Infarction) criteria major and minor bleeding. RESULTS: At 1-year follow-up, the primary end point occurred more frequently in patients with high on-treatment platelet reactivity when assessed by light transmittance aggregometry (11.7%; 95% confidence interval [CI], 8.9%-15.0% vs 6.0%; 95% CI, 4.2%-8.2%; P \textless .001), VerifyNow (13.3%; 95% CI, 10.2%-17.0% vs 5.7%; 95% CI, 4.1%-7.8%; P \textless .001) and Plateletworks (12.6%; 95% CI, 8.8%-17.2% vs 6.1%; 95% CI, 3.8%-9.2%; P = .005), which also had modest ability to discriminate between patients having and not having a primary event: light transmittance aggregometry (area under the curve [AUC], 0.63; 95% CI, 0.58-0.68), VerifyNow (AUC, 0.62; 95% CI, 0.57-0.67), and Plateletworks (AUC, 0.61; 95% CI, 0.53-0.69). The IMPACT-R, Dade PFA collagen/ADP, and Innovance PFA P2Y were unable to discriminate between patients with and without primary end point at 1-year follow-up (all AUCs included 0.50 in the CI). None of the tests identified patients at risk for bleeding. CONCLUSIONS: Of the platelet function tests assessed, only light transmittance aggregometry, VerifyNow, and Plateletworks were significantly associated with the primary end point. However, the predictive accuracy of these tests was only modest. None of the tests provided accurate prognostic information to identify low-risk patients at higher risk of bleeding following stent implantation. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00352014.
Published:
2011-06
Title:
Effect of walnut-enriched meat on the relationship between VCAM, ICAM, and LTB4 levels and PON-1 activity in ApoA4 360 and PON-1 allele carriers at increased cardiovascular risk
Authors:
Canales, A.; Sánchez-Muniz, F. J.; Bastida, S.; Librelotto, J.; Nus, M.; Corella, D.; Guillen, M.; Benedi, J.
Abstract:
BACKGROUND/OBJECTIVE: Cardiovascular risk depends largely on paraoxonase (PON-1) and apolipoprotein A4 (APOA4) gene polymorphisms. To compare the effects of consumption of walnut-enriched meat versus low-fat meat (LM) on selected soluble adhesion molecules and leukotrienes (LTB4). SUBJECTS/METHODS: In all 22 subjects at increased cardiovascular risk were taken. It is a non-blinded, cross-over, placebo-controlled study. Two 5-week experimental periods separated by 4-6 week wash-out interval. Participants consumed walnut-enriched meat during one period and LM during the other. Diet characteristics, HDLc, Apo A1, paraoxonase, sVCAM-1, sICAM-1 and LTB4 were analysed. PON-1 55, PON-1 192 and APOA4 360 polymorphism effects were also assessed. RESULTS: Individuals consuming walnut-enriched meat displayed higher paraoxonase activity (P<0.001), lower levels of sICAM and aVCAM (P=0.046, P=0.012, respectively) and leukotriene B4 (P=0.044), and lower paraoxonase-1/HDLc and paraoxonase-1/Apo A1 ratios (both, P<0.001) than those consuming LM. Paraoxonase levels correlated negatively with those of sICAM (r=-0.471, P<0.01). Significant decreases (at least P
Published:
2011-06
Title:
Evidence-based pharmacological treatment of generalized anxiety disorder
Authors:
Baldwin, David S.; Waldman, Sarah; Allgulander, Christer
Abstract:
Generalized anxiety disorder (GAD) is common in community and clinical settings. The associated individual and societal burden is substantial, but many of those who could benefit from treatment are not recognized or treated. This paper reviews the pharmacological treatment of GAD, based on findings of randomized placebo-controlled studies. Particular attention is paid to response rates to acute treatment, treatment tolerability, prediction of response, duration of treatment, and further management of patients who do not respond to initial treatment approaches. On the basis of their proven efficacy and reasonable tolerability in randomized placebo-controlled trials, recent evidence-based guidelines for pharmacological management have recommended initial treatment with either a selective serotonin reuptake inhibitor or a serotonin-norepinephrine reuptake inhibitor, although there is also good evidence for the efficacy of pregabalin and quetiapine. It is difficult to predict reliably which patients will respond well to pharmacological treatment, but response to antidepressants is unlikely if there is no evidence of an onset of effect within 4 wk. The small number of placebo-controlled relapse-prevention studies causes uncertainty about the optimal duration of treatment after a satisfactory initial response, but continuing treatment for at least 12 months is recommended. There have been few investigations of the further management of patients who have not responded to first-line treatment, but switching to another evidence-based treatment, or augmentation approaches may be beneficial.
Published:
2011-06
Title:
Hepatic steatosis, inflammation, and ER stress in mice maintained long term on a very low-carbohydrate ketogenic diet
Authors:
Garbow, Joel R.; Doherty, Jason M.; Schugar, Rebecca C.; Travers, Sarah; Weber, Mary L.; Wentz, Anna E.; Ezenwajiaku, Nkiruka; Cotter, David G.; Brunt, Elizabeth M.; Crawford, Peter A.
Abstract:
Low-carbohydrate diets are used to manage obesity, seizure disorders, and malignancies of the central nervous system. These diets create a distinctive, but incompletely defined, cellular, molecular, and integrated metabolic state. Here, we determine the systemic and hepatic effects of long-term administration of a very low-carbohydrate, low-protein, and high-fat ketogenic diet, serially comparing these effects to a high-simple-carbohydrate, high-fat Western diet and a low-fat, polysaccharide-rich control chow diet in C57BL/6J mice. Longitudinal measurement of body composition, serum metabolites, and intrahepatic fat content, using in vivo magnetic resonance spectroscopy, reveals that mice fed the ketogenic diet over 12 wk remain lean, euglycemic, and hypoinsulinemic but accumulate hepatic lipid in a temporal pattern very distinct from animals fed the Western diet. Ketogenic diet-fed mice ultimately develop systemic glucose intolerance, hepatic endoplasmic reticulum stress, steatosis, cellular injury, and macrophage accumulation, but surprisingly insulin-induced hepatic Akt phosphorylation and whole-body insulin responsiveness are not impaired. Moreover, whereas hepatic Pparg mRNA abundance is augmented by both high-fat diets, each diet confers splice variant specificity. The distinctive nutrient milieu created by long-term administration of this low-carbohydrate, low-protein ketogenic diet in mice evokes unique signatures of nonalcoholic fatty liver disease and whole-body glucose homeostasis.
Published:
2011-06
Title:
Influence of nutrition on feline calcium oxalate urolithiasis with emphasis on endogenous oxalate synthesis
Authors:
Dijcker, J. C.; Plantinga, E. A.; van Baal, J.; Hendriks, W. H.
Abstract:
The prevalence of calcium oxalate (CaOx) uroliths detected in cats with lower urinary tract disease has shown a sharp increase over the last decades with a concomitant reciprocal decrease in the occurrence of struvite (magnesium ammonium phosphate) uroliths. CaOx stone-preventative diets are available nowadays, but seem to be marginally effective, as CaOx urolith recurrence occurs in patients fed these diets. In order to improve the preventative measures against CaOx urolithiasis, it is important to understand its aetiopathogenesis. The main research focus in CaOx formation in cats has been on the role of Ca, whereas little research effort has been directed towards the role and origin of urinary oxalates. As in man, the exogenous origin of urinary oxalates in cats is thought to be of minor importance, although the precise contribution of dietary oxalates remains unclear. The generally accepted dietary risk factors for CaOx urolithiasis in cats are discussed and a model for the biosynthetic pathways of oxalate in feline liver is provided. Alanine:glyoxylate aminotransferase 1 (AGT1) in endogenous oxalate metabolism is a liver-specific enzyme targeted in the mitochondria in cats, and allows for efficient conversion of glyoxylate to glycine when fed a carnivorous diet. The low peroxisomal activity of AGT1 in cat liver is compatible with the view that felids utilised a low-carbohydrate diet throughout evolution. Future research should focus on understanding de novo biosynthesis of oxalate in cats and their adaptation(s) in oxalate metabolism, and on dietary oxalate intake and absorption by cats.
Published:
2011-06
Title:
Metabolic management of brain cancer
Authors:
Seyfried, Thomas N.; Kiebish, Michael A.; Marsh, Jeremy; Shelton, Laura M.; Huysentruyt, Leanne C.; Mukherjee, Purna
Abstract:
Malignant brain tumors are a significant health problem in children and adults. Conventional therapeutic approaches have been largely unsuccessful in providing long-term management. As primarily a metabolic disease, malignant brain cancer can be managed through changes in metabolic environment. In contrast to normal neurons and glia, which readily transition to ketone bodies (β-hydroxybutyrate) for energy under reduced glucose, malignant brain tumors are strongly dependent on glycolysis for energy. The transition from glucose to ketone bodies as a major energy source is an evolutionary conserved adaptation to food deprivation that permits the survival of normal cells during extreme shifts in nutritional environment. Only those cells with a flexible genome and normal mitochondria can effectively transition from one energy state to another. Mutations restrict genomic and metabolic flexibility thus making tumor cells more vulnerable to energy stress than normal cells. We propose an alternative approach to brain cancer management that exploits the metabolic flexibility of normal cells at the expense of the genetically defective and metabolically challenged tumor cells. This approach to brain cancer management is supported from recent studies in mice and humans treated with calorie restriction and the ketogenic diet. Issues of implementation and use protocols are presented for the metabolic management of brain cancer.
Published:
2011-06
Title:
Postprandial lipid responses to an alpha-linolenic acid-rich oil, olive oil and butter in women: a randomized crossover trial
Authors:
Svensson, Julia; Rosenquist, Anna; Ohlsson, Lena
Abstract:
CONCLUSIONS: The postprandial p-TAG and NEFA response in healthy pre-menopausal women was not significantly different after the intake of an ALA-rich oil, olive oil and butter. The ALA-rich oil significantly affected different plasma lipid fractions and improved the ratio of n-6 to n-3 fatty acids several hours postprandially.
Published:
2011-06
Title:
Ruminant and industrial sources of trans-fat and cardiovascular and diabetic diseases. [Review]
Authors:
Tardy, Anne-Laure; Morio, Beatrice; Chardigny, Jean-Michel; Malpuech-Brugere, Corinne
Abstract:
The various positional isomers of oleic acid (18 : 1DELTA9c or 9c-18 : 1) may have distinct biological effects. Detrimental effects of consumption of industrial trans-fatty acids (TFA) (elaidic acid; 18 : 1DELTA9t) from partially hydrogenated vegetable oils on CVD risk factors are well documented. In addition, epidemiological data suggest that chronic consumption of industrial sources of TFA could alter insulin sensitivity and predispose for type 2 diabetes. However, intervention studies on this issue have remained inconclusive. Moreover, very little information is available on the effect of natural sources of TFA (vaccenic acid; 18 : 1DELTA11t) coming from dairy products and ruminant meat on the development of CVD and type 2 diabetes. The review focuses on the impact of the consumption of ruminant TFA in relation to cardiovascular risk factors, inflammation and type 2 diabetes.
Published:
2011-06
Title:
Urinary biomarkers of meat consumption
Authors:
Cross, Amanda J.; Major, Jacqueline M.; Sinha, Rashmi
Abstract:
BACKGROUND: Meat intake has been positively associated with incidence and mortality of chronic diseases, including diabetes, heart disease, and several different cancers, in observational studies by using self-report methods of dietary assessment; however, these dietary assessment methods are subject to measurement error. One method to circumvent such errors is the use of biomarkers of dietary intake, but currently there are no accepted biomarkers for meat intake. METHODS: We investigated four analytes (creatinine, taurine, 1-methylhistidine, and 3-methylhistidine) specifically found in meat and excreted in urine. Twenty-four-hour urine samples were collected from 17 individuals on controlled diets containing varying levels of meat: vegetarian (0 g/d), low red meat (60 g/d), medium red meat (120 g/d), and high red meat (420 g/d), as part of two randomized crossover feeding studies. RESULTS: When compared with the low red meat diet or the vegetarian diet, the urinary levels of all four analytes were significantly higher in urine samples collected after 15 days of a high red meat diet (P < 0.0001). Only urinary 1-methylhistidine and 3-methylhistidine were statistically significantly different for every diet type, increasing as the amount of meat in the diet increased (P < 0.01 for 1-methylhistidine and P
Published:
2011-06
Title:
A carbohydrate-restricted diet during resistance training promotes more favorable changes in body composition and markers of health in obese women with and without insulin resistance
Authors:
Kreider, Richard B.; Rasmussen, Christopher; Kerksick, Chad M.; Wilborn, Colin; Taylor, Lemuel; Campbell, Bill; Magrans-Courtney, Teresa; Fogt, Donovan; Ferreira, Maria; Li, Rui; Galbreath, Melyn; Iosia, Mike; Cooke, Matt; Serra, Monica; Gutierrez, Jean; Byrd, Mike; Kresta, Julie Y.; Simbo, Sunday; Oliver, Jonathan; Greenwood, Mike
Abstract:
OBJECTIVE: To determine whether sedentary obese women with elevated levels of homeostatic model assessment (HOMA) insulin resistance (ie, > 3.5) experience greater benefits from an exercise + higher-carbohydrate (HC) or carbohydrate-restricted weight loss program than women with lower HOMA levels. METHODS: 221 women (age, 46.5 ± 12 years; body weight, 90.3 ± 16 kg; body mass index, 33.8 ± 5 kg/m(2)) participated in a 10-week supervised exercise and weight loss program. The fitness program involved 30 minutes of circuit-style resistance training 3 days per week. Subjects were prescribed low-fat (30%) isoenergetic diets that consisted of 1200 kcals per day for 1 week (phase 1) and 1600 kcals per day for 9 weeks (phase 2) with HC or higher protein (HP). Fasting blood samples, body composition, anthropometry, resting energy expenditure, and fitness measurements were obtained at 0 and 10 weeks. Subjects were retrospectively stratified into lower (LH) or higher (HH) than 3.5 HOMA groups. Data were analyzed by multivariate analysis of variance with repeated measures and are presented as mean ± standard deviation changes from baseline. RESULTS: Baseline HOMA levels in the LH group were significantly lower than those in the HH group (LH, 0.6 ± 0.7; HH, 6.3 ± 3.4; P = 0.001). Diet and training significantly decreased body weight (-3.5 ± 3 kg), fat mass (-2.7 ± 3 kg), blood glucose (-3%), total cholesterol (-4.5%), low-density lipoproteins (-5%), triglycerides (-5.9%), systolic blood pressure (-2.6%), and waist circumference (-3.7%), while increasing peak aerobic capacity (7.3%). Subjects in the HP group experienced greater weight loss (-4.4 ± 3.6 kg vs -2.6 ± 2.9 kg), fat loss (-3.4 ± 2.7 kg vs -1.7 ± 2.0 kg), reductions in serum glucose (3% vs 2%), and decreases in serum leptin levels (-30.8% vs -10.8%) than those in the HC group. Participants in the HH (-14.1%) and HP-HH (-21.6%) groups observed the greatest reduction in serum blood glucose. CONCLUSION: A carbohydrate-restricted diet promoted more favorable changes in weight loss, fat loss, and markers of health in obese women who initiated an exercise program compared with a diet higher in carbohydrate. Additionally, obese women who initiated training and dieting with higher HOMA levels experienced greater reductions in blood glucose following an HP diet.
Published:
2011-05
Title:
A carbohydrate-restricted diet during resistance training promotes more favorable changes in body composition and markers of health in obese women with and without insulin resistance
Authors:
Kreider, Richard B.; Rasmussen, Christopher; Kerksick, Chad M.; Wilborn, Colin; Taylor, Lemuel; Campbell, Bill; Magrans-Courtney, Teresa; Fogt, Donovan; Ferreira, Maria; Li, Rui; Galbreath, Melyn; Iosia, Mike; Cooke, Matt; Serra, Monica; Gutierrez, Jean; Byrd, Mike; Kresta, Julie Y.; Simbo, Sunday; Oliver, Jonathan; Greenwood, Mike
Abstract:
OBJECTIVE: To determine whether sedentary obese women with elevated levels of homeostatic model assessment (HOMA) insulin resistance (ie, > 3.5) experience greater benefits from an exercise + higher-carbohydrate (HC) or carbohydrate-restricted weight loss program than women with lower HOMA levels. METHODS: 221 women (age, 46.5 ± 12 years; body weight, 90.3 ± 16 kg; body mass index, 33.8 ± 5 kg/m(2)) participated in a 10-week supervised exercise and weight loss program. The fitness program involved 30 minutes of circuit-style resistance training 3 days per week. Subjects were prescribed low-fat (30%) isoenergetic diets that consisted of 1200 kcals per day for 1 week (phase 1) and 1600 kcals per day for 9 weeks (phase 2) with HC or higher protein (HP). Fasting blood samples, body composition, anthropometry, resting energy expenditure, and fitness measurements were obtained at 0 and 10 weeks. Subjects were retrospectively stratified into lower (LH) or higher (HH) than 3.5 HOMA groups. Data were analyzed by multivariate analysis of variance with repeated measures and are presented as mean ± standard deviation changes from baseline. RESULTS: Baseline HOMA levels in the LH group were significantly lower than those in the HH group (LH, 0.6 ± 0.7; HH, 6.3 ± 3.4; P = 0.001). Diet and training significantly decreased body weight (-3.5 ± 3 kg), fat mass (-2.7 ± 3 kg), blood glucose (-3%), total cholesterol (-4.5%), low-density lipoproteins (-5%), triglycerides (-5.9%), systolic blood pressure (-2.6%), and waist circumference (-3.7%), while increasing peak aerobic capacity (7.3%). Subjects in the HP group experienced greater weight loss (-4.4 ± 3.6 kg vs -2.6 ± 2.9 kg), fat loss (-3.4 ± 2.7 kg vs -1.7 ± 2.0 kg), reductions in serum glucose (3% vs 2%), and decreases in serum leptin levels (-30.8% vs -10.8%) than those in the HC group. Participants in the HH (-14.1%) and HP-HH (-21.6%) groups observed the greatest reduction in serum blood glucose. CONCLUSION: A carbohydrate-restricted diet promoted more favorable changes in weight loss, fat loss, and markers of health in obese women who initiated an exercise program compared with a diet higher in carbohydrate. Additionally, obese women who initiated training and dieting with higher HOMA levels experienced greater reductions in blood glucose following an HP diet.
Published:
2011-05
Title:
Comparison of standard methods for assessing dietary intake of benzo[a]pyrene
Authors:
Deziel, Nicole C.; Strickland, Paul T.; Platz, Elizabeth A.; Abubaker, Salahaddin; Buckley, Timothy J.
Abstract:
IMPACT: Limited correlation in estimated BaP intake among standard methods may contribute to inconsistent epidemiology of BaP and cancer. Copyright ©2011 AACR.
Published:
2011-05
Title:
Detection of genotoxicants in Brassicales using endogenous DNA as a surrogate target and adducts determined by 32P-postlabelling as an experimental end point
Authors:
Baasanjav-Gerber, Chimgee; Hollnagel, Heli Miriam; Brauchmann, Jana; Iori, Renato; Glatt, Hansruedi
Abstract:
Some plants use electrophilic metabolites as a defence against biological enemies. Some of them may react with DNA. We devised a new model to test this hypothesis. Plant tissue was homogenised. After incubation of the homogenate at 37°C for varying periods, the plant DNA was analysed for the presence of adducts using the (32)P-postlabelling technique. Adducts were detected with all Brassicales studied. Broccoli was investigated in detail. Adducts were absent in DNA isolated immediately after homogenisation of the plant. Subsequently, five characteristic adduct spots were formed in the homogenate, the maximum being reached after nearly 4 h. Adduct formation was low when broccoli was steamed before homogenisation, but was re-established when myrosinase was added to the homogenate, indicating that the active constituents were glucosinolates. Broccoli juice was mutagenic to Salmonella typhimurium, forming the same adduct spots in these target cells as in plant homogenate, but the relative intensity of the individual spots varied between both models. The patterns of adduct spots formed in homogenates of 15 other Brassicales species and tissues were similar to those detected with broccoli florets heads. However, the relative intensities of the spots varied. Sporadically, some spots were missing or additional spots appeared. These results, therefore, suggest that several different glucosinolates contribute to the adduct formation.
Published:
2011-05
Title:
Dietary soy and tea mitigate chronic inflammation and prostate cancer via NF?B pathway in the Noble rat model
Authors:
Hsu, Anna; Bruno, Richard S.; Lohr, Christiane V.; Taylor, Alan W.; Dashwood, Rodrick H.; Bray, Tammy M.; Ho, Emily
Abstract:
Chronic inflammation and nuclear factor-kappa B (NFκB) have been implicated in prostate cancer development; thus, dietary factors that inhibit NFκB may serve as effective chemo-preventative agents. Prostate cancer risk is significantly lower in Asian countries compared to the US, which has prompted interest in the potential chemopreventative action of Asian dietary components such as soy and green tea. This study examined the effects of dietary soy and tea on NFκB activation and inflammation in vivo using a hormone-induced rat model for prostate cancer. Male Noble rats implanted with estradiol and testosterone were divided into 4 dietary groups: control, soy, tea, or soy+ tea. NFκB activation and inflammatory cytokines were measured post implantation. The combination of soy and tea suppressed NFκB p50 binding activity and protein levels via induction of IκBα. Soy and tea also decreased prostate inflammatory infiltration, increased Bax/BcL2 ratio, and decreased protein expression of TNFα, IL-6 and IL1-β compared to control. Soy and tea attenuated prostate malignancy by decreasing prostate hyperplasia. These effects were not apparent in groups treated with soy or tea alone. The ongoing in vivo studies thus far suggest that combination of foods, such as soy and tea, may inhibit hormone-induced pro-inflammatory NFκB signals that contribute to prostate cancer development.
Published:
2011-05
Title:
Fish consumption, erythrocyte fatty acids, and preterm birth
Authors:
Klebanoff, Mark A.; Harper, Margaret; Lai, Yinglei; Thorp, John; Sorokin, Yoram; Varner, Michael W.; Wapner, Ronald J.; Caritis, Steve N.; Iams, Jay D.; Carpenter, Marshall W.; Peaceman, Alan M.; Mercer, Brian M.; Sciscione, Anthony; Rouse, Dwight J.; Ramin, Susan M.; Anderson, Garland D.; Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) Maternal-Fetal Medicine Units Network (MFMU)
Abstract:
OBJECTIVE: To estimate the association between fish consumption and erythrocyte omega-3 long-chain polyunsaturated fatty acids and preterm birth in a high-risk cohort. METHODS: This was an ancillary study to a randomized trial of omega-3 supplementation to prevent preterm birth in women with at least one previous spontaneous preterm delivery. Dietary fish intake was assessed by questionnaire and erythrocyte fatty acids were measured at enrollment (16-21 completed weeks of gestation). The association between fish consumption and preterm delivery was modeled with linear and quadratic terms. RESULTS: The probability of preterm birth was 48.6% among women eating fish less than once a month and 35.9% among women eating fish more often (P<.001). The adjusted odds ratio for preterm birth among women reporting moderately frequent fish consumption (three servings per week) was 0.60 (95% confidence interval 0.38-0.95), with no further reduction in preterm birth among women who consumed more than three servings of fish per week. Erythrocyte omega-3 levels correlated weakly but significantly with frequency of fish intake (Spearman r=0.22, P<.001); women in the lowest quartile of erythrocyte omega-3 levels were more likely to report consuming less than one fish meal per month (40.3%) than were women in the highest three quartiles (26.3%, P
Published:
2011-05
Title:
Healthy user and related biases in observational studies of preventive interventions: a primer for physicians
Authors:
Shrank, William H.; Patrick, Amanda R.; Brookhart, M. Alan
Abstract:
The current emphasis on comparative effectiveness research will provide practicing physicians with increasing volumes of observational evidence about preventive care. However, numerous highly publicized observational studies of the effect of prevention on health outcomes have reported exaggerated relationships that were later contradicted by randomized controlled trials. A growing body of research has identified sources of bias in observational studies that are related to patient behaviors or underlying patient characteristics, known as the healthy user effect, the healthy adherer effect, confounding by functional status or cognitive impairment, and confounding by selective prescribing. In this manuscript we briefly review observational studies of prevention that have appeared to reach incorrect conclusions. We then describe potential sources of bias in these studies and discuss study designs, analytical methods, and sensitivity analyses that may mitigate bias or increase confidence in the results reported. More careful consideration of these sources of bias and study designs by providers can enhance evidence-based decision-making.
Published:
2011-05
Title:
Short-term weight loss and hepatic triglyceride reduction: evidence of a metabolic advantage with dietary carbohydrate restriction
Authors:
Browning, Jeffrey D.; Baker, Jonathan A.; Rogers, Thomas; Davis, Jeannie; Satapati, Santhosh; Burgess, Shawn C.
Abstract:
BACKGROUND: Individuals with nonalcoholic fatty liver disease (NAFLD) have excess intrahepatic triglycerides. This is due, in part, to increased hepatic synthesis of fat from carbohydrates via lipogenesis. Although weight loss is currently recommended to treat NAFLD, little attention has been given to dietary carbohydrate restriction. OBJECTIVE: The aim of this study was to determine the effectiveness of 2 wk of dietary carbohydrate and calorie restriction at reducing hepatic triglycerides in subjects with NAFLD. DESIGN: Eighteen NAFLD subjects (n = 5 men and 13 women) with a mean (±SD) age of 45 ± 12 y and a body mass index (in kg/m(2)) of 35 ± 7 consumed a carbohydrate-restricted (<20 g/d) or calorie-restricted (1200-1500 kcal/d) diet for 2 wk. Hepatic triglycerides were measured before and after intervention by magnetic resonance spectroscopy. RESULTS: Mean (±SD) weight loss was similar between the groups (-4.0 ± 1.5 kg in the calorie-restricted group and -4.6 ± 1.5 kg in the carbohydrate-restricted group; P = 0.363). Liver triglycerides decreased significantly with weight loss (P < 0.001) but decreased significantly more (P = 0.008) in carbohydrate-restricted subjects (-55 ± 14%) than in calorie-restricted subjects (-28 ± 23%). Dietary fat (r = 0.643, P = 0.004), carbohydrate (r = -0.606, P = 0.008), posttreatment plasma ketones (r = 0.755, P = 0.006), and respiratory quotient (r = -0.797, P < 0.001) were related to a reduction in liver triglycerides. Plasma aspartate, but not alanine, aminotransferase decreased significantly with weight loss (P
Published:
2011-05
Title:
Significant differences in global genomic DNA methylation by gender and race/ethnicity in peripheral blood
Authors:
Zhang, Fang Fang; Cardarelli, Roberto; Carroll, Joan; Fulda, Kimberly G; Kaur, Manleen; Gonzalez, Karina; Vishwanatha, Jamboor K; Santella, Regina M; Morabia, Alfredo
Abstract:
Reduced levels of global DNA methylation are associated with genomic instability and are independent predictors of cancer risk. Little is known about the environmental determinants of global DNA methylation in peripheral blood. We examined the association between demographic and lifestyle factors and levels of global leukocyte DNA methylation in 161 cancer-free subjects enrolled in the North Texas Healthy Heart Study aged 45–75 years in 2008. We used in-person interviews for demographics and lifestyle factors, a self-administrated Block food frequency questionnaire for diet, and bioelectrical impedance analysis and CT-scan for body composition. We measured genomic DNA methylation using bisulfite conversion of DNA and pyrosequencing for LINE-1. Body composition measures including body mass index, waist circumference, areas of subcutaneous fat and visceral fat, percent of fat mass and fat-free mass were not associated with global genomic DNA methylation after controlling the effect of age, gender and race/ethnicity. Instead, female gender was significantly associated with a reduced level of global methylation (β = −2.77, 95% CI: −4.33, −1.22). Compared to non-Hispanic whites, non-Hispanic blacks (β = −2.02, 95% CI: −3.55, −0.50) had significantly lower levels of global methylation. No association was found with age, cigarette smoking, alcohol drinking and dietary intake of nutrients in one-carbon metabolism. Global leukocyte DNA methylation differs by gender and race/ethnicity, suggesting these variables need to be taken into consideration in studies of global DNA methylation as an epigenetic marker for cancer.
Published:
2011-05
Title:
Soy food consumption and breast cancer prognosis
Authors:
Caan, Bette J.; Natarajan, Loki; Parker, Barbara; Gold, Ellen B.; Thomson, Cynthia; Newman, Vicky; Rock, Cheryl L.; Pu, Minya; Al-Delaimy, Wael; Pierce, John P.
Abstract:
BACKGROUND: Contrary to earlier clinical studies suggesting that soy may promote breast tumor growth, two recent studies show that soy-containing foods are not adversely related to breast cancer prognosis. We examined, using data from the Women's Healthy Eating and Living (WHEL) study, the effect of soy intake on breast cancer prognosis. METHODS: Three thousand eighty-eight breast cancer survivors, diagnosed between 1991 and 2000 with early-stage breast cancer and participating in WHEL, were followed for a median of 7.3 years. Isoflavone intakes were measured postdiagnosis by using a food frequency questionnaire. Women self-reported new outcome events semiannually, which were then verified by medical records and/or death certificates. HRs and 95% CIs representing the association between either a second breast cancer event or death and soy intake were computed, adjusting for study group and other covariates, using the delayed entry Cox proportional hazards model. RESULTS: As isoflavone intake increased, risk of death decreased (P for trend = 0.02). Women at the highest levels of isoflavone intake (>16.3 mg isoflavones) had a nonsignificant 54% reduction in risk of death. CONCLUSION: Our study is the third epidemiologic study to report no adverse effects of soy foods on breast cancer prognosis. IMPACT: These studies, taken together, which vary in ethnic composition (two from the United States and one from China) and by level and type of soy consumption, provide the necessary epidemiologic evidence that clinicians no longer need to advise against soy consumption for women with a diagnosis of breast cancer.
Published:
2011-05
Title:
Vegetarian diet improves insulin resistance and oxidative stress markers more than conventional diet in subjects with Type 2 diabetes
Authors:
Kahleova, H.; Matoulek, M.; Malinska, H.; Oliyarnik, O.; Kazdova, L.; Neskudla, T.; Skoch, A.; Hajek, M.; Hill, M.; Kahle, M.; Pelikanova, T.
Abstract:
AIMS: The aim of this study was to compare the effects of calorie-restricted vegetarian and conventional diabetic diets alone and in combination with exercise on insulin resistance, visceral fat and oxidative stress markers in subjects with Type 2 diabetes. METHODS: A 24-week, randomized, open, parallel design was used. Seventy-four patients with Type 2 diabetes were randomly assigned to either the experimental group (n = 37), which received a vegetarian diet, or the control group (n = 37), which received a conventional diabetic diet. Both diets were isocaloric, calorie restricted (-500 kcal/day). All meals during the study were provided. The second 12 weeks of the diet were combined with aerobic exercise. Participants were examined at baseline, 12 weeks and 24 weeks. Primary outcomes were: insulin sensitivity measured by hyperinsulinaemic isoglycaemic clamp; volume of visceral and subcutaneous fat measured by magnetic resonance imaging; and oxidative stress measured by thiobarbituric acid reactive substances. Analyses were by intention to treat. RESULTS: Forty-three per cent of participants in the experimental group and 5% of participants in the control group reduced diabetes medication (P < 0.001). Body weight decreased more in the experimental group than in the control group [-6.2 kg (95% CI -6.6 to -5.3) vs. -3.2 kg (95% CI -3.7 to -2.5); interaction group × time P = 0.001]. An increase in insulin sensitivity was significantly greater in the experimental group than in the control group [30% (95% CI 24.5-39) vs. 20% (95% CI 14-25), P = 0.04]. A reduction in both visceral and subcutaneous fat was greater in the experimental group than in the control group (P = 0.007 and P = 0.02, respectively). Plasma adiponectin increased (P = 0.02) and leptin decreased (P = 0.02) in the experimental group, with no change in the control group. Vitamin C, superoxide dismutase and reduced glutathione increased in the experimental group (P = 0.002, P
Published:
2011-05
Title:
Vegetarian dietary patterns are associated with a lower risk of metabolic syndrome: the adventist health study 2
Authors:
Rizzo, Nico S.; Sabaté, Joan; Jaceldo-Siegl, Karen; Fraser, Gary E.
Abstract:
OBJECTIVE: The study objective was to compare dietary patterns in their relationship with metabolic risk factors (MRFs) and the metabolic syndrome (MetS). RESEARCH DESIGN AND METHODS: Cross-sectional analysis of 773 subjects (mean age 60 years) from the Adventist Health Study 2 was performed. Dietary pattern was derived from a food frequency questionnaire and classified as vegetarian (35%), semi-vegetarian (16%), and nonvegetarian (49%). ANCOVA was used to determine associations between dietary pattern and MRFs (HDL, triglycerides, glucose, blood pressure, and waist circumference) while controlling for relevant cofactors. Logistic regression was used in calculating odds ratios (ORs) for MetS. RESULTS: A vegetarian dietary pattern was associated with significantly lower means for all MRFs except HDL (P for trend < 0.001 for those factors) and a lower risk of having MetS (OR 0.44, 95% CI 0.30-0.64, P
Published:
2011-05
Title:
Dietary sensitivities and ADHD symptoms: thirty-five years of research
Authors:
Stevens, Laura J.; Kuczek, Thomas; Burgess, John R.; Hurt, Elizabeth; Arnold, L. Eugene
Abstract:
Artificial food colors (AFCs) have not been established as the main cause of attention-deficit hyperactivity disorder (ADHD), but accumulated evidence suggests that a subgroup shows significant symptom improvement when consuming an AFC-free diet and reacts with ADHD-type symptoms on challenge with AFCs. Of children with suspected sensitivities, 65% to 89% reacted when challenged with at least 100 mg of AFC. Oligoantigenic diet studies suggested that some children in addition to being sensitive to AFCs are also sensitive to common nonsalicylate foods (milk, chocolate, soy, eggs, wheat, corn, legumes) as well as salicylate-containing grapes, tomatoes, and orange. Some studies found "cosensitivity" to be more the rule than the exception. Recently, 2 large studies demonstrated behavioral sensitivity to AFCs and benzoate in children both with and without ADHD. A trial elimination diet is appropriate for children who have not responded satisfactorily to conventional treatment or whose parents wish to pursue a dietary investigation.
Published:
2011-04
Title:
Effect of marine n-3 fatty acids on circulating inflammatory markers in healthy subjects and subjects with cardiovascular risk factors. [Review]
Authors:
Myhrstad, Mari C. W.; Retterstol, Kjetil; Telle-Hansen, Vibeke H.; Ottestad, Inger; Halvorsen, Bente; Holven, Kirsten B.; Ulven, Stine M.
Abstract:
RESULTS AND CONCLUSION: Intervention studies with marine n-3 fatty acids administered from either fish or fish oil demonstrate different results on inflammatory markers. No firm conclusion can be drawn about the effect of marine n-3 fatty acids on circulating inflammatory markers in healthy individuals, individuals with high risk of developing CVD or individuals with CVD related diseases.
Published:
2011-04
Title:
Elevated triglycerides/HDL-cholesterol ratio associated with insulin resistance
Authors:
González-Chávez, Antonio; Simental-Mendía, Luis Ernesto; Elizondo-Argueta, Sandra
Abstract:
BACKGROUND: Cardiovascular disease is the main cause of death worldwide and insulin resistance (IR) plays an important role for its development. In addition, IR has been associated with hypertension and metabolic syndrome according to the triglyceride/HDL-cholesterol (TGL/HDL) ratio. We undertook this study to determine whether the TGL/HDL ratio is associated with IR in apparently healthy subjects. METHODS: A cross-sectional study including healthy men and nonpregnant women was performed. Individuals with IR were compared against subjects without IR. Variables studied were age, gender, body mass index, and waist circumference. Exclusion criteria were chronic diseases such as renal disease, hepatic disease, malignancy, and diabetes. RESULTS: A total of 177 subjects were enrolled, 117 females (66.1%) and 60 males (33.9%). Of these, 145 (93 females and 52 males) with IR were compared against 32 subjects (24 females and 8 males) without IR. Elevated ratio TGL/HDL ratio was detected in 89 (61.4%) and 12 (38.6%) subjects with and without IR, respectively. The elevated TGL/HDL ratio was significantly associated with IR (OR 2.64, 95% CI = 1.12-6.29). CONCLUSIONS: In apparently healthy subjects, elevated TGL/HDL ratio was significantly associated with the presence of IR.
Published:
2011-04
Title:
Fad diets in the treatment of diabetes
Authors:
Feinman, Richard D.
Abstract:
Use of the term "fad diet" reflects the contentious nature of the debate in the treatment of diabetes and generally targets diets based on carbohydrate restriction, the major challenge to traditional dietary therapy. Although standard low-fat diets more accurately conform to the idea of a practice supported by social pressure rather than scientific data, it is suggested that we might want to give up altogether unscientific terms like "fad" and "healthy." Far from faddish, diets based on carbohydrate restriction have been the historical treatment for diabetes and are still supported by basic biochemistry, and it is argued that they should be considered the "default" diet, the one to try first, in diseases of carbohydrate intolerance or insulin resistance. The barrier to acceptance of low-carbohydrate diets in the past has been concern about saturated fat, which might be substituted for the carbohydrate that is removed. However, recent re-analysis of much old data shows that replacing carbohydrate with saturated fat is, if anything, beneficial. The dialectic of impact of continued hemoglobin A(1c) versus effect of dietary saturated fat in the risk of cardiovascular disease is resolved in direction of glycemic control. Putting biased language behind us and facing the impact of recent results that point to the value of low-carbohydrate diets would offer patients the maximum number of options.
Published:
2011-04
Title:
Metabolite profiles and the risk of developing diabetes
Authors:
Wang, Thomas J.; Larson, Martin G.; Vasan, Ramachandran S.; Cheng, Susan; Rhee, Eugene P.; McCabe, Elizabeth; Lewis, Gregory D.; Fox, Caroline S.; Jacques, Paul F.; Fernandez, Céline; O'Donnell, Christopher J.; Carr, Stephen A.; Mootha, Vamsi K.; Florez, Jose C.; Souza, Amanda; Melander, Olle; Clish, Clary B.; Gerszten, Robert E.
Abstract:
Emerging technologies allow the high-throughput profiling of metabolic status from a blood specimen (metabolomics). We investigated whether metabolite profiles could predict the development of diabetes. Among 2,422 normoglycemic individuals followed for 12 years, 201 developed diabetes. Amino acids, amines and other polar metabolites were profiled in baseline specimens by liquid chromatography-tandem mass spectrometry (LC-MS). Cases and controls were matched for age, body mass index and fasting glucose. Five branched-chain and aromatic amino acids had highly significant associations with future diabetes: isoleucine, leucine, valine, tyrosine and phenylalanine. A combination of three amino acids predicted future diabetes (with a more than fivefold higher risk for individuals in top quartile). The results were replicated in an independent, prospective cohort. These findings underscore the potential key role of amino acid metabolism early in the pathogenesis of diabetes and suggest that amino acid profiles could aid in diabetes risk assessment.
Published:
2011-04
Title:
Nutrition and Alzheimer's disease: the detrimental role of a high carbohydrate diet
Authors:
Seneff, Stephanie; Wainwright, Glyn; Mascitelli, Luca
Abstract:
Alzheimer's disease is a devastating disease whose recent increase in incidence rates has broad implications for rising health care costs. Huge amounts of research money are currently being invested in seeking the underlying cause, with corresponding progress in understanding the disease progression. In this paper, we highlight how an excess of dietary carbohydrates, particularly fructose, alongside a relative deficiency in dietary fats and cholesterol, may lead to the development of Alzheimer's disease. A first step in the pathophysiology of the disease is represented by advanced glycation end-products in crucial plasma proteins concerned with fat, cholesterol, and oxygen transport. This leads to cholesterol deficiency in neurons, which significantly impairs their ability to function. Over time, a cascade response leads to impaired glutamate signaling, increased oxidative damage, mitochondrial and lysosomal dysfunction, increased risk to microbial infection, and, ultimately, apoptosis. Other neurodegenerative diseases share many properties with Alzheimer's disease, and may also be due in large part to this same underlying cause.
Published:
2011-04
Title:
Targeting Dietary Fat or Glycemic Load in the Treatment of Obesity and Type 2 Diabetes: A Randomized Controlled Trial
Authors:
Fabricatore, AN; Wadden, TA; Ebbeling, CB; Thomas, JG; Stallings, VA; Schwartz, S; Ludwig, DS
Abstract:
Aims To compare the effects of lifestyle modification programs that prescribe low-glycemic load (GL) vs. low-fat diets in a randomized trial. Methods Seventy-nine obese adults with type 2 diabetes received low-fat or low-GL dietary instruction, delivered in 40-week lifestyle modification programs with identical goals for calorie intake and physical activity. Changes in weight, HbA1c, and other metabolic parameters were compared at weeks 20 and 40. Results Weight loss did not differ between groups at week 20 (low-fat: −5.7 ± 3.7%, low-GL: −6.7 ± 4.4%, p = .26) or week 40 (low-fat: −4.5 ± 7.5%, low-GL: −6.4 ± 8.2%, p = .28). Adjusting for changes in antidiabetic medications, subjects on the low-GL diet had larger reductions in HbA1c than those on the low-fat diet at week 20 (low-fat: −0.3 ± 0.6%, low-GL: −0.7 ± 0.6%, p = .01), and week 40 (low-fat: −0.1 ± 1.2%, low-GL: −0.8 ± 1.3%, p = .01). Groups did not differ significantly on any other metabolic outcomes (p ≥ .06). Conclusions Results suggest that targeting GL, rather than dietary fat, in a low-calorie diet can significantly enhance the effect of weight loss on HbA1c in patients with type 2 diabetes.
Published:
2011-04
Title:
The influence of creatine supplementation on the cognitive functioning of vegetarians and omnivores
Authors:
Benton, David; Donohoe, Rachel
Abstract:
Creatine when combined with P forms phosphocreatine that acts as a reserve of high-energy phosphate. Creatine is found mostly in meat, fish and other animal products, and the levels of muscle creatine are known to be lower in vegetarians. Creatine supplementation influences brain functioning as indicated by imaging studies and the measurement of oxygenated Hb. Given the key role played by creatine in the provision of energy, the influence of its supplementation on cognitive functioning was examined, contrasting the effect in omnivores and vegetarians. Young adult females (n 128) were separated into those who were and were not vegetarian. Randomly and under a double-blind procedure, subjects consumed either a placebo or 20 g of creatine supplement for 5 d. Creatine supplementation did not influence measures of verbal fluency and vigilance. However, in vegetarians rather than in those who consume meat, creatine supplementation resulted in better memory. Irrespective of dietary style, the supplementation of creatine decreased the variability in the responses to a choice reaction-time task.
Published:
2011-04
Title:
The skin microbiome
Authors:
Grice, Elizabeth A.; Segre, Julia A.
Abstract:
The skin is the human body's largest organ, colonized by a diverse milieu of microorganisms, most of which are harmless or even beneficial to their host. Colonization is driven by the ecology of the skin surface, which is highly variable depending on topographical location, endogenous host factors and exogenous environmental factors. The cutaneous innate and adaptive immune responses can modulate the skin microbiota, but the microbiota also functions in educating the immune system. The development of molecular methods to identify microorganisms has led to an emerging view of the resident skin bacteria as highly diverse and variable. An enhanced understanding of the skin microbiome is necessary to gain insight into microbial involvement in human skin disorders and to enable novel promicrobial and antimicrobial therapeutic approaches for their treatment.
Published:
2011-04
Title:
Use of a food frequency questionnaire to assess diets of Jamaican adults: validation and correlation with biomarkers
Authors:
Jackson, Maria D.; Walker, Susan P.; Younger, Novie M.; Bennett, Franklyn I.
Abstract:
CONCLUSIONS: The expanded FFQ had good relative validity for estimating food group and nutrient intakes (except retinol and vitamin E) and was a reliable measure of habitual intake. Associations with biomarkers were comparable to other studies.
Published:
2011-04
Title:
(Re-)activation of neurons in aging and dementia: lessons from the hypothalamus
Authors:
Swaab, Dick F.; Bao, Ai-Min
Abstract:
Our hypothesis is that there is 'wear and tear' in the brain, which is the basis of the process of aging, but that stimulation of brain function may slow down brain aging and diminish the risk for neurodegenerative diseases such as Alzheimer's disease (AD), possibly by activating repair mechanisms. Evidence supporting this hypothesis is presented in this review. During normal aging and in AD, cell loss is not as prominent a phenomenon as is often presumed. In fact, unaltered neuronal numbers have been reported in many brain areas in AD, e.g. in the nucleus basalis of Meynert (NBM) where the number of large neurons decreases while that of small neurons increases. Decreased neuronal activity is an essential characteristic of AD, and a substantial decrease of cerebral glucose metabolism may even precede cognitive impairments. Some hypothalamic neurons remain intact and active during the process of aging, others become even hyperactive, which may lead to disorders. Arginine vasopressin (AVP) levels were found to be higher in the elderly than in young subjects. There is an age-related, sex-dependent activation of the AVP neurons in the supraoptic nucleus (SON) and in the paraventricular nucleus (PVN), which may be the basis of analogous changes in the prevalence of hypertension and hyponatraemia in the elderly. No significant functional loss of magnocellular hypothalamic neurosecretory neurons were found in the SON or PVN in AD. The activity of the corticotrophin releasing hormone (CRH) neurons in the hypothalamic PVN is the basis for the activity of the hypothalamo-pituitary-adrenal (HPA) axis, which is activated during aging in a sex-dependent way, and even more activated in AD. The activated HPA axis is a risk for depression. Environmental stimulation increases brain reserve. An increase in time spent on intellectual activities was associated with a significant decrease in probability to get AD, and occupation has even a stronger indication of diminished risk for dementia. A series of observations showed that a dysfunctional clock may underlie the disordered rhythms in AD. Additional bright light improved the rest-activity rhythms, while giving bright light and/or melatonin to AD patients ameliorated the progression of cognitive and noncognitive symptoms. This implies that neurons affected by AD can still be reactivated if the right stimuli are applied. Unknown diffusible factors from the neural stem cells improve the survival of aged and degenerating neurons in postmortem human brain slice cultures. Gene therapy with nerve growth factor aimed at the NBM showed metabolic activation of various brain regions. A microarray study of the prefrontal cortex in the course of AD revealed an increased expression of genes related to synaptic activity and changes in plasticity during the very early pre-symptomatic stages, which is proposed to represent a coping mechanism against increased soluble β-amyloid levels. In brief, these examples of the 'use it or lose it' principle during the course of aging or AD now provide novel targets for the development of therapeutic strategies aiming at the prevention and treatment of AD.
Published:
2011-03
Title:
A brief historical and theoretical perspective on patient autonomy and medical decision making: Part I: The beneficence model
Authors:
Will, Jonathan F.
Abstract:
As part of a larger series addressing the intersection of law and medicine, this essay is the first of two introductory pieces. This article explores the nature of the physician-patient relationship and of the practice of medicine dating from the Hippocratic tradition to the end of the 19th century, a period during which a beneficence-based medical ethic remained relatively stable. The medical literature dating from the Hippocratic texts to the early codes of the American Medical Association did not include a meaningful role for the patient in the decision-making process. In fact, the practice of benevolent deception - the deliberate withholding of any information thought by the physician to be detrimental to the patient's prognosis - was encouraged. However, as philosophers identified an inherent value in respecting patient self-determination and the law imposed a duty on physicians to obtain informed consent, 2,400 years of relative stability under the beneficence model gave way to the autonomy model. © 2011 American College of Chest Physicians.
Published:
2011-03
Title:
A diet high in meat protein and potential renal acid load increases fractional calcium absorption and urinary calcium excretion without affecting markers of bone resorption or formation in postmenopausal women
Authors:
Cao, Jay J.; Johnson, LuAnn K.; Hunt, Janet R.
Abstract:
Our objective in this study was to determine the effects of a high-protein and high-potential renal acid load (PRAL) diet on calcium (Ca) absorption and retention and markers of bone metabolism. In a randomized crossover design, 16 postmenopausal women consumed 2 diets: 1 with low protein and low PRAL (LPLP; total protein: 61 g/d; PRAL: -48 mEq/d) and 1 with high protein and high PRAL (HPHP; total protein: 118 g/d; PRAL: 33 mEq/d) for 7 wk each separated by a 1-wk break. Ca absorption was measured by whole body scintillation counting of radio-labeled (47)Ca. Compared with the LPLP diet, the HPHP diet increased participants' serum IGF-I concentrations (P < 0.0001), decreased serum intact PTH concentrations (P < 0.001), and increased fractional (47)Ca absorption (mean ± pooled SD: 22.3 vs. 26.5 ± 5.4%; P
Published:
2011-03
Title:
Approach to the pediatric patient with Graves' disease: when is definitive therapy warranted?
Authors:
Bauer, Andrew J
Abstract:
Pediatric Graves' disease accounts for 10-15% of thyroid disorders in patients less than 18 yr of age. The onset of symptoms may be insidious and subsequently associated with a delay in diagnosis. Decreased concentration and poor school performance are frequent complaints and can be quite frustrating for the patient and family. Severe ophthalmopathy is uncommon. The diagnosis is established by the findings of an increased heart rate and goiter in the setting of a suppressed TSH and elevated T(3) and/or T(4). The majority of pediatric patients are initially placed on antithyroid medications and maintained on these medications for prolonged periods of time in hopes of achieving remission. Unfortunately, for many children and adolescents remission is unattainable, ultimately occurring in only 15-30% of patients. Several recent studies have suggested that the age of the patient, the degree of thyrotoxicosis at diagnosis, the initial response to therapy, and the level of TSH receptor antibodies serve as reasonable predictors of remission and relapse. However, a consensus on the utility of these markers has not been reached. The present clinical case describes an adolescent with Graves' disease and highlights the negative impact that prolonged medical therapy can have on quality of life and school performance; it reviews pertinent data on the diagnosis, comorbidities, and treatment options; and it identifies gaps in knowledge for when definitive therapy should be pursued. The case serves as a reminder that earlier discussion and decision for definitive therapy should be more commonplace in caring for our pediatric patients with Graves' disease.
Published:
2011-03
Title:
Diet and sleep in children with attention deficit hyperactivity disorder: preliminary data in Australian children
Authors:
Blunden, Sarah Lee; Milte, Catherine M.; Sinn, Natalie
Abstract:
Sleep disturbances are common and consequential in children with attention deficit hyperactivity disorder (ADHD). Diet also influences ADHD symptoms. Interrelationships between diet, sleep and behaviour in children diagnosed with ADHD are little studied. We investigated, via parental report, the relationships between sleep and diet in 88 Australian children aged 6-13 years old (M = 8.94, SD = 1.78). This pilot data shows that 30 per cent of the children had sleep disturbance (≥ 2 standard deviations above the mean) with significant relationships between ADHD symptoms, sleep disturbance and diet. Parents who reported more sleep disturbance also reported a higher intake of carbohydrate, fats, and, most particularly, sugar which was also a significant predictor of night time sweating. These findings suggest an interrelationship between diet and sleep in children with ADHD. Given that both sleep and dietary intake are potentially modifiable behaviours within treatment regimes of children with ADHD, further investigation is needed.
Published:
2011-03
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