wtorek, 26 stycznia 2010

Addition of whole, semiskimmed, and skimmed bovine milk reduces the total an...

 
 

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via Nutrition Research by Lisa Ryan, Sébastien Petit on 1/1/10

Abstract: Epidemiological studies have shown that populations consuming fruits, vegetables, tea, cocoa, and red wine have lower incidences of cardiovascular disease, certain cancers, and eye disease. These health effects have largely been attributed to the polyphenol content of the foods and drinks studied. Black tea is rich in a range of polyphenolic compounds that could potentially have health-promoting properties. The scale of consumption of tea in the United Kingdom means that it could be an appropriate vehicle for increasing the antioxidant activity and polyphenol content of human plasma. However, it is common practice in the United Kingdom to add milk to tea, and some studies have suggested that this may decrease the overall antioxidant capacity. The objective of the present study was to analyze and compare the antioxidant capacity of 5 brands of tea and to test the hypothesis that the addition of different volumes of whole milk, semiskimmed, and skimmed milk may affect the antioxidant capacity. Each of the teas analyzed was a significant source of antioxidants. The addition of 10, 15, and 20 mL of whole, semiskimmed, and skimmed bovine milk to a 200-mL tea infusion decreased the total antioxidant capacity of all the brands of tea. Skimmed milk decreased the total antioxidant capacity of the tea infusion significantly (P < .05) more than either whole milk or semiskimmed milk. We conclude that black tea is a valuable source of antioxidants and that the effect of milk on the total antioxidant capacity may be related to the fat content of the milk.

 
 

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środa, 2 grudnia 2009

Understanding omega-3 polyunsaturated Fatty acids.

Understanding omega-3 polyunsaturated Fatty acids.

Calder PC, Yaqoob P.

Institute of Human Nutrition School of Medicine, Southampton General Hospital, Southampton, UK. pcc@soton.ac.uk.

Current intakes of very long-chain omega-3 fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are low in most individuals living in Western countries. A good natural source of these fatty acids is seafood, especially oily fish. Fish oil capsules contain these fatty acids also. Very long-chain omega-3 fatty acids are readily incorporated from capsules into transport (blood lipids), functional (cell and tissue), and storage (adipose) pools. This incorporation is dose-dependent and follows a kinetic pattern that is characteristic for each pool. At sufficient levels of incorporation, EPA and DHA influence the physical nature of cell membranes and membrane protein-mediated responses, lipid-mediator generation, cell signaling, and gene expression in many different cell types. Through these mechanisms, EPA and DHA influence cell and tissue physiology and the way cells and tissues respond to external signals. In most cases the effects seen are compatible with improvements in disease biomarker profiles or health-related outcomes. As a result, very long-chain omega-3 fatty acids play a role in achieving optimal health and in protection against disease. Long-chain omega-3 fatty acids not only protect against cardiovascular morbidity but also against mortality. In some conditions, for example rheumatoid arthritis, they may be beneficial as therapeutic agents. On the basis of the recognized health improvements brought about by long-chain omega-3 fatty acids, recommendations have been made to increase their intake. The plant omega-3 fatty acid, alpha-linolenic acid (ALA), can be converted to EPA, but conversion to DHA appears to be poor in humans. Effects of ALA on human health-related outcomes appear to be due to conversion to EPA, and since this is limited, moderately increased consumption of ALA may be of little benefit in improving health outcomes compared with increased intake of preformed EPA + DHA.

wtorek, 1 grudnia 2009

Use of multivitamin supplements in relation to allergic disease in 8-y-old children

Use of multivitamin supplements in relation to allergic disease in 8-y-old children
[Dietary supplements]
from American Journal of Clinical Nutrition current issue by Marmsjo, K., Rosenlund, H., Kull, I., Hakansson, N., Wickman, M., Pershagen, G., Bergstrom, A.

Background: Multivitamins are frequently consumed by children, but it is unclear whether this affects the risk of allergic disease.

Objective: We sought to study the association between multivitamin supplementation and allergic disease in 8-y-old children.

Design: Data were obtained from a Swedish birth cohort study. Information on lifestyle factors, including use of vitamin supplements, environmental exposures, and symptoms and diagnoses of allergic diseases, was obtained by parental questionnaires. In addition, allergen-specific IgE concentrations of food and airborne allergens were measured in blood samples collected at age 8 y. A total of 2423 children were included in the study. The association between use of vitamin supplements and the selected health outcomes was analyzed with logistic regression.

Results: Overall, no strong and consistent associations were observed between current multivitamin use and asthma, allergic rhinitis, eczema, or atopic sensitization at age 8 y. However, children who reported that they started taking multivitamins before or at age 4 y had a decreased risk of sensitization to food allergens (odds ratio: 0.61; 95% CI: 0.39, 0.97) and tendencies toward inverse associations with allergic rhinitis. In contrast, there was no consistent association among children who started to use multivitamins at or after age 5 y.

Conclusion: Our results show no association between current use of multivitamins and risk of allergic disease but suggest that supplementation with multivitamins during the first years of life may reduce the risk of allergic disease at school age.

Dietary protein and bone health: a systematic review and meta-analysis

Dietary protein and bone health: a systematic review and meta-analysis [Bone metabolism]
from American Journal of Clinical Nutrition current issue by Darling, A. L, Millward, D J., Torgerson, D. J, Hewitt, C. E, Lanham-New, S. A

Background: There has been a resurgence of interest in the controversial relation between dietary protein and bone health.

Objective: This article reports on the first systematic review and meta-analysis of the relation between protein and bone health in healthy human adults.

Design: The MEDLINE (January 1966 to September 2007) and EMBASE (1974 to July 2008) databases were electronically searched for all relevant studies of healthy adults; studies of calcium excretion or calcium balance were excluded.

Results: In cross-sectional surveys, all pooled r values for the relation between protein intake and bone mineral density (BMD) or bone mineral content at the main clinically relevant sites were significant and positive; protein intake explained 1–2% of BMD. A meta-analysis of randomized placebo-controlled trials indicated a significant positive influence of all protein supplementation on lumbar spine BMD but showed no association with relative risk of hip fractures. No significant effects were identified for soy protein or milk basic protein on lumbar spine BMD.

Conclusions: A small positive effect of protein supplementation on lumbar spine BMD in randomized placebo-controlled trials supports the positive association between protein intake and bone health found in cross-sectional surveys. However, these results were not supported by cohort study findings for hip fracture risk. Any effects found were small and had 95% CIs that were close to zero. Therefore, there is a small benefit of protein on bone health, but the benefit may not necessarily translate into reduced fracture risk in the long term.

Dietary fat intake and subsequent weight change in adults: results from the European Prospective Investigation into Cancer and Nutrition cohorts

Dietary fat intake and subsequent weight change in adults: results from the European Prospective Investigation into Cancer and Nutrition cohorts
[Nutritional epidemiology and public health]

from American Journal of Clinical Nutrition current issue by Forouhi, N. G, Sharp, S. J, Du, H., van der A, D. L, Halkjaer, J., Schulze, M. B, Tjonneland, A., Overvad, K., Jakobsen, M. U., Boeing, H., Buijsse, B., Palli, D., Masala, G., Feskens, E. J., Sorensen, T. I., Wareham, N. J

Background: It is unclear from the inconsistent epidemiologic evidence whether dietary fat intake is associated with future weight change.

Objective: The objective was to assess the association between the amount and type of dietary fat and subsequent weight change (follow-up weight minus baseline weight divided by duration of follow-up).

Design: We analyzed data from 89,432 men and women from 6 cohorts of the EPIC (European Prospective Investigation into Cancer and Nutrition) study. Using country-specific food-frequency questionnaires, we examined the association between baseline fat intake (amount and type of total, saturated, polyunsaturated, and monounsaturated fats) and annual weight change by using the residual, nutrient density, and energy-partition methods. We used random-effects meta-analyses to obtain pooled estimates across centers.

Results: Mean total fat intake as a percentage of energy intake ranged between 31.5% and 36.5% across the 6 cohorts (58% women; mean ± SD age: 53.2 ± 8.6 y). The mean (±SD) annual weight change was 109 ± 817 g/y in men and 119 ± 823 g/y in women. In pooled analyses adjusted for anthropometric, dietary, and lifestyle factors and follow-up period, no significant association was observed between fat intake (amount or type) and weight change. The difference in mean annual weight change was 0.90 g/y (95% CI: –0.54, 2.34 g/y) for men and –1.30 g/y (95% CI: –3.70, 1.11 g/y) for women per 1 g/d energy-adjusted fat intake (residual method).

Conclusions: We found no significant association between the amount or type of dietary fat and subsequent weight change in this large prospective study. These findings do not support the use of low-fat diets to prevent weight gain.

Green tea consumption is associated with depressive symptoms in the elderly

Green tea consumption is associated with depressive symptoms in the elderly
[Nutritional epidemiology and public health]

from American Journal of Clinical Nutrition current issue by Niu, K., Hozawa, A., Kuriyama, S., Ebihara, S., Guo, H., Nakaya, N., Ohmori-Matsuda, K., Takahashi, H., Masamune, Y., Asada, M., Sasaki, S., Arai, H., Awata, S., Nagatomi, R., Tsuji, I.

Background: Green tea is reported to have various beneficial effects (eg, anti–stress response and antiinflammatory effects) on human health. Although these functions might be associated with the development and progression of depressive symptoms, no studies have investigated the relation between green tea consumption and depressive symptoms in a community-dwelling population.

Objective: The aim of this study was to investigate the relations between green tea consumption and depressive symptoms in elderly Japanese subjects who widely consumed green tea.

Design: We conducted a cross-sectional study in 1058 community-dwelling elderly Japanese individuals aged ≥70 y. Green tea consumption was assessed by using a self-administered questionnaire, and depressive symptoms were evaluated by using the 30-item Geriatric Depression Scale with 2 cutoffs: 11 (mild and severe depressive symptoms) and 14 (severe depressive symptoms). If a participant was consuming antidepressants, he or she was considered to have depressive symptoms.

Results: The prevalence of mild and severe and severe depressive symptoms was 34.1% and 20.2%, respectively. After adjustment for confounding factors, the odds ratios (95% CI) for mild and severe depressive symptoms when higher green tea consumption was compared with green tea consumption of ≤1 cup/d were as follows: 2–3 cups green tea/d (0.96; 95% CI: 0.66, 1.42) and ≥4 cups green tea/d (0.56; 95% CI: 0.39, 0.81) (P for trend: 0.001). Similar relations were also observed in the case of severe depressive symptoms.

Conclusion:
A more frequent consumption of green tea was associated with a lower prevalence of depressive symptoms in the community-dwelling older population.


Effect of a dietary intervention and n-3 fatty acid supplementation on measures of serum lipid and insulin sensitivity in persons with HIV

Effect of a dietary intervention and n-3 fatty acid supplementation on measures of serum lipid and insulin sensitivity in persons with HIV [AIDS and other wasting syndromes]

from American Journal of Clinical Nutrition current issue by Woods, M. N, Wanke, C. A, Ling, P.-R., Hendricks, K. M, Tang, A. M, Knox, T. A, Andersson, C. E, Dong, K. R, Skinner, S. C, Bistrian, B. R

Background: Elevated serum triglyceride and low HDL-cholesterol concentrations have been reported in persons with HIV.

Objective: The effect of a dietary intervention plus n–3 (–3) fatty acid supplementation on serum triglycerides and markers of insulin sensitivity was investigated.

Design: Fifty-four persons with HIV and elevated serum triglycerides (>150 mg/dL) and/or abnormal Quantitative Insulin Sensitivity Check Index values (<0.35 but >0.30) were recruited for a dietary intervention in which total fat, type of fat, fiber, and glycemic load were controlled along with supplementation with n–3 fatty acids to achieve an intake of 6 g/d. The subjects were randomly assigned to an intervention or control group, and serum lipids, markers of insulin sensitivity, and serum phospholipid fatty acids were measured in both groups at baseline, 3 wk, and 13 wk.

Results: Triglycerides in the intervention group decreased from a median of 180 mg/dL (interquartile range: 141, 396) to 114 mg/dL (interquartile range: 84, 169) from baseline to 3 wk, whereas they remained stable in the control group (P = 0.003). Serum phospholipid fatty acids indicated a decrease in de novo lipogenesis and a decrease in arachidonic acid (% nmol; P ≤ 0.001) in the intervention group. At 3 wk, the insulin area under the curve decreased but not significantly.

Conclusions: Diet and n–3 fatty acid supplementation dramatically reduced serum triglycerides, decreased arachidonic acid in the phospholipids fraction, and appeared to decrease the de novo lipogenesis associated with the metabolic syndrome in the intervention group.

Short-term sleep loss decreases physical activity under free-living conditions but does not increase food intake under time-deprived laboratory conditions in healthy men

Short-term sleep loss decreases physical activity under free-living conditions but does not increase food intake under time-deprived laboratory conditions in healthy men [Obesity and eating disorders]

from American Journal of Clinical Nutrition current issue by Schmid, S. M, Hallschmid, M., Jauch-Chara, K., Wilms, B., Benedict, C., Lehnert, H., Born, J., Schultes, B.

Background: Short sleep duration is correlated with an increased risk of developing obesity and cardiovascular disease, but the mechanisms behind this relation are largely unknown.

Objective: We aimed to test the hypothesis that acute sleep loss decreases physical activity while increasing food intake, thereby shifting 2 crucial behavioral components of energy homeostasis toward weight gain.

Design: In 15 healthy, normal-weight men, spontaneous physical activity was registered by accelerometry during the entire experiment, and food intake as well as relevant hormones were assessed during a 15-h daytime period after 2 nights of regular sleep (bed time: 2245–0700) and after 2 nights of restricted sleep (bed time: 0245–0700). Experiments were performed in a crossover design.

Results: Sleep restriction significantly decreased physical activity during the daytime spent under free-living conditions after the first night of sleep manipulation (P = 0.008). Also, intensities of physical activity were shifted toward lower levels, with less time spent with intense activities (P = 0.046). Total energy intake, feelings of hunger, and appetite as well as ghrelin and leptin concentrations during day 2 remained unaffected by acute sleep restriction.

Conclusions: In contrast to our expectation, short-term sleep loss neither increased food intake nor affected concentrations of the hunger-regulating hormones leptin and ghrelin. However, the observed decrease in daytime physical activity may point to another potentially important behavioral mechanism for the health-impairing influence of sleep loss.

Increased food energy supply is more than sufficient to explain the US epidemic of obesity

Increased food energy supply is more than sufficient to explain the US epidemic of obesity

from American Journal of Clinical Nutrition current issue by Swinburn, B., Sacks, G., Ravussin, E.

Background: The major drivers of the obesity epidemic are much debated and have considerable policy importance for the population-wide prevention of obesity.

Objective: The objective was to determine the relative contributions of increased energy intake and reduced physical activity to the US obesity epidemic.

Design: We predicted the changes in weight from the changes in estimated energy intakes in US children and adults between the 1970s and 2000s. The increased US food energy supply (adjusted for wastage and assumed to be proportional to energy intake) was apportioned to children and adults and inserted into equations that relate energy intake to body weight derived from doubly labeled water studies. The weight increases predicted from the equations were compared with weight increases measured in representative US surveys over the same period.

Results: For children, the measured weight gain was 4.0 kg, and the predicted weight gain for the increased energy intake was identical at 4.0 kg. For adults, the measured weight gain was 8.6 kg, whereas the predicted weight gain was somewhat higher (10.8 kg).

Conclusions: Increased energy intake appears to be more than sufficient to explain weight gain in the US population. A reversal of the increase in energy intake of 2000 kJ/d (500 kcal/d) for adults and of 1500 kJ/d (350 kcal/d) for children would be needed for a reversal to the mean body weights of the 1970s. Alternatively, large compensatory increases in physical activity (eg, 110–150 min of walking/d), or a combination of both, would achieve the same outcome. Population approaches to reducing obesity should emphasize a reduction in the drivers of increased energy intake.

Green tea, black tea, and epigallocatechin modify body composition, improve glucose tolerance, and differentially alter metabolic gene expression in rats fed a high-fat diet

Green tea, black tea, and epigallocatechin modify body composition, improve glucose tolerance, and differentially alter metabolic gene expression in rats fed a high-fat diet

from Nutrition Research
by Nora Chen, Rebecca Bezzina, Edward Hinch, Paul A. Lewandowski, David Cameron-Smith, Michael L. Mathai, Markandeya Jois, Andrew J. Sinclair, Denovan P. Begg, John D. Wark, Harrison S. Weisinger, Richard S. Weisinger

Abstract: The mechanisms of how tea and epigallocatechin-3-gallate (EGCG) lower body fat are not completely understood. This study investigated long-term administration of green tea (GT), black tea (BT), or isolated EGCG (1 mg/kg per day) on body composition, glucose tolerance, and gene expression related to energy metabolism and lipid homeostasis; it was hypothesized that all treatments would improve the indicators of metabolic syndrome. Rats were fed a 15% fat diet for 6 months from 4 weeks of age and were supplied GT, BT, EGCG, or water. GT and BT reduced body fat, whereas GT and EGCG increased lean mass. At 16 weeks GT, BT, and EGCG improved glucose tolerance. In the liver, GT and BT increased the expression of genes involved in fatty acid synthesis (SREBP-1c, FAS, MCD, ACC) and oxidation (PPAR-α, CPT-1, ACO); however, EGCG had no effect. In perirenal fat, genes that mediate adipocyte differentiation were suppressed by GT (Pref-1, C/EBP-β, and PPAR-γ) and BT (C/EBP-β), while decreasing LPL, HSL, and UCP-2 expression; EGCG increased expression of UCP-2 and PPAR-γ genes. Liver triacylglycerol content was unchanged. The results suggest that GT and BT suppressed adipocyte differentiation and fatty acid uptake into adipose tissue, while increasing fat synthesis and oxidation by the liver, without inducing hepatic fat accumulation. In contrast, EGCG increased markers of thermogenesis and differentiation in adipose tissue, while having no effect on liver or muscle tissues at this dose. These results show novel and separate mechanisms by which tea and EGCG may improve glucose tolerance and support a role for these compounds in obesity prevention.

poniedziałek, 23 listopada 2009

Perceived Stress and Weight Gain in Adolescence: A Longitudinal Analysis

Perceived Stress and Weight Gain in Adolescence: A Longitudinal Analysis

Cornelia H.M. van Jaarsveld1, Jennifer A. Fidler1, Andrew Steptoe2, David Boniface1 and Jane Wardle1
1Health Behaviour Research Centre, Department of Epidemiology and Public Health, University College London, London, UK
2Psychobiology Group, Department of Epidemiology and Public Health, University College London, London, UK

Abstract

Although perceived stress has been hypothesized to be a risk factor for obesity, epidemiological studies relating stress to weight gain have shown mixed results. We examined prospective associations between perceived stress and changes in waist circumference and BMI in a large study of adolescents. As part of the Health and Behaviour in Teenagers Study (HABITS), height, weight, and waist circumference were measured annually in 4,065 adolescents aged from 11 to 16. Waist and BMI standard deviation scores (SDS) were used as indices of adiposity. Adolescents completed a measure of perceived stress each year, from which mean stress scores over the 5-year period were also calculated and divided by tertile into lower, moderate, and higher stress. Associations between perceived stress at each year and adiposity 1–4 years later and also adiposity trajectories over the whole period in relation to mean stress were investigated. Analyses were adjusted for age, sex, ethnicity, socioeconomic deprivation, pubertal timing, and smoking. Perceived stress in any year was not related prospectively to increases in waist or BMI SDS 1–4 years later, nor was there any evidence that higher stress over the whole period was associated with greater gains in waist or BMI SDS. However, waist and BMI SDS were significantly higher in the moderate- and higher-stress groups than the lower-stress group across the whole 5-year period. Persistent stress was associated with higher waist circumference and BMI in adolescence, but did not lead to differential changes over 5 years.

Antiobesity Effects of yerba maté Extract (Ilex paraguariensis) in High-fat Diet–induced Obese Mice

Antiobesity Effects of yerba maté Extract (Ilex paraguariensis) in High-fat Diet–induced Obese Mice

Demétrius P. Arçari1,2, Waldemar Bartchewsky1, Tanila W. dos Santos1, Karim A. Oliveira1, Alexandre Funck1, José Pedrazzoli1, Marina F.F. de Souza2, Mario J. Saad3, Deborah H.M. Bastos2, Alessandra Gambero1, Patricia de O. Carvalho4 and Marcelo L. Ribeiro1
1Unidade Integrada de Farmacologia e Gastroenterologia, Universidade São Francisco, Bragança Paulista, Brazil
2Departamento de Nutrição, Faculdade de Saúde Publica, Universidade de São Paulo, São Paulo, Brazil
3Departamento de Medicina Interna UNICAMP, Campinas, Brazil
4Laboratório Multidisciplinar de Pesquisa, Universidade São Francisco, Bragança Paulista, Brazil

Abstract

Because the potential of yerba maté (Ilex paraguariensis) has been suggested in the management of obesity, the aim of the present study was to evaluate the effects of yerba maté extract on weight loss, obesity-related biochemical parameters, and the regulation of adipose tissue gene expression in high-fat diet–induced obesity in mice. Thirty animals were randomly assigned to three groups. The mice were introduced to standard or high-fat diets. After 12 weeks on a high-fat diet, mice were randomly assigned according to the treatment (water or yerba maté extract 1.0 g/kg). After treatment intervention, plasma concentrations of total cholesterol, high-density lipoprotein cholesterol, triglyceride, low-density lipoprotein (LDL) cholesterol, and glucose were evaluated. Adipose tissue was examined to determine the mRNA levels of several genes such as tumor necrosis factor- (TNF-), leptin, interleukin-6 (IL-6), C-C motif chemokine ligand-2 (CCL2), CCL receptor-2 (CCR2), angiotensinogen, plasminogen activator inhibitor-1 (PAI-1), adiponectin, resistin, peroxisome proliferator-activated receptor-2 (PPAR-2), uncoupling protein-1 (UCP1), and PPAR- coactivator-1 (PGC-1). The F4/80 levels were determined by immunoblotting. We found that obese mice treated with yerba maté exhibited marked attenuation of weight gain, adiposity, a decrease in epididymal fat-pad weight, and restoration of the serum levels of cholesterol, triglycerides, LDL cholesterol, and glucose. The gene and protein expression levels were directly regulated by the high-fat diet. After treatment with yerba maté extract, we observed a recovery of the expression levels. In conclusion, our data show that yerba maté extract has potent antiobesity activity in vivo. Additionally, we observed that the treatment had a modulatory effect on the expression of several genes related to obesity.

poniedziałek, 16 listopada 2009

A Meta-Analysis Evaluating the Impact of Chitosan on Serum Lipids in Hypercholesterolemic Patients


A Meta-Analysis Evaluating the Impact of Chitosan on Serum Lipids in Hypercholesterolemic Patients

William L. Bakera, c, Alix Terciusb, Moise Angladeb, C. Michael Whitea, c, Craig I. Colemana, c

University of Connecticut Schools of
aPharmacy and
bMedicine, Storrs, Conn. and Farmington, Conn., and
cEvidence-Based Practice Center at Hartford Hospital, Hartford, Conn., USA

Address of Corresponding Author

Ann Nutr Metab 2009;55:368-374 (DOI: 10.1159/000258633)

Key Words
Chitin
Chitosan
Hypercholesterolemia
Meta-analysis

Abstract

Background/Objective: Chitosan is increasingly being used in the United States as an over-the-counter cholesterol-lowering agent. The positively charged amino groups of chitosan may have the ability to bind negatively charged molecules such as lipids and bile acids, inducing a greater fractional excretion in the feces. To better characterize the impact of chitosan on serum lipids in hypercholesterolemic patients, we performed a meta-analysis of randomized controlled trials. Methods: A systematic literature search of Medline, Embase, Cochrane Central and the Natural Medicines Comprehensive Database was conducted from the earliest possible date through May 2008. Trials were included in the analysis if they were randomized, placebo-controlled trials of chitosan in hypercholesterolemic patients and reported efficacy data on total, low-density lipoprotein (LDL), high-density lipoprotein (HDL) cholesterol or triglycerides. The weighted mean difference (WMD) of the change from baseline (in milligrams per deciliter) with 95% confidence interval was calculated as the difference between the mean in the chitosan and placebo groups using a random-effects model. Results: Six studies (n = 416 patients) met the inclusion criteria. Upon meta-analysis, the use of chitosan significantly lowered total cholesterol [WMD, -11.59 mg/dl (-21.45 to -1.73), p = 0.02] but not LDL cholesterol, HDL cholesterol or triglycerides.
Conclusions: Based upon the currently available literature, we can only say that chitosan beneficially affects total cholesterol with 95% confidence. Additional, larger randomized controlled trials are needed to better characterize the effect of chitosan on other lipoproteins.

Sustained participation in youth sport decreases metabolic syndrome in adulthood


Sustained participation in youth sport decreases metabolic syndrome in adulthood

X Yang1, R Telama2, M Hirvensalo2, J S A Viikari3 and O T Raitakari4
1LIKES Research Center for Sport and Health Sciences, Jyväskylä, Finland
2Department of Sport Sciences, University of Jyväskylä, Jyväskylä, Finland
3Department of Medicine, University of Turku, Turku, Finland
4Department of Clinical Physiology, University of Turku, Turku, Finland

Correspondence: Dr X Yang, LIKES Research Center for Sport and Health Sciences, Yliopistonkatu 20, Jyväskylä 40100, Finland. E-mail: xiaolin.yang@likes.fi

Received 13 May 2009; Revised 18 June 2009; Accepted 28 June 2009; Published online 1 September 2009.

Abstract
Objective: to explore the effect of organized youth sport on metabolic syndrome (MetS) in adulthood.
Design: Longitudinal study data from the cardiovascular risk in young Finns study.
Subjects: A total of 1493 males (n=704) and females (n=789) aged 3, 6, 9, 12, 15 and 18 years were randomly selected from five university towns and their rural surroundings in 1980. They were followed up for 21 years. In 2001 they were 24, 27, 30, 33, 36 and 39 years old.
Measurements: Youth sports participation data (participation in sport-club training and competitions) were assessed in 1980 and 1983 using a self-report questionnaire completed in connection with a medical examination. Participants were divided into athletes and non-athletes at each measurement point, and then classified into four groups: Persistent athlete, Starter, Leaver and Non-athlete. A mean score of youth sport was assessed by calculating the average of four consecutive measurements (1980–1989). MetS risk in 2001 was defined as a categorical variable based on the guidelines of the European Group for the Study of Insulin Resistance (EGIR) and as a continuous MetS-score variable by summing the z-scores of individual metabolic variables.
Results: In males and females, intense participation in youth sports over 3 years was inversely and significantly associated with clustered MetS score and prevalence of MetS defined by EGIR in adulthood (P<0.05). The association remained significant after adjustment for age, baseline clustered MetS score, smoking and total caloric intake and after additional adjustments for adult leisure-time physical activity. Starters during 3 years were less likely to have MetS than non-athletes. Leavers were at a higher risk for MetS than persistent athletes. These associations were attenuated in males by adjustment for all potential confounders. Similar associations were found using EGIR MetS as an outcome.
Conclusions: Sustained participation in organized sport lasting at least 3 years in youth is associated with reduced risk for developing MetS in adulthood.

czwartek, 5 listopada 2009

Alcohol as a Risk Factor for Type 2 Diabetes: A systematic review and meta-analysis

Alcohol as a Risk Factor for Type 2 Diabetes: A systematic review and meta-analysis

by Baliunas, D. O., Taylor, B. J., Irving, H., Roerecke, M., Patra, J., Mohapatra, S., Rehm, J.
OBJECTIVE 

To clarify the dose-response relationship between alcohol consumption and type 2 diabetes.
RESEARCH DESIGN AND METHODS 

A systematic computer-assisted and hand search was conducted to identify relevant articles with longitudinal design and quantitative measurement of alcohol consumption. Adjustment was made for the sick-quitter effect. We used fractional polynomials in a meta-regression to determine the dose-response relationships by sex and end point using lifetime abstainers as the reference group.
RESULTS 

The search revealed 20 cohort studies that met our inclusion criteria. A U-shaped relationship was found for both sexes. Compared with lifetime abstainers, the relative risk (RR) for type 2 diabetes among men was most protective when consuming 22 g/day alcohol (RR 0.87 [95% CI 0.76–1.00]) and became deleterious at just over 60 g/day alcohol (1.01 [0.71–1.44]). Among women, consumption of 24 g/day alcohol was most protective (0.60 [0.52–0.69]) and became deleterious at about 50 g/day alcohol (1.02 [0.83–1.26]).
CONCLUSIONS 

Our analysis confirms previous research findings that moderate alcohol consumption is protective for type 2 diabetes in men and women.

Sleep Duration, Lifestyle Intervention, and Incidence of Type 2 Diabetes in Impaired Glucose Tolerance: The Finnish Diabetes Prevention Study

Sleep Duration, Lifestyle Intervention, and Incidence of Type 2 Diabetes in Impaired Glucose Tolerance: The Finnish Diabetes Prevention Study

by Tuomilehto, H., Peltonen, M., Partinen, M., Lavigne, G., Eriksson, J. G., Herder, C., Aunola, S., Keinanen-Kiukaanniemi, S., Ilanne-Parikka, P., Uusitupa, M., Tuomilehto, J., Lindstrom, J., on behalf of the Finnish Diabetes Prevention Study Group
OBJECTIVE 
Both short and long sleep duration have frequently been found to be associated with an increased risk for diabetes. The aim of the present exploratory analysis was to examine the association between sleep duration and type 2 diabetes after lifestyle intervention in overweight individuals with impaired glucose tolerance in a 7-year prospective follow-up.
RESEARCH DESIGN AND METHODS 
A total of 522 individuals (aged 40–64 years) were randomly allocated either to an intensive diet-exercise counseling group or to a control group. Diabetes incidence during follow-up was calculated according to sleep duration at baseline. Sleep duration was obtained for a 24-h period. Physical activity, dietary intakes, body weight, and immune mediators (C-reactive protein and interleukin-6) were measured.
RESULTS 
Interaction between sleep duration and treatment group was statistically significant (P = 0.003). In the control group, the adjusted hazard ratios (HRs) (95% CI) for diabetes were 2.29 (1.38–3.80) and 2.74 (1.67–4.50) in the sleep duration groups 9–9.5 h and ?10 h, respectively, compared with for that of the 7–8.5 h group. In contrast, sleep duration did not influence the incidence of diabetes in the intervention group; for sleep duration groups 9–9.5 h and ?10 h, the adjusted HRs (95% CI) were 1.10 (0.60–2.01) and 0.73 (0.34–1.56), respectively, compared with that in the reference group (7–8.5 h sleep). Lifestyle intervention resulted in similar improvement in body weight, insulin sensitivity, and immune mediator levels regardless of sleep duration.
CONCLUSIONS 
Long sleep duration is associated with increased type 2 diabetes risk. Lifestyle intervention with the aim of weight reduction, healthy diet, and increased physical activity may ameliorate some of this excess risk.

poniedziałek, 2 listopada 2009

Eat less and exercise more - is it really enough to knock down the obesity pandemia?


Eat less and exercise more - is it really enough to knock down the obesity pandemia?

Hubácek JA.

Institute for Clinical and Experimental Medicine-CEM-LMG, Prague, Czech Republic. jahb@ikem.cz.

Reduced physical activity and abundant energy intake are two most common factors leading to uncontrolled body weight gain. But these factors are not under entire internal consciousness control; they are also partially genetically determined and are affected by for example food marketing practices. In addition to these two widely accepted factors, there are some other factors, whose could also contribute to the recent increase of obesity prevalence. For example, non-exercise activity thermogenesis, sleeping habits, more stable inside room temperatures (using of heating and air conditioning), high prescription of medications with weight gain as side effect, psychosocial factors, unfavourable socioeconomic status and unpleasant urban environment are the background factors which should not be omitted if obesity/BMI determination should be fully understood and kept under control. In conclusion, unhealthy life style is necessary, but not sufficient for obesity development.

Viral obesity: fact or fiction?


Viral obesity: fact or fiction?

Mitra AK, Clarke K.

Department of Community Health Sciences, The University of Southern Mississippi, Hattiesburg, MS, USA.

Summary The aetiology of obesity is multifactorial. An understanding of the contributions of various causal factors is essential for the proper management of obesity. Although it is primarily thought of as a condition brought on by lifestyle choices, recent evidence shows there is a link between obesity and viral infections. Numerous animal models have documented an increased body weight and a number of physiologic changes, including increased insulin sensitivity, increased glucose uptake and decreased leptin secretion that contribute to an increase in body fat in adenovirus-36 infection. Other viral agents associated with increasing obesity in animals included canine distemper virus, rous-associated virus 7, scrapie, Borna disease virus, SMAM-1 and other adenoviruses. This review attempted to determine if viral infection is a possible cause of obesity. Also, this paper discussed mechanisms by which viruses might produce obesity. Based on the evidence presented in this paper, it can be concluded that a link between obesity and viral infections cannot be ruled out. Further epidemiologic studies are needed to establish a causal link between the two, and determine if these results can be used in future management and prevention of obesity.

Eating Slowly Increases the Postprandial Response of the Anorexigenic Gut Hormones, Peptide YY and Glucagon-Like Peptide-1.


Eating Slowly Increases the Postprandial Response of the Anorexigenic Gut Hormones, Peptide YY and Glucagon-Like Peptide-1.

Kokkinos A, le Roux CW, Alexiadou K, Tentolouris N, Vincent RP, Kyriaki D, Perrea D, Ghatei MA, Bloom SR, Katsilambros N.

First Department of Propaedeutic Medicine (A.K., K.A., N.T., D.K., D.P., N.K.), Athens University Medical School, Laiko General Hospital, 11527 Athens, Greece; and Department of Metabolic Medicine (C.W.l.R., R.P.V., M.A.G., S.R.B.), Hammersmith Hospital, Imperial College, London W12 ONN, United Kingdom.

Context: The rate at which people eat has been suggested to be positively associated with obesity, although appetite and related gut hormones have not been measured. Objective: The objective of the study was to determine whether eating the same meal at varying speeds elicits different postprandial gut peptide responses. Design and Setting: This was a crossover study at a clinical research facility. Study Participants: Seventeen healthy adult male volunteers participated in the study. Intervention: A test meal consisting of 300 ml ice cream (675 kcal) was consumed in random order on two different sessions by each subject: meal duration took either 5 or 30 min. Main Outcome Measures: The postprandial response of the orexigenic hormone ghrelin and the anorexigenic peptides peptide YY and glucagon-like peptide-1 over 210 min was assessed. Visual analog scales for the subjective feelings of hunger and fullness were completed throughout each session. Results: Peptide YY area under the curve (AUC) was higher after the 30-min meal than after the 5-min meal (mean +/- SEM AUC 5 min meal: 4133 +/- 324, AUC 30 min meal: 5250 +/- 330 pmol/liter . min, P = 0.004), as was glucagon-like peptide-1 AUC (mean +/- SEM AUC 5 min meal: 6219 +/- 256, AUC 30 min meal: 8794 +/- 656 pmol/liter . min, P = 0.001). There was a trend for higher visual analog scale fullness ratings immediately after the end of the 30-min meal compared with immediately after the 5-min meal. There were no differences in ghrelin response. Conclusions: Eating at a physiologically moderate pace leads to a more pronounced anorexigenic gut peptide response than eating very fast.

The energy expenditure of using a "walk-and-work" desk for office workers with obesity.


The energy expenditure of using a "walk-and-work" desk for office workers with obesity.

Levine JA, Miller JM.

Endocrine Research Unit, Mayo Clinic and Mayo Foundation, Rochester, MN 55905, USA. levine.james@mayo.edu

OBJECTIVE: For many people, most of the working day is spent sitting in front of a computer screen. Approaches for obesity treatment and prevention are being sought to increase workplace physical activity because low levels of physical activity are associated with obesity. Our hypothesis was that a vertical workstation that allows an obese individual to work while walking would be associated with significant and substantial increases in energy expenditure over seated work. METHODS: The vertical workstation is a workstation that allows an office worker to use a standard personal computer while walking on a treadmill at a self-selected velocity. 15 sedentary individuals with obesity (14 women, one man; 43 (7.5) years, 86 (9.6) kg; body mass index 32 (2.6) kg/m(2)) underwent measurements of energy expenditure at rest, seated working in an office chair, standing and while walking at a self-selected speed using the vertical workstation. Body composition was measured using dual x ray absorptiometry. RESULTS: The mean (SD) energy expenditure while seated at work in an office chair was 72 (10) kcal/h, whereas the energy expenditure while walking and working at a self-selected velocity of 1.1 (0.4) mph was 191 (29) kcal/h. The mean (SD) increase in energy expenditure for walking-and-working over sitting was 119 (25) kcal/h. CONCLUSIONS: If sitting computer-time were replaced by walking-and-working, energy expenditure could increase by 100 kcal/h. Thus, if obese individuals were to replace time spent sitting at the computer with walking computer time by 2-3 h/day, and if other components of energy balance were constant, a weight loss of 20-30 kg/year could occur.