Sugar and cardiovascular disease: A statement for healthcare professionals from the Committee on Nutrition of the Council on Nutrition, Physical Activity, and Metabolism of the American Heart Association

Astaxanthin alleviates oxidative stress insults-related derangements in human vascular endothelial cells exposed to glucose fluctuations

Glycemic fluctuations may play a critical role in the pathogenesis of diabetic complications, such as cardiovascular disease. We investigated whether the oxycarotenoid astaxanthin can reduce the detrimental effects of fluctuating glucose on vascular endothelial cells. Human umbilical venous endothelial cells were incubated for 3 days in media containing 5.5mM glucose, 22 mM glucose, or 5.5mM glucose alternating with 22 mM glucose in the absence or presence of astaxanthin or N-acetyl-L-cysteine (NAC). Constant high glucose increased reactive oxygen species (ROS) generation, but such an effect was more pronounced in fluctuating glucose. This was associated with up-regulated p22(phox) expression and down-regulated peroxisome proliferator activated receptor-γ coactivator (PGC-1α) expression. Astaxanthin inhibited ROS generation, p22(phox) up-regulation, and PGC-1α down-regulation by the stimuli of glucose fluctuation. Fluctuating glucose, but not constant high glucose, significantly decreased the endothelial nitric oxide synthase (eNOS) phosphorylation level at Ser-1177 without affecting total eNOS expression, which was prevented by astaxanthin as well as by the anti-oxidant NAC. Transferase-mediated dUTP nick end labeling (TUNEL) showed increased cell apoptosis in fluctuating glucose. Glucose fluctuation also resulted in up-regulating gene expression of pro-inflammatory mediators, interleukin-6 and intercellular adhesion molecule-1. These adverse changes were subdued by astaxanthin. The phosphorylation levels of c-Jun N-terminal kinase (JNK) and p38 were significantly increased by glucose fluctuations, and astaxanthin significantly inhibited the increase in JNK and p38 phosphorylation. Taken together, our results suggest that astaxanthin can protect vascular endothelial cells against glucose fluctuation by reducing ROS generation.

A population-based study on the association between the intake of soft drinks and periodontal disease in Taiwanese adults aged 35-44 years (KCIS no. 33)

OBJECTIVE

To elucidate the association between the intake of soft drinks and periodontal disease (PD) among Taiwanese middle-aged adults.

DESIGN

The cross-sectional design was employed to assess a dose-response relationship between the intake of soft drinks and PD after controlling for relevant confounding factors, with adjusted odds ratios obtained from a multivariate logistic regression model.

SETTING

Keelung Community-based Integrated Screening (KCIS) programme, Keelung, Taiwan.

SUBJECTS

Participants (n 10 213) aged 35-44 years who had undergone oral checks for PD between 2005 and 2009.

RESULTS

A dose-response relationship between the intake of soft drinks and elevated risk for PD defined by community periodontal index ≥3 (the current status of PD) was noted (P=0·02 by trend test). Compared with infrequent intake of soft drinks (≤2 times/week), the adjusted OR increased from 1·05 (95 % CI 0·92, 1·20) for the frequency of 3-4 times/week to 1·17 (95 % CI 1·03, 1·34) for the frequency of ≥5 times/week. A similar trend (P<0·01) was also observed for PD defined by loss of attachment ≥1 (representing the long-term cumulative gum damage due to PD).

CONCLUSIONS

A dose-response relationship between the intake frequency of soft drinks and PD was observed in Taiwanese middle-aged adults. Such evidence could be used in health promotion to support reductions in soft drink intake.

Balancing expectations amidst limitations: the dynamics of food decision-making in rural Kerala

BACKGROUND

Food decision-making is a complex process and varies according to the setting, based on cultural and contextual factors. The study aimed to understand the process of food decision-making in households in rural Kerala, India, to inform the design of a dietary behaviour change intervention.

METHODS

Three focus group discussions (FGDs) and 17 individual interviews were conducted from September 2010 to January 2011 among 13 men and 40 women, between 23 and 75 years of age. An interview guide facilitated the process to understand: 1) food choices and decision-making in households, with particular reference to access; and 2) beliefs about foods, particularly fruits, vegetables, salt, sugar and oil. The interviews and FGDs were transcribed verbatim and analysed using qualitative content analysis.

RESULTS

The analysis revealed one main theme: 'Balancing expectations amidst limitations' with two sub-themes: 'Counting and meeting the costs'; and 'Finding the balance'. Food decisions were made at the household level, with money, time and effort costs weighed against the benefits, estimated in terms of household needs, satisfaction and expectations. The most crucial decisional point was affordability in terms of money costs, followed by food preferences of husband and children. Health and the risk of acquiring chronic diseases was not a major consideration in the decision-making process. Foods perceived as essential for children were purchased irrespective of cost, reportedly owing to the influence of food advertisements. The role of the woman as the homemaker has gendered implications, as the women disproportionately bore the burden of balancing the needs and expectations of all the household members within the available means.

CONCLUSIONS

The food decision-making process occurred at household level, and within the household, by the preferences of spouse and children, and cost considerations. The socio-economic status of households was identified as limiting their ability to manoeuvre this fine balance. The study has important policy implications in terms of the need to raise public awareness of the strong link between diet and chronic non-communicable diseases.

Associations of dietary intake patterns identified using reduced rank regression with markers of arterial stiffness among youth with type 1 diabetes

BACKGROUND/OBJECTIVES

Youth with type 1 diabetes (T1DM) are at substantially increased risk for adverse vascular outcomes, but little is known about the influence of dietary behavior on cardiovascular disease (CVD) risk profile. We aimed to identify dietary intake patterns associated with CVD risk factors and evaluate their impact on arterial stiffness (AS) measures collected thereafter in a cohort of youth with T1DM.

SUBJECTS/METHODS

Baseline diet data from a food frequency questionnaire and CVD risk factors (triglycerides, low density lipoprotein-cholesterol, systolic blood pressure, hemoglobin A1c, C-reactive protein and waist circumference) were available for 1153 youth aged ⩾10 years with T1DM from the SEARCH for Diabetes in Youth Study. A dietary intake pattern was identified using 33 food groups as predictors and six CVD risk factors as responses in reduced rank regression (RRR) analysis. Associations of this RRR-derived dietary pattern with AS measures (augmentation index (AIx75), n=229; pulse wave velocity, n=237; and brachial distensibility, n=228) were then assessed using linear regression.

RESULTS

The RRR-derived pattern was characterized by high intakes of sugar-sweetened beverages (SSB) and diet soda, eggs, potatoes and high-fat meats and low intakes of sweets/desserts and low-fat dairy; major contributors were SSB and diet soda. This pattern captured the largest variability in adverse CVD risk profile and was subsequently associated with AIx75 (β=0.47; P<0.01). The mean difference in AIx75 concentration between the highest and the lowest dietary pattern quartiles was 4.3% in fully adjusted model.

CONCLUSIONS

Intervention strategies to reduce consumption of unhealthy foods and beverages among youth with T1DM may significantly improve CVD risk profile and ultimately reduce the risk for AS.

A systematic review of the prevalence of nutrition labels and completeness of nutrient declarations on pre-packaged foods in China

BACKGROUND

The Chinese government launched a voluntary nutrition labelling code in 2007 and made it mandatory since 1 January 2013. This article aims to quantify the prevalence of nutrition labels and the completeness of nutrient declarations on pre-packaged foods in China and to explore the impact of the 2007 code.

METHODS

A systematic search of the published and grey literature was done, and a random-effects meta-analysis was used to obtain summary estimates.

RESULTS

There were 15 surveys identified from 13 reports. For 44% (95% confidence interval: 37-51%) of the 22 636 food items, the product label provided information on one or more nutrients. There was significant heterogeneity between the surveys (I(2) = 99%, P < 0.001) raising some uncertainty about the reliability of the estimate. The heterogeneity was in part explained by differences in labelling between food categories (P < 0.001) but not by changes in the prevalence of nutrition labels over time (P = 0.36).

CONCLUSIONS

Most pre-packaged foods in this survey had a nutrition label non-compliant with current Chinese nutrition labelling standards. The voluntary code launched in 2007 had limited impact on nutrition labelling. There is significant scope for the recently introduced mandatory labelling requirements to improve nutrition labelling in China.

Pre-clinical functional Magnetic Resonance Imaging Part II: The heart

One third of all deaths worldwide in 2008 were caused by cardiovascular diseases (CVD), and the incidence of CVD related deaths rises ever more. Thus, improved imaging techniques and modalities are needed for the evaluation of cardiac morphology and function. Cardiac magnetic resonance imaging (CMRI) is a minimally invasive technique that is increasingly important due to its high spatial and temporal resolution, its high soft tissue contrast and its ability of functional and quantitative imaging. It is widely accepted as the gold standard of cardiac functional analysis. In the short period of small animal MRI, remarkable progress has been achieved concerning new, fast imaging schemes as well as purpose-built equipment. Dedicated small animal scanners allow for tapping the full potential of recently developed animal models of cardiac disease. In this paper, we review state-of-the-art cardiac magnetic resonance imaging techniques and applications in small animals at ultra-high fields (UHF).

Human metabolome associates with dietary intake habits among African Americans in the atherosclerosis risk in communities study

The human metabolome is a measurable outcome of interactions among an individual's inherited genome, microbiome, and dietary intake. We explored the relationship between dietary intake and serum untargeted metabolomic profiles in a subsample of 1,977 African Americans from the Atherosclerosis Risk in Communities (ARIC) Study in 1987-1989. For each metabolite, we conducted linear regression to estimate its relationships with each food group and food category. Potential confounding factors included age, sex, body mass index (weight (kg)/height (m)(2)), energy intake, kidney function, and food groups. We used a modified Bonferroni correction to determine statistical significance. In total, 48 pairs of diet-metabolite associations were identified, including multiple novel associations. The food group "sugar-rich foods and beverages" was inversely associated with 5 metabolites in the 2-hydroxybutyrate-related subpathway and positively associated with 5 γ-glutamyl dipeptides. The hypothesized mechanism of these associations may be through oxidative stress. "Sugar-rich foods and beverages" were also inversely associated with 7 unsaturated long-chain fatty acids. These findings suggest that the contribution of a sugar-rich dietary pattern to increased cardiovascular disease risk may be partially attributed to oxidative stress and disordered lipid profiles. Metabolomics may reveal novel metabolic biomarkers of dietary intake and provide insight into biochemical pathways underlying nutritional effects on disease development.

Lower fructose intake may help protect against development of nonalcoholic fatty liver in adolescents with obesity

OBJECTIVES

Although obesity is a major risk factor for nonalcoholic fatty liver (NAFL), not all individuals with obesity develop the condition, suggesting that other factors such as diet may also contribute to NAFL development. We evaluated associations between fructose and total sugar intake and subsequent diagnosis of NAFL in adolescents with obesity and without obesity in a population-based cohort.

METHODS

Adolescents participating in the Western Australian Pregnancy Cohort (Raine) Study completed 3-day food records and body mass index measurement at age 14 years. At age 17 years, participants underwent abdominal ultrasound to determine NAFL status. Multivariable logistic regression models were used to analyse associations between energy-adjusted fructose and total sugar intake and NAFL status. Food diaries and liver assessments were completed for 592 adolescents.

RESULTS

The prevalence of NAFL at age 17 was 12.8% for the total group and 50% for adolescents with obesity. Fructose intake did not significantly differ between adolescents with or without NAFL in our cohort as a whole. Among adolescents with obesity, those without NAFL had significantly lower energy-adjusted fructose intake at age 14 years compared with those with NAFL (mean ± standard deviation [SD] 38.8 ± 19.8 g/day, vs 55.7 ± 14.4 g/day, P = 0.02). Energy-adjusted fructose intake was independently associated with NAFL in adolescents with obesity (OR [odds ratio] 1.09, 95% CI 1.01-1.19, P = 0.03) after the adjustment for confounding factors. Energy-adjusted total sugar intake showed less significance (OR 1.03, 95% CI 0.999-1.07, P = 0.06). No significant associations were observed in other body mass index categories.

CONCLUSIONS

Lower fructose consumption in adolescents with obesity at 14 years is associated with a decreased risk of NAFL at 17 years. Fructose rather than overall sugar intake may be more physiologically relevant in this association.

Biosensor analysis of natural and artificial sweeteners in intact taste epithelium

Sweeteners are commonly used as food additives in our daily life, which, however, have been causing a number of undesirable diseases since the last century. Therefore, the detection and quantification of sweeteners are of great value for food safety. In this study, we used a taste biosensor to measure and analyze different sweeteners, both natural and artificial sweeteners included. Electrophysiological activities from taste epithelium were detected by the multi-channel biosensors and analyzed with spatiotemporal methods. The longtime signal result showed different temporal-frequency properties with stimulations of individual sweeteners such as glucose, sucrose, saccharin, and cyclamate, while the multi-channel results in our study revealed the spatial expression of taste epithelium to sweet stimuli. Furthermore, in the analysis of sweetener with different concentrations, the result showed obvious dose-dependent increases in signal responses of the taste epithelium, which indicated promising applications in sweetness evaluation. Besides, the mixture experiment of two natural sweeteners with a similar functional unit (glucose and sucrose) presented two signal patterns, which turned out to be similar with responses of each individual stimulus involved. The biosensor analysis of common sweeteners provided new approaches for both natural and artificial sweeteners evaluation.

Addressing historic environmental exposures along the Alaska Highway

BACKGROUND

A World War II defense site at Northway, Alaska, was remediated in the 1990s, leaving complex questions regarding historic exposures to toxic waste. This article describes the context, methods, limitations and findings of the Northway Wild Food and Health Project (NWFHP).

OBJECTIVE

The NWFHP comprised 2 pilot studies: the Northway Wild Food Study (NWFS), which investigated contaminants in locally prioritized traditional foods over time, and the Northway Health Study (NHS), which investigated locally suspected links between resource uses and health problems.

DESIGN

This research employed mixed methods. The NWFS reviewed remedial documents and existing data. The NHS collected household information regarding resource uses and health conditions by questionnaire and interview. NHS data represent general (yes or no) personal knowledge that was often second hand. Retrospective cohort comparisons were made of the reported prevalence of 7 general health problems between groups based on their reported (yes or no) consumption of particular resources, for 3 data sets (existing, historic and combined) with a two-tailed Fisher's Exact Test in SAS (n = 325 individuals in 83 households, 24 of which no longer exist).

RESULTS

The NWFS identified historic pathways of exposure to petroleum, pesticides, herbicides, chlorinated byproducts of disinfection and lead from resources that were consumed more frequently decades ago and are not retrospectively quantifiable. The NHS found complex patterns of association between reported resource uses and cancer and thyroid-, reproductive-, metabolic- and cardiac problems.

CONCLUSION

Lack of detail regarding medical conditions, undocumented histories of exposure, time lapsed since the release of pollution and changes to health and health care over the same period make this exploratory research. Rather than demonstrate causation, these results document the legitimacy of local suspicions and warrant additional investigation. This article presents our findings, with discussion of limitations related to study design and limitations that are inherent to such research.

Sugar restriction: the evidence for a drug-free intervention to reduce cardiovascular disease risk

BACKGROUND/AIM

Uncertainty exists about what dietary component is most likely to cause coronary heart disease. Over the last thirty years, attention has focused on saturated fat and salt as guilty parties. More recently, evidence suggests that excess sugar intake is more likely than either traditional factor to lead to atherosclerotic disease. Some researchers have also speculated that sugar is addictive, in a similar manner to caffeine and established drugs of abuse.

METHODS

Here we review the epidemiological, biochemical and psychological evidence that implicates excess sugar intake as an important cause of ill-health.

RESULTS

We found relatively consistent evidence of association between markers of sugar intake and risk factors for cardiovascular disease, or the disease itself. This evidence contrasted with rather weaker evidence which linked either saturated fat or salt with cardiovascular disease endpoints. We also found some evidence of a sugar addiction syndrome.

CONCLUSION

We suggest that advice to restrict sugar intake should be a routine part of clinical care, particularly when patients are being counselled about cardiovascular risk.

Postprandial lipid responses to standard carbohydrates used to determine glycaemic index values

Prior studies assessing the metabolic effects of different types of carbohydrates have focused on their glycaemic response. However, the response of postprandial cardiometabolic risk indicators has not been considered in these studies. The present study assessed postprandial lipid responses to two forms of carbohydrates used as reference foods for glycaemic index determinations, white bread (50 g available carbohydrate) and glucose (50 g), under controlled conditions and with intra-individual replicate determinations. A total of twenty adults (20–70 years) underwent two cycles of challenges with each pair of reference foods (four challenges/person), administered in a random order on separate days under standard conditions. Serum lipids (total cholesterol, LDL-cholesterol, HDL-cholesterol, TAG and NEFA), glucose and insulin were monitored for 5 h post-ingestion. Oral glucose resulted in greater glycaemic and insulinaemic responses than white bread for the first 90 min and a greater subsequent decline after 120 min (P =0·0001). The initial decline in serum NEFA concentrations was greater after the oral glucose than after the white bread challenge, as was the rebound after 150 min (P = 0·001). Nevertheless, the type of carbohydrate had no significant effect on postprandial total cholesterol, LDL-cholesterol and HDL-cholesterol concentrations. Following an initial modest rise in TAG concentrations in response to both challenges, the values dropped below the fasting values for oral glucose but not for the white bread challenge. These data suggest that the type of carbohydrate used to determine the glycaemic index, bread or glucose, has little or modest effects on postprandial plasma cholesterol concentrations. Differences in TAG and NEFA concentrations over the 5 h time period were modest, and their clinical relevance is unclear.

Assessment of cardiac inflammation and remodeling during the development of streptozotocin-induced diabetic cardiomyopathy in vivo: a time course analysis

In this study, we examined cardiac inflammation, fibrosis and left ventricular (LV) function during the development of streptozotocin (STZ)-induced diabetic cardiomyopathy using an animal model of diabetes mellitus (DM). Diabetes was induced in 22 Sprague‑Dawley rats by an intraperitoneal single injection of STZ (70 mg/kg). Non-diabetic animals served as the controls (n=6). LV function was documented using the conductance catheter technique 2 and 6 weeks after the induction of diabetes. Cardiac tissue was analyzed for cardiac immune cell infiltration, oxidative stress and remodeling in rats with STZ-induced diabetes at 2 different time points by immunohistochemistry. Cardiac function was significantly impaired in the diabetic animals. After 2 weeks, the induction of diabetes resulted in impaired cardiac function indexed by a decrease in systolic and diastolic LV function. This impairment of LV performance continued for up to 6 weeks after the STZ injection. This was associated with an increase in cardiac CD3+ and CD8a+ immune cell invasion and fibrosis, indexed by an increase in collagen content (p<0.05). Furthermore, oxidative stress response and matrix remodeling were increased after 2 weeks and this continued for up to 6 weeks after the induction of diabetes. In conclusion, cardiac dysfunction is associated with cardiac inflammation and adverse remodeling in experimental diabetic cardiomyopathy. Our results suggest that the model of STZ-induced diabetic cardiomyopathy is a robust model for investigating cardiac immune response and LV remodeling processes under diabetic conditions.

Bitterness of the non-nutritive sweetener acesulfame potassium varies with polymorphisms in TAS2R9 and TAS2R31

Demand for nonnutritive sweeteners continues to increase due to their ability to provide desirable sweetness with minimal calories. Acesulfame potassium and saccharin are well-studied nonnutritive sweeteners commonly found in food products. Some individuals report aversive sensations from these sweeteners, such as bitter and metallic side tastes. Recent advances in molecular genetics have provided insight into the cause of perceptual differences across people. For example, common alleles for the genes TAS2R9 and TAS2R38 explain variable response to the bitter drugs ofloxacin in vitro and propylthiouracil in vivo. Here, we wanted to determine whether differences in the bitterness of acesulfame potassium could be predicted by common polymorphisms (genetic variants) in bitter taste receptor genes (TAS2Rs). We genotyped participants (n = 108) for putatively functional single nucleotide polymorphisms in 5 TAS2Rs and asked them to rate the bitterness of 25 mM acesulfame potassium on a general labeled magnitude scale. Consistent with prior reports, we found 2 single nucleotide polymorphisms in TAS2R31 were associated with acesulfame potassium bitterness. However, TAS2R9 alleles also predicted additional variation in acesulfame potassium bitterness. Conversely, single nucleotide polymorphisms in TAS2R4, TAS2R38, and near TAS2R16 were not significant predictors. Using 1 single nucleotide polymorphism each from TAS2R9 and TAS2R31, we modeled the simultaneous influence of these single nucleotide polymorphisms on acesulfame potassium bitterness; together, these 2 single nucleotide polymorphisms explained 13.4% of the variance in perceived bitterness. These data suggest multiple polymorphisms within TAS2Rs contribute to the ability to perceive the bitterness from acesulfame potassium.

Long-term hepatitis B surface antigen (HBsAg) kinetics during nucleoside/nucleotide analogue therapy: finite treatment duration unlikely

BACKGROUND & AIMS

Information regarding long-term HBsAg kinetics during treatment with nucleoside/nucleotide analogues is limited. The aim of the present study was to assess whether finite nucleoside/nucleotide analogue treatment duration could be envisaged during the patient's lifetime.

METHODS

Patients with chronic hepatitis B receiving different schedules of nucleoside/nucleotide analogues were followed for a median duration of 102 months, i.e., 8.5 years (interquartile range: 88-119 months). Long-term HBV DNA and HBsAg level kinetics were modeled in order to estimate time to clear HBsAg during therapy in patients with undetectable HBV DNA.

RESULTS

Antiviral therapy was associated with a slow but consistent reduction in the level of HBsAg in most of the patients. Three patterns of HBsAg level declines were identified: decline during both the detectable and undetectable HBV DNA phases; decline during the HBV DNA detectable period only; decline during the HBV DNA undetectable period only. The mean HBsAg titer at the time when HBV DNA became undetectable was 3.29 ± 0.49 Log₁₀ international units (IU)/ml, and the mean slope was -0.007 ± 0.007 Log₁₀ IU/month, i.e., an average decline of 0.084 Log₁₀ IU/year. The corresponding calculated median number of years needed to clear HBsAg was 52.2 years (interquartile range: 30.8-142.7).

CONCLUSIONS

This study, based on the very long-term follow-up of patients with chronic hepatitis B treated with potent nucleoside/nucleotide analogues, shows that HBsAg clearance is unlikely to occur during the patient's lifetime, even if HBV replication is well controlled. Thus, lifetime therapy is required in the vast majority of HBV-infected patients.

Human psychometric and taste receptor responses to steviol glycosides

Steviol glycosides, the sweet principle of Stevia Rebaudiana (Bertoni) Bertoni, have recently been approved as a food additive in the EU. The herbal non-nutritive high-potency sweeteners perfectly meet the rising consumer demand for natural food ingredients in Europe. We have characterized the organoleptic properties of the most common steviol glycosides by an experimental approach combining human sensory studies and cell-based functional taste receptor expression assays. On the basis of their potency to elicit sweet and bitter taste sensations, we identified glycone chain length, pyranose substitution, and the C16 double bond as the structural features giving distinction to the gustatory profile of steviol glycosides. A comprehensive screening of 25 human bitter taste receptors revealed that two receptors, hTAS2R4 and hTAS2R14, mediate the bitter off-taste of steviol glycosides. For some test substances, e.g., stevioside, we observed a decline in sweet intensity at supra-maximum concentrations. This effect did not arise from allosteric modulation of the hTAS1R2/R3 sweet taste receptor but might be explained by intramolecular cross-modal suppression between the sweet and bitter taste component of steviol glycosides. These results might contribute to the production of preferentially sweet and least bitter tasting Stevia extracts by an optimization of breeding and postharvest downstream processing.

How can diet influence the risk of stroke?

Cerebrovascular diseases are the second cause of mortality in the world, and hypertension is considered a main risk factor for occurrence of stroke. The mechanisms responsible for the increased stroke risk remain unclear. However, dietary interventions have been applied in the management and treatment of their risk factors, which include increased blood pressure levels, obesity, diabetes, and dyslipidemia. Further studies should be conducted to assess the effects of carotenoids, flavonoids, n-3 polyunsaturated fats, and lower salt and high glycemic index intake in risk of stroke.

Postprandial impairment of flow-mediated dilation and elevated methylglyoxal after simple but not complex carbohydrate consumption in dogs

Hyperglycemia produces oxidative stress, which may impair endothelial function. Methylglyoxal, a reactive intermediate metabolite of glucose, is known to cause oxidative stress and is produced when excess carbohydrate is consumed in diabetic patients, but postprandial responses in healthy patients are unknown. We hypothesize that methylglyoxal levels will cause impaired endothelial function via increased oxidative stress after consuming a high glycemic index meal in healthy animals. Normal-weight laboratory beagles (n = 6) were used in a crossover study that tested postprandial responses of 4 complex carbohydrate sources (barley, corn, peas, rice) vs a simple carbohydrate (glucose). Blood samples were taken prefeeding and at timed intervals after feeding to measure serum glucose, insulin, nitrotyrosine, and methylglyoxal. Flow-mediated dilation (FMD), cardiac function (echocardiography), and blood pressure measurements were determined before and 60 minutes after feeding. The mean (±SEM) glycemic indices of the complex carbohydrate sources were 29 ± 5 for peas, 47 ± 10 for corn, 51 ± 7 for barley, and 55 ± 6 for rice. Postprandial FMD was lowest in the glucose group and significantly different from both the corn group and the FMD value for all complex carbohydrates combined. Methylglyoxal was significantly elevated at 60 minutes postprandial after glucose compared with the other carbohydrate sources. No significant effects of carbohydrate source were observed for blood pressure, nitrotyrosine, or echocardiographic variables. The novel finding of this study was that methylglyoxal levels increased after a single feeding of simple carbohydrate and may be linked to the observed postprandial decrease in endothelial function. Thus, consuming low-glycemic-index foods may protect the cardiovascular system by reducing oxidative stress.

Carbohydrates for Physical Activity

Intake of carbohydrates above the dietary guidelines to support performance of physical activity is common but may be unnecessary and counterproductive. Sports nutrition guidelines have not been designed to incorporate characteristics that may make high carbohydrate consumption a source of metabolic stress that may increase oxidative stress, inflammation, and lipogenesis. This metabolic stress is linked to the physiology underlying the development of insulin resistance, type 2 diabetes mellitus, and cardiovascular diseases. This review describes research-based evidence to aid in bridging the gap between dietary guidelines for overall health and those to support physical activity. Characteristics that increase the likelihood of metabolic stress resulting from carbohydrate intake include overweight and obesity, central/visceral adiposity, older age, sedentary lifestyle, and caloric state. Carbohydrate-based foods that provide the most health benefits are whole grains, beans and legumes, fruits, and vegetables. Carbohydrate-based foods that most readily elicit metabolic stress are those with added sugars and refined grains or that have a high glycemic index. A checklist that incorporates both the number of these characteristics and prevailing guidelines for nutrition and physical activity is presented. This may be useful in determining whether additional carbohydrates are needed to support the physical activity level of the individual.

Hepatic oxidative stress in fructose-induced fatty liver is not caused by sulfur amino acid insufficiency

Fructose-sweetened liquid consumption is associated with fatty liver and oxidative stress. In rodent models of fructose-mediated fatty liver, protein consumption is decreased. Additionally, decreased sulfur amino acid intake is known to cause oxidative stress. Studies were designed to test whether oxidative stress in fructose-sweetened liquid-induced fatty liver is caused by decreased ad libitum solid food intake with associated inadequate sulfur amino acid intake. C57BL6 mice were grouped as: control (ad libitum water), fructose (ad libitum 30% fructose-sweetened liquid), glucose (ad libitum 30% glucose-sweetened water) and pair-fed (ad libitum water and sulfur amino acid intake same as the fructose group). Hepatic and plasma thiol-disulfide antioxidant status were analyzed after five weeks. Fructose- and glucose-fed mice developed fatty liver. The mitochondrial antioxidant protein, thioredoxin-2, displayed decreased abundance in the liver of fructose and glucose-fed mice compared to controls. Glutathione/glutathione disulfide redox potential (E(h)GSSG) and abundance of the cytoplasmic antioxidant protein, peroxiredoxin-2, were similar among groups. We conclude that both fructose and glucose-sweetened liquid consumption results in fatty liver and upregulated thioredoxin-2 expression, consistent with mitochondrial oxidative stress; however, inadequate sulfur amino acid intake was not the cause of this oxidative stress.

Economic instruments for obesity prevention: results of a scoping review and modified Delphi survey

BACKGROUND

Comprehensive, multi-level approaches are required to address obesity. One important target for intervention is the economic domain. The purpose of this study was to synthesize existing evidence regarding the impact of economic policies targeting obesity and its causal behaviours (diet, physical activity), and to make specific recommendations for the Canadian context.

METHODS

Arksey and O'Malley's (2005) methodological framework for conducting scoping reviews was adopted for this study and this consisted of two phases: 1) a structured literature search and review, and 2) consultation with experts in the research field through a Delphi survey and an in-person expert panel meeting in April 2010.

RESULTS

Two key findings from the scoping review included 1) consistent evidence that weight outcomes are responsive to food and beverage prices. The debate on the use of food taxes and subsidies to address obesity should now shift to how best to address practical issues in designing such policies; and 2) very few studies have examined the impact of economic instruments to promote physical activity and clear policy recommendations cannot be made at this time. Delphi survey findings emphasised the relatively modest impact any specific economic instrument would have on obesity independently. Based on empirical evidence and expert opinion, three recommendations were supported. First, to create and implement an effective health filter to review new and current agricultural polices to reduce the possibility that such policies have a deleterious impact on population rates of obesity. Second, to implement a caloric sweetened beverage tax. Third, to examine how to implement fruit and vegetable subsidies targeted at children and low income households.

CONCLUSIONS

In terms of economic interventions, shifting from empirical evidence to policy recommendation remains challenging. Overall, the evidence is not sufficiently strong to provide clear policy direction. Additionally, the nature of the experiments needed to provide definitive evidence supporting certain policy directions is likely to be complex and potentially unfeasible. However, these are not reasons to take no action. It is likely that policies need to be implemented in the face of an incomplete evidence base.

Sugarcane (Saccharum X officinarum): A Reference Study for the Regulation of Genetically Modified Cultivars in Brazil

Global interest in sugarcane has increased significantly in recent years due to its economic impact on sustainable energy production. Sugarcane breeding and better agronomic practices have contributed to a huge increase in sugarcane yield in the last 30 years. Additional increases in sugarcane yield are expected to result from the use of biotechnology tools in the near future. Genetically modified (GM) sugarcane that incorporates genes to increase resistance to biotic and abiotic stresses could play a major role in achieving this goal. However, to bring GM sugarcane to the market, it is necessary to follow a regulatory process that will evaluate the environmental and health impacts of this crop. The regulatory review process is usually accomplished through a comparison of the biology and composition of the GM cultivar and a non-GM counterpart. This review intends to provide information on non-GM sugarcane biology, genetics, breeding, agronomic management, processing, products and byproducts, as well as the current technologies used to develop GM sugarcane, with the aim of assisting regulators in the decision-making process regarding the commercial release of GM sugarcane cultivars.

Effect of conjugated linoleic acid (CLA) on lipid profile and liver histology in laboratory rats fed high-fructose diet

The objective of the study was to assess the effect of CLA on serum lipid profile, plasma malondialdehyde and liver histology in Wistar rats fed high-fructose diet. Eighteen rats were randomly assigned to three experimental groups and fed for the next 21 days. The experimental diets were: I, Control; II, Fructose (63.2% of fructose); and III, CLA+Fructose (1% CLA and 63.2% of fructose). The experimental treatments had no effect on body weight of the rats. The LDL+VLDL cholesterol, TG and liver weight were significantly increased in animals fed Fructose. MDA concentrations were significantly increased in rats fed Fructose diet but CLA+Fructose diet had no effect on this marker. In the same line, the histological examination of the livers showed a series of morphological alterations, notably hepatic steatosis in animals fed high-fructose diet. No signs of the steatosis in rats fed CLA+Fructose diet were observed. In conclusion, CLA in high-fructose diet, decreases serum LDL+VLDL and TG and plasma MDA concentrations as well as liver weight and liver cholesterol, thus opposing the effects of high-fructose diet and showing a potential antiatherogenic effect. Similarly, dietary CLA fed at 1% level (w/w) in high-fructose diet, prevented steatosis observed histologically in livers of rats fed high-fructose diets.

Opposing effects of dietary sugar and saturated fat on cardiovascular risk factors and glucose metabolism in mitochondrially impaired mice

PURPOSE

Both dietary fat and dietary sucrose are major components of Western diets that may differentially affect the risk for body mass gain, diabetes mellitus, and cardiovascular disease.

METHODS

We have phenotypically analyzed mice with ubiquitously impaired expression of mitochondrial frataxin protein that were challenged with diets differing in macronutrient content, namely high-sucrose/low-fat and high-saturated fat/low-sugar diets.

RESULTS

We find here that a high-sucrose/low-fat diet has especially detrimental effects in mice with impaired mitochondrial metabolism promoting several independent cardiovascular risk factors, including impaired glucose metabolism, fasting hyperinsulinemia, reduced glucose-stimulated insulin secretion, increased serum triglycerides, and elevated cholesterol levels due to increased expression of HMG-CoA reductase. In contrast, a high-saturated fat/low-sugar diet protects mice with impaired mitochondrial metabolism from diet-induced obesity by increasing total energy expenditure and increasing expression of ACAA2, a rate-limiting enzyme of mitochondrial beta-oxidation, whereas no concomitant improvement of glucose metabolism was observed.

CONCLUSIONS

Taken together, our results suggest that mitochondrial dysfunction may cause sucrose to become a multifunctional cardiovascular risk factor, whereas low-sugar diets high in saturated fat may prevent weight gain without improving glucose metabolism.

The neurokinin 1 receptor antagonist, ezlopitant, reduces appetitive responding for sucrose and ethanol

BACKGROUND

The current obesity epidemic is thought to be partly driven by over-consumption of sugar-sweetened diets and soft drinks. Loss-of-control over eating and addiction to drugs of abuse share overlapping brain mechanisms including changes in motivational drive, such that stimuli that are often no longer 'liked' are still intensely 'wanted' [7], . The neurokinin 1 (NK1) receptor system has been implicated in both learned appetitive behaviors and addiction to alcohol and opioids; however, its role in natural reward seeking remains unknown.

METHODOLOGY/PRINCIPAL FINDINGS

We sought to determine whether the NK1-receptor system plays a role in the reinforcing properties of sucrose using a novel selective and clinically safe NK1-receptor antagonist, ezlopitant (CJ-11,974), in three animal models of sucrose consumption and seeking. Furthermore, we compared the effect of ezlopitant on ethanol consumption and seeking in rodents. The NK1-receptor antagonist, ezlopitant decreased appetitive responding for sucrose more potently than for ethanol using an operant self-administration protocol without affecting general locomotor activity. To further evaluate the selectivity of the NK1-receptor antagonist in decreasing consumption of sweetened solutions, we compared the effects of ezlopitant on water, saccharin-, and sodium chloride (NaCl) solution consumption. Ezlopitant decreased intake of saccharin but had no effect on water or salty solution consumption.

CONCLUSIONS/SIGNIFICANCE

The present study indicates that the NK1-receptor may be a part of a common pathway regulating the self-administration, motivational and reinforcing aspects of sweetened solutions, regardless of caloric value, and those of substances of abuse. Additionally, these results indicate that the NK1-receptor system may serve as a therapeutic target for obesity induced by over-consumption of natural reinforcers.

Soft drinks consumption and nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is a common clinical condition which is associated with metabolic syndrome in 70% of cases. Inappropriate dietary fat intake, excessive intake of soft drinks, insulin resistance and increased oxidative stress combine to increase free fatty acid delivery to the liver, and increased hepatic triglyceride accumulation contributes to fatty liver. Regular soft drinks have high fructose corn syrup which contains basic sugar building blocks, fructose 55% and glucose 45%. Soft drinks are the leading source of added sugar worldwide, and have been linked to obesity, diabetes, and metabolic syndrome. The consumption of soft drinks can increase the prevalence of NAFLD independently of metabolic syndrome. During regular soft drinks consumption, fat accumulates in the liver by the primary effect of fructose which increases lipogenesis, and in the case of diet soft drinks, by the additional contribution of aspartame sweetener and caramel colorant which are rich in advanced glycation end products that potentially increase insulin resistance and inflammation. This review emphasizes some hard facts about soft drinks, reviews fructose metabolism, and explains how fructose contributes to the development of obesity, diabetes, metabolic syndrome, and NAFLD.

Storing empty calories and chronic disease risk: snack-food products, nutritive content, and manufacturers in Philadelphia corner stores

Corner stores are part of the urban food environment that may contribute to obesity and diet-related diseases, particularly for low-income and minority children. The snack foods available in corner stores may be a particularly important aspect of an urban child's food environment. Unfortunately, there is little data on exactly what snack foods corner stores stock, or where these foods come from. We evaluated snack foods in 17 Philadelphia corner stores, located in three ethnically distinct, low-income school neighborhoods. We recorded the manufacturer, calories, fat, sugar, and sodium for all snack items, excluding candy and prepared foods. We then compared the nutritive content of assessed snack items to established dietary recommendations and a school nutrition standard. In total, stores stocked 452 kinds of snacks, with only 15% of items common between all three neighborhoods. Total and unique snacks and snack food manufacturers varied by neighborhood, but distributions in snack type varied negligibly: overall, there were no fruit snacks, no vegetable snacks, and only 3.6% of all snacks (by liberal definition) were whole grain. The remainder (96.4% of snacks) was highly processed foods. Five of 65 manufacturers supplied 73.4% of all kinds of snack foods. Depending on serving size definition, 80.0-91.5% of snack foods were "unhealthy" (by the school nutrition standard), including seven of 11 wholegrain products. A single snack item could supply 6-14% of a day's recommended calories, fat, sugar, and sodium on average (or 56-169% at the extreme) for a "typical" child. We conclude that corner store snack food inventories are almost entirely unhealthful, and we discuss possible implications and next steps for research and intervention.

Carbohydrate intake and cardiometabolic risk factors in high BMI African American children

The aim of this study was to evaluate the relationship between intakes of subgroups of energy-providing carbohydrate, and markers of cardiometabolic risk factors in high BMI African American (AA) children.

A cross sectional analysis was performed on data from a sample of 9-11 year old children (n = 95) with BMI greater than the 85^th percentile. Fasting hematological and biochemical values for selected markers of cardiometabolic risk factors were related to intakes of carbohydrates and sugars.

After adjusting for gender, pubertal stage and waist circumference, multivariate regression analysis showed that higher intakes of carbohydrate (with fat and protein held constant) were associated with higher plasma concentrations of triglycerides (TG), VLDL-C, IDL-C, and worse insulin resistance (homeostasis model assessment of insulin resistance, HOMA-IR). After dividing carbohydrate into non-sugar versus sugar fractions, sugars were significantly related to higher TG, VLDL-C, IDL-C, lower adipocyte fatty acid insulin sensitivity (ISI-FFA), and was closely associated with increased HOMA-IR. Similar trends were observed for sugars classified as added sugars, and for sugars included in beverages. Further dividing sugar according to the food group from which it was consumed showed that consuming more sugar from the candy/soda food group was highly significantly associated with increased TG, VLDL-C, IDL-C and closely associated with increased HOMA-IR. Sugars consumed in all fruit-containing foods were significantly associated with lower ISI-FFA. Sugars consumed as fruit beverages was significantly associated with VLDL-C, IDL-C and ISI-FFA whereas sugars consumed as fresh, dried and preserved fruits did not show significant associations with these markers.

Sugars consumed from in all dairy foods were significantly associated with higher TG, VLDL-C and IDL-C, and with significantly lower HDL-C and ISI-FFA. These effects were associated with sugars consumed in sweetened dairy products, but not with sugars consumed in unsweetened dairy products. This analysis suggests that increases in carbohydrate energy, especially in the form of sugar, may be detrimental to cardiometabolic health in high BMI children.

Carbohydrate intake, serum lipids and apolipoprotein E phenotype show association in children

AIM

To study the association between carbohydrate intake and serum lipids in children, and influence of apolipoprotein E phenotype (apoE) on the association.

SUBJECTS/METHODS

A total of 644 children from a prospective, randomized atherosclerosis prevention trial (STRIP) participated in this longitudinal study at age 5 (n = 644), 7 (n = 585) and 9 (n = 550) years. ApoE phenotype, fasting triglyceride, total, low-density lipoprotein (LDL) and high-density lipoprotein (HDL) cholesterol concentrations and 4-day food records were analysed.

RESULTS

An increase in the total carbohydrate intake by 1 E% (percentage of total daily energy intake) associated with a decrease in HDL cholesterol by 0.006 mmol/L (p < 0.001) when adjusted for saturated, monounsaturated and polyunsaturated fatty acid, age, gender, body mass index and STRIP study group. The inverse association between total carbohydrate intake and HDL cholesterol was evident in children with apoE3 (p < 0.001) or apoE4 (p < 0.001), but not in those with apoE2 (p = 0.78). An increase in total carbohydrate intake by 1 E% increased triglycerides by 0.02 mmol/L (p < 0.001) independently of apoE phenotype, while 1 E% increase in sucrose intake increased triglycerides by 0.01 mmol/L (p < 0.001).

CONCLUSION

Carbohydrate intake has a relatively small effect on serum lipids in children. Children with the apoE3 or E4 but not with E2 phenotype show reduction in HDL cholesterol with increasing carbohydrate intake indicating that genetic and environmental factors interact with children's lipoprotein metabolism.

Dietary sugars intake and cardiovascular health: a scientific statement from the American Heart Association

High intakes of dietary sugars in the setting of a worldwide pandemic of obesity and cardiovascular disease have heightened concerns about the adverse effects of excessive consumption of sugars. In 2001 to 2004, the usual intake of added sugars for Americans was 22.2 teaspoons per day (355 calories per day). Between 1970 and 2005, average annual availability of sugars/added sugars increased by 19%, which added 76 calories to Americans' average daily energy intake. Soft drinks and other sugar-sweetened beverages are the primary source of added sugars in Americans' diets. Excessive consumption of sugars has been linked with several metabolic abnormalities and adverse health conditions, as well as shortfalls of essential nutrients. Although trial data are limited, evidence from observational studies indicates that a higher intake of soft drinks is associated with greater energy intake, higher body weight, and lower intake of essential nutrients. National survey data also indicate that excessive consumption of added sugars is contributing to overconsumption of discretionary calories by Americans. On the basis of the 2005 US Dietary Guidelines, intake of added sugars greatly exceeds discretionary calorie allowances, regardless of energy needs. In view of these considerations, the American Heart Association recommends reductions in the intake of added sugars. A prudent upper limit of intake is half of the discretionary calorie allowance, which for most American women is no more than 100 calories per day and for most American men is no more than 150 calories per day from added sugars.

Insinuation of exacerbated oxidative stress in sucrose-fed rats with a low dietary intake of magnesium: Evidence of oxidative damage to proteins

High sucrose diets and low magnesium intake have been independently implicated in induction of oxidative stress in animal models. The aim of this study was to investigate whether low dietary magnesium intake exacerbates the prooxidant effects of high sucrose feeding. Rats were fed control (C), high sucrose (HS); low magnesium (LM) and high sucrose low magnesium (HSLM) diets for 90 days and oxidative stress evaluated in terms of formation of TBARS, advanced oxidation protein products and protein carbonyls. HS and LM rats showed evidence of lipid peroxidation and protein oxidation in plasma and liver. Enhanced oxidative injury to lipids and proteins after HSLM feeding was indicated by increased carbonyl content (p <0.01) and significantly (p <0.005) higher levels of TBARS in plasma and hepatic tissue relative to both HS and LM groups. Altogether, these results illustrate the potential detrimental and cumulative effects of low magnesium intake combined with high sucrose consumption on oxidative stress variables.

Dietary fructose and glucose differentially affect lipid and glucose homeostasis

Absorbed glucose and fructose differ in that glucose largely escapes first-pass removal by the liver, whereas fructose does not, resulting in different metabolic effects of these 2 monosaccharides. In short-term controlled feeding studies, dietary fructose significantly increases postprandial triglyceride (TG) levels and has little effect on serum glucose concentrations, whereas dietary glucose has the opposite effects. When dietary glucose and fructose have been directly compared at approximately 20-25% of energy over a 4- to 6-wk period, dietary fructose caused significant increases in fasting TG and LDL cholesterol concentrations, whereas dietary glucose did not, but dietary glucose did increase serum glucose and insulin concentrations in the postprandial state whereas dietary fructose did not. When fructose at 30-60 g ( approximately 4-12% of energy) was added to the diet in the free-living state, there were no significant effects on lipid or glucose biomarkers. Sucrose and high-fructose corn syrup (HFCS) contain approximately equal amounts of fructose and glucose and no metabolic differences between them have been noted. Controlled feeding studies at more physiologic dietary intakes of fructose and glucose need to be conducted. In our view, to decrease the current high prevalence of obesity, dyslipidemia, insulin resistance, and diabetes, the focus should be on restricting the intake of excess energy, sucrose, HFCS, and animal and trans fats and increasing exercise and the intake of vegetables, vegetable oils, fish, fruit, whole grains, and fiber.

Hypothesis: could excessive fructose intake and uric acid cause type 2 diabetes?

We propose that excessive fructose intake (>50 g/d) may be one of the underlying etiologies of metabolic syndrome and type 2 diabetes. The primary sources of fructose are sugar (sucrose) and high fructose corn syrup. First, fructose intake correlates closely with the rate of diabetes worldwide. Second, unlike other sugars, the ingestion of excessive fructose induces features of metabolic syndrome in both laboratory animals and humans. Third, fructose appears to mediate the metabolic syndrome in part by raising uric acid, and there are now extensive experimental and clinical data supporting uric acid in the pathogenesis of metabolic syndrome. Fourth, environmental and genetic considerations provide a potential explanation of why certain groups might be more susceptible to developing diabetes. Finally, we discuss the counterarguments associated with the hypothesis and a potential explanation for these findings. If diabetes might result from excessive intake of fructose, then simple public health measures could have a major impact on improving the overall health of our populace.

Body mass index and nutritional intake in patients with HIV and chronic diarrhea: a secondary analysis

PURPOSE

The purpose of this study was to examine the differences in nutritional intake and body mass index (BMI) in HIV patients with chronic diarrhea via secondary analysis of patients' nutritional diaries. A secondary purpose was to evaluate the quality of diets against national dietary guidelines.

DATA SOURCES

Seventy-five ambulatory patients with HIV were included in this study. Patients were categorized using baseline BMI as normal weight (BMI 18.5-24.9 kg/m2), overweight (BMI 25.0-29.9 kg/m2), and obese (BMI >or=30.0 kg/m2). Seven-day nutritional diaries were used to estimate diet in terms of dietary fats, cholesterol, fiber, protein, and sugar. A one-way analysis of variance was conducted to evaluate the relationship between BMI and mean nutritional intake from fat, saturated fat, polyunsaturated fat, monounsaturated fat, cholesterol, fiber, and sugar.

CONCLUSIONS

39.7% and 13.3% of participants were overweight and obese, respectively. The mean intake of fat, saturated fat, and cholesterol was higher than the recommended levels by the National Cholesterol Education Program (NCEP), while the mean intake of monounsaturated fat, polyunsaturated fat, and fiber was below the NCEP guideline. Although the results were not statistically different between groups, grams of fiber intake were lowest for individuals with BMI >or=30.0 kg/m2.

IMPLICATIONS FOR PRACTICE

Advanced practice nurses should encourage increased physical activity and healthy diets at each visit for individuals living with HIV. The continued use of nutritional supplements to boost weight should also be reviewed at each visit to prevent the consumption of unnecessary calories.

The role of p66Shc deletion in age-associated arterial dysfunction and disease states

Accumulation of oxidative stress with age is hypothesized to be the primary causative mediator of age-associated diseases. Among different tissues, aging vessels are known to accumulate oxidative damage and undergo functional impairment. Oxidative stress affects the availability and/or balance of key regulators of vascular homeostasis and favors the development of cardiovascular disease. Reactive oxygen species are generated by different intracellular molecular pathways principally located in the cytoplasm and in the mitochondria. The mitochondrial enzyme p66Shc is an adaptor protein and plays an important role as a redox enzyme implicated in mitochondrial eactive oxygen species generation and translation of oxidative signals into apoptosis. Mice lacking p66Shc−/− gene display reduced production of intracellular oxidants and a 30% prolonged life span. For this reasons, a series of studies conceived to elucidate the function of p66Shc and its possible implication in age-associated cardiovascular diseases have been carried out. Indeed, p66Shc−/− mice have been shown to be protected from age-dependent endothelial dysfunction as well as age-related risk factors such as diabetes and hypercholesterolemia. This review focuses on delineating the role of the p66Shc adaptor protein and its potential implication in the pathophysiology of aging and age-related cardiovascular disease.

Presence of metabolic syndrome in football linemen

CONTEXT

Metabolic syndrome is a clustering of symptoms associated with abdominal obesity that demonstrates a high risk for cardiovascular disease and type II diabetes mellitus.

OBJECTIVE

To evaluate football linemen in National Collegiate Athletic Association Divisions I, II, and III schools for the presence of metabolic syndrome according to the American Heart Association/National Heart, Lung, and Blood Institute criteria as well as to document other related biomarkers.

DESIGN

Cross-sectional descriptive study.

SETTING

Three university locations on the first full day of football camp in early morning.

PATIENTS OR OTHER PARTICIPANTS

Of 76 football linemen, 70 were able to provide blood samples.

MAIN OUTCOME MEASURE(S)

Height, mass, blood pressure, upper-body skinfolds, and waist circumference were measured at various stations. Two small venous samples of blood were collected and analyzed in a hospital laboratory for fasting insulin, glucose, high-density lipoprotein, total cholesterol, triglycerides, C-reactive protein, and glycosylated hemoglobin. The last station was a verbal family history for cardiovascular disease and diabetes; also, athletes filled out a nutrition attitudes questionnaire.

RESULTS

Of the 70 athletes, 34 were identified as having metabolic syndrome according to measures of blood pressure, waist circumference, fasting glucose, high-density lipoprotein, and triglycerides. The mean total cholesterol-to-high-density lipoprotein cholesterol ratio for the group was 4.95, with 32 participants displaying values higher than 5.0. Twelve volunteers had total cholesterol levels greater than 200 mmol/L, 15 had high levels of C-reactive protein, and 9 had slightly elevated levels of glycosylated hemoglobin.

CONCLUSIONS

Although athletes might be assumed to be protected from risks of cardiovascular disease, we found a high incidence of metabolic syndrome and other associated adverse biomarkers for heart disease in collegiate football linemen. Early screening, awareness, and intervention may have favorable effects on the overall health outcomes of football linemen.

Fructose consumption as a risk factor for non-alcoholic fatty liver disease

BACKGROUND/AIMS

While the rise in non-alcoholic fatty liver disease (NAFLD) parallels the increase in obesity and diabetes, a significant increase in dietary fructose consumption in industrialized countries has also occurred. The increased consumption of high fructose corn syrup, primarily in the form of soft drinks, is linked with complications of the insulin resistance syndrome. Furthermore, the hepatic metabolism of fructose favors de novo lipogenesis and ATP depletion. We hypothesize that increased fructose consumption contributes to the development of NAFLD.

METHODS

A dietary history and paired serum and liver tissue were obtained from patients with evidence of biopsy-proven NAFLD (n=49) without cirrhosis and controls (n=24) matched for gender, age (+/-5 years), and body mass index (+/-3 points).

RESULTS

Consumption of fructose in patients with NAFLD was nearly 2- to 3-fold higher than controls [365 kcal vs 170 kcal (p<0.05)]. In patients with NAFLD (n=6), hepatic mRNA expression of fructokinase (KHK), an important enzyme for fructose metabolism, and fatty acid synthase, an important enzyme for lipogenesis were increased (p=0.04 and p=0.02, respectively). In an AML hepatocyte cell line, fructose resulted in dose-dependent increase in KHK protein and activity.

CONCLUSIONS

The pathogenic mechanism underlying the development of NAFLD may be associated with excessive dietary fructose consumption.

Fructose consumption as a risk factor for non-alcoholic fatty liver disease

BACKGROUND/AIMS

While the rise in non-alcoholic fatty liver disease (NAFLD) parallels the increase in obesity and diabetes, a significant increase in dietary fructose consumption in industrialized countries has also occurred. The increased consumption of high fructose corn syrup, primarily in the form of soft drinks, is linked with complications of the insulin resistance syndrome. Furthermore, the hepatic metabolism of fructose favors de novo lipogenesis and ATP depletion. We hypothesize that increased fructose consumption contributes to the development of NAFLD.

METHODS

A dietary history and paired serum and liver tissue were obtained from patients with evidence of biopsy-proven NAFLD (n=49) without cirrhosis and controls (n=24) matched for gender, age (+/-5 years), and body mass index (+/-3 points).

RESULTS

Consumption of fructose in patients with NAFLD was nearly 2- to 3-fold higher than controls [365 kcal vs 170 kcal (p<0.05)]. In patients with NAFLD (n=6), hepatic mRNA expression of fructokinase (KHK), an important enzyme for fructose metabolism, and fatty acid synthase, an important enzyme for lipogenesis were increased (p=0.04 and p=0.02, respectively). In an AML hepatocyte cell line, fructose resulted in dose-dependent increase in KHK protein and activity.

CONCLUSIONS

The pathogenic mechanism underlying the development of NAFLD may be associated with excessive dietary fructose consumption.

Final common molecular pathways of aging and cardiovascular disease: role of the p66Shc protein

Oxidative stress affects the availability of key-regulators of vascular homeostasis and controls a number of signaling pathways relevant to myocardial and vascular disease. Reactive oxygen species are generated by different intracellular molecular pathways principally located in mitochondria. The notion that mice carrying a targeted mutation of the p66(Shc) gene display prolonged lifespan, reduced production of intracellular oxidants, and increased resistance to oxidative stress-induced apoptosis prompted a series of studies aimed at defining the biochemical function of p66(Shc) and its possible implication in cardiovascular diseases. Indeed, p66(Shc-/-) mice are protected against vascular, cardiac, and renal impairment attributable to hypercholesterolemia, aging, diabetes, and ischemia/reperfusion. The present review focuses on the biochemical and physiological function of the p66(Shc) adaptor protein as well as on the mechanisms linking p66(Shc)-associated generation of free radicals to the pathophysiology of aging and cardiovascular disease. On the whole, the evidence so far reported and here discussed supports the concept that pharmacological modulation of p66(Shc) expression and activity may be a novel and effective target for the treatment of atherosclerotic vascular disease as well as myocardial adaptation to hypertrophic, inflammatory and neuro-hormonal stimuli in the overloaded heart.

Comparison of monounsaturated fat with carbohydrates as a replacement for saturated fat in subjects with a high metabolic risk profile: studies in the fasting and postprandial states

BACKGROUND

In subjects with a high prevalence of metabolic risk abnormalities, the preferred replacement for saturated fat is unresolved.

OBJECTIVE

The objective was to study whether carbohydrate or monounsaturated fat is a preferred replacement for saturated fat.

DESIGN

Fifty-two men and 33 women, selected to have any combination of HDL cholesterol < or = 30th percentile, triacylglycerol > or = 70th percentile, or insulin > or = 70th percentile, were enrolled in a 3-period, 7-wk randomized crossover study. The subjects consumed an average American diet (AAD; 36% of energy from fat) and 2 additional diets in which 7% of energy from saturated fat was replaced with either carbohydrate (CHO diet) or monounsaturated fatty acids (MUFA diet).

RESULTS

Relative to the AAD, LDL cholesterol was lower with both the CHO (-7.0%) and MUFA (-6.3%) diets, whereas the difference in HDL cholesterol was smaller during the MUFA diet (-4.3%) than during the CHO diet (-7.2%). Plasma triacylglycerols tended to be lower with the MUFA diet, but were significantly higher with the CHO diet. Although dietary lipid responses varied on the basis of baseline lipid profiles, the response to diet did not differ between subjects with or without the metabolic syndrome or with or without insulin resistance. Postprandial triacylglycerol concentrations did not differ significantly between the diets. Lipoprotein(a) concentrations increased with both the CHO (20%) and MUFA (11%) diets relative to the AAD.

CONCLUSIONS

In the study population, who were at increased risk of coronary artery disease, MUFA provided a greater reduction in risk as a replacement for saturated fat than did carbohydrate.