Carbohydrate, Memory, and Mood

From a physiologic perspective, the role of glucose in brain functioning is reviewed and the effect of diet-induced changes in blood glucose on mood and cognition are outlined. Many studies have used a glucose drink or a meal composed almost entirely of carbohydrate as an experimental tool. Because pure sources of carbohydrate will be rarely consumed, the possibility that foods of different glycemic indices will modify mood and memory is briefly considered.     

Glycemic Carbohydrate: An International Perspective

Attention to the different types of carbohydrates and their role in health and disease is relatively recent. FAO and WHO jointly published a report on carbohydrates in human nutrition in 1998, with a number of recommendations about increasing carbohydrate intake as a sound approach to the prevention of obesity. The glycemic index (GI) was recommended as a means of classifying foods on the basis of their potential for raising blood glucose; this concept was based on the understanding that the state of hyperglycemia that is observed following the intake of certain high-GI carbohydrate foods could constitute a risk factor for diseases of lifestyle.     

Glycemic Carbohydrate and Body Weight Regulation

The purpose of this review is to examine the relationship between glycemic carbohydrate and its effect on body weight regulation. By contrast to fat, carbohydrate has a positive impact on energy intake, energy expenditure, and body weight control. Despite some debate about the role of the carbohydrate-to-fat ratio in the diet and the prevalence of obesity, metabolic studies show that diets high in fat are more likely to result in body weight gain than diets high in carbohydrate. So far there are no indications that carbohydrate classes differ greatly with respect to energy expenditure and energy balance. However, the impact of carbohydrate source and class, as well as the form in which carbohydrate is consumed (i.e., solid or liquid) on body weight control requires further consideration.     

Dietary Carbohydrate, Glucose Regulation, and Cognitive Performance in Elderly Persons

Chronic intake patterns during the adult years and the acute ingestion of meals or foods influence cognitive performance in seniors. Many chronic diseases, including type 2 diabetes mellitus, cardiovascular disease, and hypertension, which are risk factors for cognitive impairment and/or dementia, share the same dietary risk factors as those for cognitive impairment. Conversely, acute macronutrient and/or food consumption improves performance on cognitive tasks. While consumption of all macronutrients enhances cognitive performance, the benefits of carbohydrate intake appear more sustained in comparison to fat and protein.     

Glycemic Carbohydrate and Health: Background and Synopsis of the Symposium

Carbohydrates are global foodstuffs and important energy sources. They also influence many physiologic functions, including brain function and physical performance and are ultimately related to human health. In 1998, ILSI Japan formed a team to conduct research on "The Medical and Nutritional Aspects of Sugars." The research included studies of several new aspects of the metabolic characteristics and physiologic effects of sugars. This paper presents some highlights of our research, including the background of the project, the metabolic characteristics of sugars, and the effect of sugars on glycemic response, memory, and appetite and food intake in humans, etc.     

Normal Roles for Dietary Fructose in Carbohydrate Metabolism

Although there are many well-documented metabolic effects linked to the fructose component of a very high sugar diet, a healthy diet is also likely to contain appreciable fructose, even if confined to that found in fruits and vegetables. These normal levels of fructose are metabolized in specialized pathways that synergize with glucose at several metabolic steps. Glucose potentiates fructose absorption from the gut, while fructose catalyzes glucose uptake and storage in the liver. Fructose accelerates carbohydrate oxidation after a meal. In addition, emerging evidence suggests that fructose may also play a role in the secretion of insulin and GLP-1, and in the maturation of preadipocytes to increase fat storage capacity. Therefore, fructose undergoing its normal metabolism has the interesting property of potentiating the disposal of a dietary carbohydrate load through several routes.     

餐后血糖应答反应的影响因素及其调控

血糖水平异常,是许多慢性病的常见特点和危险因素。血糖生成指数(GI)是反映碳水化合物餐后血糖应答水平的特征性指数。测定各类碳水化合物的血糖生成指数之后,用来指导人们的日常膳食,改善糖尿病人、心脑血管病病人和肥胖者等的健康状况,具有重要的意义。现有的证据表明,影响食物血糖应答的因素很多,包括食物本身所具有的各种特征和机体自身的状态等。对这些因素的认识,有助于更有效的推广和应用GI来指导人们的膳食,维护和改善人们,尤其是糖尿病和肥胖等慢性疾病患者的健康。本文综述了碳水化合物的消化吸收和利用过程中影响血糖应答的各种因素及其机理。     

24-Hour Glucose Profiles on Diets Varying in Protein Content and Glycemic Index

Evidence is increasing that the postprandial state is an important factor contributing to the risk of chronic diseases. Not only mean glycemia, but also glycemic variability has been implicated in this effect. In this exploratory study, we measured 24-h glucose profiles in 25 overweight participants in a long-term diet intervention study (DIOGENES study on Diet, Obesity and Genes), which had been randomized to four different diet groups consuming diets varying in protein content and glycemic index. In addition, we compared 24-h glucose profiles in a more controlled fashion, where nine other subjects followed in random order the same four diets differing in carbohydrate content by 10 energy% and glycemic index by 20 units during three days. Meals were provided in the lab and had to be eaten at fixed times during the day. No differences in mean glucose concentration or glucose variability (SD) were found between diet groups in the DIOGENES study. In the more controlled lab study, mean 24-h glucose concentrations were also not different. Glucose variability (SD and CONGA1), however, was lower on the diet combining a lower carbohydrate content and GI compared to the diet combining a higher carbohydrate content and GI. These data suggest that diets with moderate differences in carbohydrate content and GI do not affect mean 24-h or daytime glucose concentrations, but may result in differences in the variability of the glucose level in healthy normal weight and overweight individuals.     

妊娠期糖代谢异常的发病情况及相关因素探讨

目的了解妊娠期糖代谢异常的发生率，探讨其相关因素，为制定干预措施提供科学依据。方法采用回顾性研究的方法，收集2006年4月至2006年9月在本院产科门诊产检并行50g口服葡萄糖筛查试验（oral glucose challengetest，OGCT）的2020例孕妇的临床资料，进行统计分析。结果以50g OGCT≥7．8mmol／L为临界值，本组患者OGCT结果显示，妊娠期糖代谢异常的发生率为8．51％（172／2020）。本研究将个体的年龄、文化程度、孕前和行50g OGCT时，体重是否超重（体重≥80kg）或肥胖（BMI≥28kg／m^2），是否有糖尿病家族史，确定为妊娠期糖代谢异常的相关因素。对50g OGCT≥7．8mmol／L的患者进行Logistic回归分析发现，年龄越大（超过35岁），文化程度高（为研究生及以上者），糖代谢筛查时体重指数高（BMI≥28kg／m^2）及有糖尿病家族史，为妊娠期糖代谢异常发病的独立危险因素。结论妊娠期糖代谢异常的发生率较高，应根据相关因素对其进行积极干预。     

Glucose and Insulin Responses to a New Zero-Energy Fiber Source

Objective: Consumption of a number of soluble fiber sources reduces glucose and insulin responses in humans. These fibers provide some available energy. Z-trim, a completely insoluble, noncaloric fiber/fat replacer produced from grain, was developed by ARS scientist George Inglett but until this report had not been tested in humans. The objective was to test the effects of consumption of various doses of this new fiber on glucose and insulin responses in humans.

Design: Men and women (12 each) matched for age and body mass index (41 years, BMI 27) were given glucose or glucose with three levels of fiber in a Latin-square design. Blood samples were obtained before and 30, 60, 120 and 180 minutes after solutions containing glucose alone (1 g/kg body weight) and glucose plus 0.08, 0.17 and 0.33 g/kg body weight of Z-trim were consumed. Plasma glucose, insulin and glucagon were determined by enzyme or radioimmunoassays. A repeated-measures analysis of variance was conducted.

Results: Glucose responses were lower for women than for men (p = 0.02) regardless of the test solution. At 30 minutes, glucose levels of men were 0.7–1.1 mmol/L lower after the two higher levels of fiber than after glucose alone. Insulin peak responses were delayed by high amounts of Z-trim. Fasting and response levels of glucagon were higher (p < 0.002) in women than in men. The decline in glucagon usually seen after a glucose load was moderated by the addition of fiber.

Conclusion: Although high levels of this new fiber may beneficially affect glucose metabolism of middle-aged people, it is less effective than soluble fiber.     

Regular Endurance Training Does Not Influence the Glycemic Index Determination in Women

Objective: This study investigated the influence of regular endurance training on the glycemic index (GI) of a breakfast cereal in women as previous results from men indicate that endurance training may influence the GI.

Methods: Subjects were 17 sedentary (SE) and 19 endurance trained (ET) healthy, young, adult women of normal body mass index. All subjects performed two tests with the reference food glucose and two tests with a breakfast cereal in a randomized order. Capillary and venous whole blood glucose as well as venous plasma insulin was measured.

Results: The GI did not differ between SE and ET, irrespective of its calculation from the capillary (mean ± standard error: 61.4 ± 4.3 and 69.5 ± 4.7 for SE and ET respectively, p = 0.21) or the venous blood glucose (60.8 ± 8.1 and 64.4 ± 6.2, p = 0.72). The insulinemic index did not differ between the SE and ET subjects (p = 0.75).

Conclusion: The results come along with many other data, indicating that the GI seems to be independent of subject-specific factors, but are in contrast to previous results obtained with men where we found a GI dependence on the training state.     

脑梗死与糖代谢异常相关性研究

目的：观察不同损害程度脑梗死患者的血糖水平,分析其糖代谢异常情况,探讨脑梗死与糖代谢异常的关系,为脑梗死的预防、诊断、治疗提供依据。方法：选取2010年1月-2013年8月入住本院脑病科的108例急性脑梗死患者,根据梗死范围将其分为轻度组41例、中度组40例、重度组27例,通过检测空腹血糖（FPG）、餐后2 h血糖（PG）、糖化血红蛋白（HbA1c）,观察患者的糖代谢情况。结果：糖调节受损、糖尿病与正常血糖患者比较,中度及重度组脑梗死比率明显升高;糖尿病患者脑梗死中度组、重度组比率较糖调节受损患者明显升高;脑梗死中度组、重度组的HbA1c、FPG、2 h PG水平均明显高于脑梗死轻度组,重度组的HbA1c、FPG、2 h PG水平明显高于中度组,差异均有统计学意义（P〈0.05）。结论：糖代谢异常与脑梗死的发生及损害程度明显相关,良好的血糖控制有利于降低脑梗死的发生率,监测血糖并控制正常范围内可改善预后。     

Toward an Evidence-Based Definition and Classification of Carbohydrate Food Quality: An Expert Panel Report

Carbohydrate-containing crops provide the bulk of dietary energy worldwide. In addition to their various carbohydrate forms (sugars, starches, fibers) and ratios, these foods may also contain varying amounts and combinations of proteins, fats, vitamins, minerals, phytochemicals, prebiotics, and anti-nutritional factors that may impact diet quality and health. Currently, there is no standardized or unified way to assess the quality of carbohydrate foods for the overall purpose of improving diet quality and health outcomes, creating an urgent need for the development of metrics and tools to better define and classify high-quality carbohydrate foods. The present report is based on a series of expert panel meetings and a scoping review of the literature focused on carbohydrate quality indicators and metrics produced over the last 10 years. The report outlines various approaches to assessing food quality, and proposes next steps and principles for developing improved metrics for assessing carbohydrate food quality. The expert panel concluded that a composite metric based on nutrient profiling methods featuring inputs such as carbohydrate–fiber–sugar ratios, micronutrients, and/or food group classification could provide useful and informative measures for guiding researchers, policymakers, industry, and consumers towards a better understanding of carbohydrate food quality and overall healthier diets. The identification of higher quality carbohydrate foods could improve evidence-based public health policies and programming—such as the 2025–2030 Dietary Guidelines for Americans.     

Trace Substances and Health,A Handbook

Background: With emerging knowledge of the impact of the metabolic quality of glycemic carbohydrates on human health, there is a need for novel carbohydrate ingredients that can be custom-made to deliver controlled amounts of glucose to the body and to test hypotheses on the postprandial metabolic consequences of carbohydrates.

Objective: The goal of the present study was to demonstrate the applicability and action of starch-entrapped biopolymer microspheres as customized, novel, slowly digestible carbohydrates to obtain desired glycemic responses.

Methods: Starch-entrapped microspheres were developed; and starch digestion and glucose release, subsequent to their cooking (100°C, 20 min) in water, were initially monitored by measuring the rapidly digestible, slowly digestible, and resistant starch fractions using the in vitro Englyst assay. Glycemic and insulinemic responses after consumption of glucose and two different slowly digestible starch microsphere diets were compared using a crossover study in 10 healthy individuals. The mechanism of starch digestion in the microspheres was elucidated from scanning electron microscopic images of the in vitro digested microspheres.

Results: Factors such as biopolymer type and concentration, microsphere size, and starch type were manipulated to obtain starch materials with defined amounts of slowly digestible starch based on in vitro studies. Scanning electron microscopy showed that cooked starch entrapped in the dense biopolymer matrix is digested layer by layer from the outside to the inside of the microsphere. Glycemic and insulinemic responses to microsphere test diets were moderate as compared to a glucose diet, but more important, they showed extended glucose release.

Conclusions: Starch-entrapped microspheres provide a useful tool to study the postprandial metabolic consequences of slowly digestible carbohydrates.     

The Effect of Dietary Carbohydrate and Fat Manipulation on the Metabolome and Markers of Glucose and Insulin Metabolism: A Randomised Parallel Trial

High carbohydrate, lower fat (HCLF) diets are recommended to reduce cardiometabolic disease (CMD) but low carbohydrate high fat (LCHF) diets can be just as effective. The effect of LCHF on novel insulin resistance biomarkers and the metabolome has not been fully explored. The aim of this study was to investigate the impact of an ad libitum 8-week LCHF diet compared with a HCLF diet on CMD markers, the metabolome, and insulin resistance markers. n = 16 adults were randomly assigned to either LCHF (n = 8, <50 g CHO p/day) or HCLF diet (n = 8) for 8 weeks. At weeks 0, 4 and 8, participants provided fasted blood samples, measures of body composition, blood pressure and dietary intake. Samples were analysed for markers of cardiometabolic disease and underwent non-targeted metabolomic profiling. Both a LCHF and HCLF diet significantly (p < 0.01) improved fasting insulin, HOMA IR, rQUICKI and leptin/adiponectin ratio (p < 0.05) levels. Metabolomic profiling detected 3489 metabolites with 78 metabolites being differentially regulated, for example, an upregulation in lipid metabolites following the LCHF diet may indicate an increase in lipid transport and oxidation, improving insulin sensitivity. In conclusion, both diets may reduce type 2 diabetes risk albeit, a LCHF diet may enhance insulin sensitivity by increasing lipid oxidation.     

淀粉的消化特性与血糖生成指数

选择不同碳水化合物的配比制备成的不同消化特性的饼干和面包样品 ,并以葡萄糖为对照 ,以面包为参照对其血糖生成指数 (GI)和胰岛素指数 (II)进行了评估。结果显示 ,和面包相比 ,两种饼干样品水分含量较低 ,脂肪含量较高 ;在碳水化合物分类中 ,虽然饼干中糖含量 (170g kg)高于面包 (9g kg) ,但慢消化淀粉 (SDS)和抗性淀粉 (RS)占碳水化合物的比例 >60 % ,明显高于面包 (18 3 % )。以葡萄糖血糖生成指数值和胰岛素指数值作为 10 0 % ,面包的血糖生成指数值和胰岛素指数值分别为 96 2 %、10 5 2 % ,而两种饼干的血糖生成指数值均 <55% ,胰岛素指数均明显下降 (<73 % )。提示合理搭配和加工碳水化合物对工业化生产理想血糖生成指数的产品十分有利     

辽宁省阜新农村地区高血压人群体质指数与糖代谢异常关系研究

目的了解辽宁省阜新农村地区高血压人群糖代谢异常与体质指数(BMI)的相关性。方法采用分层随机整群抽样方法,对辽宁阜新农村≥35岁高血压人群进行流行病学调查及实验室检查。将BMI按不同水平分级,使用SPSS11.5软件分析不同BMI水平的糖代谢异常率,并进行多因素Logistic回归分析。结果该高血压人群中男女性超重检出率分别为32.7/和36.4/;肥胖检出率分别为6.2/和12.9/,女性高于男性(P<0.05)。空腹血糖受损(IFG)及IFG与糖尿病(DM)合计患病率男性高于女性(P<0.01)。男女性DM及IFG与DM合计患病率均随BMI水平的增高而增加(P<0.01)。调整其他危险因素后,DM患病风险随BMI水平的增高而增加,但IFG患病风险未见此趋势。结论辽宁省阜新农村地区高血压人群中BMI是糖代谢异常的独立相关因素。     

热断层扫描评估血糖代谢的试验研究

目的应用热断层扫描技术（TTM）及空腹血糖检查对血糖异常代谢进行评估与诊断,并比较两种检查方法的吻合度,旨在评价TTM对糖代谢异常的评估应用价值。方法选取行TTM全身检测与空腹血糖检查者16955例,将TTM检测的阳性和阴性与空腹血糖检查诊断的血糖升高和正常这4个参数进行诊断试验（四格表运算）,以取得各项评价指标,并将TIM评估与空腹血糖检查诊断血糖代谢的情况进行X系数检验。对空腹血糖值正常而TIM评估血糖升高的体检者进行4年随访,并统计分析其空腹血糖值的变化。结果TTM对血糖代谢异常的评估特异性较强（75％）,准确度及敏感度分别为71．9％、53．2％;两种诊断方法的吻合系数为κ=0．196,P=0．000〈0．05。结论TTM对血糖代谢异常的早期筛查有一定的应用价值,将其用于健康体检进行疾病的早期筛查,值得我们不断研究和探索。     

Rotterdam标准诊断不同表型多囊卵巢综合征中国患者糖代谢的差异评估

目的研究不同表型多囊卵巢综合征（polycystic ovary syndrom，PCOS）患者糖代谢差异，从糖代谢角度探讨多囊卵巢综合征Rotterdam标准不同诊断指标对我国患者是否适用。方法将2004年1月至2004年12月在南京大学医学院附属医院妇科门诊就诊的52例患者（病例组）中，诊断为多囊卵巢综合征的17例患者纳入PCOS组（Ⅰ组），诊断为雄激素过高症的14例患者纳入雄激素过高症组（Ⅱ组），既有多囊卵巢综合征又有雄激素过高症的21例患者纳入复合组（Ⅲ组）。所有入选对象血清硫酸脱氢表雄酮（DHEA-S）水平正常（〈5μmol／L），近2个月未服用避孕药。同期就诊，月经周期规律，经直肠超声检查显示卵巢形态学正常，诊断为单纯输卵管性不孕的8例患者纳入对照组。月经周期第2～第5天行口服75g葡萄糖耐量试验（OGTT），测量血糖（Glu）、胰高血糖素（GLY）、胰岛素（INS）和C-肽（C-P）的血浓度变化，并计算胰岛素抵抗（insulin resistance，IR）参数[胰岛素浓度／血糖浓度（I／G）]、[IR-C肽浓度／胰岛素浓度（C／I）]。结果病例组基本情况及基础激素水平与对照组相似，糖代谢表现为高胰岛素血症和胰岛素抵抗，且程度相似。结论病例组患者胰岛素抵抗程度相似，说明糖代谢异常相似。因此，就糖代谢的角度而言，Rotterdam标准的不同诊断指标对我国多囊卵巢综合征患者适用。     

微量营养素大枣对糖尿病大鼠糖脂代谢的调节作用

目的　研究微量营养素大枣 (MCHJ)对糖尿病大鼠血糖血脂的调节作用。　方法　将糖尿病模型大鼠随机分为 4组 : 组为糖尿病模型组 , 、 、 组分别为低、中、高剂量 MCHJ组。 40天后进行有关生化指标测定和形态学观察。　结果　各实验组空腹血糖值、血脂显著低于 组 ,血清胰岛素水平显著高于 组 ,且糖尿病模型组胰腺、肾脏病变较各MCHJ组严重。　结论　 MCHJ能明显地降低糖尿病大鼠血糖、血脂水平 ,改善糖脂代谢。