Decreased nerve conduction velocity may be a predictor of fingertip dexterity and subjective complaints.

We examined the causes of decreased fingertip dexterity in elderly individuals with an aim to improve their quality of life by improving their activities of daily living. We calculated nerve conduction velocity, absolute error during force adjustment tasks, and fingertip dexterity test scores for 30 young (21-34 years old) and 30 elderly (60-74 years old) participants to identify age-related changes. We also assessed subjective complaints of pain, motor function, and numbness. Motor nerve (young: 55.8 ± 3.7 m/s; elderly: 52.2 ± 5.0 m/s) and sensory nerve (young: 59.4 ± 3.4 m/s; elderly: 55.5 ± 5.3 m/s) conduction velocities decreased in an age-dependent manner. Moreover, the decrease of motor nerve conduction velocity was associated with decreased fingertip dexterity (objective index), while the decrease of sensory nerve conduction velocity was associated with subjective complaints of pain and motor function (subjective index).

Diurnal variations of brown fat thermogenesis and fat oxidation in humans.

BACKGROUND/OBJECTIVES: Disturbed circadian rhythm is associated with an increased risk of obesity and metabolic disorders. Brown adipose tissue (BAT) is a site of nonshivering thermogenesis (NST) and plays a role in regulating whole-body energy expenditure (EE), substrate metabolism, and body fatness. In this study, we examined diurnal variations of NST in healthy humans by focusing on their relation to BAT activity. METHODS: Forty-four healthy men underwent 18F-fluoro-2-deoxy-D-glucose positron emission tomography and were divided into Low-BAT and High-BAT groups. In STUDY 1, EE, diet-induced thermogenesis (DIT), and fat oxidation (FO) were measured using a whole-room indirect calorimeter at 27 °C. In STUDY 2, EE, FO, and skin temperature in the region close to BAT depots (Tscv) and in the control region (Tc) were measured at 27 °C and after 90 min cold exposure at 19 °C in the morning and in the evening. RESULTS: In STUDY 1, DIT and FO after breakfast was higher in the High-BAT group than in the Low-BAT group (P < 0.05), whereas those after dinner were comparable in the two groups. FO in the High-BAT group was higher after breakfast than after dinner (P < 0.01). In STUDY 2, cold-induced increases in EE (CIT), FO, and Tscv relative to Tc in the morning were higher in the High-BAT group than in the Low-BAT group (P < 0.05), whereas those after dinner were comparable in the two groups. CIT in the High-BAT group tended to be higher in the morning than in the evening (P = 0.056). CONCLUSION: BAT-associated NST and FO were evident in the morning, but not in the evening, suggesting that the activity of human BAT is higher in the morning than in the evening, and thus may be involved in the association of an eating habit of breakfast skipping with obesity and related metabolic disorders.

Preventive effects of tea and tea catechins against influenza and acute upper respiratory tract infections: a systematic review and meta-analysis.

PURPOSE: Gargling with tea has protective effects against influenza infection and upper respiratory tract infection (URTI). To evaluate if tea and tea catechin consumption has the same protective effects as gargling with tea, we performed a systematic review and meta-analysis. METHODS: We performed a comprehensive literature search using the PubMed, Cochrane Library, Web of Science, and Ichu-shi Web databases. The search provided six randomized controlled trials (RCTs) and four prospective cohort studies (n = 3748). The quality of each trial or study was evaluated according to the Cochrane risk-of-bias tool or Newcastle-Ottawa Scale. We collected data from publications meeting the search criteria and conducted a meta-analysis of the effect of tea gargling and tea catechin consumption for preventing URTI using a random effects model. RESULTS: Tea gargling and tea catechin consumption had significant preventive effects against URTI (risk ratio [RR] = 0.74, 95% confidence interval [CI] 0.64-0.87). In sub-analyses, a significant preventive effect was observed by study type (prospective cohort study: RR = 0.67, 95% CI 0.50-0.91; RCT: RR = 0.79, 95% CI 0.66-0.94) and disease type (influenza: RR = 0.69, 95% CI 0.58-0.84; acute URTI: RR = 0.78, 95% CI 0.62-0.98). Both gargling with tea and consuming tea catechins effectively protected against URTI (tea and tea catechins consumption: RR = 0.68, 95% CI 0.52-0.87; tea gargling: RR = 0.83, 95% CI 0.72-0.96). CONCLUSION: Our findings suggest that tea gargling and tea catechin consumption may have preventive effects against influenza infection and URTI. The potential effectiveness of these actions as non-pharmaceutical interventions, however, requires further investigation.

Novel Equations to Estimate Resting Energy Expenditure during Sitting and Sleeping.

INTRODUCTION: Young and early middle-aged office workers spend most of the day sitting or sleeping. Few studies have used a metabolic chamber to report sitting resting energy expenditure (REE) or sleeping metabolic rate (SMR) estimation equations. This study aimed to develop novel equations for estimating sitting REE and SMR, and previously published equations for SMR were compared against measured values. METHODS: The relationships among sitting REE, SMR, and body composition measured in clinical trials were analyzed. The body composition (fat-free mass [FFM] and fat mass) and energy metabolism of 85 healthy young and early middle-aged Japanese individuals were measured using dual-energy X-ray absorptiometry and a metabolic chamber, respectively. Novel estimate equations were developed using stepwise multiple regression analysis. Estimates of SMR using a new equation and 2 published equations were compared against measured SMR. RESULTS: The sitting mREE and mSMR were highly correlated (r = 0.756, p < 0.01). The new FFM-based estimate accounted for 50.4% of the variance in measured sitting REE (mREE) and 82.3% of the variance in measured SMR (mSMR). The new body weight-based estimate accounted for 49.3% of the variance in sitting mREE and 82.2% of the variance in mSMR. Compared with mSMR, the SMR estimate using an FFM-based published equation was slightly underestimated. CONCLUSION: These novel body weight- and FFM-based equations may help estimate sitting REE and SMR in young and early middle-aged adults. Previous SMR estimated FFM-based equations were slightly underestimated against measured SMR; however, we confirmed the previous SMR estimate equations could be useful. This finding suggests that sitting REE and SMR can be easily estimated from individual characteristics and applied in clinical settings.

Effect of tea catechins with caffeine on energy expenditure in middle-aged men and women: a randomized, double-blind, placebo-controlled, crossover trial.

PURPOSE: It has been reported that tea catechins increase energy metabolism, but their effect on resting metabolic rate (RMR) remains under debate. This study aimed to examine the effect of repeated intake of tea catechins on energy metabolism in the resting state in middle-aged men and women. METHODS: A total of 30 middle-aged men and women [13 women; age (mean ± SD) 52 ± 4 years; BMI 21.9 ± 2.2 kg/m2] were recruited. A randomized, double-blind, crossover study was conducted using a tea catechin-enriched beverage (611 mg catechins, 88 mg caffeine) and a placebo beverage (0 mg catechins, 81 mg caffeine) as test beverages. After 2 weeks of continuous test beverage intake, fasting RMR and energy expenditure (EE) after the ingestion of test beverage were measured. Measurements of forehead temperature (proxy for core temperature) and skin temperature were also obtained simultaneously. RESULTS: Among participants who underwent measurements, 26 (10 women; mean age 52 ± 4 years; mean BMI 22.1 ± 2.1 kg/m2) were analyzed. The EE increased significantly after ingestion of the tea catechin beverage compared with the placebo beverage (placebo treatment: 5502 ± 757 kJ/day; catechin treatment: 5598 ± 800 kJ/day; P = 0.041). No between-treatment differences in fasting RMR or the respiratory quotient were detected. In addition, the forehead and skin temperature did not differ significantly between the placebo and catechin treatments. CONCLUSION: This study revealed that continuous intake of tea catechins with caffeine for 2 weeks significantly increased EE after ingestion of the tea catechin but not fasting RMR in middle-aged men and women. CLINICAL TRIAL REGISTRY NUMBER AND WEBSITE: This trial was registered at www.umin.ac.jp/ctr/ as UMIN000025810 and UMIN000025811.

Coffee with a high content of chlorogenic acids and low content of hydroxyhydroquinone improves postprandial endothelial dysfunction in patients with borderline and stage 1 hypertension.

PURPOSE: The purpose of this study was to evaluate acute effects of coffee with a high content of chlorogenic acids and different hydroxyhydroquinone contents on postprandial endothelial dysfunction. METHODS: This was a single-blind, randomized, placebo-controlled, crossover-within-subject clinical trial. A total of 37 patients with borderline or stage 1 hypertension were randomized to two study groups. The participants consumed a test meal with a single intake of the test coffee. Subjects in the Study 1 group were randomized to single intake of coffee with a high content of chlorogenic acids and low content of hydroxyhydroquinone or coffee with a high content of chlorogenic acids and a high content of hydroxyhydroquinone with crossover. Subjects in the Study 2 group were randomized to single intake of coffee with a high content of chlorogenic acids and low content of hydroxyhydroquinone or placebo coffee with crossover. Endothelial function assessed by flow-mediated vasodilation and plasma concentration of 8-isoprostanes were measured at baseline and at 1 and 2 h after coffee intake. RESULTS: Compared with baseline values, single intake of coffee with a high content of chlorogenic acids and low content of hydroxyhydroquinone, but not coffee with a high content of chlorogenic acids and high content of hydroxyhydroquinone or placebo coffee, significantly improved postprandial flow-mediated vasodilation and decreased circulating 8-isoprostane levels. CONCLUSIONS: These findings suggest that a single intake of coffee with a high content of chlorogenic acids and low content of hydroxyhydroquinone is effective for improving postprandial endothelial dysfunction. CLINICAL TRIAL REGISTRATION: URL for Clinical Trial: https://upload.umin.ac.jp ; Registration Number for Clinical Trial: UMIN000013283.

Effects of subacute ingestion of chlorogenic acids on sleep architecture and energy metabolism through activity of the autonomic nervous system: a randomised, placebo-controlled, double-blinded cross-over trial.

Chlorogenic acids (CGA) are the most abundant polyphenols in coffee. Continuous consumption of CGA reduces body fat and body weight. Since energy metabolism and sleep are controlled by common regulatory factors, consumption of CGA might modulate sleep. Lack of sleep has been identified as a risk factor for obesity, hypertension and type 2 diabetes. The aim of this study was to determine the effects of ingesting CGA over 5 d on energy metabolism and sleep quality in humans. A total of nine healthy subjects (four male and five female) completed a placebo-controlled, double-blinded, cross-over intervention study. Subjects consumed a test beverage containing 0 or 600 mg of CGA for 5 d. On the fifth night, subjects stayed in a whole-room metabolic chamber to measure energy metabolism; sleep was evaluated using polysomnographic recording. It was found that CGA shortened sleep latency (9 (sem 2) v. 16 (sem 4) min, P<0·05) compared with the control, whereas no effect on sleep architecture, such as slow-wave sleep, rapid eye movement or waking after sleep onset, was observed. Indirect calorimetry revealed that consumption of CGA increased fat oxidation (510 (sem 84) kJ/8 h (122 (sem 20) kcal/8 h) v. 331 (sem 79) kJ/8 h (81 (sem 19) kcal/8 h), P<0·05) but did not affect energy expenditure during sleep. Consumption of CGA enhanced parasympathetic activity assessed from heart-rate variability during sleep (999 (sem 77) v. 919 (sem 54), P<0·05). A period of 5-d CGA consumption significantly increased fat oxidation during sleep, suggesting that beverages containing CGA may be beneficial to reduce body fat and prevent obesity. Consumption of CGA shortened sleep latency and did not adversely affect sleep quality.

Supplementation with cassis polyphenol has no effect on menopausal symptoms in healthy middle-aged women: A randomized, double-blind, parallel-group, placebo-controlled trial.

Hormonal changes during the menopause transition may lead to vasomotor symptoms, including hot flashes (HFs) and neuropsychiatric symptoms such as anxiety and irritability. We hypothesized that the effects of cassis polyphenol (CaP) to improve microcirculation and vasorelaxation may alleviate menopausal symptoms. We performed a randomized, double-blind, parallel-group, placebo-controlled trial involving 59 healthy women (mean [standard deviation] age, 51.3 [4.3] years; body mass index, 20.8 [2.6] kg/m2). Participants experiencing subjective menopausal symptoms consumed CaP tablets (400 mg/d, CaP group) or placebo tablets (placebo group) for 4 weeks. Participants were evaluated using questionnaires at baseline, during the 4-week intervention period, and during a 2-week postinterventional observation period. The primary objective was to evaluate the effects of supplementation with CaP on HFs in healthy Japanese women with menopausal symptoms. Additional assessments included the modified Kupperman menopausal index, World Health Organization-5 Well-Being Index, World Health Organization quality-of-life 26-item index, State-Trait Anxiety Inventory (anxiety and trait components), and Oguri-Shirakawa-Azumi sleep inventory (middle-aged and elderly versions). During the 4-week intervention period, no significant between-group differences were detected in the HF frequency, HF score, sweating frequency, menopausal symptoms, quality of life, anxiety, or sleep. During the 2-week postintervention observational period, the HF score and sweating frequency were significantly decreased in the CaP group compared with the placebo group. These findings suggest that twice daily intake of CaP for 4 weeks does not alleviate menopause symptoms, but the improvement observed in the CaP intake group during the postintervention period warrants confirmation through further large-scale studies.

Nighttime snacking reduces whole body fat oxidation and increases LDL cholesterol in healthy young women.

The increase in obesity and lipid disorders in industrialized countries may be due to irregular eating patterns. Few studies have investigated the effects of nighttime snacking on energy metabolism. We examined the effects of nighttime snacking for 13 days on energy metabolism. Eleven healthy women (means ± SD; age: 23 ± 1 yr; body mass index: 20.6 ± 2.6 kg/m(2)) participated in this randomized crossover trial for a 13-day intervention period. Subjects consumed a specified snack (192.4 ± 18.3 kcal) either during the daytime (10:00) or the night time (23:00) for 13 days. On day 14, energy metabolism was measured in a respiratory chamber without snack consumption. An oral glucose tolerance test was performed on day 15. Relative to daytime snacking, nighttime snacking significantly decreased fat oxidation (daytime snacking: 52.0 ± 13.6 g/day; nighttime snacking: 45.8 ± 14.0 g/day; P = 0.02) and tended to increase the respiratory quotient (daytime snacking: 0.878 ± 0.022; nighttime snacking: 0.888 ± 0.021; P = 0.09). The frequency of snack intake and energy intake, body weight, and energy expenditure were not affected. Total and low-density lipoprotein (LDL) cholesterol significantly increased after nighttime snacking (152 ± 26 mg/dl and 161 ± 29 mg/dl; P = 0.03 and 76 ± 20 mg/dl and 83 ± 24 mg/dl; P = 0.01, respectively), but glucose and insulin levels after the glucose load were not affected. Nighttime snacking increased total and LDL cholesterol and reduced fat oxidation, suggesting that eating at night changes fat metabolism and increases the risk of obesity.

Potential of Polyphenols for Improving Sleep: A Preliminary Results from Review of Human Clinical Trials and Mechanistic Insights.

Global epidemiologic evidence supports an interrelationship between sleep disorders and fruits and vegetable ingestion. Polyphenols, a broad group of plant substances, are associated with several biologic processes, including oxidative stress and signaling pathways that regulate the expression of genes promoting an anti-inflammatory environment. Understanding whether and how polyphenol intake is related to sleep may provide avenues to improve sleep and contribute to delaying or preventing the development of chronic disease. This review aims to assess the public health implications of the association between polyphenol intake and sleep and to inform future research. The effects of polyphenol intake, including chlorogenic acid, resveratrol, rosmarinic acid, and catechins, on sleep quality and quantity are discussed to identify polyphenol molecules that may improve sleep. Although some animal studies have investigated the mechanisms underlying the effects of polyphenols on sleep, the paucity of trials, especially randomized controlled trials, does not allow for conducting a meta-analysis to reach clear conclusions about the relationships among these studies to support the sleep-improving effects of polyphenols.

Acute Dose-Response Effectiveness of Combined Catechins and Chlorogenic Acids on Postprandial Glycemic Responses in Healthy Men: Results from Two Randomized Studies.

Epidemiologic studies show that the risk of diabetes can be reduced by ingesting green tea or coffee. Previous studies have shown that simultaneously taking green tea catechins (GTC) and coffee chlorogenic acid (CCA) alters postprandial gastrointestinal hormones secretion and improves insulin sensitivity. However, there is no evidence on the acute effects of GTC and CCA on incretin and blood glucose, and on the respective dose of polyphenols. In this randomized, double-blind, placebo-controlled crossover study, we examined the effective dose of GTC and CCA on postprandial glucose, insulin, and incretin responses to a high-fat and high-carbohydrate cookie meal containing 75 g of glucose in healthy men. Study 1 (n = 18) evaluated two doses of GTC (270 or 540 mg) containing a fixed dose of CCA (270 mg) with 113 mg of caffeine and a placebo (0 mg GTC and 0 mg CCA) with 112 mg of caffeine. Study 2 (n = 18) evaluated two doses of CCA (150 or 300 mg) containing a fixed dose of GTC (540 mg) and a placebo with 99 mg of caffeine. The single combined ingestion of GTC and CCA significantly altered the incretin response and suppressed glucose and insulin levels. These findings suggest that the effective minimum dose is 540 mg of GTC and 150 mg of CCA.

Assessment of Multidimensional Health Care Parameters Among Adults in Japan for Developing a Virtual Human Generative Model: Protocol for a Cross-sectional Study.

BACKGROUND: Human health status can be measured on the basis of many different parameters. Statistical relationships among these different health parameters will enable several possible health care applications and an approximation of the current health status of individuals, which will allow for more personalized and preventive health care by informing the potential risks and developing personalized interventions. Furthermore, a better understanding of the modifiable risk factors related to lifestyle, diet, and physical activity will facilitate the design of optimal treatment approaches for individuals. OBJECTIVE: This study aims to provide a high-dimensional, cross-sectional data set of comprehensive health care information to construct a combined statistical model as a single joint probability distribution and enable further studies on individual relationships among the multidimensional data obtained. METHODS: In this cross-sectional observational study, data were collected from a population of 1000 adult men and women (aged ≥20 years) matching the age ratio of the typical adult Japanese population. Data include biochemical and metabolic profiles from blood, urine, saliva, and oral glucose tolerance tests; bacterial profiles from feces, facial skin, scalp skin, and saliva; messenger RNA, proteome, and metabolite analyses of facial and scalp skin surface lipids; lifestyle surveys and questionnaires; physical, motor, cognitive, and vascular function analyses; alopecia analysis; and comprehensive analyses of body odor components. Statistical analyses will be performed in 2 modes: one to train a joint probability distribution by combining a commercially available health care data set containing large amounts of relatively low-dimensional data with the cross-sectional data set described in this paper and another to individually investigate the relationships among the variables obtained in this study. RESULTS: Recruitment for this study started in October 2021 and ended in February 2022, with a total of 997 participants enrolled. The collected data will be used to build a joint probability distribution called a Virtual Human Generative Model. Both the model and the collected data are expected to provide information on the relationships between various health statuses. CONCLUSIONS: As different degrees of health status correlations are expected to differentially affect individual health status, this study will contribute to the development of empirically justified interventions based on the population. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/47024.

Effect of Catechins on Upper Respiratory Tract Infections in Winter: A Randomized, Placebo-Controlled, Double-Blinded Trial.

Tea catechins are plant-derived compounds that improve immune functions. Previous randomized control trials have demonstrated the efficacy of primarily epi-type catechins against upper respiratory tract infections (URTIs). Green tea can be consumed in several ways, including popular bottled beverages. These beverages, however, require sterilization during manufacturing, which results in catechin isomerization. We conducted a randomized, double-blinded, placebo-controlled trial involving healthy Japanese participants to evaluate whether catechin consumption via bottled beverages has an alleviating effect on the duration and severity of URTIs in winter. The catechin group (490 mg catechin, 0.14%, containing 59% epi-type catechin, n = 55) showed reduced durations of running nose, nasal congestion, and headache, compared with the placebo group (0 mg catechin, n = 54; p = 0.013, 0.018, and <0.001, respectively). Furthermore, when considering physical symptoms, the duration of nasopharyngeal symptoms improved significantly in the catechin group (p < 0.001) compared with that in the control group. The daily consumption of catechin thus reduced the duration and severity of URTIs in healthy men and women. Humans are regularly exposed to several potential infectious threats, and the oral administration of heat-epimerized tea catechins might help prevent and reduce the severity of URTIs.

Effects of Ingesting Both Catechins and Chlorogenic Acids on Glucose, Incretin, and Insulin Sensitivity in Healthy Men: A Randomized, Double-Blinded, Placebo-Controlled Crossover Trial.

Epidemiologic studies have revealed that consuming green tea or coffee reduces diabetes risk. We evaluated the effects of the combined consumption of green tea catechins and coffee chlorogenic acids (GTC+CCA) on postprandial glucose, the insulin incretin response, and insulin sensitivity. Eleven healthy men were recruited for this randomized, double-blinded, placebo-controlled crossover trial. The participants consumed a GTC+CCA-enriched beverage (620 mg GTC, 373 mg CCA, and 119 mg caffeine/day) for three weeks; the placebo beverages (PLA) contained no GTC or CCA (PLA: 0 mg GTC, 0 mg CCA, and 119 mg caffeine/day). Postprandial glucose, insulin, glucagon-like peptide-1 (GLP-1), and glucose-dependent insulinotropic polypeptide (GIP) responses were measured at baseline and after treatments. GTC+CCA consumption for three weeks showed a significant treatment-by-time interaction on glucose changes after the ingestion of high-fat and high-carbohydrate meals, however, it did not affect fasting glucose levels. Insulin sensitivity was enhanced by GCT+CCA compared with PLA. GTC+CCA consumption resulted in a significant increase in postprandial GLP-1 and a decrease in GIP compared to PLA. Consuming a combination of GTC and CCA for three weeks significantly improved postprandial glycemic control, GLP-1 response, and postprandial insulin sensitivity in healthy individuals and may be effective in preventing diabetes.

Concomitant use of tea catechins affects absorption and serum triglyceride-lowering effects of monoglucosyl hesperidin.

The present study investigated whether combined ingestion of green tea catechins (GTC) and monoglucosyl hesperidin (GHES) influences the pharmacokinetic parameters of polyphenols and serum triglycerides (TG). We conducted 2 randomized, controlled trials. Study 1: 8 healthy male subjects participated in a crossover study in which they ingested a test beverage containing GHES (0, 84, 168, or 336 mg GHES) with GTC, or 336 mg GHES without GTC. After ingestion, the pharmacokinetic changes in plasma hesperetin (HEP) and catechins were measured. Study 2: 36 healthy male and female subjects (mean age, 53 ± 2 years; mean BMI, 25.2 ± 0.5 kg m-2) were recruited for a double-blind, placebo-controlled study in which they ingested a test beverage containing 165 mg GHES with 387 mg GTC or a placebo beverage daily for 4 weeks. Fasting serum TG and other lipids and glucose metabolites were analyzed. Study 1 showed that the pharmacokinetics of HEP did not differ significantly between the 336 mg GHES without GTC treatment and the 168 mg GHES with GTC treatment. Study 2 showed that continuous ingestion of 165 mg GHES and 387 mg GTC for 4 weeks significantly decreased fasting serum TG levels compared with baseline values (change in TG, -30 ± 13 mg dl-1, P = 0.040) in the intention-to-treat analysis. In conclusion, our findings suggest that GTC affects the oral bioavailability of GHES, and combined ingestion of low doses of GHES with GTC effectively improves fasting TG levels.

Effects of Timing of Acute and Consecutive Catechin Ingestion on Postprandial Glucose Metabolism in Mice and Humans.

We examined the effects of the timing of acute and consecutive epigallocatechin gallate (EGCG) and catechin-rich green tea ingestion on postprandial glucose in mice and human adults. In mouse experiments, we compared the effects of EGCG administration early (morning) and late (evening) in the active period on postprandial glucose. In human experiments, participants were randomly assigned to the morning-placebo (MP, n = 10), morning-green tea (MGT, n = 10), evening-placebo (EP, n = 9), and evening-green tea (EGT, n = 9) groups, and consumed either catechin-rich green tea or a placebo beverage for 1 week. At baseline and after 1 week, participants consumed their designated beverages with breakfast (MP and MGT) or supper (EP and EGT). Venous blood samples were collected in the fasted state and 30, 60, 120, and 180 min after each meal. Consecutive administration of EGCG in the evening, but not in the morning, reduced postprandial glucose at 30 (p = 0.006) and 60 (p = 0.037) min in the evening trials in mice. In humans, ingestion of catechin-rich green tea in the evening decreased postprandial glucose (three-factor analysis of variance, p < 0.05). Thus, catechin intake in the evening more effectively suppressed elevation of postprandial glucose.

The effects of diacylglycerol oil on fat oxidation and energy expenditure in humans and animals.

Studies in animals and humans indicate that diets containing diacylglycerol (DAG) oil (containing >80% DAG) decrease body weight gain and body fat accumulation, especially visceral fat. Body weight and body fat are controlled by energy expenditure, fat oxidation, fat storage capacity, and appetite control. Recent researches indicate that DAG oil, compared with conventional oils, has distinct metabolic effects. We review the evidence concerning the effects of DAG oil intake on fat oxidation and energy expenditure. In humans, dietary DAG is more susceptible to oxidation, and in animals 1,3-DAG, a major component of DAG oil, is rapidly oxidized. Short-term human studies with indirect calorimetry demonstrate greater fat oxidation with DAG oil consumption compared with triacylglycerol (TAG) oil consumption. Furthermore, DAG oil consumption for 14 days stimulates energy expenditure. Based on these reports, enhanced fat oxidation and energy expenditure by daily DAG oil intake could contribute to long-term reductions in body weight and fat accumulation. The literature provides support for the notion that dietary DAG is more rapidly oxidized than dietary TAG, and that, compared with TAG oil, DAG oil consumption increases whole body fat oxidation. The effects of DAG oil consumption on energy expenditure, however, remain inconclusive. (c) 2009 International Union of Biochemistry and Molecular Biology, Inc.

Coffee Abundant in Chlorogenic Acids Reduces Abdominal Fat in Overweight Adults: A Randomized, Double-Blind, Controlled Trial.

The components of roasted or green coffee beans that promote abdominal fat reduction are not clear. We investigated the effects of daily consumption of coffee enriched in chlorogenic acids (CGA) on abdominal fat area in a randomized, double-blind, parallel controlled trial. Healthy, overweight men and women (n = 150, body mass index (BMI) ≥25 to <30 kg/m2) were randomly allocated to high-CGA (369 mg CGA/serving) or control (35 mg CGA/serving) coffee groups. Instant coffee was consumed once daily for 12 weeks, with four-week pre- and post-observation periods. Abdominal fat area and anthropometric measurements were analyzed at baseline and at four, eight, and 12 weeks, and 142 subjects completed the trial. Visceral fat area (VFA), total abdominal fat area (TFA), body weight, and waist circumference significantly decreased in the CGA group compared with the control group, with a group × time interaction (p < 0.001, p = 0.001, p = 0.025, and p = 0.001, respectively). Changes in VFA and TFA from baseline to 12 weeks were significantly greater in the CGA group than in the control group (-9.0 ± 13.9 cm2 vs. -1.0 ± 14.3 cm2, p < 0.001; -13.8 ± 22.9 cm2 vs. -2.0 ± 16.2 cm2, p < 0.001). No severe adverse events occurred. Consumption of high-CGA coffee for 12 weeks by overweight adults might lower VFA, TFA, BMI, and waist circumference.

Effect of Short-Term Increase in Meal Frequency on Glucose Metabolism in Individuals with Normal Glucose Tolerance or Impaired Fasting Glucose: A Randomized Crossover Clinical Trial.

Effects of meal frequency on blood glucose levels and glucose metabolism were evaluated over 3 days in adult males with normal glucose tolerance (NGT, n = 9) or impaired fasting glucose (IFG, n = 9) in a randomized, crossover comparison study. Subjects were provided with an isocaloric diet 3 times daily (3M) or 9 times daily (9M). Blood glucose was monitored on Day 3 using a continuous glucose monitoring system, and subjects underwent a 75-g oral glucose tolerance test (OGTT) on Day 4. Daytime maximum blood glucose, glucose range, duration of glucose ≥180 mg/dL, and nighttime maximum glucose were significantly lower in the NGT/9M condition than in the NGT/3M condition. Similar findings were observed in the IFG subjects, with a lower daytime and nighttime maximum glucose and glucose range, and a significantly higher daytime minimum glucose in the 9M condition than in the 3M condition. The OGTT results did not differ significantly between NGT/3M and NGT/9M conditions. In contrast, the incremental area under the curve tended to be lower and the maximum plasma glucose concentration was significantly lower in the IFG/9M condition than in the IFG/3M condition. In IFG subjects, the 9M condition significantly improved glucose metabolism compared with the 3M condition. Higher meal frequency may increase glucagon-like peptide 1 secretion and improve insulin secretion.

Effects of timing of acute catechin-rich green tea ingestion on postprandial glucose metabolism in healthy men.

Green tea polyphenols, particularly catechins, decrease fasting and postprandial glucose. However, no studies have compared the timing of green tea ingestion on glucose metabolism and changes in catechin concentrations. Here, we examined the effects of timing of acute catechin-rich green tea ingestion on postprandial glucose metabolism in young men. Seventeen healthy young men completed four trials involving blood collection in a fasting state and at 30, 60, 120, and 180 min after meal consumption in a random order: 1) morning placebo trial (09:00 h; MP trial), 2) evening placebo trial (17:00 h; EP trial), 3) morning catechin-rich green tea trial (09:00 h; MGT trial), and 4) evening catechin-rich green tea trial (17:00 h; EGT trial). The concentrations of glucose at 120 min (P=.031) and 180 min (P=.013) after meal intake were significantly higher in the MGT trials than in the MP trials. Additionally, the concentration of glucose was significantly lower in EGT trials than in the EP trials at 60 min (P=.014). Moreover, the concentrations of glucose-dependent insulinotropic polypeptide were significantly lower in the green tea trials than in the placebo trials at 30 min (morning: P=.010, evening: P=.006) and 60 min (morning: P=.001, evening: P=.006) after meal intake in both the morning and evening trials. Our study demonstrated that acute ingestion of catechin-rich green tea in the evening reduced postprandial plasma glucose concentrations.