Dietary flavonoids intake and risk of type 2 diabetes: a meta-analysis of prospective cohort studies

Analysis of 17 polyphenolic compounds in organic and conventional legumes by high-performance liquid chromatography-diode array detection (HPLC-DAD) and evaluation of their antioxidant activity

Consumption of legumes has become popular among health-conscious consumers due to the high levels of nutrients such as proteins, dietary fibres, minerals, vitamins and micronutrients like polyphenols. Ten legumes cultivars organically and conventionally grown were compared regarding their chemical profiles in terms of total phenolic content (TPC), total anthocyanin content (TAC), total flavonoid content (TFC) and their antioxidant capacity. The chemical profiles (i.e. free phenolics and anthocyanins) were determined with aid of new high-performance liquid chromatography-diode array detection (HPLC-DAD) method able to identify two individual anthocyanins and 15 polyphenols. Results showed that phenolic acids, namely gallic acid, caffeic acid, syringic acid and ferulic acid, are mainly significantly higher in the organic samples with respect to the conventional ones. All organic legumes showed a higher antioxidant capacity with respect to conventional samples with the exception of red and yellow dehulled lentils.

Polyphenols from Root, Tubercles and Grains Cropped in Brazil: Chemical and Nutritional Characterization and Their Effects on Human Health and Diseases

Throughout evolution, plants have developed the ability to produce secondary phenolic metabolites, which are important for their interactions with the environment, reproductive strategies and defense mechanisms. These (poly)phenolic compounds are a heterogeneous group of natural antioxidants found in vegetables, cereals and leguminous that exert beneficial and protective actions on human health, playing roles such as enzymatic reaction inhibitors and cofactors, toxic chemicals scavengers and biochemical reaction substrates, increasing the absorption of essential nutrients and selectively inhibiting deleterious intestinal bacteria. Polyphenols present in some commodity grains, such as soy and cocoa beans, as well as in other vegetables considered security foods for developing countries, including cassava, taro and beetroot, all of them cropped in Brazil, have been identified and quantified in order to point out their bioavailability and the adequate dietary intake to promote health. The effects of the flavonoid and non-flavonoid compounds present in these vegetables, their metabolism and their effects on preventing chronic and degenerative disorders like cancers, diabetes, osteoporosis, cardiovascular and neurological diseases are herein discussed based on recent epidemiological studies.

Phytochemical Constituents, Health Benefits, and Industrial Applications of Grape Seeds: A Mini-Review

Grapes are one of the most widely grown fruits and have been used for winemaking since the ancient Greek and Roman civilizations. Grape seeds are rich in proanthocyanidins which have been shown to possess potent free radical scavenging activity. Grape seeds are a complex matrix containing 40% fiber, 16% oil, 11% proteins, and 7% complex phenols such as tannins. Grape seeds are rich sources of flavonoids and contain monomers, dimers, trimers, oligomers, and polymers. The monomeric compounds includes (+)-catechins, (−)-epicatechin, and (−)-epicatechin-3-O-gallate. Studies have reported that grape seeds exhibit a broad spectrum of pharmacological properties against oxidative stress. Their potential health benefits include protection against oxidative damage, and anti-diabetic, anti-cholesterol, and anti-platelet functions. Recognition of such health benefits of proanthocyanidins has led to the use of grape seeds as a dietary supplement by the consumers. This paper summarizes the studies of the phytochemical compounds, pharmacological properties, and industrial applications of grape seeds.

Comparison of direct sequencing and amplification refractory mutation system for detecting epidermal growth factor receptor mutation in non-small-cell lung cancer patients: a systematic review and meta-analysis

BACKGROUND

Direct sequencing and amplification refractory mutation system (ARMS) are commonly used to detect epidermal growth factor receptor (EGFR) mutation status in patients with non-small-cell lung cancer to inform the decision-making on tyrosine kinase inhibitors treatment. This study aimed to systematically compare the two methods in terms of the rate of detected mutations and the association of detected mutations with clinical outcomes.

MATERIAL AND METHODS

PubMed, EMBASE, China National Knowledge Infrastructure (in Chinese) and Wanfang database (in Chinese) were searched to identify relevant studies. Meta-analyses of EGFR mutation rates, rate differences, and the associations of EGFR mutations with clinical outcomes of tyrosine kinase inhibitors treatment were conducted.

RESULTS

Eight hundred and sixty-six records were retrieved and 26 studies with 3282 patients were included. The pooled rate of mutations detected by ARMS (41%, 95% confidence interval (CI) 35% to 47%) was significantly higher than that by direct sequencing (28%, 95%CI 22% to 34%), with a weighted rate difference of 11% (95%CI 8% to 13%). There was a consistent trend that the associations between ARMS-detected mutations and clinical outcomes were stronger than those between direct-sequencing-detected mutations and clinical outcomes (pooled risk ratio for objective response: 5.18 vs. 2.25; hazard ratio for progression-free survival: 0.30 vs. 0.42; hazard ratio for overall survival: 0.46 vs. 0.54).

CONCLUSIONS

More patients with EGFR mutations can be identified by ARMS than by direct sequencing, and those identified by ARMS seems to be able to benefit more from tyrosine kinase inhibitors than those identified by direct sequencing.

Dietary Polyphenols, Mediterranean Diet, Prediabetes, and Type 2 Diabetes: A Narrative Review of the Evidence

Dietary polyphenols come mainly from plant-based foods including fruits, vegetables, whole grains, coffee, tea, and nuts. Polyphenols may influence glycemia and type 2 diabetes (T2D) through different mechanisms, such as promoting the uptake of glucose in tissues, and therefore improving insulin sensitivity. This review aims to summarize the evidence from clinical trials and observational prospective studies linking dietary polyphenols to prediabetes and T2D, with a focus on polyphenol-rich foods characteristic of the Mediterranean diet. We aimed to describe the metabolic biomarkers related to polyphenol intake and genotype-polyphenol interactions modulating the effects on T2D. Intakes of polyphenols, especially flavan-3-ols, and their food sources have demonstrated beneficial effects on insulin resistance and other cardiometabolic risk factors. Several prospective studies have shown inverse associations between polyphenol intake and T2D. The Mediterranean diet and its key components, olive oil, nuts, and red wine, have been inversely associated with insulin resistance and T2D. To some extent, these associations may be attributed to the high amount of polyphenols and bioactive compounds in typical foods conforming this traditional dietary pattern. Few studies have suggested that genetic predisposition can modulate the relationship between polyphenols and T2D risk. In conclusion, the intake of polyphenols may be beneficial for both insulin resistance and T2D risk.

Dietary polyphenol intake and risk of type 2 diabetes in the Polish arm of the Health, Alcohol and Psychosocial factors in Eastern Europe (HAPIEE) study

This study aimed to test the association between dietary content of total and individual classes of polyphenols and incident cases of type 2 diabetes in Polish adults participating to the Health, Alcohol and Psychosocial factors In Eastern Europe study. At baseline, diet by 148-item FFQ and health information were collected from 5806 participants free of diabetes. Self-reported incident type 2 diabetes was ascertained at 2–4-year follow-up visit. OR and 95 % CI of type 2 diabetes comparing the various categories of polyphenol intake to the lowest one (reference category) and as 1 sd increase modelled as continuous variable were calculated by performing age-, energy-, and multivariate-adjusted logistic regression models. During the follow-up, 456 incident cases of type 2 diabetes occurred. When comparing extreme quartiles, intake of total polyphenol was inversely associated with the risk of type 2 diabetes (OR 0·43; 95 % CI 0·30, 0·61); 1 sd increase was associated with a reduced risk of diabetes (OR 0·68; 95 % CI 0·59, 0·79). Among the main classes of polyphenols, flavonoids, phenolic acids, and stilbenes were independent contributors to this association. Both subclasses of phenolic acids were associated with decreased risk of type 2 diabetes, whereas among subclasses of flavonoids, high intake of flavanols, flavanones, flavones and anthocyanins was significantly associated with decreased risk of type 2 diabetes. Total dietary polyphenols and some classes of dietary polyphenols were associated with lower risk of type 2 diabetes.

Unfolding Novel Mechanisms of Polyphenol Flavonoids for Better Glycaemic Control: Targeting Pancreatic Islet Amyloid Polypeptide (IAPP)

Type 2 diabetes (T2D) is characterised by hyperglycaemia resulting from defective insulin secretion, insulin resistance, or both. The impact of over-nutrition and reduced physical activity, evidenced by the exponential rise in obesity and the prevalence of T2D, strongly supports the implementation of lifestyle modification programs. Accordingly, an increased consumption of fruits and plant-derived foods has been advocated, as their intake is inversely correlated with T2D prevalence; this has been attributed, in part, to their contained polyphenolic compounds. Over the last decade, a body of work has focussed on establishing the mechanisms by which polyphenolic compounds exert beneficial effects to limit carbohydrate digestion, enhance insulin-mediated glucose uptake, down-regulate hepatic gluconeogenesis and decrease oxidative stress; the latter anti-oxidative property being the most documented. Novel effects on the inhibition of glucocorticoid action and the suppression of amylin misfolding and aggregation have been identified more recently. Amyloid fibrils form from spontaneously misfolded amylin, depositing in islet cells to elicit apoptosis, beta cell degeneration and decrease insulin secretion, with amyloidosis affecting up to 80% of pancreatic islet cells in T2D. Therefore, intervening with polyphenolic compounds offers a novel approach to suppressing risk or progression to T2D. This review gives an update on the emerging mechanisms related to dietary polyphenol intake for the maintenance of glycaemic control and the prevention of T2D.

Significance of Microbiota in Obesity and Metabolic Diseases and the Modulatory Potential by Medicinal Plant and Food Ingredients

Metabolic syndrome is a cluster of three or more metabolic disorders including insulin resistance, obesity, and hyperlipidemia. Obesity has become the epidemic of the twenty-first century with more than 1.6 billion overweight adults. Due to the strong connection between obesity and type 2 diabetes, obesity has received wide attention with subsequent coining of the term "diabesity." Recent studies have identified unique contributions of the immensely diverse gut microbiota in the pathogenesis of obesity and diabetes. Several mechanisms have been proposed including altered glucose and fatty acid metabolism, hepatic fatty acid storage, and modulation of glucagon-like peptide (GLP)-1. Importantly, the relationship between unhealthy diet and a modified gut microbiota composition observed in diabetic or obese subjects has been recognized. Similarly, the role of diet rich in polyphenols and plant polysaccharides in modulating gut bacteria and its impact on diabetes and obesity have been the subject of investigation by several research groups. Gut microbiota are also responsible for the extensive metabolism of polyphenols thus modulating their biological activities. The aim of this review is to shed light on the composition of gut microbes, their health importance and how they can contribute to diseases as well as their modulation by polyphenols and polysaccharides to control obesity and diabetes. In addition, the role of microbiota in improving the oral bioavailability of polyphenols and hence in shaping their antidiabetic and antiobesity activities will be discussed.

Association of Dietary Flavonoid Intake with Prevalence of Type 2 Diabetes Mellitus and Cardiovascular Disease Risk Factors in Korean Women Aged ≥30 Years

The purpose of this study was to investigate the association between dietary flavonoid intake and the prevalence of type 2 diabetes mellitus (T2DM) and cardiovascular disease (CVD) risk factors among Korean women aged ≥30 y. This study used data collected from the 2007-2012 Korean National Health and Nutrition Examination Survey. We excluded subjects who had energy intake <500 kcal or ≥5,000 kcal, were diagnosed with chronic disease, were taking medication, or were pregnant or lactating. The final subjects included 7,963 women, and they were divided into 2 groups, the normal fasting glucose (NFG) group (n=7,738) and the T2DM group (n=225). The intake of flavonoids was estimated on the basis of the flavonoid database. After adjustment for confounding factors, the mean intakes of fruits, anthocyanidins, and flavones were significantly lower in the T2DM group than in the NFG group. In multiple regression analysis, the dietary flavone intake was negatively associated with systolic blood pressure, triglyceride, TG/HDL-cholesterol, and homesostatic model assessment of insulin resistance. Daily intake of flavones above the 25th percentile was associated with a lower prevalence of T2DM compared with intake below the 25th percentile (OR=0.593, 95% confidence interval (CI): 0.414-0.847). These study results showed that dietary flavone intake may have some beneficial effects in reducing CVD risks and prevalence of T2DM in Korean women.

Chlorogenic acid isomer contents in 100 plants commercialized in Brazil

This study analysed 100 plants employed in Brazil as ingredients to infusions for their caffeic acid, 3-caffeoylquinic acid (3-CQA), 4-caffeoylquinic acid (4-CQA), 5-caffeoylquinic acid (5-CQA), 3,4-dicaffeoylquinic acid (3,4-DQA), 3,5-dicaffeoylquinic acid (3,5-DQA), and 4,5-dicaffeoylquinic acid (4,5-DQA) contents. The samples were collected from public markets and analysed using ultra-high performance liquid chromatography (UPLC). The highest concentrations of chlorogenic acids were found in yerba mate (Ilex paraguariensis), 9,2g·100g^-1, white tea (Camellia sinensis), winter's bark (Drimys winteri), green tea (Camellia sinensis), elderflower (Sambucus nigra), and Boehmeria caudata (known as assa-peixe in Brazil), 1,1g·100g^-1. The present work showcased the investigation of chlorogenic acids in a wide range of plants not yet studied in this regard and also resulted in a comparative table which explores the content of six isomers in the samples.

A Critical Review on Polyphenols and Health Benefits of Black Soybeans

Polyphenols are plant secondary metabolites containing antioxidant properties, which help to protect chronic diseases from free radical damage. Dietary polyphenols are the subject of enhancing scientific interest due to their possible beneficial effects on human health. In the last two decades, there has been more interest in the potential health benefits of dietary polyphenols as antioxidant. Black soybeans (Glycine max L. Merr) are merely a black variety of soybean containing a variety of phytochemicals. These phytochemicals in black soybean (BSB) are potentially effective in human health, including cancer, diabetes, cardiovascular diseases, cerebrovascular diseases, and neurodegenerative diseases. Taking into account exploratory study, the present review aims to provide up-to-date data on health benefit of BSB, which helps to explore their therapeutic values for future clinical settings. All data of in vitro and in vivo studies of BSB and its impact on human health were collected from a library database and electronic search (Science Direct, PubMed, and Google Scholar). The different pharmacological information was gathered and orchestrated in a suitable spot on the paper.

Flavonoid intake and mortality from cardiovascular disease and all causes: A meta-analysis of prospective cohort studies

BACKGROUND AND AIMS

Accumulating studies have suggested that flavonoid intake is associated with a decreased risk of coronary heart disease and cardiovascular disease (CVD). There are many epidemiological studies on flavonoid intake and mortality, but no comprehensive investigation has yet been conducted. To quantitatively assess the association between flavonoid intake and mortality from CVD and all-causes, we performed a meta-analysis of prospective cohort studies.

METHODS

Eligible studies were identified by searching PubMed and Web of Science databases for all articles published up to May 2016 and via hand searching. Study-specific estimates adjusting for potential confounders were combined to calculate a pooled relative risk (RR) with 95% confidence interval (CI) using a random-effects model.

RESULTS

A total of 15 prospective cohort studies that examined the association between flavonoid intake and mortality from CVD and all-causes were identified. The pooled RR of CVD mortality for the highest versus lowest category of flavonoid intake was 0.86 (95% CI: 0.75, 0.98). By subclass of flavonoids, all classes, except flavonols and isoflavones, showed significant inverse associations. A nonlinear association was found between flavonoid intake and CVD mortality in the dose-response analysis. For total mortality, a high intake of flavonoids was associated with lower total mortality (pooled RR = 0.86, 95% CI: 0.73, 1.00).

CONCLUSIONS

Our findings indicate that a high intake of flavonoids is associated with reduced risk of mortality from CVD and all causes in men and women. These results support current recommendations of high fruit and vegetables intake as a part of a healthy diet.

Legume consumption is inversely associated with type 2 diabetes incidence in adults: A prospective assessment from the PREDIMED study

BACKGROUND & AIMS

Legumes, a low-energy, nutrient-dense and low glycemic index food, have shown beneficial effects on glycemic control and adiposity. As such, legumes are widely recommended in diabetic diets, even though there is little evidence that their consumption protects against type 2 diabetes. Therefore the aim of the present study was to examine the associations between consumption of total legumes and specific subtypes, and type 2 diabetes risk. We also investigated the effect of theoretically substituting legumes for other protein- or carbohydrate-rich foods.

METHODS

Prospective assessment of 3349 participants in the PREvención con DIeta MEDiterránea (PREDIMED) study without type 2 diabetes at baseline. Dietary information was assessed at baseline and yearly during follow-up. We used Cox regression models to estimate hazard ratios (HRs) and 95% confidence intervals (95% CIs) for type-2 diabetes incidence according to quartiles of cumulative average consumption of total legumes, lentils, chickpeas, dry beans and fresh peas.

RESULTS

During a median follow-up of 4.3 years, 266 new cases of type 2 diabetes occurred. Individuals in the highest quartile of total legume and lentil consumption had a lower risk of diabetes than those in the lowest quartile (HR: 0.65; 95% CI: 0.43, 0.96; P-trend = 0.04; and HR: 0.67; 95% CI: 0.46-0.98; P-trend = 0.05, respectively). A borderline significant association was also observed for chickpeas consumption (HR 0.68; 95% CI: 0.46, 1.00; P-trend = 0.06). Substitutions of half a serving/day of legumes for similar servings of eggs, bread, rice or baked potato was associated with lower risk of diabetes incidence.

CONCLUSIONS

A frequent consumption of legumes, particularly lentils, in the context of a Mediterranean diet, may provide benefits on type 2 diabetes prevention in older adults at high cardiovascular risk.

TRIAL REGISTRATION

The trial is registered at http://www.controlled-trials.com (ISRCTN35739639). Registration date: 5th October 2005.

Absorption Profile of (Poly)Phenolic Compounds after Consumption of Three Food Supplements Containing 36 Different Fruits, Vegetables, and Berries

The market of plant-based nutraceuticals and food supplements is continuously growing due to the increased consumer demand. The introduction of new products with relevant nutritional characteristics represents a new way of providing bioactive compounds and (poly)phenols to consumers, becoming a strategy to ideally guarantee the health benefits attributed to plant foodstuffs and allowing the increase of daily bioactive compound intake. A paramount step in the study of nutraceuticals is the evaluation of the bioavailability and metabolism of their putatively active components. Therefore, the aim of the present study was to investigate the absorption profile of the (poly)phenolic compounds contained in three different plant-based food supplements, made of 36 different plant matrices, which were consumed by 20 subjects in an open one-arm study design. Blood samples were collected at baseline and 1, 2, 5, and 10 h after capsule intake. Twenty quantifiable metabolites deriving from different (poly)phenolic compounds were identified. Results showed that the consumption of the three capsules allowed the effective absorption of several (poly)phenolic compounds and metabolites appearing at different times in plasma, thereby indicating different absorption profiles. The capsules thus ensured potential health-promoting molecules to be potentially available to target tissues and organs.

The 3-dimensional miniplate is more effective than the standard miniplate for the management of mandibular fractures: a meta-analysis

PURPOSE

The study aimed to determine the superiority between 3-dimensional (3D) miniplate and standard miniplate for mandibular fractures (MFs) treatment.

BACKGROUND

Controversial results on the use of standard miniplate and 3D miniplate have remained for management of MFs.

METHODS

Several electronic databases were retrieved up to September 2014 to identify eligible studies. The quality of studies was assessed, and the relative risk (RR) with its corresponding 95% confidence interval (CI) was assessed to measure the effect size. Subgroup analyses by different fracture regions and different 3D miniplate sizes were performed. Publication bias was measured by a funnel plot.

RESULTS

There were 13 studies included for the meta-analysis, consisting of 593 participants. The 3D miniplate achieved significant lower incidences of malocclusion (RR 0.43, 95% CI 0.24-0.77, P = 0.004) and hardware failure (RR 0.31, 95% CI 0.13-0.74, P = 0.008) than the standard miniplate. There were no significant differences between the two miniplates on the incidence of the remaining outcomes: wound dehiscence, infection, paresthesia, and nonunion/malunion. Subgroup analyses indicated that 3D miniplate caused a lower hardware failure than standard with the size of 8 or 10 holes (RR 0.23, 95% CI 0.08-0.66, P = 0.006). Besides, publication bias was not detected.

CONCLUSION

The 3D miniplate is superior to the standard miniplate on the reduction of postoperative complication rates for the management of MFs. More holes in the 3D miniplate might contribute to a successful treatment.

Dietary sources of polyphenols in the Mediterranean healthy Eating, Aging and Lifestyle (MEAL) study cohort

The aim of this study was to estimate the dietary intake and major food sources of polyphenols in the Mediterranean healthy Eating, Aging and Lifestyles (MEAL) study cohort. A total of 1937 individuals (18 + y) of urban population of Catania, Italy, completed a validated 110-item food frequency questionnaire; Phenol-Explorer database was used to estimate polyphenol intake. Mean intake of polyphenols was 663.7 mg/d; the most abundant classes were phenolic acids (362.7 mg/d) and flavonoids (258.7 mg/d). The main dietary sources of total polyphenols were nuts, followed by tea and coffee as source of flavanols and hydroxycinnamic acids, respectively, fruits (i.e. cherries were sources of anthocyanins and citrus fruits of flavanones) and vegetables (i.e. artichokes and olives were sources of flavones and spinach and beans of flavonols); chocolate, red wine and pasta contributed to flavanols and tyrosols, respectively. These findings will be useful to assess the potential benefits of foods with high polyphenol content.

Flavonoids

Diabetes Mellitus is one of the major healthcare problems faced by the society today and has become alarmingly epidemic in many parts of the world. Despite enormous knowledge and technology advancement, available diabetes therapeutics only provide symptomatic relief by reducing blood glucose level, thereby, just slows down development and progression of diabetes and its associated complications. Thus, the need of the day is to develop alternate strategies that can not only prevent the progression but also reverse already “set-in” diabetic complications. Many flavonoids are reported, traditionally as well as experimentally, to be beneficial in averting diabetes and lowering risk of its accompanying complications. In the present chapter we have convened different flavonoids beneficial in diabetes and comorbid complications and discussed their mechanisms of action. Further, we conclude that coupling current therapeutics with flavonoids might provide exceptional advantage in the management of diabetes and its complications.

Grape Polyphenols' Effects in Human Cardiovascular Diseases and Diabetes

The consumption of fruits and vegetables, as well as foods enriched in bioactive compounds and nutraceuticals, has increased due to consumers' interest in the relevance of food composition for human health. Considerable recent interest has focused on bioactive phenolic compounds in grape, as they possess many biological activities, such as antioxidant, cardioprotective, anticancer, anti-inflammation, anti-ageing and antimicrobial properties. Observational studies indicate that the intake of polyphenol-rich foods improves vascular health, thereby significantly reducing the risk of hypertension, and cardiovascular disease (CVD). Other researchers have described the benefits of a grape polyphenol-rich diet for other types of maladies such as diabetes mellitus. This is a comprehensive review on the consumption of polyphenolic grape compounds, concerning their potential benefits for human health in the treatment of cardiovascular diseases and diabetes.

Quercetin intake, MATE1 polymorphism, and metabolic syndrome in Korean population: Hallym aging study

Multidrug and toxic compound extrusion transporter-1 (MATE1) is a quercetin transporter. We examined the associations of quercetin intake and polymorphism of MATE1 in relation to metabolic syndrome (MetS) in Hallym Aging Study. Quercetin intake and the measurements for MetS were assessed in 2004. Six tagging single nucleotide polymorphisms (SNPs) at MATE1 gene were genotyped in 428 Korean adults in 2012. We found a lower prevalence of MetS with quercetin intake; compared to the lowest quartile, odds ratios (ORs, 95% confidence intervals; CIs) were 0.44 (0.24-0.84) for the 3^rd quartile. Individuals with the minor allele of MATE1, rs2453589, tended to have a lower prevalence of MetS compared to those with the major allele (OR=0.69; CI=0.36-1.34). However, interactions between quercetin intake and six MATE1 polymorphisms in relation to MetS were not significant (p for interaction ≥0.37). In conclusion, intake of quercetin was associated with MetS in Korean populations.

Coffee consumption and risk of all-cause, cardiovascular, and cancer mortality in smokers and non-smokers: a dose-response meta-analysis

Coffee consumption has been associated with several benefits toward human health. However, its association with mortality risk has yielded contrasting results, including a non-linear relation to all-cause and cardiovascular disease (CVD) mortality and no association with cancer mortality. As smoking habits may affect the association between coffee and health outcomes, the aim of the present study was to update the latest dose-response meta-analysis of prospective cohort studies on the association between coffee consumption and mortality risk and conduct stratified analyses by smoking status and other potential confounders. A systematic search was conducted in electronic databases to identify relevant studies, risk estimates were retrieved from the studies, and dose-response analysis was modeled by using restricted cubic splines. A total of 31 studies comprising 1610,543 individuals and 183,991 cases of all-cause, 34,574 of CVD, and 40,991 of cancer deaths were selected. Analysis showed decreased all-cause [relative risk (RR) = 0.86, 95 % confidence interval (CI) = 0.82, 0.89)] and CVD mortality risk (RR = 0.85, 95 % CI = 0.77, 0.93) for consumption of up to 4 cups/day of coffee, while higher intakes were associated with no further lower risk. When analyses were restricted only to non-smokers, a linear decreased risk of all-cause (RR = 0.94, 95 % CI = 0.93, 0.96), CVD (RR = 0.94, 95 % CI = 0.91, 0.97), and cancer mortality (RR = 0.98, 95 % CI = 0.96, 1.00) for 1 cup/day increase was found. The search for other potential confounders, including dose-response analyses in subgroups by gender, geographical area, year of publication, and type of coffee, showed no relevant differences between strata. In conclusion, coffee consumption is associated with decreased risk of mortality from all-cause, CVD, and cancer; however, smoking modifies the observed risk when studying the role of coffee on human health.

Flavonoid and lignan intake and pancreatic cancer risk in the European prospective investigation into cancer and nutrition cohort

Despite the potential cancer preventive effects of flavonoids and lignans, their ability to reduce pancreatic cancer risk has not been demonstrated in epidemiological studies. Our aim was to examine the association between dietary intakes of flavonoids and lignans and pancreatic cancer risk in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort. A total of 865 exocrine pancreatic cancer cases occurred after 11.3 years of follow-up of 477,309 cohort members. Dietary flavonoid and lignan intake was estimated through validated dietary questionnaires and the US Department of Agriculture (USDA) and Phenol Explorer databases. Hazard ratios (HR) and 95% confidence intervals (CIs) were calculated using age, sex and center-stratified Cox proportional hazards models, adjusted for energy intake, body mass index (BMI), smoking, alcohol and diabetes status. Our results showed that neither overall dietary intake of flavonoids nor of lignans were associated with pancreatic cancer risk (multivariable-adjusted HR for a doubling of intake = 1.03, 95% CI: 0.95-1.11 and 1.02; 95% CI: 0.89-1.17, respectively). Statistically significant associations were also not observed by flavonoid subclasses. An inverse association between intake of flavanones and pancreatic cancer risk was apparent, without reaching statistical significance, in microscopically confirmed cases (HR for a doubling of intake = 0.96, 95% CI: 0.91-1.00). In conclusion, we did not observe an association between intake of flavonoids, flavonoid subclasses or lignans and pancreatic cancer risk in the EPIC cohort.

Consumption of citrus and cruciferous vegetables with incident type 2 diabetes mellitus based on a meta-analysis of prospective study

BACKGROUND

Observational studies and meta-analyses suggested that increased total fruits and vegetables consumption have a protective role in incidence of type 2 diabetes mellitus (T2DM). However, we still don't know whether the subtypes, such as citrus fruits and cruciferous vegetables (CV), have a preventive role.

METHODS

We systematically searched the MEDLINE and EMBASE databases up to December 31, 2014. Summary relative risks (SRRs) and 95% confidence intervals (CIs) were calculated using random-effects models.

RESULTS

Seven distinct prospective cohort studies (five articles) were identified for this study. A total of 16,544 incident cases of type 2 diabetes were ascertained among 306,723 participants with follow-up periods ranging from 4.6 to 24 years. Based on four prospective cohort studies, we found that overall, consumption of CV had a protective role in the T2DM incidence (highest vs. lowest analysis: SRR=0.84, 95% CI: 0.73 to 0.96), with evidence of significant heterogeneity (P=0.09, I(2)=54.4%). This association was independent of the main risk factors for cardiovascular disease: smoking, alcohol use, BMI, and physical activity etc. Consumption of citrus fruits did not have a protective role in the T2DM development (highest vs. lowest analysis: SRR=1.02, 95% CI: 0.96 to 1.08), with no evidence of significant heterogeneity (P=0.49, I(2)=0).

CONCLUSIONS

Higher consumption of CV, but not citrus fruits, is associated with a significantly decreased risk of type 2 diabetes. Further large prospective studies are needed to elucidate both relationships.

Metabolic transformations of dietary polyphenols: comparison between in vitro colonic and hepatic models and in vivo urinary metabolites

Studies on metabolism of polyphenols have revealed extensive transformations in the carbon backbone by colonic microbiota; however, the influence of microbial and hepatic transformations on human urinary metabolites has not been explored. Therefore, the aims of this study were (1) to compare the in vitro microbial phenolic metabolite profile of foods and beverages with that excreted in urine of subjects consuming the same foodstuff and (2) to explore the role of liver on postcolonic metabolism of polyphenols by using in vitro hepatic models. A 24-h urinary phenolic metabolite profile was evaluated in 72 subjects participating in an 8-week clinical trial during which they were randomly assigned to diets differing for polyphenol content. Polyphenol-rich foods and beverages used in the clinical trial were subjected to human fecal microbiota in the in vitro colon model. Metabolites from green tea, one of the main components of the polyphenol-rich diet, were incubated with primary hepatocytes to highlight hepatic conversion of polyphenols. The analyses were performed using targeted gas chromatography with mass spectrometer (GCxGC-TOFMS:colon model; GC-MS: urine and hepatocytes). A significant correlation was found between urinary and colonic metabolites with C1-C3 side chain (P=.040). However, considerably higher amounts of hippuric acid, 3-hydroxybenzoic acid and ferulic acid were detected in urine than in the colon model. The hepatic conversion showed additional amounts of these metabolites complementing the gap between in vitro colon model and the in vivo urinary excretion. Therefore, combining in vitro colon and hepatic models may better elucidate the metabolism of polyphenols from dietary exposure to urinary metabolites.

Dietary polyphenols are inversely associated with metabolic syndrome in Polish adults of the HAPIEE study

Purpose

The aim of this study was to evaluate the association between total and individual classes and subclasses of dietary polyphenol intake and prevalence of metabolic syndrome (MetS) in the Polish arm of the Health, Alcohol and Psychosocial factors In Eastern Europe cohort study.

Methods

A cross-sectional population-based survey including 8821 adults (51.4 % female) was conducted in Kraków, Poland. Dietary polyphenol intake was evaluated using food frequency questionnaires and matching food consumption data with the Phenol-Explorer database. MetS was defined according to the International Diabetes Federation definition. Linear and logistic regression models were performed to estimate odds ratios (ORs) and confidence intervals (CIs).

Results

Significant differences in age and energy intake among different categories of total dietary polyphenol intake were found. Body mass index (BMI), waist circumference (WC), blood pressure, and triglycerides were significantly lower among individuals in the higher quartiles of polyphenol intake, but a linear association was found only for BMI and WC. After adjusting for potential confounding factors, individuals in the highest quartile of polyphenol intake were less likely to have MetS (OR 0.80; 95 % CI 0.64, 0.98 and OR 0.70; 95 % CI 0.56, 0.86 for both men and women, respectively). High total polyphenol intake was negatively associated with WC, blood pressure, high lipoprotein cholesterol, and triglycerides in women, and fasting plasma glucose in both genders. Among individual classes of polyphenols, phenolic acids and stilbenes were significantly associated with MetS; lignans and stilbenes with WC; phenolic acids with blood pressure and triglycerides; and flavonoids with fasting plasma glucose. Among specific subclasses of polyphenols, hydroxycinnamic acids, flavanols, and dihydrochalcones had the most relevant role.

Conclusions

Total and individual classes and subclasses of dietary polyphenols were inversely associated with MetS and some of its components.

Electronic supplementary material

The online version of this article (doi:10.1007/s00394-016-1187-z) contains supplementary material, which is available to authorized users.

Characteristics and Health Benefits of Phytochemicals

In food science the term 'phytochemicals' includes a variety of plant ingredients with different structures that are capable of health-promoting effects. Phytonutrients are natural substances but are not called nutrients in the traditional sense, since they are synthesized by plants neither in energy metabolism nor in anabolic or catabolic metabolism, but only in specific cell types. They differ from primary plant compounds in that they are not essential to the plant. Phytonutrients perform important tasks in the secondary metabolism of plants as repellents to pests and sunlight as well as growth regulators. They occur only in low concentrations and usually have a pharmacological effect. Since antiquity, these effects have been used in naturopathy in the form of medicinal herbs, spices, teas, and foods. With the development of highly sensitive analytical methods, a variety of these substances could be identified. These phytochemicals may have health benefits or adverse health effects, depending on the dosage. In the past, these effects were studied in cell and tissue cultures as well as in animal models. Meanwhile there are numerous epidemiological data that point to the extensive health potential of phytochemicals in humans. A high dietary intake of phytochemicals with vegetables, fruits, nuts, legumes, and whole grain is associated with a reduced risk for cardiovascular and other diseases.

Association between vitamin C Intake and the risk of cervical neoplasia: A meta-analysis

To assess the association between vitamin C intake and cervical neoplasia (CN) risk. Databases including PubMed, Embase, and Springer link were retrieved up to June 10, 2014 with predefined strategy. The combined odds ratios (ORs) and their 95% confidence intervals (CIs) were calculated for overall and subgroup analyses. The publication bias was assessed using Begg's test and Egger's test. Sensitivity analysis was also conducted. Twelve studies consisting of 1 prospective cohort study and 11 case-control studies were included. In overall analysis, vitamin C intake was significantly associated with the reduced risk of CN (OR = 0.58; 95% CI: 0.44 to 0.75; P < 0.001). Subgroup analysis stratified by vitamin C dose indicated all dose categories achieved a reduced CN risk. Furthermore, increased vitamin C intake by 50 mg/day was related to the reduced risk of CN (OR = 0.92; 95% CI: 0.89 to 0.94; P < 0.05). No publication bias was detected by Begg's test (P = 0.169) and no apparent fluctuation was observed in summary OR by sensitivity analysis. Vitamin C intake was inversely associated with the risk of CN and this association was dose-dependent. However, more randomized controlled trials are required for further validation.

Improving the estimation of flavonoid intake for study of health outcomes

Imprecision in estimating intakes of non-nutrient bioactive compounds such as flavonoids is a challenge in epidemiologic studies of health outcomes. The sources of this imprecision, using flavonoids as an example, include the variability of bioactive compounds in foods due to differences in growing conditions and processing, the challenges in laboratory quantification of flavonoids in foods, the incompleteness of flavonoid food composition tables, and the lack of adequate dietary assessment instruments. Steps to improve databases of bioactive compounds and to increase the accuracy and precision of the estimation of bioactive compound intakes in studies of health benefits and outcomes are suggested.

Synthetic sugar cassettes for the efficient production of flavonol glycosides in Escherichia coli

Background

A multi-monocistronic synthetic vector was used to assemble multiple genes of a nucleotide diphosphate (NDP)-sugar biosynthetic pathway to construct robust genetic circuits for the production of valuable flavonoid glycosides in Escherichia coli. Characterized functional genes involved in the biosynthesis of uridine diphosphate (UDP)-glucose and thymidine diphosphate (TDP)-rhamnose from various microbial sources along with glucose facilitator diffusion protein (glf) and glucokinase (glk) from Zymomonas mobilis were assembled and overexpressed in a single synthetic multi-monocistronic operon.

Results

The newly generated NDP-sugars biosynthesis circuits along with regiospecific glycosyltransferases from plants were introduced in E. coli BL21 (DE3) to probe the bioconversion of fisetin, a medicinally important polyphenol produced by various plants. As a result, approximately 1.178 g of fisetin 3-O-glucoside and 1.026 g of fisetin 3-O-rhamnoside were produced in UDP-glucose and TDP-rhamnose biosynthesis systems respectively, after 48 h of incubation in 3 L fermentor while supplementing 0.9 g of fisetin. These yields of fisetin glycosides represent ~99% of bioconversion of exogenously supplemented fisetin. The systems were also found to be highly effective in bio-transforming other flavonols (quercetin, kaempferol, myricetin) into their respective glycosides, achieving over 95% substrate conversion.

Conclusion

The construction of a synthetic expression vector for bacterial cell factory followed by subsequent re-direction of metabolic flux towards desirable products have always been revolutionized the biotechnological processes and technologies. This multi-monocistronic synthetic vector in a microbial platform is customizable to defined task and would certainly be useful for applications in producing and modifying such therapeutically valued plant secondary metabolites.

Electronic supplementary material

The online version of this article (doi:10.1186/s12934-015-0261-1) contains supplementary material, which is available to authorized users.

A New Database Facilitates Characterization of Flavonoid Intake, Sources, and Positive Associations with Diet Quality among US Adults

BACKGROUND

Epidemiologic studies demonstrate inverse associations between flavonoid intake and chronic disease risk. However, lack of comprehensive databases of the flavonoid content of foods has hindered efforts to fully characterize population intakes and determine associations with diet quality.

OBJECTIVES

Using a newly released database of flavonoid values, this study sought to describe intake and sources of total flavonoids and 6 flavonoid classes and identify associations between flavonoid intake and the Healthy Eating Index (HEI) 2010.

METHODS

One day of 24-h dietary recall data from adults aged ≥ 20 y (n = 5420) collected in What We Eat in America (WWEIA), NHANES 2007-2008, were analyzed. Flavonoid intakes were calculated using the USDA Flavonoid Values for Survey Foods and Beverages 2007-2008. Regression analyses were conducted to provide adjusted estimates of flavonoid intake, and linear trends in total and component HEI scores by flavonoid intake were assessed using orthogonal polynomial contrasts. All analyses were weighted to be nationally representative.

RESULTS

Mean intake of flavonoids was 251 mg/d, with flavan-3-ols accounting for 81% of intake. Non-Hispanic whites had significantly higher (P < 0.001) intakes of total flavonoids (275 mg/d) than non-Hispanic blacks (176 mg/d) and Hispanics (139 mg/d). Tea was the primary source (80%) of flavonoid intake. Regardless of whether the flavonoid contribution of tea was included, total HEI score and component scores for total fruit, whole fruit, total vegetables, greens and beans, seafood and plant proteins, refined grains, and empty calories increased (P < 0.001) across flavonoid intake quartiles.

CONCLUSIONS

A new database that permits comprehensive estimation of flavonoid intakes in WWEIA, NHANES 2007-2008; identification of their major food/beverage sources; and determination of associations with dietary quality will lead to advances in research on relations between flavonoid intake and health. Findings suggest that diet quality, as measured by HEI, is positively associated with flavonoid intake.

Hypoglycemic effects of aqueous persimmon leaf extract in a murine model of diabetes

Previously, powdered persimmon leaves have been reported to have glucose- and lipid-lowering effects in diabetic (db/db) mice. As persimmon leaf is commonly consumed as tea, an aqueous extract of persimmon leaves (PLE) was prepared and its anti-diabetic efficacy was investigated. In the present study, PLE was tested for its inhibitory activity on α-glucosidase in vitro. An oral maltose tolerance test was performed in diabetic mice. Next, the acute effect of PLE was examined in streptozotocin-induced diabetic mice. Last, the long-term effect of PLE supplementation was assessed in db/db after eight weeks. An oral glucose tolerance test, biochemical parameters, as well as histological analyses of liver and pancreas were evaluated at the end of the study. PLE inhibited α-glucosidase activity and increased antioxidant capacity. Streptozotocin-induced diabetic mice pre-treated with PLE displayed hypoglycemic activity. Daily oral supplementation with PLE for eight weeks reduced body weight gain without affecting food intake, enhanced the glucose tolerance during the oral glucose tolerance test (OGTT), improved blood lipid parameters, suppressed fat accumulation in the liver and maintained islet structure in db/db mice. Further mechanistic study showed that PLE protected pancreatic islets from glucotoxicity. In conclusion, the results of the present study indicated that PLE exhibits considerable anti-diabetic effects through α-glucosidase inhibition and through the maintenance of functional β-cells. These results provided a rationale for the use of persimmon leaf tea for the maintenance of normal blood glucose levels in diabetic patients.

Neuroprotective Effects of Rutin in Streptozotocin-Induced Diabetic Rat Retina

Diabetic retinopathy is widely recognized as a neurodegenerative disease of the eye. Increased oxidative stress has been considered the central factor in damaging neural retina in diabetes. Flavonoids, being powerful antioxidants, play protective roles in several oxidative stress-mediated neurodegenerative diseases. In this study, we analyzed the neuroprotective effects of a potential flavonoid, rutin, in the diabetic rat retina. Diabetes was induced in male Wistar rats by single injection of streptozotocin (65 mg/kg). In age-matched control (non-diabetic) and 1 week of diabetic rats, rutin (100 mg/kg/day) was orally administered and continued for 5 weeks. In another group of diabetic rats, only saline was supplemented. After treatments, retinas from all the groups were isolated and analyzed for potential neurotrophic factors and apoptotic and oxidative stress markers using biochemical and immunoblotting techniques. Our results indicate that rutin possesses antidiabetic activity, as blood glucose level decreased and insulin level increased in diabetic rats. In the diabetic retina, rutin supplementation enhanced the reduced levels of brain-derived neurotrophic factor (BDNF), nerve growth factor (NGF), and glutathione (GSH) (P < 0.05), and reduced the level of thiobarbituric acid-reactive substances (TBARS) (P < 0.05). In addition, rutin treatment showed antiapoptotic activity by decreasing the level of caspase-3 and increasing the level of Bcl-2 in the diabetic retina. These results suggest the effectiveness of rutin in ameliorating the levels of neuroprotective factors in diabetic retina. Therefore, rutin might be a potential flavonoid that can prevent the retinal damage and subsequently the development of diabetic retinopathy.

Modulation of glucose transporter protein by dietary flavonoids in type 2 diabetes mellitus

Diabetes mellitus (DM) is a metabolic diseases characterized by hyperglycemia due to insufficient or inefficient insulin secretory response. This chronic disease is a global problem and there is a need for greater emphasis on therapeutic strategies in the health system. Phytochemicals such as flavonoids have recently attracted attention as source materials for the development of new antidiabetic drugs or alternative therapy for the management of diabetes and its related complications. The antidiabetic potential of flavonoids are mainly through their modulatory effects on glucose transporter by enhancing GLUT-2 expression in pancreatic β cells and increasing expression and promoting translocation of GLUT-4 via PI3K/AKT, CAP/Cb1/TC10 and AMPK pathways. This review highlights the recent findings on beneficial effects of flavonoids in the management of diabetes with particular emphasis on the investigations that explore the role of these compounds in modulating glucose transporter proteins at cellular and molecular level.

Single-incision laparoscopic appendectomy versus conventional 3-port laparoscopic appendectomy for appendicitis: an updated meta-analysis of randomized controlled trials

PURPOSE

To compare the efficacy and safety of single-incision laparoscopic appendectomy (SILA) and conventional 3-port laparoscopic appendectomy (3-port LA) for appendectomy.

METHODS

We searched the PubMed, Embase, Springer link, and the Cochrane library databases up to April, 2014, for relevant randomized controlled trials (RCTs). Data were pooled by weighted mean differences (WMDs) or odds ratios (ORs) with their 95% confidence intervals (CIs).

RESULTS

We found 11 RCTs, with a collective total of 731 patients treated with SILA and 725 patients treated with 3-point LA. Results indicated no significant differences between SILA and 3-port LA in primary outcomes, including wound infection, intra-abdominal abscess, postoperative ileus, and total postoperative complications, and some secondary outcomes, including postoperative pain scores and length of hospital stay. However, SILA was associated with significantly longer operative times (WMD = 6.78, 95% CI = 3.78-9.79, P < 0.00001) and higher doses of analgesia (WMD = 0.96, 95% CI = 0.45-1.47, P = 0.0002) than the 3-port LA.

CONCLUSION

Although there was no significant difference in the safety of SILA vs. that of 3-port LA, our findings do not support the application of SILA because of its significantly longer operative times and the higher doses of analgesia required compared with those for 3-point LA.

Tandem mass spectrometric fragmentation behavior of lignans, flavonoids and triterpenoids in Streblus asper

RATIONALE

An unambiguous identification of compounds can be achieved by comparison of known fragmentation patterns. While the literature about fragmentation mechanisms of lignans, flavonoids and triterpenoids is few. So the present study analyses the fragmentation mechanisms of these compounds isolated from Streblus asper.

METHODS

Electrospray ionization ion trap mass spectrometry (ESI-ITMS) and atmospheric pressure chemical ionization ion trap mass spectrometry (APCI-ITMS) were used to obtain the MS(n) spectra of the compounds. By analyzing the differences between the ions, the fragmentation mechanisms of these compounds were explored.

RESULTS

Of the 29 compounds detected, 17, 7, and 5 were lignans, flavonoids and triterpenoids, respectively. The majority of lignans were found to give [M - H](-) ions of sufficient abundance for MS(n) analyses. The flavonoids were prone to the loss of CO and H2O. The triterpenoids always lost one formic acid molecule and two hydrogens, or one H2O from [M - H](-) to form the most abundant product ion in the MS(n) spectrum.

CONCLUSIONS

ESI/APCI-ITMS were demonstrated to be fast, effective and practical tools to characterize the structures of flavonoids, triterpenoids and lignans. Results of the present study can help identify the analogous constituents by analyzing their MS(n) spectra.

Coffee and beverages are the major contributors to polyphenol consumption from food and beverages in Japanese middle-aged women

Food and beverages rich in polyphenols have been shown to reduce the risk of non-communicable diseases. The present study estimated polyphenol levels and consumption from food and beverages in Japanese women. Randomly recruited housewives living in the area around Tokyo (n 109; aged 21–56 years; Group 1) recorded all beverages and foods they ingested for 7 d, and the total polyphenol (TP) consumption was estimated based on the TP content of each item measured with a modified Folin–Ciocalteu method. For Group 1, TP was consumed at 841 (sd 403) mg/d (range 113–1759 mg/d), and beverages were a larger source of TP (79 %) than food (21 %). The largest single source of TP was coffee at 47 %, followed by green tea, black tea, chocolate, beer and soya sauce, at 16, 5·7, 3·3, 3·2 and 3·1 %, respectively. In terms of food groups, cereals/noodles, vegetables, fruits, beans and seeds, and seasonings (except for soya sauce) contributed 5·0, 4·0, 1·4, 1·8 and 2·4 %, respectively. Another group of housewives who consumed at least one cup of coffee per d were separately recruited (n 100; Group 2) in the same area. Their consumption of TP was higher at 1187 (sd 371) mg/d (range 440–2435 mg/d) than Group 1 (P < 0·001), and the difference mostly came from the coffee consumption. We conclude that not food but beverages, especially coffee, may be the major contributor to TP consumption in Japanese women.

Dietary factors affecting polyphenol bioavailability

While many epidemiological studies have associated the consumption of polyphenols within fruits and vegetables with a decreased risk of developing several chronic diseases, intervention studies have generally not confirmed these beneficial effects. The reasons for this discrepancy are not fully understood but include potential differences in dosing, interaction with the food matrix, and differences in polyphenol bioavailability. In addition to endogenous factors such as microbiota and digestive enzymes, the food matrix can also considerably affect bioaccessibility, uptake, and further metabolism of polyphenols. While dietary fiber (such as hemicellulose), divalent minerals, and viscous and protein-rich meals are likely to cause detrimental effects on polyphenol bioaccessibility, digestible carbohydrates, dietary lipids (especially for hydrophobic polyphenols, e.g., curcumin), and additional antioxidants may enhance polyphenol availability. Following epithelial uptake, polyphenols such as flavonoids may reduce phase II metabolism and excretion, enhancing polyphenol bioavailability. Furthermore, polyphenols may act synergistically due to their influence on efflux transporters such as p-glycoprotein. In order to understand polyphenol bioactivity, increased knowledge of the factors affecting polyphenol bioavailability, including dietary factors, is paramount.