Dietary flavonoid intake and weight maintenance: three prospective cohorts of 124,086 US men and women followed for up to 24 years

Fluorescent Products of Anthocyanidin and Anthocyanin Oxidation

We found that the oxidation of cyanidin with hydrogen peroxide, tert-butyl hydroperoxide, 2,2'-azobis(2-methylpropionamidine), 3-morpholinosydnonimine hydrochloride, sodium hypochlorite, Fe³⁺, and Fe²⁺ induced the appearance of a new fluorescence band, centered at 525-540 nm when excited at 470-490 nm. The intensity of this fluorescence was related to the oxidant concentration. The same fluorescence was induced by the oxidation of other anthocyanidins, an anthocyanin (cyanidin-3-O-glucoside) as well as anthocyanin-rich red cabbage extract, and blackcurrant and elderberry juices. Peroxidized blood plasma also induced the appearance of cyanidin fluorescence. We also showed that the formation of the fluorescent product of pelargonidin can be observed in a culture of the MRC-5 human fetal lung fibroblast cell line and the DU-145 human prostate carcinoma cell line. Our results suggest that this new anthocyanidin/anthocyanin fluorescence may be an indicator of oxidation, especially of food products, where these compounds are present or added as colorants, and can also be useful to detect oxidation in biomedical experiments.

Role of Flavonoids in The Interactions among Obesity, Inflammation, and Autophagy

Nowadays, obesity is considered as one of the main concerns for public health worldwide, since it encompasses up to 39% of overweight and 13% obese (WHO) adults. It develops because of the imbalance in the energy intake/expenditure ratio, which leads to excess nutrients and results in dysfunction of adipose tissue. The hypertrophy of adipocytes and the nutrients excess trigger the induction of inflammatory signaling through various pathways, among others, an increase in the expression of pro-inflammatory adipocytokines, and stress of the endoplasmic reticulum (ER). A better understanding of obesity and preventing its complications are beneficial for obese patients on two facets: treating obesity, and treating and preventing the pathologies associated with it. Hitherto, therapeutic itineraries in most cases are based on lifestyle modifications, bariatric surgery, and pharmacotherapy despite none of them have achieved optimal results. Therefore, diet can play an important role in the prevention of adiposity, as well as the associated disorders. Recent results have shown that flavonoids intake have an essential role in protecting against oxidative damage phenomena, and presents biochemical and pharmacological functions beneficial to human health. This review summarizes the current knowledge of the anti-inflammatory actions and autophagic flux of natural flavonoids, and their molecular mechanisms for preventing and/or treating obesity.

Proanthocyanidins: Components, Pharmacokinetics and Biomedical Properties

Proanthocyanidins (PAs) are a group of polyphenols enriched in plant and human food. In recent decades, epidemiological studies have upheld the direct relationship between PA consumption and health benefits; therefore, studies on PAs have become a research hotspot. Although the oral bioavailability of PAs is quite low, pharmacokinetics data revealed that some small molecules and colonic microbial metabolites of PAs could be absorbed and exert their health beneficial effects. The pharmacological effects of PAs mainly include anti-oxidant, anticancer, anti-inflammation, antimicrobial, cardiovascular protection, neuroprotection, and metabolism-regulation behaviors. Moreover, current toxicological studies show that PAs have no observable toxicity to humans. This review summarizes the resources, extraction, structures, pharmacokinetics, pharmacology, and toxicology of PAs and discusses the limitations of current studies. Areas for further research are also proposed.

Personal use of permanent hair dyes and cancer risk and mortality in US women: prospective cohort study

OBJECTIVE

To evaluate the associations between personal use of permanent hair dyes and cancer risk and mortality.

DESIGN

Prospective cohort study.

SETTING AND PARTICIPANTS

117 200 women enrolled in the Nurses' Health Study, an ongoing prospective cohort study of female nurses in the United States. The women were free of cancer at baseline, reported information on personal use of permanent hair dyes, and were followed for 36 years.

EXPOSURE

Status, duration, frequency, and integral use (cumulative dose calculated from duration and frequency) of permanent hair dyes. Age at first use and time since first use of permanent hair dyes.

MAIN OUTCOME MEASURES

Associations of personal use of permanent hair dyes with risk of overall cancer and specific cancers, and cancer related death. Age and multivariable adjusted hazard ratios and 95% confidence intervals were estimated by using Cox proportional hazard models.

RESULTS

Ever users of permanent hair dyes had no significant increases in risk of solid cancers (n=20 805, excluding non-melanoma skin cancers; hazard ratio 0.98, 95% confidence interval 0.96 to 1.01) or hematopoietic cancers overall (n=1807; 1.00, 0.91 to 1.10) compared with non-users. Additionally, ever users did not have an increased risk of most specific cancers (cutaneous squamous cell carcinoma, bladder cancer, melanoma, estrogen receptor positive breast cancer, progesterone receptor positive breast cancer, hormone receptor positive breast cancer, brain cancer, colorectal cancer, kidney cancer, lung cancer, and most of the major subclasses and histological subtypes of hematopoietic cancer) or cancer related death (n=4860; 0.96, 0.91 to 1.02). Basal cell carcinoma risk was slightly increased for ever users (n=22 560; 1.05, 1.02 to 1.08). Cumulative dose was positively associated with risk of estrogen receptor negative breast cancer, progesterone receptor negative breast cancer, hormone receptor negative breast cancer, and ovarian cancer. An increased risk of Hodgkin lymphoma was observed only for women with naturally dark hair (based on 70 women, 24 with dark hair), and a higher risk of basal cell carcinoma was observed for women with naturally light hair.

CONCLUSION

No positive association was found between personal use of permanent hair dye and risk of most cancers and cancer related mortality. The increased risk of basal cell carcinoma, breast cancer (estrogen receptor negative, progesterone receptor negative, hormone receptor negative) and ovarian cancer, and the mixed findings in analyses stratified by natural hair color warrant further investigation.

An overview and update on the epidemiology of flavonoid intake and cardiovascular disease risk

There is an accumulating body of literature reporting on dietary flavonoid intake and the risk of cardiovascular disease (CVD) in prospective cohort studies. This makes apparent the need for an overview and update on the current state of the science. To date, at least 27 prospective cohorts (in 44 publications) have evaluated the association between estimated habitual flavonoid intake and CVD risk. At this time, the totality of evidence suggests long-term consumption of flavonoid-rich foods may be associated with a lower risk of fatal and non-fatal ischemic heart disease (IHD), cerebrovascular disease, and total CVD; disease outcomes which are principally, though not exclusively, composed of cases of atherosclerotic CVD (ASCVD). To date, few studies have investigated outcome specific ASCVD, such as peripheral artery disease (PAD) or ischemic stroke. Of the flavonoid subclasses investigated, evidence more often implicates diets rich in anthocyanins, flavan-3-ols, and flavonols in lowering the risk of CVD. Although inferences are restricted by confounding and other inherent limitations of observational studies, causality appears possible based on biological plausibility, temporality, and the relative consistency of the reported associations. However, whether the associations observed represent a benefit of the isolated bioactives per se, or are a signal of the bioactives acting in concert with the co-occurring nutrient matrix within flavonoid-bearing foods, are issues of consideration. Thus, the simple interpretation, and the one most relevant for dietary advice, is that consumption of flavonoid-rich foods or diets higher in flavonoids, appear nutritionally beneficial in the prevention of CVD.

Dietary flavonoid intake and risk of periodontitis

BACKGROUND

The anti-inflammatory effect associated with flavonoid-containing foods and beverages could potentially impact the risk of periodontal disease. We prospectively investigate the associations between habitual flavonoid intake and incidence of periodontitis.

METHODS

The study population was 34,940 men from the Health Professionals Follow-Up Study, who were healthy and free of periodontal disease at baseline (1986). Participants in the study provided medical and dental history through mailed questionnaires biennially, and provided dietary data through semi-quantitative food frequency questionnaires every 4 years. We examined the associations between total flavonoids and six flavonoid subclasses (flavonoid polymers, anthocyanins, flavan-3-ols, flavanones, flavones, and flavonols) and incidence of periodontitis using Cox proportional hazard models. We adjusted for age, smoking, body mass index, physical activity, alcohol consumption, Alternative Healthy Eating Index, and diabetes.

RESULTS

There was no association between total flavonoids and the risk of periodontitis. The hazard ratio comparing the highest quintile of total flavonoid to the lowest quintile was 0.97 (95% confidence interval: 0.87 to 1.08, P-value for trend = 0.61). Similar comparisons for flavonoids subclasses also did not show significant associations.

CONCLUSION

No association was detected between habitual flavonoid intake and risk of periodontitis in the study population.

Flavonoid Intakes in the US Diet Are Linked to Higher Socioeconomic Status and to Tea Consumption: Analyses of NHANES 2011-16 Data

BACKGROUND

Many of the health benefits of tea have been attributed to its flavonoid content. Tea consumption in US adults varies by socioeconomic status (SES).

OBJECTIVES

The present objective was to explore intakes of total flavonoids and flavonoid subclasses by participant sociodemographics and by patterns of tea consumption.

METHODS

The present analyses were based on 2 d of dietary recalls for 17,506 persons aged >9 y in the 2011-2016 NHANES. The What We Eat in America nutrient composition database was merged with the USDA Expanded Flavonoid database, which included total flavonoids and flavan-3-ols (including catechins), flavanones, flavonols, anthocyanidins, flavones, and isoflavones. Flavonoid intakes were compared by sex, age, race/ethnicity, education, and income-to-poverty ratio (IPR) in univariate analyses. Flavonoid intakes of children and adults were also compared by tea consumption status. Time trends in flavonoid intakes were also examined.

RESULTS

Mean total flavonoid intake was 219 mg/d, of which flavan-3-ols provided 174 mg/d, or 79%. The highest total flavonoid intakes were found in adults aged 51-70 y (293 mg/d), non-Hispanic whites (251 mg/d) and in groups with college education (251 mg/d) and higher income (IPR >3.5: 249 mg/d) (P < 0.001 for all). The socioeconomic gradient was significant for anthocyanidins, flavonols, and flavones (P < 0.001 for all) but not for flavan-3-ols, and persisted across 3 cycles of NHANES. Adult tea consumers had higher intakes of total flavonoids (610 mg/d compared with 141 mg/d) and flavan-3-ols (542 mg/d compared with 97.8 mg/d) than did nonconsumers (P < 0.001). Time trend analyses showed that both tea consumption and flavonoid intakes were unchanged from 2011 to 2016.

CONCLUSIONS

Flavonoid intakes in children and adults in the NHANES 2011-16 sample were associated with higher SES and were largely determined by tea consumption. Studies of diet and disease risk need to take sociodemographic gradients and eating and drinking habits into account.

Cyanidin-3-O-glucoside restores insulin signaling and reduces inflammation in hypertrophic adipocytes

Obesity is a metabolic disorder characterized by excess adipose tissue, macrophages infiltration, and inflammation which in turn lead to insulin-resistance. Epidemiological evidences reported that anthocyanins possess not only high antioxidant and antiinflammatory activities, but also improve metabolic complications associated with obesity. The aim of this work was to evaluate the in vitro beneficial effects of cyanidin-3-O-glucoside (C3G) in counteracting inflammation and insulin-resistance in 3T3-L1 hypertrophic adipocytes exposed to palmitic acid (PA). In the present study murine 3T3-L1 adipocytes were pretreated with C3G for 24 h and then exposed to palmitic acid (PA) for 24 h. Real-time PCR, western blotting analysis and Oil Red O staining were applied for investigating the mechanism involved in adipocytes dysfunction. C3G pretreatment reduced lipid accumulation, PPARγ pathway and NF-κB pathway induced by PA in murine adipocytes. In addition, our data demonstrated that PA reduced insulin signaling via IRS-1 Ser³⁰⁷phosphorylation while C3G dose-dependently improved insulin sensitivity restoring IRS-1/PI3K/Akt pathway. Furthermore, C3G improved adiponectin mRNA levels altered by PA in 3T3-L1 murine and SGBS human adipocytes. Herein reported data demonstrate that C3G ameliorated adipose tissue dysfunction, thus suggesting new potential roles for this compound of nutritional interest in the prevention of pathological conditions linked to obesity.

Consumption of Spinacia Oleracea (spinach) and aerobic exercise controls obesity in rats by an inhibitory action on pancreatic lipase

Context: Spinaciaoleracea (spinach) is abundant in antioxidant phytoconstituents, termed as the natural antioxidant mixture (NAO).Objective: This study evaluates the anti-hyperlipidemicand anti-obesity effects of an antioxidant-rich extract of Spinaciaoleracea (NAOE) and aerobic exercise (AE) in rats fed with high fat diet (HFD).Methods: Rats received NAOE (200 and 400 mg/kg), the standard drug orlistat (10 mg/kg), AE and NAOEAE (NAOE 400 mg/kg + AE) daily with HFD for 21 d.Results: Orlistat, NAOE and NAOEAE treatments to HFD-fed rats significantly reduced the HFD-elevated food intake, weight gain, pancreatic lipase activity and lipid peroxidation, and successfully restored the HFD-skewed lipid profile and antioxidant levels.Conclusions: It may be concluded that NAOE exhibited a promising anti-hyperlipidemic effect by its inhibitory action on pancreatic lipase. The combination treatment NAOEAE produced the best results indicating the essential role of exercise along with consumption of antioxidant-rich foods in maintaining a normal lipid profile and controlling obesity.

What is the best diet for cardiovascular wellness? A comparison of different nutritional models

Cardiovascular diseases (CVD) represent to date the leading cause of mortality in both genders in the developed countries. In this context, a strong need for CVD prevention is emerging through lifestyle modification and nutrition. In fact, several studies linked CVD with unhealthy nutrition, alcohol consumption, stress, and smoking, together with a low level of physical activity. Thus, the primary aim is to prevent and reduce CVD risk factors, such as impaired lipid and glycemic profiles, high blood pressure and obesity. Different types of diet have been, therefore, established to optimize the approach regarding this issue such as the Mediterranean diet, Dietary Approaches to Stop Hypertension diet (DASH), vegetarian diet, ketogenic diet, and Japanese diet. Depending on the diet type, recommendations generally emphasize subjects to increase vegetables, fruits, whole grains, and pulses consumption, but discourage or recommend eliminating red meat, sweets, and sugar-sweetened beverages, along with processed foods that are high in sugar, salt, fat, or low in dietary fiber. In particular, we evaluated and compared the peculiar aspects of these well-known dietary patterns and, thus, this review evaluates the critical factors that increase CVD risk and the potential application and benefits of nutritional protocols to ameliorate dietary and lifestyle patterns for CVD prevention.

The Targeted Impact of Flavones on Obesity-Induced Inflammation and the Potential Synergistic Role in Cancer and the Gut Microbiota

Obesity is an inflammatory disease that is approaching pandemic levels, affecting nearly 30% of the world's total population. Obesity increases the risk of diabetes, cardiovascular disorders, and cancer, consequentially impacting the quality of life and imposing a serious socioeconomic burden. Hence, reducing obesity and related life-threatening conditions has become a paramount health challenge. The chronic systemic inflammation characteristic of obesity promotes adipose tissue remodeling and metabolic changes. Macrophages, the major culprits in obesity-induced inflammation, contribute to sustaining a dysregulated immune function, which creates a vicious adipocyte-macrophage crosstalk, leading to insulin resistance and metabolic disorders. Therefore, targeting regulatory inflammatory pathways has attracted great attention to overcome obesity and its related conditions. However, the lack of clinical efficacy and the undesirable side-effects of available therapeutic options for obesity provide compelling reasons for the need to identify additional approaches for the prevention and treatment of obesity-induced inflammation. Plant-based active metabolites or nutraceuticals and diets with an increased content of these compounds are emerging as subjects of intense scientific investigation, due to their ability to ameliorate inflammatory conditions and offer safe and cost-effective opportunities to improve health. Flavones are a class of flavonoids with anti-obesogenic, anti-inflammatory and anti-carcinogenic properties. Preclinical studies have laid foundations by establishing the potential role of flavones in suppressing adipogenesis, inducing browning, modulating immune responses in the adipose tissues, and hindering obesity-induced inflammation. Nonetheless, the understanding of the molecular mechanisms responsible for the anti-obesogenic activity of flavones remains scarce and requires further investigations. This review recapitulates the molecular aspects of obesity-induced inflammation and the crosstalk between adipocytes and macrophages, while focusing on the current evidence on the health benefits of flavones against obesity and chronic inflammation, which has been positively correlated with an enhanced cancer incidence. We conclude the review by highlighting the areas of research warranting a deeper investigation, with an emphasis on flavones and their potential impact on the crosstalk between adipocytes, the immune system, the gut microbiome, and their role in the regulation of obesity.

The Influence of Supplementation of Anthocyanins on Obesity-Associated Comorbidities: A Concise Review

Anthocyanins are water-soluble plant pigments, and based on their chemical structure (nature, position, and the number of sugar moieties attached; the number of hydroxyl groups; acylation of sugars with acids) about 635 different anthocyanins have been identified and reported from plants. Cyanidin, peonidin, pelargonidin, petunidin, and malvidin are the commonly found anthocyanidins (aglycon forms of anthocyanins) in edible plants out of almost 25 anthocyanidins that are identified (based on the position of methoxyl and hydroxyl groups in the rings) in nature. Anthocyanins are known for numerous health benefits including anti-diabetes, anti-obesity, anti-inflammatory bowel disease, anti-cancer, etc. Obesity can be defined as excessive or abnormal adipose tissue and body mass, which increases the risk of developing chronic diseases such as diabetes, cardiovascular diseases, cancers, etc. The manuscript summarizes the recent updates in the effects of anthocyanins supplementation on the health status of obese subjects, and briefly the results of in vitro and in vivo studies. Several studies confirmed that the consumption of anthocyanins-rich food improved obesity-associated dysbiosis in gut microbiota and inflammation in adipose tissue. Anthocyanin consumption prevents obesity in healthy subjects, and aids in maintaining or reducing the body weight of obese subjects, also improving the metabolism and energy balance. Though preclinical studies proved the beneficial effects of anthocyanins such as the fact that daily intake of anthocyanin rich fruits and vegetables might aid weight maintenance in every healthy individual, Juҫara pulp might control the inflammatory status of obesity, Queen garnet plum juice reduced the blood pressure and risk factors associated with metabolic disorders, and highbush organic blueberries improved the metabolism of obese individuals, we don't have an established treatment procedure to prevent or manage the over-weight condition and its comorbidities. Thus, further studies on the optimum dose, duration, and mode of supplementation of anthocyanins are required to develop an anthocyanins-based clinical procedure.

A mixture of citrus polymethoxyflavones, green tea polyphenols and lychee extracts attenuates adipogenesis in 3T3-L1 adipocytes and obesity-induced adipose inflammation in mice

Adipocyte-macrophage interaction in obesity can cause adipose tissue inflammation and contribute to insulin resistance. Here, we investigated the effect of SlimTrym®-a formulated product containing citrus polymethoxyflavones (PMFs), green tea extract, and lychee polyphenols-on 3T3-L1 adipocyte differentiation and obesity-induced inflammation. SlimTrym® inhibited mitotic clonal expansion (MCE) of 3T3-L1 adipocytes by inducing G1 cell cycle arrest via upregulation of p21 and p53. SlimTrym® attenuated adipogenic differentiation by downregulating adipogenic factors, such as CCAAT-enhancer-binding proteins (C/EBPs) and peroxisome proliferator-activated receptor γ (PPARγ), and upregulating AMP-activated protein kinase (AMPK). Pretreatment with compound C significantly reduced SlimTrym®-mediated suppression of lipid accumulation. SlimTrym® reduced the expression of pro-inflammatory cytokines, including monocyte chemoattractant protein 1 (MCP-1), interleukin (IL)-1β and IL-6, in co-cultured 3T3-L1 adipocytes and RAW264.7 macrophages. C57BL/6 mice administered with SlimTrym® for 16 weeks showed markedly reduced high-fat diet (HFD)-induced infiltration of monocytes/macrophages in adipose tissue; however, the level of M2 macrophage markers (CD163 and IL-10) was increased. Taken together, these findings indicate that SlimTrym® exerts both anti-adipogenic and anti-inflammatory effects, and can potentially treat obesity and adipose tissue inflammation.

Associations between changes in fruit and vegetable consumption and weight change in Japanese adults

BACKGROUND

Fruits and vegetables may induce greater satiety, reduce hunger, decrease energy intake, and modulate energy metabolism, thereby playing a role in weight loss.

OBJECTIVE

To determine the associations between changes in fruit and vegetable consumption and weight change over a 5-year interval in Japanese adults.

METHODS

This cohort study included 54,015 subjects (54.6% female, mean age 56.5 years) of the Japan Public Health Center-based Prospective Cohort Study who had no known history of major chronic diseases at baseline. Data on fruit and vegetable consumption were collected using a validated food frequency questionnaire. Body weight was self-reported. We used multivariable linear mixed-effects regression models to examine the associations between changes in fruit and vegetable consumption and change in body weight.

RESULTS

On average, body weight decreased by 25 g [95% confidence interval (CI), 3, 47] for every 100 g/d increase in total vegetable consumption. Change in fruit consumption was nonlinearly associated with weight change. Fruit consumption was directly associated with weight change among subjects who increased consumption (70 g; 95% CI, 39, 101) but was not associated with weight change among subjects who reduced or did not change fruit consumption. These associations did not vary by sex, age, and body mass index (BMI) at baseline. The association with vegetables was restricted to yellow/red vegetables (- 74 g; 95% CI, - 129, - 18) and allium vegetables (- 129 g; 95% CI, - 231, - 28). Lower-fiber vegetables were inversely associated with weight change, whereas lower-fiber fruits or higher-energy fruits were directly associated with weight change beyond 0 g/d change in consumption.

CONCLUSIONS

Change in vegetable consumption was inversely associated with weight change while fruit consumption was positively associated with weight change among subjects who increased consumption. The influence of fruits and vegetables on weight change may depend on the characteristics of the fruits and vegetables.

Polyphenol intake and differentiated thyroid cancer risk in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort

Polyphenols are bioactive compounds with several anticarcinogenic activities; however, human data regarding associations with thyroid cancer (TC) is still negligible. Our aim was to evaluate the association between intakes of total, classes and subclasses of polyphenols and risk of differentiated TC and its main subtypes, papillary and follicular, in a European population. The European Prospective Investigation into Cancer and Nutrition cohort included 476,108 men and women from 10 European countries. During a mean follow-up of 14 years, there were 748 incident differentiated TC cases, including 601 papillary and 109 follicular tumors. Polyphenol intake was estimated at baseline using validated center/country-specific dietary questionnaires and the Phenol-Explorer database. In multivariable-adjusted Cox regression models, no association between total polyphenol and the risks of overall differentiated TC (HRQ4 vs. Q1 = 0.99, 95% confidence interval [CI] 0.77-1.29), papillary (HRQ4 vs. Q1 = 1.06, 95% CI 0.80-1.41) or follicular TC (HRQ4 vs. Q1 = 1.10, 95% CI 0.55-2.22) were found. No associations were observed either for flavonoids, phenolic acids or the rest of classes and subclasses of polyphenols. After stratification by body mass index (BMI), an inverse association between the intake of polyphenols (p-trend = 0.019) and phenolic acids (p-trend = 0.007) and differentiated TC risk in subjects with BMI ≥ 25 was observed. In conclusion, our study showed no associations between dietary polyphenol intake and differentiated TC risk; although further studies are warranted to investigate the potential protective associations in overweight and obese individuals.

Recent Research on the Health Benefits of Blueberries and Their Anthocyanins

Awareness of the human health benefits of blueberries is underpinned by a growing body of positive scientific evidence from human observational and clinical research, plus mechanistic research using animal and in vitro models. Blueberries contain a large number of phytochemicals, including abundant anthocyanin pigments. Of their various phytochemicals, anthocyanins probably make the greatest impact on blueberry health functionality. Epidemiological studies associate regular, moderate intake of blueberries and/or anthocyanins with reduced risk of cardiovascular disease, death, and type 2 diabetes, and with improved weight maintenance and neuroprotection. These findings are supported by biomarker-based evidence from human clinical studies. Among the more important healthful aspects of blueberries are their anti-inflammatory and antioxidant actions and their beneficial effects on vascular and glucoregulatory function. Blueberry phytochemicals may affect gastrointestinal microflora and contribute to host health. These aspects have implications in degenerative diseases and conditions as well as the aging process. More evidence, and particularly human clinical evidence, is needed to better understand the potential for anthocyanin-rich blueberries to benefit public health. However, it is widely agreed that the regular consumption of tasty, ripe blueberries can be unconditionally recommended.

The role of the gut microbiome in the association between habitual anthocyanin intake and visceral abdominal fat in population-level analysis

BACKGROUND

Flavonoid intake modifies the composition of the gut microbiome, which contributes to the metabolism of flavonoids. Few studies have examined the contribution of the gut microbiome to the health benefits associated with flavonoid intake.

OBJECTIVES

We aimed to examine associations between habitual intakes of flavonoid subclasses and MRI-determined visceral (VAT) and subcutaneous (SAT) adipose tissue. Uniquely, we also identified associations between the aforementioned measurements and gut microbiome composition sequenced from 16S ribosomal RNA genes.

METHODS

We undertook cross-sectional analyses of 618 men and women (n = 368 male), aged 25-83 y, from the PopGen cohort.

RESULTS

Higher intake of anthocyanins was associated with lower amounts of VAT [tertile (T)3-T1:  -0.49 dm3; β: -8.9%; 95% CI: -16.2%, -1.1%; P = 0.03] and VAT:SAT ratio (T3-T1: -0.04; β: -7.1%; 95% CI: -13.5%, -0.3%; P = 0.03). Higher intakes of anthocyanin-rich foods were also inversely associated with VAT [quantile (Q)4-Q1: -0.39 dm3; β: -9.9%; 95% CI: -17.4%, -1.6%; P = 0.02] and VAT:SAT ratio (Q4-Q1: -0.04; β: -6.5%; 95% CI: -13.3%, -0.9%; P = 0.03). Participants with the highest intakes of anthocyanin-rich foods also had higher microbial diversity (Q4-Q1: β: 0.18; 95% CI: 0.06, 0.31; P < 0.01), higher abundances of Clostridiales (Q4-Q1: β: 449; 95% CI: 96.3, 801; P = 0.04) and Ruminococcaceae (Q4-Q1: β: 313; 95% CI: 33.6, 591; P = 0.04), and lower abundance of Clostridium XIVa (Q4-Q1: β: -41.1; 95% CI: -72.4, -9.8; P = 0.04). Participants with the highest microbial diversity, abundances of Clostridiales and Ruminococcaceae, and lower abundance of Clostridium XIVa had lower amounts of VAT. Up to 18.5% of the association between intake of anthocyanin-rich foods and VAT could be explained by the gut microbiome.

CONCLUSIONS

These novel data suggest that higher microbial diversity and abundance of specific taxa in the Clostridiales order may contribute to the association between higher intake of anthocyanins and lower abdominal adipose tissue.

Association between dietary flavonoid intake and obesity among adults in Korea

This study aimed to investigate the association between dietary flavonoid intake and the prevalence of obesity using body mass index (BMI), waist circumference, and percent body fat (%BF) according to sex among Korean adults. Based on the Korean Health and Nutrition Examination Survey 2008-2011, 23 118 adults in Korea were included. Dietary intakes were obtained using 24-h dietary recall data. A higher total intake of flavonoid was associated with a lower prevalence of obesity in women, based on %BF (odds ratio [95% confidence interval] = 0.82 [0.71-0.94]), and abdominal obesity (0.81 [0.71-0.92]). The intake of flavonols (0.88 [0.78-0.99]), flavanones (0.81 [0.72-0.92]), flavanols (0.85 [0.74-0.97]), isoflavones (0.85 [0.75-0.96]), and proanthocyanidins (0.81 [0.71-0.92]) was inversely associated with abdominal obesity, and a higher intake of flavanones (0.87 [0.76-0.99]) and proanthocyanidins (0.85 [0.75-0.98]) was associated with a lower prevalence of obesity, with respect to %BF in women. In contrast, the intake of flavonols (1.16 [1.02-1.33]), flavanones (1.18 [1.04-1.35]), and anthocyanidins (1.27 [1.11-1.46]) was positively associated with obesity based on BMI in men. In conclusion, high intake of dietary flavonoids may be associated with a decreased prevalence of abdominal obesity and obesity, based on %BF, among women. Novelty Higher flavonoid intake was associated with decreased prevalence of abdominal obesity and obesity based on %BF in Korean women. However, in men, the intake of flavonols, flavanones, and anthocyanidins was positively associated with obesity as given by BMI.

Improved Understanding of Interactions between Risk Factors for Child Obesity May Lead to Better Designed Prevention Policies and Programs in Indonesia

The nutrition transition in low-middle income countries is marked by rising intakes of highly caloric, low nutrient-dense (junk) foods, decreasing intakes of fruits and vegetables, and sedentary behavior. The objective of this study was to explore interactions among fruit-and-vegetable intake, junk food energy intake, sedentary behavior, and obesity in Indonesian children. We conducted this school-based, case-control study in 2013 in Yogyakarta Special Province, Indonesia. The cases were 244 obese children aged 7–12 years having a BMI ≥95th percentile of an age- and sex-specific distribution from the Centers for Disease Control and Prevention. The controls (n = 244) were classroom-matched children with a BMI <85th percentile. Using conditional logistic regression, the relative odds (95% confidence intervals; OR: 95% CI) of obesity given reported frequent fruit-and-vegetable intake (≥3 servings/day), low junk food energy (≤1050 kcal/day) intake and low sedentary behavior (<5 h/day) was 0.46 (0.30–0.69), 0.61 (0.37–0.98), and 0.18 (0.12–0.28), respectively. Effect sizes were dose-responsive and appeared additive. For example, children with low sedentary behavior and frequent fruit-and-vegetable intake were 92% less likely (OR = 0.08; 0.04–0.15) to be obese than children not exceeding either of these thresholds. Similarly, children frequently eating fruits and vegetables and reporting a low junk food energy intake were 70% less likely (OR = 0.30; 0.15–0.59) to be obese. The findings were unchanged after adjusting for child, maternal, and household covariates. Preventive interventions for child obesity need multiple components to improve diets and raise levels of physical activity rather than just addressing one of the three types of assessed behaviors.

Plant-Based Diets in the Reduction of Body Fat: Physiological Effects and Biochemical Insights

Obesity affects over one-third of Americans and increases the risk of cardiovascular disease and type II diabetes. Interventional trials have consistently demonstrated that consumption of plant-based diets reduces body fat in overweight and obese subjects, even when controlling for energy intake. Nonetheless, the mechanisms underlying this effect have not been well-defined. This review discusses six major dietary mechanisms that may lead to reduced body fat. These include (1) reduced caloric density, (2) improved gut microbiota symbiosis, (3) increased insulin sensitivity, (4) reduced trimethylamine-N-oxide (TMAO), (5) activation of peroxisome proliferator-activated receptors (PPARs), and (6) over-expression of mitochondrial uncoupling proteins. Collectively, these factors improve satiety and increase energy expenditure leading to reduced body weight.

Anthocyanins and Their C6-C3-C6 Metabolites in Humans and Animals

Research on the bioavailability of anthocyanins has focused, historically, on the non-flavonoid (C6-Cn) products that arise from anthocyanins in vivo. However, this review focuses on the products of anthocyanins that still possess the flavonoid structure (C6-C3-C6). Described herein are aspects of the in vivo pool of C6-C3-C6 anthocyanin-derived intermediates. Properties related to molecular size, shape, and polarity conveyed by six major anthocyanidin structures are discussed. The presence of a glycoside or not, and a variety of possible phase 2 conjugates, gives rise to a chemically diverse pool of C6-C3-C6 intermediates. Chemical properties influence the in vivo stability of anthocyanin-derived products, as well as their suitability as a substrate for xenobiotic conjugation and transport, and their association with the biomatrix. The flavonoid structure is associated with bioactivity and the particular properties of these C6-C3-C6 products of anthocyanins determines their deposition in the body, which may influence in vivo processes and ultimately health outcomes.

Acute Ingestion of a Mixed Flavonoid and Caffeine Supplement Increases Energy Expenditure and Fat Oxidation in Adult Women: A Randomized, Crossover Clinical Trial

This randomized, double-blinded, crossover study measured the acute effect of ingesting a mixed flavonoid-caffeine (MFC) supplement compared to placebo (PL) on energy expenditure (EE) and fat oxidation (FATox) in a metabolic chamber with premenopausal women (n = 19, mean ± SD, age 30.7 ± 8.0 year, BMI 25.7 ± 3.4 kg/m²). The MFC supplement (658 mg flavonoids, split dose 8:30, 13:00) contained quercetin, green tea catechins, and anthocyanins from bilberry extract, and 214 mg caffeine. Participants were measured twice in a metabolic chamber for a day, four weeks apart, with outcomes including 22 h EE (8:30-6:30), substrate utilization from the respiratory quotient (RQ), plasma caffeine levels (16:00), and genotyping for the single-nucleotide polymorphism (SNP) rs762551. Areas under the curve (AUC) for metabolic data from the MFC and PL trials were calculated using the trapezoid rule, with a mixed linear model (GLM) used to evaluate the overall treatment effect. The 22 h oxygen consumption and EE were significantly higher with MFC than PL (1582 ± 143, 1535 ± 154 kcal/day, respectively, p = 0.003, trial difference of 46.4 ± 57.8 kcal/day). FATox trended higher for MFC when evaluated using GLM (99.2 ± 14.0, 92.4 ± 14.4 g/22 h, p = 0.054). Plasma caffeine levels were significantly higher in the MFC versus PL trial (5031 ± 289, 276 ± 323 ng/mL, respectively, p < 0.001). Trial differences for 22 h EE and plasma caffeine were unrelated after controlling for age and body mass (r = -0.249, p = 0.139), and not different for participants with the homozygous allele 1, A/A, compared to C/A and C/C (p = 0.50 and 0.56, respectively). In conclusion, EE was higher for MFC compared to PL, and similar to effects estimated from previous trials using caffeine alone. A small effect of the MFC on FATox was measured, in contrast to inconsistent findings previously reported for this caffeine dose. The trial variance for 22 h EE was not significantly related to the variance in plasma caffeine levels or CYP1A2*1F allele carriers and non-carriers.

The Gastrointestinal Tract as Prime Site for Cardiometabolic Protection by Dietary Polyphenols

Substantial evidence from nutritional epidemiology links polyphenol-rich diets with reduced incidence of chronic disorders; however, biological mechanisms underlying polyphenol-disease relations remain enigmatic. Emerging evidence is beginning to unmask the contribution of the gastrointestinal tract on whole-body energy homeostasis, suggesting that the intestine may be a prime target for intervention and a fundamental site for the metabolic actions of polyphenols. During their transit through the gastrointestinal tract, polyphenols may activate enteric nutrient sensors ensuing appropriate responses from other peripheral organs to regulate metabolic homeostasis. Furthermore, polyphenols can modulate the absorption of glucose, attenuating exaggerated hormonal responses and metabolic imbalances. Polyphenols that escape absorption are metabolized by the gut microbiota and the resulting catabolites may act locally, activating nuclear receptors that control enteric functions such as intestinal permeability. Finally, polyphenols modulate gut microbial ecology, which can have profound effects on cardiometabolic health.

Gynura procumbens Standardised Extract Reduces Cholesterol Levels and Modulates Oxidative Status in Postmenopausal Rats Fed with Cholesterol Diet Enriched with Repeatedly Heated Palm Oil

Gynura procumbens (Lour.) Merr. (GP) has been reported in previous studies to possess antihyperlipidaemic, antioxidative, and cardioprotective properties. This study was aimed to determine the effect of standardised 80% ethanol extract of GP on lipid profiles and oxidative status of hypercholesterolemic rats. Postmenopausal (PM) Sprague-Dawley rats were ovariectomised and fed with 2% cholesterol diet fortified with five times heated palm oil to develop hyperlipidaemia status. Two doses of the extract (250 and 500 mg/kg) and atorvastatin (10 mg/kg) were administered once daily via oral gavage for 24 weeks. Systolic blood pressure (SBP) was increased during the first month in the postmenopausal group and decreased with GP supplementation. Lipid droplets accumulation was shown at the tunica media (TM) area of the aorta in the postmenopausal group and reduced with GP supplementation. Total cholesterol (TC), total triglycerides (TG), low-density lipoprotein (LDL), and malondialdehyde (MDA) levels increased (p < 0.05) at 3 and 6 months in the postmenopausal group and were reduced with GP supplementation. GP also increased high-density lipoprotein (HDL) level in the postmenopausal group. Superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) activities were reduced in the postmenopausal group compared to control in the sham group but increased (p < 0.05) with GP supplementation. The results showed that the higher dose of GP (500 mg/kg) gave better effect. GP has the ability to reduce oxidative stress and prevent membrane cell damage through antioxidant enzyme activity modification and lipid profile changes in postmenopausal rats related to atherosclerosis.

Protective Effects of Anthocyanins in Obesity-Associated Inflammation and Changes in Gut Microbiome

Obesity is a complex disease and a major public health epidemic. Chronic, low-grade inflammation is a common underlying feature of obesity and associated metabolic diseases; adipose tissue is a major contributor to this systemic inflammation. Evidence shows that obesity-associated inflammation may originate from gut dysfunction, including changes in intestinal bacteria or microbiome profiles. Increasingly, food and plant bioactive compounds with antioxidant and anti-inflammatory properties are proposed to ameliorate obesity-associated inflammation. Among these, the health-promoting effects of anthocyanin-rich foods are of interest here. Specifically, this review summarizes the reported benefits of anthocyanins in obesity-associated inflammation and underlying molecular mechanisms, including the role of gut microbiome and cell signaling pathways regulated by anthocyanins both in vivo and in vitro.

Effect of Steamed Onion (ONIRO) Consumption on Body Fat and Metabolic Profiles in Overweight Subjects: A 12-Week Randomized, Double-Blind, Placebo-Controlled Clinical Trial

Objective: The aim of the study is to investigate the effect of Jeju steamed onion (ONIRO) on body fat and metabolic profiles in overweight subjects.Methods: This randomized, double-blind, placebo-controlled clinical intervention was conducted and completed at one clinical research site. The subjects (n = 70) were randomly divided into placebo or test group and were instructed to take before each meal either the placebo or ONIRO capsule for 12 weeks. Anthropometric as well as serum and metabolic parameters, including triglycerides, cholesterol, low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol, leptin, adiponectin, C-peptide, and aspartate aminotransferase (AST) were measured at baseline and after 12 weeks. Body composition was also measured by dual-energy x-ray absorptiometry (DEXA) and computed tomography (CT). This trial is registered under the trial registration code clinicaltrials.gov: NCT03645382 (https://register.clinicaltrials.gov).Results: Compared to the placebo, ONIRO supplementation for significantly reduced the percentage of body fat and fat mass as measured by DEXA (p = 0.028 and 0.022, respectively) with no significant effects on lean body mass. CT analyses at the L1 level showed a significant decrease in the areas of whole fat, visceral fat, and subcutaneous fat (p = 0.009, p = 0.039, p = 0.020, respectively), while CT scan of L4 resulted in a significant reduction of whole fat area and subcutaneous area (p = 0.006 and p = 0.012, respectively). The levels of triglycerides (TG) and C-peptide were significantly lower after 12 weeks of ONIRO treatment.Conclusions: These findings suggest that ONIRO supplementation reduces total body fat, notably abdominal visceral fat, with positive changes of the clinically relevant metabolic parameters serum TG and C-peptide.

A Provegetarian Food Pattern Emphasizing Preference for Healthy Plant-Derived Foods Reduces the Risk of Overweight/Obesity in the SUN Cohort

Provegetarian diets (i.e., preference for plant-derived foods but not exclusion of animal foods) have been associated with a reduced risk of long-term weight gain and could be more easily embraced than strict vegetarian diets. However, not all plant-derived foods are equally healthy. In the “Seguimiento Universidad de Navarra” (SUN) cohort, we prospectively evaluated the association between different provegetarian food patterns and the incidence of overweight/obesity in 11,554 participants with initial body mass index <25 kg/m². A provegetarian food pattern (FP) was built by assigning positive scores to plant foods and reverse scores to animal foods. A healthful and an unhealthful provegetarian FP, which distinguished between healthy (fruits/vegetables/whole grains/nuts/legumes/olive oil/coffee) and less-healthy plant foods (fruit juices/potatoes/refined grains/pastries/sugary beverages), were also built. A total of 2320 new cases of overweight or obesity were identified after a median follow-up of 10.3 years. Higher baseline conformity with the overall provegetarian FP was inversely associated with overweight/obesity (HR comparing extreme quintiles: 0.85; 95% CI: 0.75 to 0.96; p-trend: 0.014). This association was stronger for the healthful FP (HR: 0.78; 95% CI: 0.67 to 0.90; p-trend: <0.001) and was not apparent for the unhealthful FP (HR: 1.07; 95% CI: 0.92 to 1.23; p-trend: 0.551). In a large prospective cohort of relatively young adults, better conformity with a healthy provegetarian diet was associated with a reduced long-term risk of overweight/obesity, whereas no consistent trend was found for a FP that emphasized less-healthy plant foods.

Dietary Flavonoids for Immunoregulation and Cancer: Food Design for Targeting Disease

Flavonoids, one of the most abundant phytochemicals in a diet rich in fruits and vegetables, have been recognized as possessing anti-proliferative, antioxidant, anti-inflammatory, and estrogenic activities. Numerous cellular and animal-based studies show that flavonoids can function as antioxidants by preventing DNA damage and scavenging reactive oxygen radicals, inhibiting formation of DNA adducts, enhancing DNA repair, interfering with chemical damage by induction of Phase II enzymes, and modifying signaling pathways. Recent evidence also shows their ability to regulate the immune system. However, findings from clinical trials have been mixed with no clear consensus on dose, frequency, or type of flavonoids best suited to elicit many of the beneficial effects. Delivery of these bioactive compounds to their biological targets through "targeted designed" food processing strategies is critical to reach effective concentration in vivo. Thus, the identification of novel approaches that optimize flavonoid bioavailability is essential for their successful clinical application. In this review, we discuss the relevance of increasing flavonoid bioavailability, by agricultural engineering and "targeted food design" in the context of the immune system and cancer.

Blueberries improve biomarkers of cardiometabolic function in participants with metabolic syndrome-results from a 6-month, double-blind, randomized controlled trial

BACKGROUND

Anthocyanin-rich blueberry intake is associated with reduced type 2 diabetes and cardiovascular disease (CVD) risk in prospective studies, although long-term randomized controlled trials (RCTs) have not been conducted in at-risk populations.

OBJECTIVE

In the longest-duration RCT to date, we examined the effect of 6-mo blueberry intake on insulin resistance and cardiometabolic function in metabolic syndrome.

METHODS

A double-blind, parallel RCT (n = 115; age 63 ± 7 y; 68% male; body mass index 31.2 ± 3.0 kg/m2) was conducted, which fed 2 dietarily achievable blueberry intakes [equivalent to 1/2 and 1 cup/d (75/150 g)] compared with matched placebo. Insulin resistance was assessed via the homeostasis model assessment of insulin resistance (primary endpoint) and confirmed by [6-6-2H2]-glucose-labeled, 2-step hyperinsulinemic clamp (n = 20). Clinically relevant cardiometabolic endpoints [including flow-mediated dilatation, augmentation index, lipoprotein status (by nuclear magnetic resonance spectroscopy), and nitric oxide (NO)-related metabolite assay] and anthocyanin metabolism were assessed.

RESULTS

A daily intake of 1 cup of blueberries improved endothelial function (flow-mediated dilatation: +1.45%; 95% CI: 0.83%, 2.1%; P = 0.003), systemic arterial stiffness (augmentation index: -2.24%; 95% CI: -3.97%, -0.61%; P = 0.04) and attenuated cyclic guanosine monophosphate concentrations. In statin nonusers (n = 71), elevated high-density lipoprotein cholesterol (+0.08 mmol/L; P = 0.03), high-density lipoprotein particle density (+0.48n, ×10-6; P = 0.002) and apolipoprotein A-I (+0.05 g/L; P = 0.01) concentrations were observed following the 1-cup/d intervention. Treatment compliance was 94.1% (wrapper returns) and total concentrations of anthocyanin-derived phenolic acid metabolites significantly increased, dose-dependently, in serum and 24-h urine (P < 0.01 and P < 0.001, respectively). Insulin resistance, pulse wave velocity, blood pressure, NO, and overall plasma thiol status were unaffected. Likewise, a half cup per day had no effect on any biomarkers.

CONCLUSIONS

Despite insulin resistance remaining unchanged we show, to our knowledge, the first sustained improvements in vascular function, lipid status, and underlying NO bioactivity following 1 cup blueberries/d. With effect sizes predictive of 12-15% reductions in CVD risk, blueberries should be included in dietary strategies to reduce individual and population CVD risk. This study was registered at clinicaltrials.gov as NCT02035592.

The relationship of flavonoid intake during pregnancy with excess body weight and gestational diabetes mellitus

OBJECTIVE

To investigate the relationship of flavonoid intake during pregnancy with maternal excessive body weight and gestational diabetes mellitus (GDM).

SUBJECTS AND METHODS

A cross-sectional study was conducted among 785 adult women in singleton pregnancies, and data were collected at the time of the oral glucose tolerance test. For the body mass index (BMI) classification according to the gestational age, the criteria of Atalah was used, and the diagnosis of GDM was based on the World Health Organization of 2014. Two 24-hour dietary recalls were obtained, and the usual intake was determined by the Multiple Source Method. Adjusted multinomial logistic regression was used to investigate the relationship of the flavonoids with overweight and obesity, and adjusted non-conditional logistic regression for the relationship of the flavonoids with GDM.

RESULTS

The mean (SD) age of the women was 28 (5) years, 32.1% were overweight, 24.6% were obese and 17.7% were diagnosed with GDM. The median (P25, P75) of total flavonoid intake was 50 (31,75) mg/day. Considering the eutrophic women as the reference, the pregnant women with a higher total flavonoid intake [OR 0.62 (95% CI 0.38; 0.96)] and anthocyanidin intake [OR 0.62 (95% CI 0.40; 0.99)] were less likely to be obese when compared to the women with lower intakes. No association of the flavonoids intake with overweight or GDM was found.

CONCLUSION

A very low intake of flavonoids was observed. The data suggest that the intake of foods naturally rich in total flavonoids and anthocyanidin has a beneficial role regarding obesity among pregnant women.

Dietary Flavonoids as Cancer Chemopreventive Agents: An Updated Review of Human Studies

Over the past few years, interest in health research has increased, making improved health a global goal for 2030. The purpose of such research is to ensure healthy lives and promote wellbeing across individuals of all ages. It has been shown that nutrition plays a key role in the prevention of some chronic diseases such as obesity, cardiovascular disease, diabetes, and cancer. One of the aspects that characterises a healthy diet is a high intake of vegetables and fruits, as both are flavonoid-rich foods. Flavonoids are one of the main subclasses of dietary polyphenols and possess strong antioxidant activity and anti-carcinogenic properties. Moreover, some population-based studies have described a relationship between cancer risk and dietary flavonoid intake. In this context, the goal of this review was to provide an updated evaluation of the association between the risk of different types of cancers and dietary flavonoid intake. We analysed all relevant epidemiological studies from January 2008 to March 2019 using the PUBMED and Web of Science databases. In summary, this review concludes that dietary flavonoid intake is associated with a reduced risk of different types of cancer, such as gastric, breast, prostate, and colorectal cancers.

Flavonoids Alleviating Insulin Resistance through Inhibition of Inflammatory Signaling

During the past 20 years, many studies have focused on polyphenol compounds for their potential beneficial health effects. Flavonoids represent a large class of phenolic compounds found in fruits, vegetables, nuts, grains, cocoa, tea, and other beverages. Flavonoids have shown antioxidant and anti-inflammatory activities. Given the putative relationship between inflammation and insulin resistance, the consumption of flavonoids or flavonoid-rich foods has been suggested to reduce the risk of diabetes by targeting inflammatory signals. This is the first comprehensive review summarizing the current research progress on the inhibition of inflammation and alleviation of insulin resistance by flavonoids as well as the mechanistic link between these disorders. Laboratory and human studies on the activities of major flavonoids (flavones, isoflavones, flavonols, etc.) are discussed.

Flavonoids: Broad Spectrum Agents on Chronic Inflammation

Flavonoids are major plant constituents with numerous biological/pharmacological actions both in vitro and in vivo. Of these actions, their anti-inflammatory action is prominent. They can regulate transcription of many proinflammatory genes such as cyclooxygenase-2/inducible nitric oxide synthase and many cytokines/chemokines. Recent studies have demonstrated that certain flavonoid derivatives can affect pathways of inflammasome activation and autophagy. Certain flavonoids can also accelerate the resolution phase of inflammation, leading to avoiding chronic inflammatory stimuli. All these pharmacological actions with newly emerging activities render flavonoids to be potential therapeutics for chronic inflammatory disorders including arthritic inflammation, meta-inflammation, and inflammaging. Recent findings of flavonoids are summarized and future perspectives are presented in this review.

A Selective Role of Dietary Anthocyanins and Flavan-3-ols in Reducing the Risk of Type 2 Diabetes Mellitus: A Review of Recent Evidence

Type 2 diabetes mellitus (T2DM) is the most common form of DM and its prevalence is increasing worldwide. Because it is a progressive disease, prevention, early detection and disease course modification are possible. Diet plays a critical role in reducing T2DM risk. Therapeutic dietary approaches routinely recommend diets high in plant foods (i.e., vegetables, fruits, whole-grains). In addition to essential micronutrients and fiber, plant-based diets contain a wide-variety of polyphenols, specifically flavonoid compounds. Evidence suggests that flavonoids may confer specific benefits for T2DM risk reduction through pathways influencing glucose absorption and insulin sensitivity and/or secretion. The present review assesses the relationship between dietary flavonoids and diabetes risk reduction reviewing current epidemiology and clinical research. Collectively, the research indicates that certain flavonoids, explicitly anthocyanins and flavan-3-ols and foods rich in these compounds, may have an important role in dietary algorithms aimed to address diabetes risk factors and the development of T2DM.

A two-year study of parental obesity status and childhood obesity in China

BACKGROUND AND AIMS

We evaluated the association between parental obesity and their children's obesity parameters [e.g., percentage of body fat (PBF)] over time.

METHODS AND RESULTS

The study included 2066 Chinese parents-children trios (n = 1001 girls and 1065 boys, aged 6-14 years). Children's height, weight, waist circumference (WC) and PBF (bioelectrical impedance analysis) were annually assessed from 2014 (baseline) to 2016. Information on parental height and body weight, and children's diet and physical activity was collected in 2014. The association between parental obesity and changes in their children's PBF during follow-up was analyzed using a mixed effects model. We also examined changes in children's BMI and WC in secondary analyses. Baseline mean BMI, WC, and PBF for children were 17.6 ± 3.5 kg/m², 60.5 ± 9.6 cm, and 16.6 ± 6.5%, respectively. We observed that maternal, but not paternal, obesity was associated with a greater increase in children's PBF during the follow-up. An adjusted mean difference in annual increase of PBF was 0.41% [95% confidence interval (CI): 0.01%, 0.84%] for children with obese mothers, compared with those with normal-weight mothers. Both maternal and paternal obesity was associated with a greater increase in their children's BMI and WC (p trend<0.01 for both); however, the associations were stronger in mother-children pairs than those in father-children pairs.

CONCLUSIONS

Maternal obesity was associated with a greater increase in PBF in Chinese school-aged children.

Effects of malvidin, cyanidin and delphinidin on human adipose mesenchymal stem cell differentiation into adipocytes, chondrocytes and osteocytes

BACKGROUND

Anthocyanidins are plant phytochemicals found at high concentrations in berries, vegetables and flowers. Anthocyanidins have been extensively investigated due to their antioxidative, antidiabetic and anti-inflammatory effects. Few studies show that anthocyanidins decrease obesity and improve bone density. However, the effects of anthocyanidins on tissue regeneration have not been sufficiently clarified. Human mesenchymal stem cells (MSCs) are multipotent adult stem cells responsible for the regeneration of fat, bone and cartilage. Although MSCs are often used for screening of biologically active compounds, so far, the effect of anthocyanidins on MSC differentiation has not been addressed.

PURPOSE

The aim of this study was to analyse the effect of anthocyanidins malvidin, cyanidin and delphinidin on adipose tissue-derived MSC differentiation into adipocytes, osteocytes and chondrocytes.

STUDY DESIGN AND METHODS

Differentiation into adipocytes, osteocytes and chondrocytes was carried out in the defined cell culture conditions in the presence or absence of malvidin, cyanidin and delphinidin. The differentiation was confirmed by cytochemical staining and tissue-specific gene and protein expression. Antiobesity and anti-diabetes drug liraglutide was used as a reference drug in this study.

RESULTS

Delphinidin inhibited MSC adipogenesis and downregulated FABP4 and adiponectin genes. Malvidin induced a significantly higher accumulation of calcium deposits in MSCs comparing to untreated MSCs, as well as upregulated the osteocyte-specific gene BMP-2 and Runx-2 expression and induced BMP-2 secretion. Cyanidin and delphinidin demonstrated a chondrogenesis stimulating effect by upregulation of Col2a1 and aggrecan.

CONCLUSION

Altogether, our data show that anthocyanidins malvidin, cyanidin and delphinidin exert favourable effects on MSC osteogenesis and chondrogenesis whereas delphinidin inhibits adipogenesis. These results suggest that anthocyanidin effects on tissue regeneration could be further analysed in depth in vivo.

Grape polyphenols reduce gut-localized reactive oxygen species associated with the development of metabolic syndrome in mice

High-fat diet (HFD)-induced leaky gut syndrome combined with low-grade inflammation increase reactive oxygen species (ROS) in the intestine and may contribute to dysbiosis and metabolic syndrome (MetS). Poorly bioavailable and only partially metabolizable dietary polyphenols, such as proanthocyanidins (PACs), may exert their beneficial effects on metabolic health by scavenging intestinal ROS. To test this hypothesis, we developed and validated a novel, noninvasive, in situ method for visualizing intestinal ROS using orally administered ROS-sensitive indocyanine green (ICG) dye. C57BL/6J mice fed HFD for 10 weeks accumulated high levels of intestinal ROS compared to mice fed low-fat diet (LFD). Oral administration of poorly bioavailable grape polyphenol extract (GPE) and β-carotene decreased HFD-induced ROS in the gut to levels comparable to LFD-fed mice, while administration of more bioavailable dietary antioxidants (α-lipoic acid, vitamin C, vitamin E) did not. Forty percent of administered GPE antioxidant activity was measured in feces collected over 24 h, confirming poor bioavailability and persistence in the gut. The bloom of beneficial anaerobic gut bacteria, such as Akkermansia muciniphila, associated with improved metabolic status in rodents and humans may be directly linked to protective antioxidant activity of some dietary components. These findings suggest a possible mechanistic explanation for the beneficial effects of poorly bioavailable polyphenols on metabolic health.

Flavanols are potential anti-obesity agents, a systematic review and meta-analysis of controlled clinical trials

BACKGROUND

The anti-obesity potential of flavonoids has been shown by animal and human studies. In this meta-analysis, we systematically reviewed controlled clinical trials and quantified the effects of flavonoids and flavonoid subclasses on obesity-related anthropometric measures.

METHODS AND RESULTS

PubMed, EMBASE, Scopus, Web of Science, and ProQuest databases were searched to identify trials examining the effect of flavonoids on body mass index (BMI), waist circumference, and body fat percentage. Fifty eight trials passed the eligibility process. Analysis endpoints were calculated as the mean difference between baseline and post-treatment. Flavonoids were in subclasses of flavanols, flavonols, isoflavones, flavanones, anthocyanins, and proanthocyanidins. They were mostly in the form of supplements and dosages varying from 40 to 1300 mg/day. Among flavonoid subclasses, flavanols showed potential for decreasing BMI, in the overall population (mean difference (MD) = -0.28 kg/m², P = 0.04; n = 21) and in the subgroups of Asians (MD = -0.42 kg/m²; P = 0.046; n = 13), ages < 50 years (MD = -0.50 kg/m²; P = 0.008; n = 14), BMI ≥ 25 kg/m² (MD = -0.30 kg/m²; P = 0.049; n = 15), and at doses ≥ 500 mg/day (MD = -0.36 kg/m²; P = 0.049; n = 12). Isoflavones also decreased BMI of non-Asian populations (MD = -0.26 kg/m²; P = 0.035; n = 13) and doses ≥ 75 mg/day (MD = -0.34 kg/m²; P = 0.027; n = 8). In the overall assessment, flavanols also decreased waist circumference (MD = -0.60 cm; P = 0.02; n = 18) but had no significant effect on body fat percentage. The available trials did not reveal significant effects from flavonols, flavanones, and anthocyanins on the specified anthropometric measures.

CONCLUSIONS

Overall results of this meta-analysis showed that flavanols have potential against obesity.

Flavonoids intake and risk of type 2 diabetes mellitus: A meta-analysis of prospective cohort studies

Epidemiological studies exploring the role of flavonoids intake in preventing type 2 diabetes mellitus (T2DM) showed inconsistent results. Therefore, we performed a meta-analysis of relevant studies to examine the relationship between flavonoids intake and risk of T2DM. We hypothesized that flavonoids intake may decrease the risk of developing T2DM.A systematical search in PubMed and Embase until September 2017 was performed to identify eligible prospective cohort studies. The summary relative risks (RRs) and 95% confidence intervals (CIs) were calculated using random-effect models. Dose-response pattern between total flavonoids intake and T2DM risk was also estimated.Eight prospective studies were included with 312,015 participants, of whom 19,953 developed T2DM during the follow-up periods of 4 to 28 years. Compared with lower consumption, high intake of total flavonoids was associated with a decreased risk of T2DM (RR: 0.89, 95% CI: 0.82-0.96). Among flavonoid subclasses, inverse correlations with T2DM were achieved for intakes of anthocyanidins, flavan-3-ols, flavonols, and isoflavones. Dose-response meta-analysis indicated a curvilinear relationship between total flavonoids intake and incident T2DM (P for nonlinearity = .042), with a significant risk reduction at an intake of ≥550 mg/day. When assuming a linear pattern, the risk of T2DM was decreased by 5% for each 300-mg/day increment in total flavonoids intake (RR: 0.95, 95% CI: 0.93-0.97).Our study suggests that higher intakes of total flavonoids and subclasses (anthocyanidins, flavan-3-ols, flavonols, and isoflavones) are associated with lower risk of T2DM.

Association between dietary flavonoids intake and obesity in a cohort of adults living in the Mediterranean area

Dietary polyphenols, including flavonoids, are abundantly present in a healthy and balanced diet. Evidence for their role in preventing non-communicable diseases is emerging. We examined the association between estimated habitual intake of dietary flavonoid and obesity in a cohort study. After adjusting for potential confounding factors, inverse association between total flavonoid intake and excess weight (BMI ≥25) was found (OR = 0.66, 95% CI: 0.45, 0.99); among individual classes of flavonoids, only flavanones were inversely associated with excess body weight (OR = 0.68, 95% CI: 0.48, 0.97). However, when considering adjustment for dietary factors (adherence to the Mediterranean diet), the associations were no more significant. When considering obesity as the outcome (BMI ≥30), individuals with high intake of total flavonoids and flavonols resulted less likely to be obese (OR = 0.38, 95% CI: 0.21, 0.66 and OR = 0.63, 95% CI: 0.39, 0.99, respectively), even after adjustment for confounding factors. The results of the present study add to the current literature further evidence of the association between higher flavonoid intake and decreased body weight. Further studies are needed to confirm retrieved association.

Differential effects of dietary flavonoids on adipogenesis

Propose

Obesity is a fast growing epidemic worldwide. During obesity, the increase in adipose tissue mass arise from two different mechanisms, namely, hyperplasia and hypertrophy. Hyperplasia which is the increase in adipocyte number is characteristic of severe obese patients. Recently, there has been much interest in targeting adipogenesis as therapeutic strategy against obesity. Flavonoids have been shown to regulate several pathways and affect a number of molecular targets during specific stages of adipocyte development.

Methods

Presently, we provide a review of key studies evaluating the effects of dietary flavonoids in different stages of adipocyte development with a particular emphasis on the investigations that explore the underlying mechanisms of action of these compounds in human or animal cell lines as well as animal models.

Results

Flavonoids have been shown to regulate several pathways and affect a number of molecular targets during specific stages of adipocyte development. Although most of the studies reveal anti-adipogenic effect of flavonoids, some flavonoids demonstrated proadipogenic effect in mesenchymal stem cells or preadipocytes.

Conclusion

The anti-adipogenic effect of flavonoids is mainly via their effect on regulation of several pathways such as induction of apoptosis, suppression of key adipogenic transcription factors, activation of AMPK and Wnt pathways, inhibition of clonal expansion, and cell-cycle arrest.

Anthocyanins Function as Anti-Inflammatory Agents in a Drosophila Model for Adipose Tissue Macrophage Infiltration

Epidemiological and preclinical studies have demonstrated that bioactive foods like flavonoids, polyphenolic compounds derived from fruits and vegetables, exert a protective action against obesity, cardiovascular disorders, and Adipocyte Tissue Macrophage infiltration (ATM). All these pathologies are characterized by increase in reactive oxygen species (ROS) and in proinflammatory cytokines that have been shown to favor the migration of immune cells, particularly of macrophages, in metabolically active organs like the liver and adipose tissue, that in Drosophila are constituted by a unique organ: the fat body. This study, using a unique Drosophila model that mimics human ATM, reveals the beneficial effects of flavonoids to reduce tissue inflammation. Our data show that anthocyanin-rich food reduces the number of hemocytes, Drosophila macrophages, infiltrating the fat cells, a process that is associated with reduced production of ROS and reduced activation of the JNK/SAPK p46 stress kinase, suggesting a fundamental function for anthocyanins as antioxidants in chronic inflammation and in metabolic diseases.

Quercetin and iron metabolism: What we know and what we need to know

Iron is a life-supporting micronutrient that is required in the human diet, and is essential for maintaining physiological homeostasis. Properly harnessing a redox-active metal such as iron is a great challenge for cells and organisms because an excess of highly reactive iron catalyzes the formation of reactive oxygen species and can lead to cell and tissue damage. Quercetin is a typical flavonoid that is commonly found in fruits and vegetables and has versatile biological effects. From a classical viewpoint, owing to its unique chemical characteristics, quercetin has long been associated with iron metabolism only in the context of its iron-chelating and ROS-scavenging activities. However, within the field of human iron biology, expanding concepts of the roles of quercetin are flourishing, and great strides are being made in understanding the interactions between quercetin and iron. This progress highlights the varied roles of quercetin in iron metabolism, which involve much more than iron chelation alone. A review of these studies provides an ideal context to summarize recent progress and discuss compelling evidence for therapeutic opportunities that could arise from a better understanding of the underlying mechanisms.