Flavonoid Intake Research Articles

The protective effects of dietary intake of flavonoids and its subclasses on metabolic syndrome incidence

This study aimed to evaluate the association between the intake of total flavonoids and flavonoid subclasses and metabolic syndrome (MetS) risk and to assess the modulating effects of lifestyle factors on these associations. A total of 1915 participants from the Tehran Lipid and Glucose Study were followed-up during 2006–2008 and 2016–2018. Their dietary intake was assessed by a food frequency questionnaire at baseline and within three-year intervals afterward. Moreover, the modifying effect of weight gain on the association between total flavonoids and MetS was assessed by Cox regression analysis. Participants in the highest tertile of flavonoid, flavonol, and flavone had a significantly lower MetS risk as compared to those in the lowest tertile. Also, in participants with weight gain <7%, all flavonoid subclasses had a more pronounced risk-reducing effect. Overall, the total flavonoid, flavonol, and flavone reduced the risk of MetS; this association could be modified by weight gain.

Effect of Flavonoid-Rich Foods and Flavonoids on the Risk of Cancer Recurrence Among Korean Breast Cancer Survivor

Abstract Objectives Flavonoid intakes have been shown to associate with breast cancer incidence, but it is not clear the association between flavonoids and cancer recurrence. The purpose of the present study was to investigate the hypothesis that intakes of flavonoids and flavonoid-rich foods were negatively associated with cancer recurrence. Methods Among 572 women after breast cancer surgery, 66 patients had cancer recurrence during follow–up until 114 months with a median period of disease-free survival of 43 months ranged 6–103 months. Dietary data were collected using structured 24-h dietary recall, and the intake of flavonoid was calculated based on the Korea Rural Development Administration flavonoid database. Results There was no significant association of flavonoid and flavonoid-rich food intake with cancer recurrence and disease-free survival among all patients. On the other hand, among overweight and obese patients, Kaplan-Meier survival curves revealed a significant effect of dietary flavonoids (P = 0.04) and flavonoid-rich foods (P = 0.03) on disease-free survival, but not overall survival. Intakes of flavonoid (HR = 0.244, 95% CI: 0.09–0.66) and flavonoid-rich food (HR = 0.223, 95% CI: 0.08–0.59) were also negatively associated with cancer recurrence after adjusting for confounding factors in overweight and obese patients. Consumption of flavonoids and flavonoid-rich foods was lower in overweight and obese patients with cancer recurrence than those without recurrence. Conclusions To the best of our knowledge, this was the first study to examine the association between flavonoid intake and cancer recurrence/disease-free survival in breast cancer patients. The present study suggested that intakes of flavonoids and flavonoid-rich foods could have a beneficial effect on cancer recurrence among overweight and obese breast cancer survivors. Further clinical studies are needs to confirm whether supplementation of flavonoids reduces cancer recurrence. Funding Sources This work was supported by a National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (NRF-2018R1A2B6002486).

A Prospective Study of Dietary Flavonoid Intake and Risk of Glioma in US Men and Women

Abstract Objectives Flavonoids are a diverse group of plant constituents with demonstrated neuroprotective and anti-tumor effects. Flavonoid intake may decrease glioma risk, an association that has not yet been investigated in humans. The objective of this study was to evaluate the association between dietary flavonoid consumption and glioma risk in participants in the female Nurses’ Health Study (1984–2014, n = 81,688) and Nurses’ Health Study II (1991–2017, n = 95,228), and the male Health Professionals Follow-up Study (1986–2014, n = 49,884). Methods Exposure was average long-term (up to 30 years) and recent (up to 12 years) intake of total flavonoids and six flavonoid subclasses, derived from validated quadrennial food frequency questionnaires. The primary outcome was incident glioma, confirmed by medical record review. Results We documented 536 incident cases of glioma across 5,936,386 person-years of follow-up. Long-term total flavonoid, flavan-3-ol, and polymer intake was associated with decreased glioma risk in pooled analyses comparing highest to lowest quintile of consumption (total flavonoid hazard ratio (HR) = 0.79, 95% CI: 0.59–1.05, P-trend = 0.04; flavan-3-ol HR = 0.76, 95% CI: 0.57–1.01, P-trend = 0.04; polymer HR = 0.82, 95% CI: 0.61–1.09, P-trend = 0.05). Associations with recent intake were weaker and not statistically significant. There were no associations with other flavonoid subclasses. After additional adjustment for tea consumption, there was no significant association between flavan-3-ol or polymer consumption and glioma. Conclusions Increased dietary intake of flavan-3-ol and polymeric flavonoids, especially those predominant in tea, was associated with decreased glioma risk in a prospective cohort of men and women. Habitual consumption of foods and beverages containing flavan-3-ols and polymeric flavonoids may protect against the development of glioma. Funding Sources This work was supported by the U.S. National Institutes of Health.

Associations Between a Targeted Metabolomics Panel of Urinary Flavonoids and Flavonoid Intakes from Fruits and Vegetables Across Dietary Assessment Periods

Abstract Objectives Aligning dietary intake and food composition data with biomarkers of exposure is critical for advancing assessment methodology. Flavonoids present in fruits and vegetables (FV) are rapidly metabolized and excreted in urine; therefore they may serve as acute intake biomarkers. Yet, the optimal dietary assessment period has not been determined. The objective of this study was to evaluate associations between a targeted metabolomics panel of six urinary flavonoids and dietary intakes of these flavonoids from FV across varying dietary assessment periods. Methods In this cross-sectional study, three-day diet records from 17 individuals were analyzed via Nutrition Data System for Research to determine FV intakes over one-day, two-day, and three-day assessment periods. Dietary flavonoids from FV were estimated via the Phenol-Explorer database; total intakes of targeted flavonoids (quercetin, kaempferol, isorhamnetin, phloretin, naringenin, hesperetin) were calculated by summing aglycone and glycosylated forms. Twenty-four-hour (24-h) urine was collected on the final day of diet records. Urinary flavonoid aglycones were quantified using HPLC; total urinary flavonoids were calculated by summing targeted flavonoids. Spearman correlations between flavonoid intakes and urinary flavonoids were analyzed by dietary assessment period. Results Mean targeted flavonoid intake from FV was 53.6 mg/day. Ten specific FV provided &amp;gt;95% of dietary flavonoids, with greatest contributions from citrus (orange juice, grapefruit, orange) and onion. Mean urinary flavonoid excretion was 9.5 μmol/24-h. Urinary flavonoids were moderately associated with flavonoid intakes from the one-day assessment period on the day prior to urine collection (rs = 0.485, P = 0.048) and summed intakes from the two-day assessment period (rs = 0.598, P = 0.011), but not from intakes over the three-day assessment period. Conclusions Urinary flavonoids are most strongly associated with dietary flavonoids consumed within two days of 24-h urine collection, indicating two-day diet records aligned with 24-h urine collection is optimal for assessing (poly)phenol exposure from FV in future research. Funding Sources OSU CCTS, Rosita Schiller Award, OSU Comprehensive Cancer Center MCC Program, and OSU CAFFRE.

Prospective Associations of Dietary Intakes of Total Antioxidant Capacity and Its Subclasses With Metabolic Syndrome in Adults Aged 40 Years and Older

Abstract Objectives This study aimed to evaluate the association between dietary intakes of total antioxidant capacity (TAC) and its subclasses (flavonoids and its individual subclass and individual vitamins) and incidence risk of Metabolic syndrome (MetS) in the KoGES_CArdioVascular disease Association Study (CAVAS). Methods A total of 11,272 participants over 40 years of age who did not have MetS from CAVAS were enrolled. Cumulative average TAC and flavonoid intake were calculated from repeated food frequency questionnaires composed of 106 items using data during follow-up. Using a modified Poisson regression model, we estimated incidence rate ratios (IRRs) and 95% confidence intervals (CIs) for MetS in men and women separately and subsequently pooled these results. Results Over 56,425 person-year of follow-up, there were 2,218 incident cases of MetS. While both TAC and flavonoids were inversely associated with MetS development in the pooled multivariable analysis (fourth vs. first quartile, IRR: 0.88; 95% CI 0.76–1.01 for TAC and 0.83, 0.73, 0.95 for flavonoids), there were relatively clear inverse associations between intake of certain subclasses and incidence of MetS. Among flavanones, theaflavins, anthocyanins, and carotenoids were obvious inversely associated with MetS (0.57; 0.50, 0.65 for flavanones, 0.55; 0.48, 0.63 for anthocyanins, 0.60; 0.52, 0.69 for carotenoids). However, the associations were relatively weak in flavones and flavonols (0.96; 0.84, 1.10 for flavones and 0.84; 0.73, 0.96 for flavonols). Conclusions Intake of specific antioxidants such as flavanones, anthocyanins, carotenoids may provide health benefits in preventing MetS. More prospective studies are warranted to elucidate the association between TAC and individual subclasses and the incidence of MetS and chronic disease. Funding Sources This work was supported by the Research Program funded by the Korea Centers for Disease Control and Prevention (2004-E71004–00, 2005-E71011–00, 2006-E71009–00, 2007-E71002–00, 2008-E71004–00, 2009-E71006–00, 2010-E71003–00, 2011-E71002–00, 2012-E71007–00, 2013-E71008–00, 2014-E71006–00, 2014-E71006–01, 2016-E71001–00, 2017N-E71001–00) and was supported the National Research Foundation of Korea(NRF) grant funded by the Korea government (MSIT) (No. NRF-2020R1A2C1004815).

Metabolic functions of flavonoids: From human epidemiology to molecular mechanism

Dietary flavonoid intake is associated with the regulation of nutrient metabolism in the living body. Observational and cohort studies have reported a negative association between flavonoid intake and the risk of metabolic and cardiovascular diseases. Several intervention trials in humans have also supported the benefits of dietary flavonoids. In experimental studies using animal models, a daily diet rich in typical flavonoids such as catechins, anthocyanin, isoflavone, and quercetin was shown to improve whole-body energy expenditure, mitochondrial activity, and glucose tolerance. For some flavonoids, molecular targets for the metabolic modulations have been suggested. Although the effect of flavonoids on neurons has been unclear, several flavonoids have been shown to regulate thermogenesis and feeding behavior through modulating autonomic and central nervous systems. Based on epidemiological and experimental studies, this review summarizes the evidence on the metabolic benefits of flavonoids and their potential mechanism of action in metabolic regulation.

Rat plasma protein binding of kaempferol-3-O-rutinoside from Lu'an GuaPian tea and its anti-inflammatory mechanism for cardiovascular protection.

Previous study found a high content of kaempferol-3-O-rutinoside (KR) in Lu'an GuaPian tea, however, the rat plasma protein binding and mechanism of KR for cardiovascular protection are unclear. Thus, we studied plasma protein binding using ultrafiltration followed by UPLC, and screened its inhibition against LPS-induced inflammation injury in vitro as well as the underlying mechanism by molecular docking and western blot. KR showed over 74% plasma protein binding ratio. Furthermore, KR may act on the toll-like receptor 4 (TLR4) and myeloid differentiation factor 88 (MyD88). In vitro experiments showed that KR decreases the overexpression of TLR4, MyD88, and nuclear factor-κB (NF-κB), which further validates the molecular docking results, suggesting that KR could block TLR4/MyD88/NF-κB signaling. These results indicate that KR could be a potential active agent in the protection of myocardial injury. PRACTICAL APPLICATIONS: Health benefits of tea are largely dependent on the intake of flavonoids. Flavonoids are a group of compounds beneficial to cardiovascular disease and an important part of "functional foods." Lu'an GuaPian tea is mainly produced in Lu'an City, Anhui Province and is one of the top 10 famous teas in China. Kaempferol-3-O-rutinoside in Lu'an GuaPian has good hypoglycemic effect, mainly manifested in a strong inhibition of α-glucosidase and α-amylase activities. Present study showed that kaempferol-3-O-rutinoside could block TLR4/MyD88/NF-κB signaling, suggesting that it could be a potential active agent in the protection of myocardial injury.

Abstract MP66: Higher Habitual Flavonoid Intakes Are Associated With A Lower Incidence Of Diabetes

Introduction: The promotion of evidence-based diets is an important s trategy to mitigate the global health and economic burden of diabetes. Higher flavonoid intakes are associated with a lower risk of obesity and diabetes. Less clear are associations of the flavonoid subclasses with diabetes, the mediating impact of body fat, and the identification of subpopulations that may receive the greatest benefit. Hypothesis: Higher flavonoid intakes will be associated with lower body fat at baseline and a lower risk of diabetes during follow-up. Methods: Incident diabetes was assessed in 54,787 participants of the Danish Diet, Cancer, and Health Study followed-up for 23 years. Dietary intake and objective measures of body fat were assessed at baseline; habitual flavonoid intake was calculated using the Phenol-Explorer database and body fat was objectively assessed using bioelectrical impedance. Incidence of diabetes was obtained using Danish National Patient and Prescription Registries. Cross-sectional associations between flavonoid intakes and body fat were assessed using multivariable-adjusted linear regression models. Non-linear associations between flavonoid intake and incident diabetes were examined using restricted cubic splines based on multivariable-adjusted Cox proportional hazards models. Results: Among 54,787 participants without diabetes at baseline (median [IQR] age of 56 [52 - 60] years; (47.3%) men), 6,700 individuals were diagnosed with diabetes. Participants in the highest total flavonoid intake quintile (median, 1,202 mg/d) had a 1.52 kg lower body fat (95% CI: -1.74, -1.30) and a 19% lower risk of diabetes [HR (95% CI): 0.81 (0.75, 0.87)] after multivariable adjustments and compared to participants in the lowest intake quintile (median, 174 mg/d). Body fat mediated 51.6% of the association between flavonoid intake and incident diabetes. Neither smoking status, BMI, nor sex appeared to modify the association between total flavonoid intake and incident diabetes. However, the difference (flavonoid intake quintile 5 - quintile 1) in the 20-year estimated absolute risk of diabetes was greatest for current smokers (males: 2.19%, females: 1.65%) and those with a BMI ≥30 kg/m 2 (males: 5.56%, females: 4.59%), likely owing to the higher prevalence of diabetes in these “at risk” subgroups. Moderate to high intakes of flavonols, flavanol monomers, flavanol oligo+polymers, and anthocyanins, and the individual compounds within these subclasses, were associated with a lower risk of diabetes. Conclusion: In this Danish prospective cohort study, we observed that higher flavonoid intakes were cross-sectionally associated with lower body fat, and longitudinally associated with a lower risk of diabetes. Our results suggest that promoting a diet abundant in flavonoid-rich foods may help to ameliorate diabetes risk, in part through a reduction in body fat.

Ingestion of Okinawa Island Vegetables Increases IgA Levels and Prevents the Spread of Influenza RNA Viruses.

Background: It has been hypothesized that flavonoid ingestion stimulates immunity, promotes health, and prevents human illness. The aim of this analysis was to evaluate the association of the levels of immunoglobulin A (IgA) with the prevention of influenza infections and with the polyphenols contained in Okinawan vegetables. Methods: IgA, immunoglobulin G (IgG), immunoglobulin M (IgM), and soluble interleukin-2 receptor (sIL-2R) levels were measured in 44 outpatients who regularly ingested vegetables grown on Okinawa Island (200–300 g/day for ≥ 300 days/year) with no history of influenza infection and in 73 patients who ingested the vegetables irregularly or not at all with a history of influenza infection. Results: The patients who regularly ate Okinawan vegetables had higher IgA, IgG, and IgM levels than those who did not. On the other hand, patients who did not consume Okinawan vegetables and had influenza had lower IgA, IgG, and IgM levels. In addition, the IgA and IgG levels showed significant positive correlations with the sIL-2R levels in both groups. Conclusions: It may be beneficial to eat vegetables abundant in polyphenols every day. Secretory IgA antibodies are an important part of the immune defense against viral diseases. People who ingest Okinawan vegetables have high IgA levels and might be more likely to develop immunity against influenza RNA viruses.

Dietary flavonoids are associated with longitudinal treatment outcomes in neovascular age-related macular degeneration.

To assess whether dietary intake of flavonoids are associated with longitudinal treatment outcomes of patients with neovascular age-related macular degeneration (nAMD). 547 participants with nAMD were recruited at baseline, 494 were followed-up after receiving 12 months of anti-vascular endothelial growth factor (anti-VEGF) therapy. Baseline dietary intake of flavonoids was determined using a validated food frequency questionnaire. At follow-up, presence of intra-retinal and sub-retinal fluid (IRF and SRF), retinal pigment epithelium detachment and measurements of central macular thickness (CMT) were recorded from optical coherence tomography scans. Visual acuity (VA) was documented using LogMAR charts. Participants in the first tertile of intake of the flavonol quercetin, and the flavan-3-ols epigallocatechin-3-gallate and epigallocatechin had significantly worse vision than participants in the third tertile-multivariable-adjusted least square (LS) mean VA: 14.68 vs. 19.53 (p = 0.04); 14.06 vs. 18.89 (p = 0.04); 13.86 vs. 18.86 (p = 0.03), respectively. Participants in the first compared to the third tertile of flavan-3-ol, epigallocatechin-3-gallate and epigallocatechin intake all had a twofold higher risk of IRF, multivariable-adjusted p trend of: 0.03, 0.01 and 0.02, respectively. The first vs. the third tertile of tea intake had significantly worse vision (LS mean VA: 13.49 vs. 19.04, p = 0.02), increased risk of IRF (OR 2.13, 95% CI 1.18-3.85) and greater mean CMT (279.59 μm vs. 256.52 μm, p = 0.04). Higher intakes of dietary flavonoids, specifically flavonols and flavan-3-ols, could be associated with better long-term treatment outcomes in nAMD patients receiving anti-VEGF therapy. Confirmation of these associations in interventional studies could result in promising new therapeutic approaches to the treatment of nAMD.

Antioxidants Such as Flavonoids and Carotenoids in the Diet of Bogor, Indonesia Residents

Due to the strong antioxidant activity of flavonoids and carotenoids, daily consumption of these bioactive compounds has the potential for reducing the risk of many chronic and degenerative diseases caused by or contributed to by oxidative stress. Currently, the available research results related to the flavonoid and carotenoid intake in Asian countries are very limited, especially for Indonesian population. The present study was conducted in Bogor City and Bogor District, West Java, Indonesia. Food consumption data was obtained through the food frequency questionnaire (FFQ) method, involving 200 respondents aged 25–65 years old. Flavonoids and carotenoids contents of the consumed food items were determined by referring to the databases developed by the United States Department of Agriculture (USDA), scientific journals, and calculation based on the recipes recorded in the survey. The total flavonoid intake of Bogor adults was estimated as 149.5 mg/day, consisting of 49.4% isoflavones, 24.0% flavonols, 9.4% flavanones, 7.0% flavan-3-ols, 6.0% flavones, and 4.2% anthocyanidins, and was contributed to mainly by legumes (70.7%), vegetables (10.1%), and fruits (7.3%). At the same time, the estimated total carotenoid intake reached 7.6 mg/day, and was contributed to mainly by vegetables (53.9%), fruits (20.2%), and snacks (14.4%), with β-carotene consumed in the highest proportion (49.9%), followed by lycopene (19.9%), lutein and zeaxanthin (13.5%), α-carotene (6.9%), and β-cryptoxanthin (2.6%). The effects of different respondents’ characteristics, such as area of residence (city vs. district), gender (male vs. female), and age (25–40, 41–55, and 56–65 years old) on the flavonoid and carotenoid intake varied widely, due to the differences in the overall consumption patterns of the respective respondents’ groups.

Association between health risk factors and dietary flavonoid intake in cohort studies

The aim of this study was to identify the health risk factors associated with flavonoid intake in cohort studies investigating the association between dietary polyphenols and the risk of cardiovascular disease (CVD). A systematic search of the PubMed and EMBASE databases was performed. Prospective studies with the background characteristics given for categories of flavonoid intake were eligible to inclusion. A bivariate meta-analysis summarising the intercepts and slopes of the linear regression and a dose-response meta-analysis of differences in means were used to analyse the relationships. The intake of total flavonoids was inversely associated with BMI, alcohol consumption, saturated fat intake, and current smoking, and positively associated with vitamin E, folate, fibre, beta-carotene intake, multivitamin supplement use, and high physical activity. The results of this study underline the importance of considering the association between dietary flavonoid consumption and CVD risk in the context of a healthy lifestyle.

Going “Green” in the Prevention and Management of Atherothrombotic Diseases: The Role of Dietary Polyphenols

During the 20th century processed and ready-to-eat foods became routinely consumed resulting in a sharp rise of fat, salt, and sugar intake in people’s diets. Currently, the global incidence of obesity, raised blood lipids, hypertension, and diabetes in an increasingly aged population contributes to the rise of atherothrombotic events and cardiovascular diseases (CVD) mortality. Drug-based therapies are valuable strategies to tackle and help manage the socio-economic impact of atherothrombotic disorders though not without adverse side effects. The inclusion of fresh fruits and vegetables rich in flavonoids to human diets, as recommended by WHO offers a valuable nutritional strategy, alternative to drug-based therapies, to be explored in the prevention and management of atherothrombotic diseases at early stages. Though polyphenols are mostly associated to color and taste in foods, food flavonoids are emerging as modulators of cholesterol biosynthesis, appetite and food intake, blood pressure, platelet function, clot formation, and anti-inflammatory signaling, supporting the health-promoting effects of polyphenol-rich diets in mitigating the impact of risk factors in atherothrombotic disorders and CVD events. Here we overview the current knowledge on the effect of polyphenols particularly of flavonoid intake on the atherothrombotic risk factors and discuss the caveats and challenges involved with current experimental cell-based designs.

Mass spectrometry-based metabolomics for the discovery of candidate markers of flavonoid and polyphenolic intake in adults

Robust biological markers of dietary exposure are essential in improving the understanding of the link between diet and health outcomes. Polyphenolic compounds, including flavonoids, have been proposed to mitigate the risk of chronic diseases where oxidative stress and inflammation play a central role. Biomarkers can provide objective measurement of the levels of polyphenolic compounds. In this study, we provide methodology to identify potential candidate markers of polyphenol intake in human serum. Seventeen participants from the UK arm of the Global Allergy and Asthma Network of Excellence (GA2LEN) had their dietary intake estimated using a validated food frequency questionnaire, and serum samples were assessed using mass spectrometry to identify potential candidate markers. 144 features were assigned identities, of these we identified four biologically relevant compounds (rhamnazin 3-rutinoside, 2-galloyl-1,4-galactarolactone methyl ester, 2″,32″-di-O-p-coumaroylafzelin and cyclocommunin), which were significantly increased in the serum of participants with high predicted level of fruit and vegetable intake. 2-galloyl-1,4-galactarolactone methyl ester was strongly correlated with total flavonoids (r = 0.62; P = 0.005), flavan-3-ols (r = 0.67; P = 0.002) as well as with other four subclasses. Rhamnazin 3-rutinoside showed strong correlation with pro-anthocyanidins (r = 0.68; P = 0.001), flavones (r = 0.62; P = 0.005). Our results suggest that serum profiling for these compounds might be an effective way of establishing the relative intake of flavonoids and could contribute to improve the accuracy of epidemiological methods to ascertain flavonoid intake.

Dietary flavonoid intake and risk of esophageal squamous cell carcinoma: A population-based case-control study

ObjectivesThe aim of this population-based case-control study was to investigate the association between dietary consumption of the total flavonoids, subclasses, and specific flavonoids and the risk of esophageal squamous cell carcinoma (ESCC) among adults in a high-risk area of China. MethodsWe recruited 820 ESCC participants and 863 control participants from Yanting County. Dietary flavonoids were assessed using a validated 76-item food frequency questionnaire. Odds ratios (ORs) with 95% confidence intervals (CIs) were estimated using logistic regression after considering potential confounders. ResultsComparing the highest and lowest intake quartiles, we observed a negative association of ESCC risk with consumption of isoflavones (OR = 0.34, 95% CI = 0.23–0.50, P for trend < 0.001), daidzein (OR = 0.31, 95% CI = 0.21–0.45, P for trend < 0.001), genistein (OR = 0.34, 95% CI = 0.23–0.50, P for trend < 0.001), and glycitein (OR = 0.32, 95% CI = 0.22–0.48, P for trend < 0.001) after adjustment for potential confounders. A more pronounced negative association was observed when comparing the third quartile, rather than the fourth, with the lowest quartile for consumption of anthocyanidins (OR = 0.58, 95% CI = 0.42–0.80, P for trend = 0.004), delphinidin (OR = 0.57, 95% CI = 0.41–0.78, P for trend = 0.004), and cyanidin (OR = 0.48, 95% CI = 0.35–0.66, P for trend = 0.003) after considering potential confounders. Consumption of total flavonoids, flavones, flavonols, and six other specific flavonoids (quercetin, myricetin, kaempferol, luteolin, apigenin, and peonidin) was not associated with ESCC risk. ConclusionsThe results suggest that increased dietary intake of isoflavones and moderate consumption of anthocyanidins were associated with a decreased risk of ESCC. Future nutritional guidelines may emphasize foods or supplements rich in specific isoflavones and anthocyanidins for ESCC chemoprevention.

Dietary Flavonoids and Cardiovascular Disease: A Comprehensive Dose-Response Meta-Analysis.

Dietary flavonoids have shown potential in the prevention of noncommunicable diseases. The aim of the present study is to conduct a dose-response meta-analysis on the association between dietary intake of total, subclasses and individual flavonoids and risk of cardiovascular disease (CVD). Electronic databases are searched. A total of 39 prospective cohort studies are included, comprising 1 501 645 individuals and a total of 33 637 cases of CVD, 23 664 of coronary heart disease (CHD), and 11 860 of stroke. Increasing dietary intake of total flavonoids is linearly associated with a lower risk of CVD. Among the main classes of flavonoids, increasing intake of anthocyanins and flavan-3-ols is inversely associated with risk of CVD, while flavonols and flavones with CHD. Only increasing flavanones showed a linear inverse association with stroke risk. Catechins showed a favorable effect toward all cardiovascular outcomes. Among individual compounds, intake of quercetin and kaempferol is linearly associated with lower risk of CHD and CVD, respectively. However, higher intake of all the aforementioned compounds is associated, with a various extent, with a lower risk of CVD when considering comparison of extreme categories of consumption. The results of this study provide evidence of potential cardiovascular benefits of a flavonoid-rich diet.

Variety in fruits and vegetables, diet quality and lifestyle in an older adult mediterranean population

Previous studies, mainly focused on quantity rather than variety, have shown beneficial associations between the amount of fruit and vegetable consumed, diet quality and healthy lifestyle. The aim is to evaluate the association between fruit and vegetable consumption, diet quality and lifestyle in an elderly Mediterranean population, considering both variety and the combination of quantity and variety (QV). A cross-sectional analysis of 6647 participants (51.6% of males) was conducted in the framework of the PREDIMED-Plus study. A variety score was created as the sum of vegetables and/or fruits consumed at least once per month using food frequency questionnaires. Dietary Reference Intakes (EAR and IA values) were used to estimate the prevalence of inadequate intake of dietary fiber and micronutrients. Logistic regression models were performed to examine the association between fruit and vegetable consumption and not meeting the DRIs, by tertiles of fruit and vegetable variety and QV categories. Participants with higher fruit and vegetable variety score reported a significant higher intake of fiber, vitamins, minerals and flavonoids and were significantly more likely to be physically active and non-smoker. Besides, higher variety in fruit and vegetable consumption was associated with lower prevalence of having an inadequate intake of fiber [(0.13 (0.11-0.16)], two or more [(0.17 (0.14-0.21)], three or more [(0.15 (0.13-0.18)] and four or more [(0.11 (0.10-0.14)] micronutrients in our participants. Higher quantity and variety in fruit and vegetable consumption was associated with lower prevalence of having an inadequate intake of fiber [(0.05 (0.04-0.06)], two or more [(0.08 (0.06-0.10)], three or more [(0.08 (0.06-0.09)] and four or more [(0.06 (0.05-0.07)] micronutrients. Greater variety in fruit and vegetable intake was associated with better nutrient adequacy, diet quality and healthier lifestyle in an elderly Mediterranean population.

Linking biomarkers of oxidative stress and disease with flavonoid consumption: From experimental models to humans

Identification of the links among flavonoid consumption, mitigation of oxidative stress and improvement of disease in humans has significantly advanced in the last decades. This review used (−)-epicatechin (EC) as an example of dietary flavonoids, and inflammation, endothelial dysfunction/hypertension and insulin resistance/diabetes as paradigms of human disease. In these pathologies, oxidative stress is part of their development and/or their perpetuation. Evidence from both, rodent studies and characterization of mechanisms in cell cultures are encouraging and mostly support indirect antioxidant actions of EC and EC metabolites in endothelial dysfunction and insulin resistance. Human studies also show beneficial effects of EC on these pathologies based on biomarkers of disease. However, there is limited available information on oxidative stress biomarkers and flavonoid consumption to allow establishing conclusive associations. The evolving discovery of metabolites that could serve as reliable markers of intake of specific flavonoids constitutes a powerful tool to link flavonoid consumption to disease and prevention of oxidative stress in human populations.

Association between dietary flavonoid intakes and C-reactive protein levels: a cross-sectional study in Taiwan.

Although the intake of specific flavonoid-rich foods may reduce C-reactive protein (CRP) levels, the association between dietary flavonoid intakes and CRP is inconsistent. We aim to describe dietary flavonoid intakes in a Taiwanese nationally representative sample and to investigate the association between flavonoid intakes and CRP. We conducted a cross-sectional study based on 2592 adults from the Nutrition and Health Survey in Taiwan 2005-8. Flavonoid intakes were estimated by linking the 24-h dietary recall with the U.S. Department of Agriculture flavonoid database and divided into quartiles. Adjusted estimates of the flavonoid intakes for the continuous and binary (elevated CRP: >0⋅3 mg/dl) variables were performed by using general linear and logistic regression. We found that tea, orange, tofu and sweet potato leaves/water spinach constituted the major food items of the total flavonoid intake. The total flavonoid intake was lower among women and elderly. Compared with the lowest total flavonoid intake quartile, participants in higher quartiles were associated with a lower CRP status (adjusted odds ratio (OR): 0⋅61, 95 % confidence interval (CI): 0⋅44-0⋅86 for the highest quartiles). The trends were similar for flavonol and flavan-3-ol intakes. Compared with non-consumers, tea consumers were likely to have a lower CRP status (adjusted OR: 0⋅74, 95 % CI: 0⋅57-0⋅97). In brief, a higher total flavonoid intake and tea consumption were inversely associated with CRP levels, indicating that a high-flavonoid diet may contribute to anti-inflammatory effects. A Taiwanese flavonoid content table is necessary for conducting further studies related to flavonoids in Taiwan.

Flavonoid intake and incident dementia in the Danish Diet, Cancer, and Health cohort.

IntroductionProspective studies investigating flavonoid intake and dementia risk are scarce. The aims of this study were to examine associations between flavonoid intake and the risk of incident dementia and to investigate whether this association differs in the presence of lifestyle risk factors for dementia.MethodsWe examined associations in 55,985 participants of the Danish Diet, Cancer, and Health Study followed for 23 years. The Phenol‐Explorer database was used to estimate flavonoid intakes. Information on incident dementia and dementia subtypes was obtained using Danish patient and prescription registries. Hazard ratios (HRs) were calculated using restricted cubic splines in multivariable‐adjusted Cox proportional hazards models.ResultsFor incident dementia, moderate compared to low intakes of flavonols (HR: 0.90 [0.82, 0.99]), flavanol oligo+polymers (HR: 0.87 [0.79, 0.96]), anthocyanins (HR: 0.84 [0.76, 0.93]), flavanones (HR: 0.89 [0.80, 0.99]), and flavones (HR: 0.85 [0.77, 0.95]) were associated with a lower risk. For vascular dementia, moderate intakes of flavonols (HR: 0.69 [0.53, 0.89]) and flavanol oligo + polymers (HR: 0.65 [0.51, 0.83]) were associated with lower risk. Flavonoid intakes were not significantly associated with Alzheimer's disease or unspecified dementia. The inverse association between total flavonoid intake and incident dementia was stronger in “ever” smokers than in “never” smokers and in those without hypercholesterolemia versus those with hypercholesteremia. Furthermore, the inverse association of vascular dementia with a moderate total flavonoid intake was stronger in “ever” smokers and those who were “normal” to “overweight” versus “never” smokers or those who were “obese,” respectively.ConclusionA moderate intake of flavonoid‐rich foods may help to reduce dementia risk.