Intake Of Flavanones Research Articles

Association between dietary flavanones intake and lipid profiles according to the presence of metabolic syndrome in Korean women with type 2 diabetes mellitus.

BACKGROUND/OBJECTIVESThis study was aimed at examining the association between dietary flavanones intake and lipid profiles according to the presence of metabolic syndrome (MetS) in Korean women with type 2 diabetes mellitus (T2DM).SUBJECTS/METHODSA cross-sectional analysis was performed among 502 female T2DM patients (non-MetS group; n = 129, MetS group; n = 373) who were recruited from the Huh's Diabetes Clinic in Seoul, Korea between 2005 and 2011. The dietary intake was assessed by a validated semi-quantitative food frequency questionnaire (FFQ) and the data was analyzed using the Computer Aided Nutritional Analysis program (CAN-Pro) version 4.0 software. The intake of flavanones was estimated on the basis of the flavonoid database.RESULTSIn the multiple linear regression analysis after adjustment for confounding factors, daily flavanones intake was negatively associated with CVD risk factors such as total cholesterol, LDL-cholesterol, and apoB and apoB/apoA1 ratio only in the MetS group but not in the non-MetS group. Multiple logistic regression analysis revealed that the odds ratio for a higher apoB/apoA1 ratio above the median (≥ 0.74) was significantly low in the 4th quartile compared to that in the 1st quartile of dietary flavanones intake [OR: 0.477, 95% CI: 0.255-0.894, P for trend = 0.0377] in the MetS group.CONCLUSIONSDietary flavanones intake was inversely associated with the apoB/apoA1 ratio, suggesting a potential protective effect of flavanones against CVD in T2DM women with MetS.

Dietary Flavonoid Intake and Incident Coronary Heart Disease in the Reasons for Geographic and Racial Differences in Stroke Study (REGARDS)

Dietary Flavonoid Intake and Incident Coronary Heart Disease in the Reasons for Geographic and Racial Differences in Stroke Study (REGARDS)

Urinary Excretion of Select Dietary Polyphenol Metabolites Is Associated with a Lower Risk of Type 2 Diabetes in Proximate but Not Remote Follow-Up in a Prospective Investigation in 2 Cohorts of US Women1–3

Background: Polyphenols are phytochemicals that possess antioxidant and anti-inflammatory properties and improve glucose metabolism in animal experiments, although data from prospective epidemiologic studies examining polyphenol intakes in relation to type 2 diabetes (T2D) risk are inconsistent.Objectives: We examined urinary excretion of select flavonoid and phenolic acid metabolites, as biomarkers of intake, in relation to T2D risk.Methods: Eight polyphenol metabolites (naringenin, hesperetin, quercetin, isorhamnetin, catechin, epicatechin, caffeic acid, and ferulic acid) were quantified in spot urine samples by liquid chromatography/mass spectrometry among 1111 T2D case-control pairs selected from the Nurses’ Health Study (NHS) and NHSII.Results: Higher urinary excretion of hesperetin was associated with a lower T2D risk after multivariate adjustment: the OR comparing top vs. bottom quartiles was 0.68 (95% CI: 0.49, 0.96), although a linear trend was lacking (P = 0.30). The other measured polyphenols were not significantly associated with T2D risk after multivariate adjustment. However, during the early follow-up period [≤4.6 y (median) since urine sample collection], markers of flavanone intakes (naringenin and hesperetin) and flavonol intakes (quercetin and isorhamnetin) were significantly associated with a lower T2D risk. The ORs (95% CIs) comparing extreme quartiles were 0.61 (0.39, 0.98; P-trend: 0.03) for total flavanones and 0.55 (0.33, 0.92; P-trend: 0.04) for total flavonols (P-interaction with follow-up length: ≤0.04). An inverse association was also observed for caffeic acid during early follow-up only: the OR was 0.52 (95% CI: 0.32, 0.84; P-trend: 0.03). None of these markers was associated with T2D risk during later follow-up. Metabolites of flavan-3-ols and ferulic acid were not associated with T2D risk in either period.Conclusions:These results suggest that specific flavonoid subclasses, including flavanones and flavonols, as well as caffeic acid, are associated with a lower T2D risk in relatively short-term follow-up but not during longer follow-up. Substantial within-person variability of the metabolites in single spot urine samples may limit the ability to capture associations with long-term disease risk.

Flavonoid intake in European adults (18 to 64 years).

BackgroundFlavonoids are a group of phenolic secondary plant metabolites that are ubiquitous in plant-based diets. Data from anthropological, observational and intervention studies have shown that many flavonoids are bioactive. For this reason, there is an increasing interest in investigating the potential health effects of these compounds. The translation of these findings into the context of the health of the general public requires detailed information on habitual dietary intake. However, only limited data are currently available for European populations.ObjectiveThe objective of this study is to determine the habitual intake and main sources of anthocyanidins, flavanols, flavanones, flavones, flavonols, proanthocyanidins, theaflavins and thearubigins in the European Union.DesignWe use food consumption data from the European Food Safety Authority (EFSA) and the FLAVIOLA Food Composition Database to estimate intake of flavonoids.ResultsMean (±SEM) intake of total flavonoids in Europe was 428±49 mg/d, of which 136±14 mg/d were monomeric compounds. Gallated flavan-3-ols (53±12 mg/d) were the main contributor. The lowest flavonoid intake was observed in Mediterranean countries (monomeric compounds: 95±11 mg/d). The distribution of intake was skewed in many countries, especially in Germany (monomeric flavonoids; mean intake: 181 mg/d; median intake: 3 mg/d).ConclusionsThe habitual intake of flavonoids in Europe is below the amounts found to have a significant health effect.

Orange juice–derived flavanone and phenolic metabolites do not acutely affect cardiovascular risk biomarkers: a randomized, placebo-controlled, crossover trial in men at moderate risk of cardiovascular disease

Background: Epidemiologic data suggest inverse associations between citrus flavanone intake and cardiovascular disease (CVD) risk. However, insufficient randomized controlled trial data limit our understanding of the mechanisms by which flavanones and their metabolites potentially reduce cardiovascular risk factors.Objective: We examined the effects of orange juice or a dose-matched hesperidin supplement on plasma concentrations of established and novel flavanone metabolites and their effects on cardiovascular risk biomarkers in men at moderate CVD risk.Design: In an acute, randomized, placebo-controlled crossover trial, 16 fasted participants (aged 51–69 y) received orange juice or a hesperidin supplement (both providing 320 mg hesperidin) or control (all matched for sugar and vitamin C content). At baseline and 5 h postintake, endothelial function (primary outcome), blood pressure, arterial stiffness, cardiac autonomic function, platelet activation, and NADPH oxidase gene expression and plasma flavanone metabolites were assessed. Before each intervention, a diet low in flavonoids, nitrate/nitrite, alcohol, and caffeine was followed, and a standardized low-flavonoid evening meal was consumed.Results: Orange juice intake significantly elevated mean ± SEM plasma concentrations of 8 flavanone (1.75 ± 0.35 μmol/L, P < 0.0001) and 15 phenolic (13.27 ± 2.22 μmol/L, P < 0.0001) metabolites compared with control at 5 h postconsumption. Despite increased plasma flavanone and phenolic metabolite concentrations, cardiovascular risk biomarkers were unaltered. After hesperidin supplement intake, flavanone metabolites were not different from the control, suggesting altered absorption/metabolism compared with the orange juice matrix.Conclusions: After single-dose flavanone intake within orange juice, circulating flavanone and phenolic metabolites collectively reached a concentration of 15.20 ± 2.15 μmol/L, but no effects were observed on cardiovascular risk biomarkers. Longer-duration randomized controlled trials are required to examine previous associations between higher flavanone intakes and improved cardiovascular health and to ascertain the relative importance of food matrix and flavanone-derived phenolic metabolites. This trial was registered at clinicaltrials.gov as NCT01530893.

Chronic administration of a microencapsulated probiotic enhances the bioavailability of orange juice flavanones in humans

Orange juice (OJ) flavanones are bioactive polyphenols that are absorbed principally in the large intestine. Ingestion of probiotics has been associated with favorable changes in the colonic microflora. The present study examined the acute and chronic effects of orally administered Bifidobacterium longum R0175 on the colonic microflora and bioavailability of OJ flavanones in healthy volunteers. In an acute study volunteers drank OJ with and without the microencapsulated probiotic, whereas the chronic effects were examined when OJ was consumed after daily supplementation with the probiotic over 4 weeks. Bioavailability, assessed by 0–24h urinary excretion, was similar when OJ was consumed with and without acute probiotic intake. Hesperetin-O-glucuronides, naringenin-O-glucuronides, and hesperetin-3′-O-sulfate were the main urinary flavanone metabolites. The overall urinary excretion of these metabolites after OJ ingestion and acute probiotic intake corresponded to 22% of intake, whereas excretion of key colon-derived phenolic and aromatic acids was equivalent to 21% of the ingested OJ (poly)phenols. Acute OJ consumption after chronic probiotic intake over 4 weeks resulted in the excretion of 27% of flavanone intake, and excretion of selected phenolic acids also increased significantly to 43% of (poly)phenol intake, corresponding to an overall bioavailability of 70%. Neither the probiotic bacterial profiles of stools nor the stool moisture, weight, pH, or levels of short-chain fatty acids and phenols differed significantly between treatments. These findings highlight the positive effect of chronic, but not acute, intake of microencapsulated B. longum R0175 on the bioavailability of OJ flavanones.

Abstract P320: Dietary Flavonoid Intake and Ischemic Stroke

Introduction: Diets rich in plant-based foods have been associated with lower stroke risk. Plant-based foods contain a variety of potentially cardioprotective compounds, including flavonoids. We assessed the hypothesis that total flavonoid and flavonoid subclass intakes are associated with incident ischemic stroke in a population-based cohort oversampled for non-Hispanic blacks and Stroke Belt residents. Methods: Between 2003 and 2007, REGARDS enrolled black and white Americans age ≥ 45 years. Participants were 20,413 men and women who completed a Block 98 food frequency questionnaire (FFQ) and without stroke at baseline. Total flavonoid and flavonoid subclass (anthocyanidin, flavan-3-ol, flavanone, flavonol, flavone, proanthocyanidin and isoflavone) intakes were estimated using the food consumption reported by the FFQ and the flavonoid contents of each food using USDA databases. Incident strokes were captured by participant report and adjudicated by experts. Quintiles of flavonoid intake were examined as predictors of incident stroke using Cox regression models using the first quintile as the referent. Tests for trend used the quintile medians. Results: Adjusting for age and caloric intake, there was a statistically significant inverse association between total flavonoid intake and ischemic stroke (Q5 v Q1: HR=0.68; 95% CI=0.51, 0.90; p-trend=0.04) however, this association weakened after additional adjustment for demographic, socioeconomic and health behavior factors as well as self-reported CHD at baseline (Q5 v Q1: HR=0.77; 95% CI=0.58, 1.03; p-trend=0.31). A similar pattern was seen for flavanones (age, energy adjusted HR=0.74; 95% CI= 0.57, 0.95; p-trend=0.02; fully adjusted HR= 0.82; 95%CI=0.65, 1.05; p-trend=0.06). Effect estimates for total flavonoids, flavanones, proanthocyanidins, and isoflavones, suggested a protective, though nonlinear association with risk reduction emerging at the second quintile, though these did not achieve statistical significance (total flavonoids, fully adjusted HR (95% CI): Q2= 0.80 (0.61, 1.04); Q3= 0.85 (0.65, 1.11); Q4=0.92 (0.70, 1.19); Q5= 0.77 (0.58, 1.03)). Total flavonoid and flavanone intake were significantly associated with IS in fully adjusted models in women (total: Q5 v Q1 HR=0.62; 95% CI= 0.41, 0.94; p-trend=0.15; flavanones HR=0.65; 95% CI=0.44, 0.95; p-trend=0.03) but not in men (total: Q5 v Q1 HR=0.95; 95% CI= 0.63, 1.42; flavanones HR=0.80; 95% CI=0.58, 1.09; p-interaction=0.67). There was no effect modification by race or region of residence. Conclusion: Total dietary flavonoids and flavanones are associated with a reduction in risk of incident ischemic stroke, particularly in women. The emergence of a protective effect at the second quintile for total flavonoids, flavanones, proanthocyanidins and isoflavones is consistent with previous studies of dietary flavonoid intake and CVD mortality.

Association between flavonoid intake and diabetes risk among the Koreans

BackgroundWe investigated the association between flavonoid intake and type 2 diabetes mellitus (T2DM) risk factors including serum fasting glucose, insulin level, and insulin resistance. MethodsA total of 4186 participants who were involved in the 2007–2009 Korean National Health and Nutrition Examination Survey were examined. The participants were divided into 2 groups by fasting plasma glucose (FPG) as follows: normal fasting glucose (NFG; FPG <100mg/dl) and impaired fasting glucose (IFG) groups (FPG ≥100mg/dl). ResultsIn the IFG group, body weight, body mass index, and waist circumference were increased. Fasting insulin level and homeostasis model assessment estimate of insulin resistance as markers of insulin resistance were higher in the IFG group. Intakes of energy and nutrients, including protein, fat, carbohydrate, crude fiber, vitamin C, calcium, phosphorus, and iron, did not differ between the 2 groups. For the male subjects, the energy-adjusted flavanone intake was lower in the IFG group than in the NFG group. Insulin and insulin resistance were inversely correlated with intakes of flavones and flavonols among the male subjects. ConclusionThese findings can provide valuable information for further development of appropriate strategies for diabetes prevention in Korea.

Intake of dietary flavonoids and risk of epithelial ovarian cancer

Background: The impact of different dietary flavonoid subclasses on risk of epithelial ovarian cancer is unclear, with limited previous studies that have focused on only a few compounds.Objective: We prospectively examined associations between habitual flavonoid subclass intake and risk of ovarian cancer.Design: We followed 171,940 Nurses’ Health Study and Nurses’ Health Study II participants to examine associations between intakes of total flavonoids and their subclasses (flavanones, flavonols, anthocyanins, flavan-3-ols, flavones, and polymeric flavonoids) and risk of ovarian cancer by using Cox proportional hazards models. Intake was calculated from validated food-frequency questionnaires collected every 4 y.Results: During 16–22 y of follow-up, 723 cases of ovarian cancer were confirmed through medical records. In pooled multivariate-adjusted analyses, total flavonoids were not statistically significantly associated with ovarian cancer risk (HR for the top compared with the bottom quintile: 0.85; 95% CI: 0.66, 1.09; P-trend = 0.17). However, participants in the highest quintiles of flavonol and flavanone intakes had modestly lower risk of ovarian cancer than did participants in the lowest quintile, although the P-trend was not significant [HRs: 0.76 (95% CI: 0.59, 0.98; P-trend = 0.11) and 0.79 (95% CI: 0.63,1.00; P-trend = 0.26), respectively]. The association for flavanone intake was stronger for serous invasive and poorly differentiated tumors (comparable HR: 0.68; 95% CI: 0.50, 0.92; P-heterogeneity = 0.10, P-trend = 0.07) compared with nonserous and less-aggressive tumors. Intakes of other subclasses were not significantly associated with risk. In food-based analyses used to compare subjects who consumed >1 and ≤1 cup black tea/d, the HR was 0.68 (95% CI: 0.51, 0.90; P < 0.01).Conclusions: Higher intakes of flavonols and flavanones as well as black tea consumption may be associated with lower risk of ovarian cancer. Additional prospective studies are required to confirm these findings.

Dietary Flavonoid Intake and Thyroid Cancer Risk in the NIH–AARP Diet and Health Study

Experimental studies suggested that flavonoids may influence thyroid carcinogenesis, but epidemiologic evidence is sparse. No study has examined different classes of flavonoids in relation to thyroid cancer risk. Using data from the NIH-AARP Diet and Health Study, which enrolled 491,840 U.S. men and women, ages 50 to 71 years at baseline, we prospectively examined the risk of thyroid cancer in relation to dietary intakes of catechins, flavanones, flavonols, anthocyanidins, flavones, isoflavones, and total flavonoids. Dietary intakes were assessed using a food frequency questionnaire. Cancer cases were ascertained by linkage to state cancer registries. Multivariable-adjusted Cox proportional hazard models were used to estimate HRs and 95% confidence intervals (CI). During follow up (mean = 9 years), we identified 586 thyroid cancer cases. Thyroid cancer risk was inversely associated with dietary flavan-3-ols [HRQ5 vs. Q1 (95% CI): 0.70 (0.55, 0.91), PTrend = 0.03], but positively associated with flavanones [HRQ5 vs. Q1 (95% CI): 1.50 (1.14, 1.96), PTrend = 0.004]. Other classes of flavonoids and total flavonoids were not associated with thyroid cancer risk. Similar associations were found for papillary thyroid cancer. Our findings suggest that dietary intake of different classes of dietary flavonoids may have divergent effects on thyroid cancer risk. More studies are needed to clarify a role of flavonoids in thyroid cancer development. Results from our study suggest a potential nutritional etiology of thyroid cancer. Cancer Epidemiol Biomarkers Prev; 23(6); 1102-8. ©2014 AACR.

Pilot study of diet and microbiota: interactive associations of fibers and polyphenols with human intestinal bacteria.

Several studies have addressed the use of dietary fibers in the modulation of intestinal microbiota; however, information about other highly correlated components in foods, such as polyphenols, is scarce. The aim of this work was to explore the association between the intake of fibers and polyphenols from a regular diet and fecal microbiota composition in 38 healthy adults. Food intake was recorded using an annual food frequency questionnaire (FFQ). Quantification of microbial populations in feces was performed by quantitative PCR. A negative association was found between the intake of pectins and flavanones from oranges and the levels of Blautia coccoides and Clostridium leptum. By contrast, white bread, providing hemicellulose and resistant starch, was directly associated with Lactobacillus. Because some effects on intestinal microbiota attributed to isolated fibers or polyphenols might be modified by other components present in the same food, future research should be focused on diet rather than individual compounds.

Dietary Flavonoid Intake and Smoking-Related Cancer Risk: A Meta-Analysis

PurposeTo systematically investigate the effects of dietary flavonoids and flavonoid subclasses on the risk of smoking-related cancer in observational studies.MethodsSummary estimates and corresponding standard errors were calculated using the multivariate-adjusted odds ratio (OR) or relative risk (RR) and 95% CI of selected studies and weighted by the inverse variance.ResultsA total of 35 studies, including 19 case-controls (9,525 cases and 15,835 controls) and 15 cohort studies (988,082 subjects and 8,161 cases), were retrieved for the meta-analysis. Total dietary flavonoids and most of the flavonoid subclasses were inversely associated with smoking-related cancer risk (OR: 0.82, 95% CI: 0.72-0.93). In subgroup analyses by cancer site, significant associations were observed in aerodigestive tract and lung cancers. Total dietary flavonoid intake was significantly associated with aerodigestive tract cancer risk (OR: 0.67, 95% CI: 0.54-0.83) marginally associated with lung cancer risk (OR: 0.84, 95% CI: 0.71-1.00). Subgroup analyses by smoking status showed significantly different results. The intake of total flavonoids, flavonols, flavones, and flavanones, as well as the flavonols quercetin and kaempferol was significantly associated with decreased risk of smoking-related cancer in smokers, whereas no association was observed in non-smokers, except for flavanones. In meta-analysis for the effect of subclasses of dietary flavonoids by cancer type, aerodigestive tract cancer was inversely associated with most flavonoid subclasses.ConclusionThe protective effects of flavonoids on smoking-related cancer risk varied across studies, but the overall results indicated that intake of dietary flavonoids, especially flavonols, was inversely associated with smoking-related cancer risk. The protective effects of flavonoids on smoking-related cancer risk were more prominent in smokers.

Proanthocyanidins and other flavonoids in relation to endometrial cancer risk: a case–control study in Italy

Background:Because of their antioxidant and antimutagenic properties, flavonoids may reduce cancer risk. Some flavonoids have antiestrogenic effects that can inhibit the growth and proliferation of endometrial cancer cells.Methods:In order to examine the relation between dietary flavonoids and endometrial cancer, we analysed data from an Italian case–control study including 454 incident, histologically confirmed endometrial cancers and 908 hospital-based controls. Information was collected through a validated food-frequency questionnaire. We applied data on food and beverage composition to estimate the intake of flavanols, flavanones, flavonols, anthocyanidins, flavones, isoflavones, and proanthocyanidins. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated from multiple logistic regression models conditioned on age and study centre and adjusted for major confounding factors.Results:Women in the highest quartile category of proanthocyanidins with ⩾3 mers vs the first three quartile categories had an OR for endometrial cancer of 0.66 (95% CI=0.48–0.89). For no other class of flavonoids, a significant overall association was found. There was a suggestion of an inverse association for flavanones and isoflavones among women with body mass index <25 kg m−2, and, for flavanones, among parous or non-users of hormone-replacement therapy women.Conclusion:High consumption of selected proanthocyanidins may reduce endometrial cancer risk.

Comparison of daily flavonoid intake and major food sources in 1990 with 2006 in Nurses’ Health Study and Health Professional Follow‐Up Study

Emerging studies have reported flavonoid intake in relation to risk of chronic disease, but few studies have investigated the change of flavonoid intake in U.S. adults over time. The present study aimed to compare the daily intakes of total flavonoid, its subclasses, and major food sources in 1990 with that in 2006 in prospective studies. A total of 78,884 women from the Nurses’ Health Study and 37,882 men from the Health Professionals Follow‐Up Study completed food frequency questionnaires in 1990 and 2006. Daily intakes of total flavonoid and its subclasses were calculated by using an updated USDA database. Averaged total flavonoid intake in 2006 was higher than that in 1990 in women (357 mg/d vs 353 mg/d, P=0.025) and men (389 mg/d vs 353 mg/d, P&lt;0.0001). Similar increase was found for dietary flavonols, flavones, anthocyanins and polymers, while intakes of flavanones and flavan‐3‐ols decreased. Major food sources of total flavonoids and each subclass remained comparable across 16 years but contributions of each food item decreased while food diversity increased in 2006. Total flavonoid intake in 1990 was higher in older age and in groups with lower body mass index and alcohol intake, and was higher in non‐smokers than their counterparts (P&lt;0.05). In conclusion, intakes of total flavonoid and some subclasses increased over time and major food sources remained similar.

The Risk of Lung Cancer Related to Dietary Intake of Flavonoids

It has been hypothesized that flavonoids in foods and beverages may reduce cancer risk through antioxidation, inhibition of inflammation, and other antimutagenic and antiproliferative properties. We examined associations between intake of 5 flavonoid subclasses (anthocyanidins, flavan-3-ols, flavones, flavonols, and flavanones) and lung cancer risk in a population-based case-control study in Montreal, Canada (1061 cases and 1425 controls). Flavonoid intake was estimated from a food frequency questionnaire that assessed diet 2 yr prior to diagnosis (cases) or interview (controls). Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using unconditional logistic regression. Overall, total flavonoid intake was not associated with lung cancer risk, the effect being similar regardless of sex and smoking level. However, low flavonoid intake from food, but not from beverages, was associated with an increased risk. The adjusted ORs (95% CIs) comparing the highest vs. the lowest quartiles of intake were 0.63 (0.47–0.85) for total flavonoids, 0.82 (0.61–1.11) for anthocyanidins, 0.67 (0.50–0.90) for flavan-3-ols, 0.68 (0.50–0.93) for flavones, 0.62 (0.45–0.84) for flavonols, and 0.70 (0.53–0.94) for flavanones. An inverse association with total flavone and flavanone intake was observed for squamous cell carcinoma but not adenocarcinoma. In conclusion, low flavonoid intake from food may increase lung cancer risk.

Habitual flavonoid intakes are positively associated with bone mineral density in women

Dietary flavonoids exert bone-protective effects in animal models, but there is limited information on the effect of different flavonoid subclasses on bone health in humans. The aim of this observational study was to examine the association between habitual intake of flavonoid subclasses with bone mineral density (BMD) in a cohort of female twins. A total of 3160 women from the TwinsUK adult twin registry participated in the study. Habitual intakes of flavonoids and subclasses (flavanones, anthocyanins, flavan-3-ols, polymers, flavonols, and flavones) were calculated from semiquantitative food frequency questionnaires using an updated and extended U.S. Department of Agriculture (USDA) database. Bone density was measured using dual-energy X-ray absorptiometry. In multivariate analyses, total flavonoid intake was positively associated with higher BMD at the spine but not at the hip. For the subclasses, the magnitude of effect was greatest for anthocyanins, with a 0.034 g/cm(2) (3.4%) and 0.029 g/cm(2) (3.1%) higher BMD at the spine and hip, respectively, for women in the highest intake quintile compared to those in the lowest. Participants in the top quintile of flavone intake had a higher BMD at both sites; 0.021 g/cm(2) (spine) and 0.026 g/cm(2) (hip). At the spine, a greater intake of flavonols and polymers was associated with a higher BMD (0.021 and 0.024 g/cm(2) , respectively), whereas a higher flavanone intake was positively associated with hip BMD (0.008 g/cm(2) ). In conclusion, total flavonoid intake was positively associated with BMD, with effects observed for anthocyanins and flavones at both the hip and spine, supporting a role for flavonoids present in plant-based foods on bone health. .

Dietary Flavonoids and Risk of Stroke in Women

To date, few studies have examined associations between the wide range of flavonoid subclasses and risk of ischemic, hemorrhagic, and total stroke. We conducted a prospective study among 69 622 women from the Nurses' Health Study. Total flavonoid and subclass intakes were calculated from semiquantitative food frequency questionnaires collected every 4 years using an updated and extended US Department of Agriculture flavonoid database. During 14 years of follow-up, 1803 incident strokes were confirmed. After adjusting for potential confounders, women in the highest compared with the lowest quintile of flavanone intake had a relative risk of ischemic stroke of 0.81 (95% CI, 0.66-0.99; P=0.04). Citrus fruits/juices, the main dietary source of flavanones, tended to be associated with a reduced risk for ischemic stroke (relative risk, 0.90; 95% CI, 0.77-1.05) comparing extreme quintiles. Total flavonoid intake was not inversely associated with risk of stroke; however, increased intake of the flavanone subclass was associated with a reduction in the risk of ischemic stroke. Citrus fruit consumption may be associated with a reduction in stroke risk, and experimental data support these epidemiological associations that the flavanone content of citrus fruits may potentially be cardioprotective. Further prospective studies are needed to confirm these associations.

Estimated dietary intakes of flavonols, flavanones and flavones in the European Prospective Investigation into Cancer and Nutrition (EPIC) 24 hour dietary recall cohort

Flavonols, flavanones and flavones (FLAV) are sub-classes of flavonoids that exert cardioprotective and anti-carcinogenic properties in vitro and in vivo. We aimed to estimate the FLAV dietary intake, their food sources and associated lifestyle factors in ten European countries participating in the European Prospective Investigation into Cancer and Nutrition (EPIC) study. FLAV intake and their food sources for 36037 subjects, aged between 35 and 74 years, in twenty-seven study centres were obtained using standardised 24h dietary recall software (EPIC-SOFT). An ad hoc food composition database on FLAV was compiled using data from US Department of Agriculture and Phenol-Explorer databases and was expanded using recipes, estimations and flavonoid retention factors in order to increase its correspondence with the 24h dietary recall. Our results showed that the highest FLAV-consuming centre was the UK health-conscious group, with 130·9 and 97·0mg/d for men and women, respectively. The lowest FLAV intakes were 36·8mg/d in men from Umeå and 37·2mg/d in women from Malmö (Sweden). The flavanone sub-class was the main contributor to the total FLAV intake ranging from 46·6 to 52·9% depending on the region. Flavonols ranged from 38·5 to 47·3% and flavones from 5·8 to 8·6%. FLAV intake was higher in women, non-smokers, increased with level of education and physical activity. The major food sources were citrus fruits and citrus-based juices (especially for flavanones), tea, wine, other fruits and some vegetables. We concluded that the present study shows heterogeneity in intake of these three sub-classes of flavonoids across European regions and highlights differences by sex and other sociodemographic and lifestyle factors.

Flavonoid intake in relation to cognitive function in later life in the Lothian Birth Cohort 1936

Previous studies have suggested a link between flavonoid intake and better cognitive function in later life but have not been able to control for possible confounding by prior intelligence quotient (IQ). The aim of the present study was to address this issue in a cross-sectional survey of 1091 men and women born in 1936, in whom IQ was measured at age 11 years. At the age of 70 years, participants carried out various neuropsychological tests and completed a FFQ. Associations between test scores and nutrient intake were assessed by linear regression with adjustment for potentially confounding variables. Total fruit, citrus fruits, apple and tea intakes were initially found to be associated with better scores in a variety of cognitive tests, but the associations were no longer statistically significant after adjusting for confounding factors, including childhood IQ. Flavanone intake was initially found to be associated with better scores in verbal fluency (P=0·003, with standardised regression coefficient 0·10), but, again, the association was no longer statistically significant after adjusting for confounding factors. These findings do not support a role for flavonoids in the prevention of cognitive decline in later life. Studies of diet and cognitive function should include measurement of potential confounding variables, including prior IQ wherever possible.

An assessment of dietary flavonoid intake in the UK and Ireland

Accurate estimates of flavonoid intake are important for public health studies and potential policies related to these phytochemicals. As an alternative to studies involving population samples and individual food consumption surveys, the international FAO Food Balance Sheets (FBS) were used in the current study to estimate flavonoid consumption among the populations of the UK and Republic of Ireland. A supplemented USDA database was prepared for flavonoid analyses of the foods reported in the FBS. Twenty-three flavonoids from five groups (anthocyanidins, flavonols, flavanols, flavanones, and flavones) were analyzed. Estimated per-capita daily flavonoid intake (all five groups) was 182 mg and 177 mg for the UK and Ireland, respectively. In both cases, anthocyanidins and flavanols accounted for about 65% of total consumption. Combined intake of flavones, flavanones, and flavonols was 60 mg/day in the UK and 69 mg/day in Ireland. These flavonoid intake values are compared with those previously reported for the UK and other countries. Overall, these novel results contribute to establishing accurate reference points for national flavonoid intakes.