Dietary Flavonoid Intake Research Articles

The association between dietary flavonoid intake and frailty risk among middle-aged and elderly US adults: A nationally representative study

Given the global ageing population, exploring potential dietary prevention strategies to reduce the public health burden of frailty is critically important. Dietary flavonoids offer multiple health benefits; however, there is a scarcity of research evidence regarding their association with the risk of frailty in middle-aged and older adults. This study aimed to assess the association between dietary flavonoid intake and frailty risk among middle-aged and older U.S. adults and to analyse the potential roles of different flavonoid subclasses. This study involved 9063 participants aged ≥40 years. Frailty was evaluated using a frailty index, and flavonoid intake was estimated through two 24-h dietary recalls. Analyses were carried out via multivariable logistic regression, restricted cubic spline models, weighted quantile sum regression, and quantile g-computation models. Additionally, subgroup analyses and interaction tests were conducted for age and gender. The results indicated that higher intakes of total flavonoids and subclasses (anthocyanidins, flavan-3-ols, flavanones, flavones, flavonols) were significantly associated with a lower prevalence of frailty, but isoflavone intake was not associated with frailty. A nonlinear, L-shaped dose-response relationship was observed between total flavonoids and frailty risk. Flavonols and flavanones were identified as the main contributors to the overall effect. Age influenced the association between dietary flavonoids and frailty, with middle-aged adults benefiting more than older adults. This study provides new evidence supporting an inverse association between dietary flavonoid intake and frailty risk, especially for foods rich in flavonols and flavanones.

Correlation of dietary flavonoid intake with chronic bronchitis, emphysema, and asthma in U.S. adults: A large, national, cross-sectional study.

To explore the relationship between dietary flavonoids and bronchitis, emphysema and asthma. A total of 11743 United States adults were extracted from the National Health and Nutrition Examination Survey (NHANES) in 2007-2008, 2009-2010 and 2017-2018. Of these, 47.7% were male and 52.3% female. Dietary flavonoid intake assessed using FDNNS and 24-hour dietary recall data. Inclusion of demographics (gender, age, education, family income), behavioral factors (BMI, smoking, drinking status, diet), chronic disease information (diabetes, hypertension) as covariates to eliminate confounding. Stepwise logistic regression was used to analyze the association between total dietary flavonoid intake and the risk of chronic respiratory disease. Weighted quantile sum regression (WQS) was used to analyze the association between 29 dietary flavonoids and the risk of chronic respiratory disease. Restricted cubic spline was used to analyze the dose-response relationship between dietary flavonoid intake and risk of chronic respiratory disease. Stepwise logistic regression results showed that higher flavonoid intake in men was associated with a lower risk of CB and asthma (OR of CB: 0.55(0.31-0.97); OR of asthma: 0.72(0.52-0.99)), and WQS results showed a mixed health effect for total flavonoids and chronic respiratory tract in response to the 29 flavonoid fractions (OR of asthma: 0.97(0.94-0.99); OR of emphysema: 0.95(0.90-0.99)). Glycitein had the highest health contribution of 26.2% for emphysema; Eriodictyol had the highest health contribution of 32.13% for asthma, respectively. The RCS showed a dose-response relationship between flavonoids and respiratory tract health. The maximum dose for ingesting flavonoids to gain respiratory health benefits is 1500 mg/d. Higher dietary flavonoid intake was associated with lower chronic respiratory risk in adult U.S. men. Also 29 dietary flavonoid components have an overall health effect on respiratory health. Glycitein and Eriodictyol may have potential health effects on the respiratory system. 1500 mg/day may be the Tolerable Upper Intake Level of dietary flavonoids for respiratory health in U.S. adults.

Association Between Dietary Flavonoid Intake and Cardiovascular Health in Cancer Survivors: A Cross-Sectional Study.

Flavonoids are naturally occurring compounds with diverse health-promoting properties. The purpose of this study was to explore the associations between dietary flavonoid intake and cardiovascular health in cancer survivors. We obtained data from the National Health and Nutrition Examination Survey (NHANES) 2007-2008, 2009-2010, and 2017-2018 cycles. Weighted linear regression and restricted cubic spline (RCS) were used to explore the correlation between dietary flavonoid intake and cardiovascular health (Life's Essential 8 (LE8) score) in cancer survivors. Then, weighted quantile sum (WQS) regression and quantile-based g-computation (qgcomp) models were performed to assess the mixed effects of the six flavonoid subclasses and to determine the major flavonoid types. Additionally, the protective effect of high flavonoid intake on cardiovascular health was further evaluated in different subgroups, and mediation analysis was used to explore mediating factors. After adjusting for all covariates, compared to those in the first quartile, participants in the fourth quartile of total flavonoids, anthocyanidins, flavonols, flavanones, and flavones intake exhibited increases in LE8 scores of 3.24% (95% CI: 0.45-6.03, P for trend=0.030), 6.25% (95% CI: 3.14-9.36, P for trend<0.001), 3.01% (95% CI: 1.33-4.69, P for trend= 0.003), 3.23% (95% CI: 0.18-6.27, P for trend=0.030), and 5.01% (95% CI: 2.42-7.61, P for trend<0.001), respectively. Meanwhile, significant non-linear relationships were supported by the RCS models. However, the weighted linear regression and RCS models did not reveal any clear correlations between isoflavone or flavan-3-ol intake and the LE8 score. Regarding mixed effects, anthocyanidin, flavonol, flavanone, and flavone intake were positively related to the LE8 score according to both the WQS and qgcomp models, and anthocyanidin intake was the major contributor. Our study indicated that dietary flavonoid intake is positively associated with cardiovascular health in cancer survivors, among which anthocyanidin intake might provide the most benefit.

Associations Between Flavonoid Intake and Subclinical Atherosclerosis: The MESA.

Flavonoids may play a role in mitigating atherosclerotic cardiovascular diseases, with evidence suggesting effects may differ between vascular beds. Studies examining associations with subclinical markers of atherosclerosis between subpopulations with different underlying risks of atherosclerosis are lacking. Among 5599 participants from the MESA (Multi-Ethnic Study of Atherosclerosis), associations between dietary flavonoid intakes (estimated from a food frequency questionnaire) and subclinical measures of atherosclerosis (ankle-brachial index, carotid plaques and intima-media thickness, and coronary artery calcification) were examined using repeated measures models. Exposures and outcomes were measured at exam 1 (2000-2002) and exam 5 (2010-2011). Stratified analyses and interaction terms were used to explore effect modification by time, sex, race/ethnicity, and smoking status. In the analytic population, at baseline, ≈46% were males with a median age of 62 (interquartile range, 53-70) years and total flavonoid intakes of 182 (interquartile range, 98-308) mg/d. After multivariable adjustments, participants with the highest (quartile 4) versus lowest (quartile 1) total flavonoid intakes had 26% lower odds of having an ankle-brachial index <1 (odds ratio, 0.74 [95% CI, 0.60-0.92]) and 18% lower odds of having a carotid plaque (odds ratio, 0.82 [95% CI, 0.69-0.99]), averaged over exams 1 and 5. Moderate (quartile 3) to high (quartile 4) intakes of flavonols, flavanol monomers, and anthocyanins were associated with 19% to 34% lower odds of having an ankle-brachial index <1 and 18% to 20% lower odds of having carotid plaque. Participants with the highest intakes of anthocyanins (quartile 4) at baseline had a marginally slower rate of carotid plaque progression than those with moderate intakes (quartiles 2 and 3). There were no significant associations with intima-media thickness or coronary artery calcification. Observed associations did not differ by sex, race/ethnicity, or smoking status. In this multi-ethnic population, higher dietary flavonoid intakes were associated with lower odds of peripheral and carotid artery atherosclerosis. Increasing intakes of healthy, flavonoid-rich foods may protect against atherosclerosis in the peripheral and carotid arteries.

Association of dietary flavonoid intake with the prevalence and all-cause mortality of depressive symptoms: Findings from analysis of NHANES

BackgroundThis study aimed to explore the relationship between flavonoids intake and the prevalence and all-cause mortality of depressive symptoms in American adults. MethodsAnalyzing 2007–2008, 2009–2010, and 2017–2018 NHANES data, we examined the association between dietary flavonoid and depressive symptoms, including specific subclasses assessment and mortality outcomes tracking until December 31, 2019. Our methodology included weighted multivariate logistic regression, weighted cox proportional hazards regression and restricted cubic spline (RCS) models, supported by stratified and sensitivity analyses. ResultsAmong the 12,340 participants in total, 1129 exhibited depressive symptoms. The multiple logistic regression analysis showed a significant reduction in total flavonoid and subclass intake in individuals with current depressive symptoms. Adjusted odds ratios (ORs) for the highest quartiles were 0.69 for anthocyanidins and 0.63 for flavones. Interaction effects emerged in non-hypertensive, higher-income, and normal-weight groups for flavones intake. The RCS model indicated an L-shaped association between depressive symptoms and total flavonoid intake, with inflection points at 346 mg/day. During a median follow-up of 119 months, 148 deaths occurred among patients with depressive symptoms. Hazard ratios (HRs) for all-cause mortality showed a significant positive correlation between total flavonoid intake and survival in model 1 (HR = 0.56), with an optimal intake range of 45.2–948.3 mg/day according to the RCS model. LimitationsThe study relied on U.S. population survey data, potentially limiting generalizability. Unmeasured confounding factors may exist, and genetic factors were not considered. ConclusionsAdequate intake of flavonoids, especially anthocyanidins and flavones, is associated with reduced odds of depressive symptoms. Additionally, optimal intake ranges of flavonoid intake for mental health benefits were observed for all-cause mortality in population with depressive symptoms.

Dietary flavonoid intake and risk of hormone-related cancers: A population-based prospective cohort study

BackgroundDietary flavonoids may have potential effects on hormone-related cancers (HRCs) due to their anti-cancer properties via regulating hormones and suppressing inflammation and oxidative stress. We aimed to examine the association of flavonoid intake with risks of HRCs and whether this association was mediated by blood biomarkers involved in biological mechanisms. MethodsThis prospective cohort study from UK Biobank included 187,350 participants free of cancer when the last dietary recall was completed. The dietary intakes of flavonoids and subclasses were assessed using 24-hour dietary recalls. Venous blood was collected at baseline and assayed for biomarkers of inflammation, hormones, and oxidative stress. Hazard ratios (HR) and 95 % confidential intervals (CI) for the associations between flavonoid intake and HRCs risk were estimated by the cause-specific Cox proportional hazards model. The role of blood biomarkers in the flavonoids-HRCs association was investigated through mediation analysis. ResultsOver a median follow-up of 9.5 years, 3,392 female breast cancer, 417 ovarian cancer, 516 endometrial cancer, 4,305 prostate cancer, 45 testicular cancer, and 146 thyroid cancer cases were documented. Compared to the lowest quintile, multivariable-adjusted HRs (95 % CIs) in the highest quintile of total flavonoid intake were 0.89 (0.80–0.99) for breast cancer, 0.68 (0.50–0.92) for ovarian cancer, and 0.88 (0.80–0.98) for female-specific cancers. For subclasses, intakes of flavonols and anthocyanidins were inversely associated with the risk of female-specific cancers (Ptrend <0.05). Anthocyanidin intake was positively related to prostate cancer risk, whereas isoflavone intake was inversely linked to thyroid cancer risk (Ptrend <0.05). Additionally, certain biomarkers of inflammation, hormones and oxidative stress jointly mediated the association of flavonoid intake with the risk of female-specific cancers and prostate cancer. ConclusionsOur findings highlighted the importance of dietary flavonoids for the prevention of HRCs in the general population, providing epidemiological evidence for dietary guidelines.

Intake of dietary flavonoids in relation to overactive bladder among U.S. adults: a nutritional strategy for improving urinary health.

The increasing influence of overactive bladder (OAB) on physical as well as mental health of individuals is becoming more pronounced annually, as evidenced by the urge urinary incontinence and nocturia. Symptoms in OAB patients may be influenced by inflammation and oxidative stress. Flavonoids are recognized as significant anti-inflammatory and antioxidant agents, which are commonly available in fruits, tea, vegetables, etc. Previous research has demonstrated the therapeutic potential of flavonoids and their subclasses in treating inflammation, and oxidative stress. Despite this, there remains a paucity of research exploring the potential correlation between flavonoid consumption, specifically within distinct subclasses, and OAB. Thus, our study aims to investigate the relationship between flavonoid intake and OAB to identify possible dietary interventions for OAB management. We utilized the survey data from the National Health and Nutrition Examination Survey (NHANES) and the USDA Food and Nutrient Database for Dietary Studies (FNDDS) to investigate the relationship between dietary intake of total and subclass flavonoids and the risk of OAB based on 13,063 qualified American adults. The dietary flavonoid intake was estimated from two 24-h dietary recalls. Weighted multivariate logistic regression model, quantile-based g-computation, restricted cubic spline model, and stratified analysis were used to explore the association between flavonoid intake and OAB, respectively. The participants diagnosed with OAB exhibited a higher percentage of being female, older, Non-Hispanic Black, unmarried, former drinkers, having a lower annual household income, lower poverty to income ratio, lower educational attainment, and a higher likelihood of being obese and smokers. Upon adjusting for confounding factors, the weighted logistic regression models revealed that the third quartile of consumption of anthocyanidin and the second quartile of consumption of flavone were significantly associated with the reduced odds of OAB, while total flavonoid consumption did not show a significant correlation with the risk of OAB. The quantile-based g-computation model indicated that flavone, anthocyanidin and flavonol were the primary contributors to the observed negative correlation. Furthermore, the restricted cubic spline models demonstrated a J-shaped non-linear exposure-response association between anthocyanidin intake and the risk of OAB (P nonlinear = 0.00164). The stratified and interaction analyses revealed that the relationship between anthocyanidin intake and the risk of OAB was significantly influenced by age (P interaction = 0.01) and education level (P interaction = 0.01), while the relationship between flavone intake and the risk of OAB was found to vary by race (P interaction = 0.02) and duration of physical activity (P interaction = 0.05). Our research suggests that consuming a diet rich in flavonoid subclass anthocyanidin and flavone is associated with a reduced risk of OAB, potentially offering clinical significance in the prevention of OAB development. This underscores the importance of dietary adjustments in the management of OAB symptoms.

Flavonoid-Rich Fruit Intake in Midlife and Late-Life and Associations with Risk of Dementia: The Framingham Heart Study

BackgroundFruits are an important source of flavonoids, and greater intake of dietary flavonoids in older adults has been shown to be associated with decreased risk of dementia. It is unclear whether this relationship is similar or different between younger adults and older adults.ObjectivesWe examined for associations between midlife and late-life intake of flavonoid-rich fruits and incident dementia. We hypothesized that greater total cumulative intake of flavonoid-rich fruits in midlife and late-life adults would be associated with reduced risk of all-cause dementia.DesignLongitudinal, cohort study design.SettingFramingham Heart Study, which is a longitudinal, multi-generational community-based cohort based in Framingham, Massachusetts, USA.ParticipantsParticipants from the Framingham Heart Study Offspring cohort were included (n = 2,790) who attended the fifth core exam between 1991 to 1995, and were dementiafree and at least 45 years of age at that time, as well as had valid food frequency questionnaires from the fifth to ninth core exams.MeasurementsConsumption of fruits with high flavonoid content or are important contributors to overall flavonoid intake was collected via food frequency questionnaire. Flavonoid-rich fruits from the food frequency questionnaire included raisins or grapes, prunes, bananas, fresh apples or pears, apple juice or cider, oranges, orange juice, grapefruit, grapefruit juice, strawberries, blueberries, and peaches, apricots, or plums. Dementia ascertainment was based on a multidisciplinary consensus committee, and included all-cause dementia and Alzheimer’s disease dementia diagnoses based on research criteria. Cox models were used to examine associations between cumulative fruit intake and incident dementia, stratified by midlife (45–59 years; n = 1,642) and late-life (60–82 years; n = 1,148).ResultsGreater cumulative total fruit intake in midlife, but not late-life, was significantly associated with a 44% decreased risk of all-cause dementia (HR = 0.56; 95% CI = 0.32–0.98; p = 0.044). Decreased risk of all-cause dementia was also associated with higher intake of apples or pears in midlife and late-life, as well as higher intake of raisins or grapes in midlife only, and higher intake of oranges, grapefruit, blueberries, and peaches, apricots, or plums in late-life only.ConclusionsAmong participants from the Framingham Heart Study, greater overall consumption of flavonoid-rich fruits in midlife was associated with reduced risk of dementia, though intake of specific fruits in midlife and late-life may have a protective role against developing dementia. These findings may help to inform future recommendations on when dietary interventions may be most beneficial to healthy brain aging across the life course.

Flavonoids intake and weight-adjusted waist index: insights from a cross-sectional study of NHANES.

This study conducted data on 15,446 adults to explore the impact of flavonoids on weight-adjusted waist index (WWI). This was a nationwide cross-sectional study among US adults aged 20 years or older. Dietary intake of flavonoids was assessed through 24-h recall questionnaire. WWI was calculated by dividing waist circumference (WC) by the square root of weight. We utilized weighted generalized linear regression to evaluate the association between flavonoids intake and WWI, and restricted cubic splines (RCS) to explore potential non-linear relationships. Our findings indicated that individuals with lower WWI experienced a notable increase in their consumption of total flavonoids, flavanones, flavones, flavan-3-ols, and anthocyanidins intake (β (95% CI); -0.05(-0.09, -0.01); -0.07(-0.13, 0.00); -0.07(-0.11, -0.02); -0.06(-0.11, 0.00); -0.13(-0.18, -0.08), respectively), with the exception of flavonols and isoflavones. Additionally, consumption of total flavonoids, flavonols, flavanones, isoflavones, and flavan-3-ols had a non-linear relationship with WWI (all P for non-linearity < 0.05). Furthermore, the effect of total flavonoids on WWI varied in race (P for interaction = 0.011), gender (P for interaction = 0.038), and poverty status (P for interaction = 0.002). These findings suggested that increase the intake of flavonoids might prevent abdominal obesity, but further prospective studies are requested before dietary recommendation.

Associations of dietary flavonoid intake with the risk of all-cause and cardiovascular mortality in adults

Background and AimsFlavonoids are widely distributed polyphenolic compounds in the diet that possess various health-promoting effects. This study aimed to investigate the association between dietary flavonoid intake and all-cause and cardiovascular mortality in adults. Methods and ResultsThe data on the six main subclasses of flavonoids, including isoflavones, anthocyanidins, flavan-3-ols, flavanones, flavones, and flavonols, were obtained from the 2007-2010 National Health and Nutrition Examination Survey (NHANES) dataset of adults. The participants were followed up until December 30, 2019. Cox regression models were used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) for dietary flavonoid intake and mortality. The study included a total of 8,758 adults (mean age 44.00 years; 47.40% men). A median follow-up of 10.7 years yielded 1,113 all-cause deaths and 261 cardiovascular deaths were recorded. In comparison to category 1, category 4 of flavan-3-ols, flavonols, and total flavonoids were associated with lower risks of all-cause mortality, with multivariable-adjusted HRs of 0.71 (95% CI: 0.55–0.92, Ptrend=0.021), 0.58 (95% CI: 0.45–0.74, Ptrend<0.001), and 0.63 (95% CI: 0.50–0.80, Ptrend=0.010), respectively. Similarly, higher intake of category 4 flavonoids was associated with a reduced risk of cardiovascular mortality, with HRs of 0.68 (95% CI: 0.29–0.89, Ptrend=0.035) for flavones, 0.41 (95% CI: 0.22–0.78, Ptrend=0.001) for flavonols, and 0.54 (95% CI: 0.36–0.80, Ptrend=0.021) for total flavonoids. ConclusionDietary flavonoid intake is associated with all-cause and cardiovascular mortality. Increasing dietary flavonoid intake may reduce the risk of death in adults.

Dietary Flavonoid and Subclass Intakes are not Associated with Markers of Bone Health in U.S. Adults Age 50+ Years

Background Dietary flavonoid intakes have been associated with improved markers of bone health in Chinese and Scottish cohorts, but little data exist in middle aged to older adults in the United States. Objectives The objective of our research was to assess if dietary flavonoid intakes are associated with bone mineral density (BMD), bone mineral content (BMC), and bone area of the lumbar spine and femoral neck in a nationally representative population of middle aged to older U.S. adults. We further sought to investigate if relationships of the main flavonoid subgroups (i.e., anthocyanins, flavan-3-ols, flavanones, flavones, flavonols, and isoflavones) exist, as a secondary objective. Methods Cross-sectional data from individuals aged 50+ years enrolled in the 2017–2018 National Health and Nutrition Examination Survey (NHANES) were used in our analyses (N = 2590). Weighted multivariate logistic regression models were used to investigate the relationship between quartiles of flavonoid intake and BMD, BMC, and bone area of the lumbar spine and femoral neck of participants. Results Mean age of participants was 63.4 ± 0.52 years and 64.1 ± 0.52 years for men and women, respectively. Average total flavonoid intake was 217 ± 19.4 mg/day and 306 ± 26.9 mg/day for men and women, respectively. Total flavonoid intakes were not significantly associated with BMD, BMC, or bone area of the femoral neck or lumbar spine in male or female participants. Flavonoid subclass intakes were also not consistently associated with improved markers of bone health. Conclusion Although several limitations exist, this cross-sectional analysis of U.S. adults aged 50+ years provides contradictory evidence to the hypothesis that higher flavonoid and flavonoid subclass intakes beneficially impacts markers of bone health. Large prospective cohort investigations that better capture long-term dietary flavonoid intake and ascertain fractures the primary outcome, as well as randomized controlled trials, are needed to fully elucidate the effects flavonoids on bone health.

The relationship between dietary total flavonoids and thyroid function in U.S.adults, NHANES 2007-2010.

Although small studies have shown that flavonoids can affect thyroid disease, few epidemiological studies have explored the relationship between dietary total flavonoids (TFs) intake and serum thyroid function. The aim of this research was to evaluate the relationship between TFs and serum thyroid function. Our study included 4,949 adults from the National Health and Nutrition Examination Survey (NHANES) 2007-2010. Multivariable linear regression, subgroup analyses, and interaction terms were used to explore the relationships between TFs and thyroid function. And we also used restricted cubic splines (RCS) to investigate possible nonlinear relationships. After adjusting for covariates, we found that log10-transformated dietary total flavonoids intake (LgTFs) was negatively associated with total thyroxine (TT4) (β = -0.153, 95% CI = -0.222 to -0.084, P<0.001). Subgroup analyses revealed a stronger and statistically supported association in subjects with high annual family income (β = -0.367, P<0.001, P for interaction = 0.026) and subjects with high poverty to income ratio (PIR) (β = -0.622, P<0.001, P for interaction = 0.042). And we found a U-shaped curve association between LgTFs and free triiodothyronine (FT3) (inflection point for LgTFs: 2.063). The results of our study demonstrated that a higher intake of total flavonoids in the diet was negatively associated with a lower TT4. Furthermore, the associations were more pronounced in high annual family income and high PIR adults. And we found a U-shaped relationship between LgTFs and FT3. These findings provided guidance for future thyroid dysfunction diet guidelines.

The associations between dietary flavonoids intake and risk of depressive symptom in diabetic patients: Data from NHANES 2007–2008, 2009–2010, and 2017–2018

BackgroundThe increasing incidence of depressive symptoms in diabetic patients contributes to the global burden of disease, but few epidemiological studies have evaluated the relationship between dietary flavonoids intake and depressive symptoms in diabetic patients in American adults. ObjectiveThis study intended to evaluate the associations of dietary flavonoids intake and depressive symptoms in diabetic patients in American adults. MethodsWe conducted a cross-sectional analysis of 1993 adults aged ≥20 years old who participated in the 2007–2008, 2009–2010, and 2017–2018 National Health and Nutrition Examination Surveys (NHANES). Chi-square test and independent-sample t-test were used to compare subjects' characteristics. Logistic regression model was further used to analyze the relationship between dietary flavonoid intake and depressive symptoms in diabetic patients. Restricted cubic spline (RCS) analysis was used to investigate the non-linear relationship between dietary flavonoid intake and the prevalence of depressive symptoms in diabetic patients. The weighted quartile sum (WQS) regression was used to analyze the effect of 29 flavonoids monomers. ResultsThe results showed that the total flavonoid intake in the third quartile (OR, 0.635; 95 % CI,0.419–0.962; P, 0.032) was significantly associated with a reduced risk of depressive symptoms in diabetic patients compared with the lowest quartile. And there was a U-shaped association between dietary flavonoid intake and risk of depressive symptoms in diabetic patients. Top contributors of flavonoid monomers were eriodictyol, naringenin, and theaflavin-3′-gallate, accounting for a percentage of 30.83 %, 22.17 %, and 6.92 %, respectively. ConclusionModerate (56.07–207.12 mg/day) dietary flavonoid intake was associated with a reduced risk of depressive symptoms in diabetic patients. The important flavonoid monomers were eriodictyol, naringenin, and theaflavin-3′-gallate.

Dietary Flavonoid Intakes in France Are Linked to Brewed Tea Consumption and to Socioeconomic Status: Analyses of the Third French Individual and National Food Consumption (INCA3) Survey for Children and Adults.

Flavonoids from green and black tea may benefit cardiovascular health. Brewed tea consumption and flavonoid intake in France have not been previously explored. This study assessed the dietary intake of flavonoids among French children and adults, using 3 days' dietary recall for 3896 persons aged >4 y in the Third French Individual and National Food Consumption Survey (INCA3). Foods consumed by INCA 3 participants were manually matched with the flavonoid content of foods from the French PhenolExplorer database and the US Department of Agriculture expanded flavonoid database (2018 version). The six subclasses of flavonoids were flavan-3-ols, flavanones, anthocyanidins, flavonols, flavones, and isoflavones. Flavonoid intake was stratified by age subgroups (children and adults separately) and examined using socio-demographics and tea consumption patterns. Mean flavonoid intake was 210 mg/d. Flavonoids in the French diet were predominantly flavan-3-ols (147 mg/d), of which tea is the main source. The effects of age, education, income, and socio-professional category (SPC) on flavonoid intake were all significant (p < 0.0001). Brewed tea consumers were 31.88% of French adults and 3.79% of children. Brewed tea consumption and flavonoid intake were highly correlated. The highest brewed tea and flavonoid intakes were found among individuals with the highest SPC and education levels. Flavonoid intake in France was associated with brewed tea consumption and with higher education and income.

Dietary Total Polyphenol, Flavonoid, and Lignan Intakes Are Associated with Obesity and Diabetes-Related Traits: A Case-Control Study.

Purpose: Dietary phytochemicals have been under examination as adjuvants for the prevention and treatment of obesity and diabetes. This study aimed at examining the potential associations of dietary "Phytochemical Index" (PI) and polyphenol intake with obesity and diabetes-related parameters. Materials and Methods: The case-control study involved 331 participants (156 overweight/obese and 175 normal weight), aged 18-50 years. Dietary intake was assessed using the 24-hr dietary recall method, and the PI score was calculated as the percentage of energy intake provided by phytochemical-rich foods. Polyphenol intakes were calculated using Phenol-Explorer and U.S. Department of Agriculture databases. Anthropometrical measurements were taken, serum glucose, insulin, and lipid profiles were analyzed, homeostatic model assessment for insulin resistance (HOMA-IR) was calculated, and blood pressure was measured. Linear regression analyses were used to examine the potential associations. Results: Participants with higher PI scores had higher total and some sub-classes polyphenol intakes compared with lower ones (P < 0.05, for each). Dietary PI score was not associated with any of the anthropometrical measurements; however, total polyphenol and flavonoids intakes were inversely associated with body mass index (β = -0.269, P = 0.049; β = -0.262, P = 0.048; respectively), waist circumference (β = -0.127, P = 0.021; β = -0.130, P = 0.016; respectively), and waist-to-hip ratio (β = -20.724, P = 0.032; β = -22.199, P = 0.018; respectively) after adjusting for potential confounders. Either dietary PI score or total and sub-class polyphenol intakes were not associated with a better metabolic profile, except for the lignan intake, which was inversely associated with HOMA-IR (β = -0.048, P = 0.011). Conclusions: Higher dietary polyphenol intake may have potential in the prevention of obesity and diabetes, and validated practical tools are essential for the assessment of polyphenol intake in clinical practice.

Association between dietary flavonoid intake and hypertension among U.S. adults.

Hypertension is one of the major risk factors for cardiovascular disease. Dietary flavonoids have been reported to reduce inflammation, protect against oxidative stress, protect the vascular endothelium, and improve vascular health. However, the relationship between dietary flavonoid intake and the prevalence of hypertension remains controversial. This study included 8010 adults from the 2007-2010 and 2017-2018 National Health and Nutrition Examination Surveys (NHANES). The relationship between dietary flavonoid intake and the prevalence of hypertension was explored by weighted logistic regression and weighted restricted cubic spline. We found an inverse relationship between total anthocyanin intake and the prevalence of hypertension in the fourth quartile compared with the first quartile [0.81(0.66,0.99), p = 0.04]. Moreover, the prevalence of hypertension tended to decrease with increasing total anthocyanin intake in participants over 60 years of age. In addition, we found a U-shaped relationship between the prevalence of hypertension and total flavan-3-ol intake. Total flavan-3-ol intake was inversely associated with hypertension prevalence in the third quartile compared with the first quartile [0.79 (0.63,0.99), p = 0.04]. Moreover, there was a significant negative association between the prevalence of hypertension and total flavan-3-ol intake when total flavan-3-ol intake was below 48.26 mg/day. Our study found a negative association between the prevalence of hypertension and moderate total anthocyanins intake and total flavan-3-ols intake. Our study provides evidence from a population-based study for a negative association between dietary flavonoid intake and the prevalence of hypertension.

The association of dietary total flavonoids and their subclasses with the risk of type 2 diabetes: a prospective cohort study.

Data from mechanistic studies suggest flavonoids may benefit glucose metabolism, but their associations with type 2 diabetes (T2D) remain unclear. This study examined the prospective associations of dietary intake of total, classes, and individual flavonoids, as well as their source foods, with T2D in the CArdioVascular disease Association Study (CAVAS). A total of 16,666 Korean men and women were enrolled at baseline, and 953 were newly diagnosed with T2D over a median follow-up of 5.96years. Intake of flavonoids was cumulatively averaged using all food frequency questionnaires before the censoring events. A Poisson regression model was used to estimate incidence rate ratios (IRRs) and 95% confidence intervals (CIs). Women with higher total flavonoid, flavonol, isoflavone, and proanthocyanidin intake had a lower risk of T2D (fourth vs. first quartile, IRR 0.62; 95% CI 0.44-0.89; P for linearity and non-linearity < 0.05 for total flavonoids), while in men, flavanones, anthocyanins, and proanthocyanidins, but not total flavonoids, were inversely associated with T2D risk (all P interaction for sex > 0.05). The key source foods contributing to flavonoid intake were also different between men and women, except for apples: tangerines and strawberries in men and green leafy vegetables and soy products in women. A higher intake of total flavonoids, particularly from vegetables, soybeans, and apples, may be associated with lower risk of T2D in women. However, flavonoids from fruits, rather than total flavonoids, may be inversely associated in men. The association between flavonoid intake and the risk of T2D may be contingent upon the dietary sources of flavonoids consumed.

Association of dietary flavonoid intakes with prevalence of chronic respiratory diseases in adults

Background and aimsFlavonoids are a class of secondary plant metabolites that have been shown to have multiple health benefits, including antioxidant and anti-inflammatory. This study was to explore the association between dietary flavonoid consumption and the prevalence of chronic respiratory diseases (CRDs) in adults.Methods and resultsThe six main types of flavonoids, including isoflavones, anthocyanidins, flavan-3-ols, flavanones, flavones, and flavonols, were obtained from the National Health and Nutrition Examination Survey (NHANES) 2007–2010 and 2017–2018 by the two 24-h recall interviews. The prevalence of CRDs, including asthma, emphysema, and chronic bronchitis, was determined through a self-administered questionnaire. The analysis included 15,753 participants aged 18 years or older who had completed a diet history interview. After adjustment for potential confounders, the inverse link was found with total flavonoids, anthocyanidins, flavanones, and flavones, with an OR (95%CI) of 0.86 (0.75–0.98), 0.84 (0.72–0.97), 0.80(0.69–0.92), and 0.85(0.73–0.98) for the highest group compared to the lowest group. WQS regression revealed that the mixture of flavonoids was negatively linked with the prevalence of CRDs (OR = 0.88 [0.82–0.95], P < 0.01), and the largest effect was mainly from flavanones (weight = 0.41). In addition, we found that flavonoid intake was negatively linked with inflammatory markers, and systemic inflammation significantly mediated the associations of flavonoids with CRDs, with a mediation rate of 12.64% for CRP (P < 0.01).ConclusionHigher flavonoid intake was related with a lower prevalence of CRDs in adults, and this relationship may be mediated through systemic inflammation.

Association between dietary flavonol intake and mortality risk in the U.S. adults from NHANES database

Using updated National Health and Nutrition Examination Survey (NHANES) follow-up data, and a large nationwide representative sample of adult U.S. citizens, the aim of this study was to explore the relationship between dietary flavonol intake, all-cause and cause-specific mortality risks. In this prospective cohort study based on NHANES (2007–2008, 2009–2010, and 2017–2018), a total of 11,679 participants aged 20 years and above were evaluated. The amount and type of food taken during a 24-h dietary recall were used to estimate dietary flavonol intake, which includes total flavonol, isorhamnetin, kaempferol, myricetin, and quercetin. Each analysis of the weighted data was dealt with in accordance with the NHANES reporting requirements' intricate stratification design. The Cox proportional risk regression model or Fine and Gray competing risks regression model were applied to evaluate all-cause and cause-specific mortality risks, respectively. The follow-up period was calculated using the time interval between the baseline and the death date or December 31, 2019 (whichever occurs first). Each data analysis was performed between October 1, 2023, and October 22, 2023. Dietary flavonol intake included total flavonol, isorhamnetin, kaempferol, myricetin, and quercetin. Up to December 31, 2019, National Death Index (NDI) mortality data were used to calculate mortality from all causes as well as cause-specific causes. A total of 11,679 individuals, which represents 44,189,487 U.S. non-hospitalized citizens, were included in the study; of these participants, 49.78% were male (n = 5816), 50.22% were female (n = 5, 863); 47.56% were Non-Hispanic White (n = 5554), 18.91% were Non-Hispanic Black (n = 2209), 16.23% were Mexican American (n = 1895), and 17.30% were other ethnicity (n = 2021); The mean [SE] age of the sample was 46.93 [0.36] years, with a median follow-up of 7.80 years (interquartile range, 7.55–8.07 years). After adjusting covariates, Cox proportional hazards models and fine and gray competing risks regression models for specific-cause mortality demonstrated that total flavonol intake was associated with all-cause (HR 0.64, 95% CI 0.54–0.75), cancer-specific (HR 0.45, 95% CI 0.28–0.70) and CVD-specific (HR 0.67, 95% CI 0.47–0.96) mortality risks; isorhamnetin intake was associated with all-cause (HR 0.72, 95% CI 0.60–0.86), and cancer-specific (HR 0.62, 95% CI 0.46–0.83) mortality risks; kaempferol intake was associated with all-cause (HR 0.74, 95% CI 0.63–0.86), and cancer-specific (HR 0.62, 95% CI 0.40–0.97) mortality risks; myricetin intake was associated with all-cause (HR 0.77, 95% CI 0.67–0.88), AD-specific (HR 0.34, 95% CI 0.14–0.85), and CVD-specific (HR 0.61, 95% CI 0.47–0.80) mortality risks; quercetin intake was associated with all-cause (HR 0.66, 95% CI 0.54–0.81), cancer-specific (HR 0.54, 95% CI 0.35–0.84), and CVD-specific (HR 0.61, 95% CI 0.40–0.93) mortality risks; there was no correlation observed between dietary flavonol intake and DM-specific mortality. According to the current study, all-cause, AD, cancer, and CVD mortality risks declined with increased dietary flavonoid intake in the U.S. adults. This finding may be related to the anti-tumor, anti-inflammatory, and anti-oxidative stress properties of flavonol.

The relationship of dietary flavonoids and periodontitis in US population: a cross-sectional NHANES analysis.

We investigated the association between dietary flavonoids intake and periodontitis. This cross-sectional study analyzed data from the US National Health and Nutrition Examination Survey 2009-2010 on 3025 participants aged between 30 and 80 years who had full-mouth periodontal examination and dietary flavonoids intake data. This study used periodontal pocket depth (PPD) and clinical attachment loss (CAL) as periodontitis markers. Data were analyzed using multivariate linear regression. After adjusting confounders, the middle tertile of total dietary flavonoids was associated with decreased mean PPD (0.06mm, P = 0.016) and mean CAL (0.13mm, P = 0.001) and the top tertile of total dietary flavonoids was significantly associated with decreases in mean PPD (0.05mm, P = 0.029) and mean CAL (0.11mm, P = 0.010). Both the middle and top tertiles of total flavonoids intake were significantly related with decreased mean CAL in females, those flossing 0 days/week, overweight and non-diabetic population but not in males, smokers, those flossing 1-6 days/week and diabetic population. Higher anthocyanidins, flavones and flavonols intake was significantly associated with decreased mean PPD and mean CAL while higher flavanones intake was only significantly associated with decreased mean CAL. Higher anthocyanidins intake was particularly related with greatest decreases in mean CAL (top tertile: 0.22mm, middle tertile: 0.17mm, both P < 0.010). However, no significant associations were found between isoflavones and flavan_3_ols intake and mean CAL. Higher dietary flavonoids intake may be beneficial for periodontal health. Additional anthocyanidins, flavanones, flavones and flavonols intake was associated with improved periodontal health.