Usual Intake of Flavonoids Is Inversely Associated with Metabolic Syndrome in African American and White Males but Not Females in Baltimore City, Maryland, USA

Associations Between Polyphenol Intake, Cardiometabolic Risk Factors and Metabolic Syndrome in the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil)

BACKGROUND

Fruit- and vegetable-rich diets may protect against metabolic syndrome (MetS), partly due to their high polyphenol content.

OBJECTIVES

This study examined the association between dietary polyphenol intake, MetS risk, and cardiometabolic factors in the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil).

METHODS

A total of 6387 participants (mean age 49.8 y, 65% female) were included. Food intake was assessed via a semiquantitative Food Frequency Questionnaire with polyphenol content from the Phenol-Explorer database. MetS was defined using the Joint Interim Statement. Logistic regressions assessed associations between polyphenol intake tertiles and cardiometabolic risk factors, as well as the odds of MetS during the follow-up period.

RESULTS

During a median of 8.19 y follow-up, 2031 cases of MetS occurred. The second and third tertiles of total polyphenol intake were associated with 22% and 23% lower odds of MetS, respectively, after adjusting for sociodemographic, lifestyle, and dietary factors (T2 vs. T1, odds ratio [OR] 0.78 [95% confidence interval {CI}: 0.68, 0.90]; T3 vs. T1, OR 0.77 [0.66, 0.90]). Inverse associations were also found between phenolic acids, lignans, stilbenes, other polyphenols, and the odds of MetS. Although no significant link was observed for total flavonoids, flavan-3-ols showed inverse associations with MetS (monomers: T3 vs. T1, OR 0.92 [0.80, 0.94]; dimers to polymers: T3 vs. T1, OR 0.82 [0.70, 0.96]). Total polyphenol intake was also inversely associated with waist-hip ratio, diastolic blood pressure, systolic blood pressure, HOMA-IR, triglycerides, and C-reactive protein, and positively associated with total cholesterol, LDL cholesterol, and HDL cholesterol.

CONCLUSIONS

Higher intakes of dietary polyphenols, particularly phenolic acids, lignans, stilbenes, other polyphenols, and flavan-3-ols, were inversely associated with the odds of MetS and its components. These findings suggest that promoting polyphenol-rich diets could be a valuable strategy in reducing cardiometabolic risk and preventing MetS in the population, potentially informing dietary guidelines and public health interventions.

The association between dietary flavonoid intake and bone mineral density and osteoporosis in US adults: data from NHANES 2007-2008, 2009-2010 and 2017-2018

BACKGROUND

Epidemiological studies investigating the association between flavonoid intake and bone mineral density (BMD) draw inconsistent conclusions. Our study aims to investigate the association between flavonoid intake and BMD and osteoporosis and the mediating role of composite dietary antioxidant index (CDAI) in their relationship using data from the National Health and Nutrition Examination Survey (NHANES).

METHODS

The study assessed the relationship between flavonoid intake and femur BMD and osteoporosis in 10,225 individuals from NHANES 2007-2010 and 2017-2018. Multivariable linear regression analyses were used to detect the association between flavonoid intake and femur BMD in adult Americans. Restricted cubic splines (RCS) were used to examine the nonlinear relationship between flavonoid intake and their subclasses and osteoporosis risk in individuals 20 years or older. We explored the mediating role of CDAI in the association between flavonoid intake and BMD.

RESULTS

In fully adjusted multivariable regression analyses, compared with people in the first quartile, people in the fourth quartile of total flavonoid intake have a higher BMD at total femur (0.013, 95% CI: 0.004, 0.022, P = 0.001), femur neck (0.010, 95% CI: 0.004, 0.017, P = 0.001), trochanter (0.010, 95% CI: 0.004, 0.017, P = 0.001), and intertrochanter (0.012, 95% CI: 0.003, 0.020, P = 0.006). The positive relationship between flavonoid intake and femur BMD was present in both sexes. Furthermore, we found that people in the fourth quartile of total flavonoid intake have a lower risk of osteoporosis compared with the first quartile (OR = 0.686, 95% CI: 0.528-0.890, P = 0.005). RCS found a linear inverse relationship between total flavonoid intake and osteoporosis in individuals ≥ 20 years (Overall P = 0.015, nonlinear P = 0.086). Moreover, CDAI partially mediates the association of total flavonoid intake with femur BMD.

CONCLUSIONS

Our findings suggest that higher flavonoid intake is associated with higher BMD and lower risk of osteoporosis in Americans. Furthermore, we found distinct associations between different flavonoid subclasses and osteoporosis risk. More studies with stronger evidence are needed to explore the causal association between flavonoid intake and bone health and their underlying mechanisms.

Association between dietary intake of flavonoid and chronic kidney disease in US adults: Evidence from NHANES 2007-2008, 2009-2010, and 2017-2018

BACKGROUND

Studies investigating the relationship between flavonoid intake and chronic kidney disease (CKD) are limited. This study investigated the association between daily flavonoid intake and CKD in US adults by using data for 2007-2008, 2009-2010, and 2017-2018 from the National Health and Nutrition Examination Survey (NHANES) database.

METHODS

This study employed a cross-sectional design and used data from three cycles of the continuous NHANES: 2007-2008, 2009-2010, and 2017-2018. NHANES researchers collected data related to consumption of various food and beverages from participants by employing 24-h dietary recall questionnaires. CKD is defined as an estimated glomerular filtration rate of < 60 mL/min/1.73m2 or a urine albumin-to-creatinine ratio of ≥ 30 mg/g.

RESULTS

The odds ratios (OR) for CKD risk in the second (Q2), third (Q3), and fourth (Q4) quartiles of total flavonoid intake, compared with that in the first (Q1) quartile, were 0.780 (95% CI: 0.600, 1.015), 0.741 (95% CI: 0.573, 0.957), and 0.716 (95% CI: 0.554, 0.925), respectively (with a P value for the trend of 0.040). According to the restricted cubic spline analysis, total flavonoid intake exhibited a non-linear relationship with CKD risk (P < 0.001).

CONCLUSION

Our findings suggest that a potential J-shaped relationship was observed between total flavonoid consumption and CKD risk, with an inflection point at 69.58 mg/d. Our study indicates that a moderate intake of flavonoids may confer renal benefits which may offer novel strategies for CKD treatment.

Association between ultra-processed food and flavonoid intakes in a nationally representative sample of the US population

Consumption of ultra-processed food (UPF) has been associated with several chronic diseases and poor diet quality. It is reasonable to speculate that the consumption of UPF negatively associates with flavonoid dietary intake; however, this assumption has not been previously examined. The present study aims to assess association between the dietary contribution of UPF and flavonoid intake in the US population aged 0 years and above. We performed a cross-sectional analysis of dietary data collected by 24-h recalls from 7640 participants participating in the National Health and Nutrition Examination Survey 2017-2018. Foods were classified according to the Nova classification system. The updated US Department of Agriculture (USDA) Database for the Flavonoid Content of Selected Foods (Release 3.3) database was used to estimate total and six classes of flavonoid intakes. Flavonoid intakes were compared across quintiles of dietary contribution of UPF (% of total energy intake) using linear regression models. The total and five out of six class flavonoid intakes decreased between 50 and 70 % across extreme quintiles of the dietary contribution of UPF (Pfor linear trend < 0·001); only isoflavones increased by over 260 %. Our findings suggest that consumption of UPF is associated with lower total and five of six class flavonoid intakes and with higher isoflavone intakes, supporting previous evidence of the negative impact of UPF consumption on the overall quality of the diet and health outcomes.

Dietary polyphenols and the risk of metabolic syndrome: a systematic review and meta-analysis

BACKGROUND

Accumulating evidence has suggested that dietary polyphenols may be protective against metabolic syndrome (MetS); however, the available evidence is contradictory. The aim of this meta-analysis was to assess the association between dietary intake of polyphenols and the odds of MetS.

METHODS

The PubMed and Scopus databases were systematically searched to obtain eligible studies. The risk of MetS for the highest versus the lowest intakes of total, subclasses and individual polyphenols were examined by pooling odds ratios (OR) and 95% confidence intervals (95%CI) using the random effects model.

RESULTS

A total of 14 studies (6 cohort and 8 cross-sectional studies) involving a total of 50,366 participants with 10,879 cases of MetS were included. When various polyphenol compounds were pooled, they were significantly related to a 22% decreased odds of MetS (([5 studies]; OR: 0.78; 95%CI: 0.72-0.85). Higher intakes of total flavonoids (([9 studies]; OR: 0.78; 95%CI: 0.72-0.85), flavan-3-ols (([2 studies]; OR: 0.64; 95%CI: 0.43-0.94), isoflavones (([3 studies]; OR: 0.84; 95%CI: 0.75-0.93), stilbenes (([4 studies]; OR: 0.86; 95%CI: 0.76-0.97), flavones (([2 studies]; OR: 0.79; 95%CI: 0.71-0.89), and quercetin (([2 studies]; OR: 0.63; 95%CI: 0.43-0.93) were also significantly associated with a decreased risk of MetS. The associations were not modified by the age of the participants. No association was found for total polyphenols, phenolic acids, lignans, anthocyanins, and flavonols.

CONCLUSION

The results of this meta-analysis supported that higher polyphenol intake can lower the risk of MetS.

Dietary flavonoids intake contributes to delay biological aging process: analysis from NHANES dataset

BACKGROUND

Diet may influence biological aging and the discrepancy (∆age) between a subject's biological age (BA) and chronological age (CA). We aimed to investigate the correlation of dietary flavonoids with the ∆age of organs (heart, kidney, liver) and the whole body.

METHOD

A total of 3193 United States adults were extracted from the National Health and Nutrition Examination Survey (NHANES) in 2007-2008 and 2017-2018. Dietary flavonoids intake was assessed using 24-h dietary recall method. Multiple linear regression analysis was performed to evaluate the association of dietary flavonoids intake with the ∆age of organs (heart, kidney, liver) and the whole body. BA was computed based on circulating biomarkers, and the resulting ∆age was tested as an outcome in linear regression analysis.

RESULTS

The ∆age of the whole body, heart, and liver was inversely associated with higher flavonoids intake (the whole body ∆age β = - 0.58, cardiovascular ∆age β = - 0.96, liver ∆age β = - 3.19) after adjustment for variables. However, higher flavonoids intake positively related to renal ∆age (β = 0.40) in participants with chronic kidney disease (CKD). Associations were influenced by population characteristics, such as age, health behavior, or chronic diseases. Anthocyanidins, isoflavones and flavones had the strongest inverse associations between the whole body ∆age and cardiovascular ∆age among all the flavonoids subclasses.

CONCLUSION

Flavonoids intake positively contributes to delaying the biological aging process, especially in the heart, and liver organ, which may be beneficial for reducing the long-term risk of cardiovascular or liver disease.