Dietary flavonoid intake is inversely associated with cardiovascular disease risk as assessed by body mass index and waist circumference among adults in the United States

Authors: Sebastian, Rhonda; Enns, Cecilia; Goldman, Joseph; Moshfegh, Alanna

Submitted to: Nutrients
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/27/2017
Publication Date: 8/2/2017
Citation: Sebastian, R.S., Enns, C.W., Goldman, J.D., Moshfegh, A.J. 2017. Dietary flavonoid intake is inversely associated with cardiovascular disease risk as assessed by body mass index and waist circumference among adults in the United States. Nutrients 9(8):E827. Available: https://www.mdpi.com/2072-6643/9/8/827.
DOI: https://doi.org/10.3390/nu9080827

Interpretive Summary: Flavonoids are polyphenolic compounds that occur ubiquitously in plants. Though longitudinal studies have shown inverse relationships between incidence of cardiovascular disease (CVD) and flavonoid intake, it is not known whether these findings imply an analogous association between flavonoid intake and risk of these diseases in the U.S. population as a whole. Using a special database, the Flavonoid Values for USDA Survey Foods and Beverages 2007-2010, we calculated intake of total flavonoids and 5 flavonoid classes using one day of dietary recall collected from adults 20+ years (n=10,538) participating in What We Eat in America (WWEIA), NHANES 2007-2010. We classified individuals into categories of CVD risk in National Institutes of Health, National Heart, Lung, and Blood Institute guidelines, based on body mass index (BMI) and waist circumference (WC) measurements. Sampling weights were applied to derive nationally representative estimates. Total flavonoid intake differed by many characteristics, including sex, age, race/ethnicity, and health status. Tea was the primary source (78%) of total flavonoids intake. However, different foods and beverages contributed important amounts of various flavonoid classes. The majority of adults (53%) were classified as being at high, very high, or extremely high risk of CVD (high+ CVD risk), and more women than men (59% vs. 43%) were so classified. Inverse trends in the percentage of individuals at high+ CVD risk were found with greater intake of total flavonoids and three flavonoid classes: anthocyanidins (found in fruits, particularly berries), flavan-3-ols (found in tea), and flavanones (found in citrus fruits). When men and women were analyzed separately, the inverse associations between intakes of both total flavonoids and flavan-3-ols and high+ CVD risk were found for men only, whereas the inverse association between intake of anthocyanidins and high+ CVD risk was found for both men and women. This information will be of benefit to epidemiologists who study diet-disease relationships, as well as to policymakers who may ultimately set national guidance regarding intake of flavonoids. These findings have the potential to be of benefit to the entire adult U.S. population, as they contribute to the accumulating body of evidence suggesting that flavonoids may be an important component of a cardioprotective diet.

Technical Abstract: Flavonoids are bioactive compounds that may reduce disease risk. To date, no research has examined whether flavonoid intake is related to cardiovascular disease (CVD) risk defined by anthropometric measures. The objective of this study was to determine whether flavonoid intake is associated with having combined BMI and waist circumference (WC) measures considered indicative of high, very high, or extremely high risk for diabetes, hypertension, and CVD (high+ CVD risk) in a nationally representative sample of U.S. adults. Data from one 24-hour recall for 5,232 males and 5,306 females 20+ y who participated in What We Eat in America (WWEIA), NHANES 2007-2010 were analyzed. CVD risk was assessed based on BMI and WC, as described in NIH National Heart, Lung, and Blood Institute guidelines. Intakes of flavonoids (total and five classes) were calculated using the database Flavonoid Values for USDA Survey Foods and Beverages 2007-2010. Logistic regression provided adjusted estimates of the percentages of individuals at high+ CVD risk by category of flavonoid intake (total and class), and linear trends were assessed via orthogonal polynomial contrasts. Fifty-three percent of adults were classified at high+ CVD risk. After adjusting for demographic, lifestyle, and dietary confounders, inverse linear trends were found in the percentage of adults at high+ CVD risk by intake of total flavonoids, anthocyanidins, flavan-3-ols, and flavanones (p<0.01). For individuals in the highest versus the lowest intake category of anthocyanidins, flavan-3-ols, and flavanones, relative risk (RR) was 0.86 (99% CI: 0.79, 0.93), 0.88 (99% CI: 0.79, 0.98), and 0.89 (99% CI: 0.80, 0.98), respectively. No significant associations were seen between intakes of flavones or flavonols and high+ CVD risk. Among U.S. adults, dietary intakes of total flavonoids, anthocyanidins, flavan-3-ols, and flavanones are inversely associated with levels of BMI and WC that are predictive of high+ CVD risk.