Flavonol-rich Diet Lowers Mortality and Disease Risk

In a recent prospective cohort study published in Scientific Reports, researchers delved into the connection between flavonol intake and cause-specific as well as all-cause mortality risk among adults in the United States. They discovered that a heightened dietary intake of flavonol is linked to a reduced risk of all-cause mortality, Alzheimer’s disease (AD), cancer, and cardiovascular disease (CVD)-related mortality risk.

Background

Flavonoids, biologically active polyphenolic compounds found in various plant-based foods, encompass six subclasses, with flavonols being the most prevalent and active. Primary flavonols such as quercetin, kaempferol, myricetin, and isorhamnetin abound in tea, onions, and berries. Flavonoid consumption is recognized for its potential to bolster endothelial function, maintain nitric oxide status, and impact biological processes related to lipid metabolism, platelet function, inflammation, oxidative stress, and blood pressure. Moreover, flavonoids are noted for their anti-tumor effects, targeting crucial molecules and pathways, leading to apoptosis and inhibiting cell growth and metastasis.

Nonetheless, the relationship between flavonol intake and mortality risk has yet to be extensively explored. Therefore, leveraging data from the National Health and Nutrition Examination Survey (NHANES) database, researchers in this study delved into the connection between flavonol intake (total flavonol, kaempferol, myricetin, isorhamnetin, and quercetin), all-cause mortality risk, and cause-specific mortality risk (AD, CVD, cancer, and diabetes mellitus (DM)).

About the Study

The study encompassed 11,679 individuals aged≥ 20 who underwent questionnaires, in-person assessments, and laboratory tests. Exclusion criteria comprised lack of flavonol intake and missing basic and demographic information. Flavonol intake data were extracted from the US Department of Agriculture Survey Food and Beverage Flavonoid Values database (2003–2004). Detailed dietary interviews captured information on foods and beverages consumed in the preceding 24 hours, enabling the estimation of total flavonol amounts in various foods and the calculation of participants’ daily flavonol intake.

For mortality analysis, data from the National Death Index file and the 2019 Public Access Link mortality dataset were utilized. Mortality was categorized by causes such as cancer, CVD, DM, AD, and other causes, following the International Statistical Classification of Diseases and Related Health Problems 10 (ICD-10) codes. Follow-up extended from the interview date to either the date of death or the study’s conclusion on December 31, 2019. Participants were stratified based on sociodemographic variables, including age, sex, race/ethnicity, marital status, education level, poverty ratio, alcohol consumption, body mass index (BMI), disease history, and the presence of various health conditions. Statistical analysis encompassed Cox regression, Fine and Gray competing risks regression models, hazard ratios (HR), chi-square tests, and sensitivity analyses.

Results and Discussion

Participants with the highest total flavonol intake tended to be male, younger, Non-Hispanic White, married, educated, above the poverty line, alcohol consumers, with BMI 18.5–30.0 kg/m2 and had a history of DM, hypertension, hyperlipidemia, congestive heart failure, coronary heart disease, angina, heart attack, and stroke. Increasing total flavonol intake exhibited a decreasing trend in all-cause mortality as well as AD, cancer, and CVD-specific mortality (p < 0.05 for all). Similar decreasing trends were observed for isorhamnetin, kaempferol, and quercetin intakes across various mortality categories, while myricetin intake demonstrated a decreasing trend in AD mortality.