Exploring flavonoid intake and all-cause mortality in diverse health conditions: Insights from NHANES 2007–2010 and 2017–2018

Objectives

Flavonoids exhibit antioxidative, anti-inflammatory, and anticancer properties, yet the relationship between flavonoid intake and all-cause mortality in the obese population remains unclear.

Methods

This study included NHANES participants from 2007 to 2010 and 2017 to 2018. Cox regression analysis evaluated the impact of total flavonoid intake on all-cause mortality among participants with varying comorbidity profiles. Subgroup analysis was conducted by separately analyzing the six sub-classes of total flavonoids (anthocyanidins, flavan-3-ols, flavanones, flavones, flavonols, and isoflavones). Sensitivity analysis was used to investigate the impact of total flavonoid intake on all-cause mortality among patients with different comorbidities.

Results

During a median follow-up period of 9.92 years (interquartile range (IQR), 5.54–14.29 years), a total of 639 participants died. COX regression analysis revealed a positive impact of flavonoid intake on all-cause mortality among participants with chronic kidney disease, with greater benefits observed in obese participants [hazard ratio (HR): 0.22, 95% CI: 0.11–0.44). In metabolically healthy obese participants (HR: 0.15, 95% CI: 0.07–0.35), obese individuals with diabetes (HR: 0.51, 95% CI: 0.29–0.88), and obese individuals with comorbid cardiovascular disease (HR: 0.37, 95% CI: 0.17–0.83), flavonoid intake was associated with a reduced risk of all-cause mortality. Restricted cubic spline (RCS) analysis indicated a non-linear relationship in obese participants, with optimal intake levels ranging from 319.4978 to 448.6907 mg/day, varying based on different comorbidity profiles. Subgroup analysis revealed varying effects of total flavonoid components in different health conditions, with hazard ratios ranging from 0.06 for higher levels of flavonol to 0.59 for higher levels of anthocyanidins in the Cox model. Sensitivity analyses further indicated that individuals with obesity and comorbid diabetes or CKD see the greatest benefit from flavonoid intake.

Conclusions

The consumption of flavonoids may be associated with a decreased risk of all-cause mortality. Consumption of flavonoids is particularly beneficial for individuals with obesity and comorbidities.