Basic characteristics of including participants

The 2007-2008, 2009-2010, and 2018-2019 NHANES circles evaluated a total of 11,679 participants aged 20 years and older, representing 44,189,487 non-institutionalized residents in the United States. Table 1 lists the minimum, 25th percentile, median, mean, 75th percentile, and maximum value for each flavonol intake. Table 2 provides an overview of the basic characteristics of the participants. The results showed that subjects in the category with the highest total flavonol intake had a higher proportion of the following characteristics: Male (1682 [55.84%] vs 1238 [44.16%]), tend to be younger (80+, 107 years) [2.15%] vs. 3.76 [15.72%]), non-Hispanic whites (1542) [74.6%] versus 429 [6.78%]), married or living with a partner (1933) [67.95%] versus 987 [32.05%]), Educational background“¥¥HS (2306 [86.84%] versus 614 [13.16%]), above the poverty line (2433 [89.63%] versus 487 [10.37%]), drinking (2619) [92.80%] vs.301 [7.20%]), BMI 18.5-30.0 (1785 [63.50%] vs. 40 [1.29%]), DM history (8467) [72.50%] vs. 3212 [27.5%]), hypertension (6718 [57.52%] versus 4961 [42.48%]), hyperlipidemia (3104) [26.58%] vs 8575 [73.42%]), congestive heart failure (11,352 [97.20%] versus 327 [2.80%]), coronary heart disease (11,207 [95.96%] versus 472 [4.04%]), angina (11,390 [97.53%] versus 289 [2.47%]), heart attack (11,165 [95.60%] versus 514 [4.40%]), and stroke (11,206 [95.95%] versus 473 [4.05%]). Additionally, participants who took isorhamnetin, kaempferol, myricetin, and quercetin showed similar characteristics. More detailed information on the participants’ basic characteristics and dietary flavonol intake is shown in Table 2.

Differences in flavonol intake, survival status, and cause of death among participants

Table 3 shows the general characteristics of participants’ flavonol intake by survival status or cause of death.As total flavonol intake increases, all-cause mortality, AD-specific mortality, cancer-specific mortality, and CVD-specific mortality (all P trend value < 0.050). Increased intake of isorhamnetin tends to reduce all-cause mortality, Alzheimer's disease mortality, cancer mortality, CVD mortality, DM mortality, and other-cause mortality (all-cause mortality). P trend value < 0.050). As kaempferol intake increases, all-cause mortality, Alzheimer's disease-specific mortality, cancer-specific mortality, CVD-specific mortality, and other-cause mortality tend to decrease (all-cause mortality mortality rate). P for trends < 0.050). As the intake of myricetin increases, the mortality rate from Alzheimer's disease tends to decrease (P for trend = 0.003). As quartiles of quercetin intake increase, all-cause mortality, cancer mortality, and other-cause mortality (all-cause mortality) tend to decrease. P for trends < 0.050).

All-cause mortality by sociodemographic variables and baseline characteristics of medical history

We applied Cox regression analysis to examine the relationship between baseline characteristics (including sociodemographic variables and medical history) and all-cause mortality among US participants. Detailed results are shown in Table 4. 10 years old. Female (HR 0.77; 95% CI 0.69 to 0.86), Mexican American (HR 0.36; 95% CI 0.28 to 0.47), had at least high school education (HR 0.49; 95% CI 0.43 to 0.57), and were married. living with a partner (HR 0.64; 95% CI 0.56 to 0.72) and drinking alcohol (HR 0.60; 95% CI 0.46 to 0.78) were associated with a lower risk of all-cause mortality. Additionally, covariates included BMI ≤18.5 (HR 1.76; 95% CI 1.11-2.81), medical history including DM (HR 2.99; 95% CI 2.55-3.51), hypertension (HR 4.25; 95% CI 3.62-5.00), Hyperlipidemia (HR 4.25; 95% CI 3.62-5.00), congestive heart failure (HR 8.42; 95% CI 6.89-10.29), coronary heart disease (HR 5.35; 95% CI 4.58-6.24), angina (HR 3.70; 95% CI 2.86-4.79), heart attack (HR 4.67; 95% CI 3.85-5.67), and heart attack (HR 5.54; 95% CI 4.25-7.21) were associated with higher risk of all-cause mortality was significantly associated with that.

Association between dietary flavonol intake and all-cause mortality

After adjusting for age, gender, race/ethnicity, marital status, education level, poverty income ratio, alcohol intake, BMI, and medical history, multivariate Cox regression analyzes showed that total flavonol intake in the highest category was associated with all causes. A significant correlation was shown between the two. Risk of death (HR 0.64, 95% CI 0.54 to 0.75, P < 0.001 for trends), compared with the bottom quartile (Table 5). Furthermore, we investigated the association between the intake of four types of flavonols and the risk of all-cause mortality. Isorhamnetin (HR 0.72, 95% CI 0.60 to 0.86, P trend < 0.001), kaempferol (HR 0.74, 95% CI 0.63 to 0.86; P trend < 0.001), myricetin (HR 0.77, 95% CI 0.67 to 0.88; P trend < 0.001) and quercetin (HR 0.66, 95% CI 0.54 to 0.81; P For trends < 0.001), all intakes in the highest quartile were associated with all-cause mortality risk compared with the lowest quartile (Table 5).

Relationship between dietary flavonol intake and cause-specific mortality rate

Of the 11,679 subjects in this study, 43 (0.03%) died of AD, 336 (2.88%) died of cancer, 486 (4.16%) died of CVD, and 46 (0.40%) died of DM. 457 people (3.91%) died. Died of other causes. After adjusting for covariates, multivariate Cox regression analysis showed that the highest quartile of total flavonol intake was significantly associated with lower cancer-specific mortality (HR 0.45, 95 % CI 0.28-0.70, P trend = 0.003), CVD-specific mortality (HR 0.67, 95% CI 0.47 to 0.96; P trend = 0.080) and mortality from other causes (HR 0.64, 95% CI 0.51 to 0.81; P for trend = 0.003), compared to the lowest quartile. Isorhamnetin intake in the highest quartile was significantly associated with lower cancer-specific mortality (HR 0.62, 95% CI 0.46 to 0.83; P trend = 0.010), and mortality from other causes (Q4 vs. Q1, HR 0.66, 95% CI 0.47 to 0.92; P for trend = 0.010), compared to the lowest quartile. The highest category of kaempferol intake was significantly associated with lower cancer-specific mortality (HR 0.62, 95% CI 0.40 to 0.97; P trend = 0.020), compared to the lowest category. Myricetin intake in the highest category was significantly associated with lower risk of Alzheimer’s disease-specific mortality (HR 0.34, 95% CI 0.14 to 0.85; P trend = 0.090), cancer-specific mortality risk (HR 0.65, 95% CI 0.42 to 0.99; P trend = 0.010), CVD-specific mortality risk (HR 0.61, 95% CI 0.47 to 0.80; P trend < 0.001), and risk of death from other causes (HR 0.70, 95% CI 0.53 to 0.91; P for trend = 0.010), compared to the lowest category. Quercetin intake in the top quartile was significantly associated with a lower risk of cancer-specific mortality (HR 0.54, 95% CI 0.35 to 0.84; P trend = 0.004), CVD-specific mortality risk (HR 0.61, 95% CI 0.40 to 0.93; P for trend = 0.130), risk of death from other causes (HR 0.61, 95% CI 0.46 to 0.80; P < 0.001 for trend) compared to the bottom quartile (Table 5).

Subgroup analysis stratified by race/ethnicity

After adjusting for age, sex, race/ethnicity, marital status, education level, poverty income ratio, alcohol intake, BMI, and medical history, subgroup analyzes stratified by race/ethnicity showed that total flavonols (HR 0.59) , 95% CI 0.49). -0.72, P trend < 0.001), isolaminetin (HR 0.63, 95% CI 0.52 to 0.77; P trend < 0.001), kaempferol (HR 0.62, 95% CI 0.50 to 0.76; P trend < 0.001), myricetin (HR 0.97, 95% CI 0.81 to 1.17; P trend < 0.001) and quercetin (HR 0.68, 95% CI 0.55 to 0.83; P Intake in the highest quartile (trend < 0.001) was significantly associated with lower risk of all-cause mortality among non-Hispanic whites compared with the lowest quartile. More detailed results are shown in Table 6. Dietary flavonol intake has a more pronounced protective effect for non-Hispanic white populations compared to non-Hispanic blacks, Mexican Americans, and other races/ethnicities.

Sensitivity analysis

In sensitivity analyses, we applied final models that included age squared (Cox proportional risk regression model and Fine and Gray competing risk regression model) to adjust for potential nonlinear associations between age and mortality. The observed results were consistent with those presented in the main analysis, indicating that the results were relatively robust (Table 5).