Associations Of Dietary Fiber Intake Research Articles

The possible association of dietary fiber intake with the incidence of depressive symptoms in the Korean population

ABSTRACT Objectives This study investigates the effect of dietary fiber on the prevention of depressive symptoms. Methods In a cohort of 88,826 Korean adults (57,284 men and 31,542 women), we longitudinally evaluated the risk of depressive symptoms according to quartiles of dietary fiber intake for 5.8 years of follow-up. A food frequency questionnaire was used in evaluating dietary fiber intake. Depressive symptoms were assessed by the Center for Epidemiological Studies-Depression (CES-D) scale, in which CES-D ≥ 16 was defined as depressive symptoms. The Cox proportional hazards model was used to calculate the adjusted hazard ratio (HR) and 95% confidence intervals (CI) for depressive symptoms (adjusted HR [95% CI]). Subgroup analysis was performed for gender and BMI (≥25 or <25). Result In men, the risk of depressive symptoms significantly decreased with the increase of dietary fiber (quartile 1: reference, quartile 2: 0.93 [0.87–0.99], quartile 3: 0.91 [0.85–0.98] and quartile 4: 0.84 [0.77–0.92]). This association was more prominently observed in men with BMI ≥ 25 (quartile 1: reference, quartile 2: 0.95 [0.86–1.06], quartile 3: 0.88 [0.79–0.99] and quartile 4: 0.84 [0.73–0.97]). Women did not show a significant association between quartile groups of dietary fiber intake and the risk of depressive symptoms across subgroup analysis for BMI. Conclusion High intake of dietary fiber is potentially effective in reducing depressive symptoms in Korean men. The protective effect of dietary fiber on depressive symptoms may vary by gender and obesity.

Sex difference in the association of dietary fiber intake with visceral fat volume in Japanese adults.

Dietary fiber is a possible nutritional component which aids in the prevention of visceral fat accumulation. We examined the association between dietary fiber intake and visceral fat volume (VFV) by sex, and further analysed the association by major food sources of dietary fiber. In this cross-sectional study, we measured VFV in 2779 Japanese (1564 men and 1215 women) aged 40-89 who underwent positron emission tomography/computed tomography for cancer screening between 2004 and 2005. Dietary fiber intake was calculated based on a validated semi-quantitative food frequency questionnaire. The association between dietary fiber intake and VFV was investigated using multivariate linear regression models after adjustment for potential confounders. Total, soluble, and insoluble fiber intakes were inversely associated with VFV in men (Q1: 3740 cm3, Q4: 3517 cm3, Ptrend: 0.0006 for total fiber), but not in women (Q1: 2207 cm3, Q4: 2193 cm3,Ptrend: 0.88 for total fiber). Statistically significant sex difference was observed (Pinteraction = 0.001 for total fiber). Subgroup analyses by major food sources revealed that dietary fiber intakes from beans, vegetables and fruits showed an inverse association with VFV in men, while cereal fiber intake showed a tendency toward a positive association in both sexes (Q1: 3520 cm3, Q4: 3671 cm3, Ptrend: 0.05 in men, Q1: 2147 cm3, Q4: 2227 cm3, Ptrend: 0.10 in women). We observed a sex-specific association between dietary fiber intake and VFV in Japanese adults. This study suggests that efforts against visceral fat accumulation should take account of the source of dietary fiber.

Gut Microbiota and Blood Metabolites Related to Fiber Intake and Type 2 Diabetes.

Consistent evidence suggests diabetes-protective effects of dietary fiber intake. However, the underlying mechanisms, particularly the role of gut microbiota and host circulating metabolites, are not fully understood. We aimed to investigate gut microbiota and circulating metabolites associated with dietary fiber intake and their relationships with type 2 diabetes (T2D). This study included up to 11 394 participants from the HCHS/SOL (Hispanic Community Health Study/Study of Latinos). Diet was assessed with two 24-hour dietary recalls at baseline. We examined associations of dietary fiber intake with gut microbiome measured by shotgun metagenomics (350 species/85 genera and 1958 enzymes; n=2992 at visit 2), serum metabolome measured by untargeted metabolomics (624 metabolites; n=6198 at baseline), and associations between fiber-related gut bacteria and metabolites (n=804 at visit 2). We examined prospective associations of serum microbial-associated metabolites (n=3579 at baseline) with incident T2D over 6 years. We identified multiple bacterial genera, species, and related enzymes associated with fiber intake. Several bacteria (eg, Butyrivibrio, Faecalibacterium) and enzymes involved in fiber degradation (eg, xylanase EC3.2.1.156) were positively associated with fiber intake, inversely associated with prevalent T2D, and favorably associated with T2D-related metabolic traits. We identified 159 metabolites associated with fiber intake, 47 of which were associated with incident T2D. We identified 18 of these 47 metabolites associated with the identified fiber-related bacteria, including several microbial metabolites (eg, indolepropionate and 3-phenylpropionate) inversely associated with the risk of T2D. Both Butyrivibrio and Faecalibacterium were associated with these favorable metabolites. The associations of fiber-related bacteria, especially Faecalibacterium and Butyrivibrio, with T2D were attenuated after further adjustment for these microbial metabolites. Among United States Hispanics/Latinos, dietary fiber intake was associated with favorable profiles of gut microbiota and circulating metabolites for T2D. These findings advance our understanding of the role of gut microbiota and microbial metabolites in the relationship between diet and T2D.

Association of Dietary Fiber and Measures of Physical Fitness with High-Sensitivity C-Reactive Protein.

Dietary fiber intake and physical fitness are independently associated with high-sensitivity C-reactive protein (hs-CRP) levels. Nevertheless, the association between dietary fiber intake, measures of physical fitness, and hs-CRP levels has not yet been fully evaluated. We investigated the influence of a combination of dietary fiber intake and measures of physical fitness, including hand grip strength, resistance training, and metabolic equivalents of tasks, on hs-CRP levels. Data collected from the Korea National Health and Nutrition Examination Survey (KNHANES) spanning 2015 to 2018 were used in this study. A total of 16,934 participants (7434 men and 9500 women aged ≥19 years) were included in this study. After adjusting for confounding factors (age, education, income, marital status, smoking status, drinking habits, total energy intake, and aerobic physical activity), we employed a multivariable logistic model to examine the association of dietary fiber intake and measures of physical fitness with hs-CRP levels. Among women, the odds of high hs-CRP levels were lower in those with the highest dietary fiber intake and superior grip strength compared to in women with the lowest dietary fiber intake and weaker grip strength (odds ratio [OR] = 0.40, 95% confidence interval [CI] = 0.24-0.68). The highest dietary fiber intake who participated in resistance exercise at least three times per week had a reduced odds of high hs-CRP levels compared with those with the lowest dietary fiber intake who did not engage in resistance exercise in both men and women (OR = 0.53, 95% CI = 0.32-0.89; OR = 0.40, 95% CI = 0.19-0.84, respectively). Our findings indicate that dietary fiber intake and high levels of physical fitness were associated with reduced odds of elevated hs-CRP levels.

Association Between Dietary Fiber Intake and Low Muscle Strength Among Korean Adults.

The health benefits of dietary fiber are widely recognized, but its impact on muscle health remains unclear. Therefore, this study aimed to elucidate the relationship between dietary fiber intake and muscle strength through a cross-sectional analysis of data from the Korea National Health and Examination Survey (KNHANES). Data from a single 24-h dietary recall and handgrip strength tests of 10,883 younger adults aged 19 to 64 years and 3,961 older adults aged ≥ 65 years were analyzed. Low muscle strength was defined as handgrip strength < 28 kg for men and < 18 kg for women. Multivariable linear and logistic regression analyses were conducted to determine the association of dietary fiber intake with muscle strength. Approximately 43% of Korean adults met the recommended intake of dietary fiber, and those with higher dietary fiber consumption also had higher total energy and protein intake. After adjusting for confounding variables, dietary fiber intake was found to be positively associated with maximal handgrip strength in younger women aged 19 to 64 years (β = 0.015; standard error [SE] = 0.006) and older men aged ≥ 65 years (β = 0.035; SE = 0.014). For older women aged ≥ 65 years, those in the lowest quartile of dietary fiber intake had a higher risk of low muscle strength than those in the highest quartile after adjustment of confounders (odds ratio 1.709; 95% confidence interval 1.130-2.585). These results suggest that adequate dietary fiber intake may reduce the risk of sarcopenia in older Korean women.

Longitudinal Associations of Dietary Fiber Intake with Glycated Hemoglobin and Estimated Insulin Sensitivity in Adults with and without Type 1 Diabetes.

Dietary fiber, an essential bioactive compound in plant-based diets, is of public health concern based on habitual low intakes in the general population. Not much data are available on how habitual dietary fiber is associated with glycemic control in type 1 diabetes (T1D) as well as in prediabetes and normoglycemic adults. To address this gap, we conducted a six-year longitudinal analysis of an original cohort in adults with and without T1D (n = 1255; T1D: n = 563; non-diabetes mellitus (non-DM): n = 692). Dietary data were collected from a validated food frequency questionnaire, biochemical measures were obtained after an overnight fast, and anthropometric measurements were collected at baseline as well as after three and six years for the follow-up study. Glycated hemoglobin (HbA1c) and estimated insulin sensitivity (eIS) were the main outcomes examined. In adjusted analyses, dietary fiber intake was inversely associated with HbA1c in a minimally adjusted model, but it was positively associated with eIS in a model involving all relevant covariates in non-DM adults. These associations were not significant in the T1D group. Furthermore, when examined by HbA1c cut-offs for glycemic control, an inverse association with dietary fiber was only observed in adults with prediabetes (all p < 0.05). At a six-year mean (±SD) dietary fiber intake of 17.4 ± 8.8 g for non-DM and 17.0 ± 8.2 g for the T1D group, protective associations against poor glycemic control were observed in those without diabetes and in prediabetes.

Associations of dietary fiber intake with chronic inflammatory airway diseases and mortality in adults: a population-based study.

The objective of this study was to investigate the potential association between dietary fiber intakes and the prevalence of chronic inflammatory airway diseases (CIAD), as well as mortality in participants with CIAD. Data was collected from the National Health and Nutrition Examination Survey (NHANES) 2013-2018, with dietary fiber intakes being calculated as the average of two 24-h dietary reviews and divided into four groups. CIAD included self-reported asthma, chronic bronchitis, and chronic obstructive pulmonary disease (COPD). Through December 31, 2019, mortality was identified from the National Death Index. In cross-sectional studies, multiple logistic regressions were used to assess dietary fiber intakes associated with the prevalence of total and specific CIAD. Dose-response relationships were tested using restricted cubic spline regression. In prospective cohort studies, cumulative survival rates were calculated using the Kaplan-Meier method and compared using log-rank tests. Multiple COX regressions were used to assess dietary fiber intakes associated with mortality in participants with CIAD. A total of 12,276 adults were included in this analysis. The participants had a mean age of 50.70 ± 17.4 years and was 47.2% male. The prevalence of CIAD, asthma, chronic bronchitis, and COPD were 20.1, 15.2, 6.3, and 4.2%, respectively. The median daily consumption of dietary fiber was 15.1 [IQR 10.5, 21.1] g. After adjusting for all confounding factors, linear and negative associations were observed between dietary fiber intakes and the prevalence of total CIAD (OR = 0.68 [0.58-0.80]), asthma (OR = 0.71 [0.60-0.85]), chronic bronchitis (OR = 0.57 [0.43-0.74]) and COPD (OR = 0.51 [0.34-0.74]). In addition, the fourth quartile of dietary fiber intake levels remained significantly associated with a decreased risk of all-cause mortality (HR = 0.47 [0.26-0.83]) compared to the first quartile. Dietary fiber intakes were found to be correlated with the prevalence of CIAD, and higher dietary fiber intakes were associated with a reduced mortality in participants with CIAD.

Dietary fiber intake and risk of gallstone: a case–control study

BackgroundGallstone disease (GSD) and its complications are major public health issues globally. Although many community-based studies had addressed the risk factors for GSD, little is known about the associations between dietary factors and risk of disease. The present study aimed to investigate the potential associations between dietary fibers with the risk of gallstone disease.MethodsIn this case–control study, 189 GSD patients with less than one month of diagnosis and 342 age‑matched controls were enrolled. Dietary intakes were assessed using a 168-item semi-quantitative validated food frequency questionnaire. Crude and multivariable-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated through cox proportional hazards regression models.ResultsComparing the highest versus the lowest tertile, significant reverse associations were observed between odds of GSD and each category of dietary fiber intake including total (OR T3 vs. T1 = 0.44, 95% CI: 0.37–0.7, P for trend = 0.015), soluble (OR T3 vs. T1 = 0.51, 95% CI: 0.3–0.8, P for trend = 0.048) and insoluble (OR T3 vs. T1 = 0.56, 95% CI: 0.3–0.9, P for trend < 0.001). The relationship between dietary fiber intake and the risk of gallstones was more prominent in overweight and obese subjects than in subjects with a normal body mass index.ConclusionComprehensive assessment of the associations of dietary fiber intake with GSD showed that higher intakes of dietary fiber were significantly associated with reduced GSD risk.

Association of Dietary Fiber Intake With Gastrointestinal Tract Cancer Among Korean Adults

This cohort study assesses the association between dietary fiber intake and incident gastrointestinal tract cancer among Korean adults.

Abstract 69: Dietary Fiber, Gut Microbiota, Circulating Metabolomics, and Risk of Diabetes in US Hispanics/Latinos: The Hispanic Community Health Study/Study of Latinos (HCHS/SOL)

Introduction: Emerging evidence suggesting diabetes -protective effects of dietary fiber intake. However, the underlying mechanisms are not fully understood. Hypothesis: We hypothesize that higher dietary fiber intake can alter gut microbial composition /functional capacity and host circulating metabolomic profile, which may contribute to lower risk of diabetes. Methods: We evaluated the associations of dietary fiber intake with gut microbiome (measured by shotgun metagenomic sequencing, n=2959) and serum metabolome (639 metabolites measured by untargeted metabolomic approach, n=6198) in the HCHS/SOL cohort. We further examined prospective associations of baseline fiber/microbial-associated metabolites with incident diabetes over 6-years follow-up. Results: We identified 39 bacterial genera associated with fiber intake, after adjustment for sociodemographic, behavioral, and clinical factors. 12 of these fiber-associated genera were related with diabetes (e.g. the fiber-associated Roseburia was inversely associated with diabetes, Fig.1A ). We identified 83 fiber-associated metabolites which were clustered into 13 modules in network, 7 of which were significantly associated with risk of diabetes ( Fig.1B ). Some of these diabetes-associated metabolite modules were also associated with fiber/diabetes-associated bacterial taxa ( Fig.1C ). In particular, indolepropionate module, and another module comprised of the pro-vitamins such as beta-cryptoxanthin, were positively associated with fiber (all P&lt;0.001) and inversely associated with diabetes risk (RR [95% CI] = 0.78[0.69, 0.89] and 0.83[0.72, 0.94] respectively), and both associated with the fiber-degradation genera Butyrivibrio (P&lt;0.001). Conclusion: Among US Hispanics/Latinos, higher fiber intake was associated with favorable profiles of gut microbiota and circulating metabolites for diabetes, suggesting a potential role of gut microbiota and related metabolites in the link between dietary fiber intake and risk of diabetes.

Dietary fiber intake and metabolic syndrome in postmenopausal African American women with obesity

Fiber intake may be associated with lower risk of metabolic syndrome (MetS) but data from metabolically unhealthy African American women is sparse. We examined the association of dietary fiber intake and MetS among postmenopausal African American women with obesity. Baseline cross-sectional data from the Focused Intervention on Exercise to Reduce CancEr (FIERCE) trial of 213 women (mean age 58.3 years) were used. Dietary intake was assessed by Food Frequency Questionnaires (FFQs). Multivariate linear and logistic regressions were performed to estimate associations of MetS with fiber intake and adherence to dietary fiber intake guidelines, respectively. Mean daily fiber intake was (10.33 g/1000kcal) in women with impaired metabolic health. We observed an inverse association of total fiber intake with MetS. One unit increase in energy-adjusted fiber intake was associated with a 0.10 unit decrease in the MetS z-score (p = 0.02). Similar results were obtained for both soluble and insoluble fiber. In multivariate-adjusted analyses, participants not adherent to fiber intake recommendations were more likely to have MetS as compared to those reporting intakes in the recommended range (adjusted odds ratio 4.24, 95% CI: 1.75, 10.30). Of the MetS components, high fasting glucose and high triglycerides were all associated with lower intake of fiber. Study participants who consumed a higher amount of fiber had a better overall metabolic profile and were less likely to have MetS in our cross-sectional analysis of postmenopausal African American women with obesity and unhealthy metabolic profiles.

Association between Dietary Fiber Intake and Mortality among Colorectal Cancer Survivors: Results from the Newfoundland Familial Colorectal Cancer Cohort Study and a Meta-Analysis of Prospective Studies.

Simple SummaryHigh dietary fiber intake has been linked to a lower risk of Colorectal cancer (CRC), but the role of dietary fiber in CRC survival is understudied. We examined dietary fiber intake for its relevance to CRC survival in a cohort of 504 CRC patients and a meta-analysis including results from four prospective cohort studies. We found that high dietary fiber intake was negatively correlated with all-cause mortality and CRC-specific mortality among CRC survivors. These new findings support the protective effect of dietary fiber on CRC survival. By enhancing fiber intake, this research may contribute to the development of novel therapies that add to our armamentarium for CRC.We examined dietary fiber intake for its relevance to Colorectal cancer (CRC) survival in a cohort of CRC patients and a meta-analysis including results from four prospective cohort studies. We analyzed 504 CRC patients enrolled in the Newfoundland Familial Colorectal Cancer Study (NFCCS) who were newly diagnosed with CRC between 1999 and 2003. Follow-up for deaths was through April 2010. All participants completed a self-administered food frequency questionnaire to evaluate their dietary intakes one year before diagnosis. Multivariable Cox proportional hazard models were used to explore the associations of dietary fiber intake with all-cause mortality and CRC-specific mortality. In the meta-analysis, we identified prospective cohort studies published between January 1991 and December 2021 by searching PubMed, EMBASE, and Cochrane Library. Fixed-effects or random-effects models were used to combine the study-specific hazard ratio (HR) from our original analysis and three other cohorts. In the NFCCS, we found that CRC patients with the second quartile of dietary fiber intake had a 42% lower risk of all-cause mortality (HR: 0.58, 95% CI: 0.35–0.98) and 58% lower risk of CRC-specific mortality (HR: 0.42, 95% CI: 0.21–0.87) compared with those with the lowest quartile. In the meta-analysis, a similar inverse association between dietary fiber and total mortality was detected among CRC patients; each 10 g/day increase in dietary fiber intake was associated with a 16% decreased risk of total mortality. The dose–response meta-analysis showed a linear relationship between dietary fiber intake and all-cause mortality, with no sign of a plateau. For CRC-specific mortality, intriguingly, the benefit associated with increasing dietary fiber intake achieved its maximum at approximately 22 g/day, and no further reduction in CRC-specific mortality was observed beyond this intake level. Our results suggest that high dietary fiber intake may be associated with prolonged survival among CRC patients. Our findings add to the sparse literature on the role of dietary fiber in CRC survival.

Associations between dietary fiber intake and mortality from all causes, cardiovascular disease and cancer: a prospective study

ObjectiveSeveral studies suggest that dietary fiber intake may reduce mortality risk, but this might depend on the fiber types and the evidence regarding the role of soluble fiber or insoluble fiber on death risk remain limited and inconsistent. Therefore, this study aimed to comprehensively evaluate multiple types of dietary fiber intake on mortality from all causes, cardiovascular disease and cancer in the large-scale Prostate, Lung, Colorectal, and Ovarian Cancer (PLCO) Screening Trial.MethodsA multivariate Cox proportional hazards model was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs).ResultsThis study finally included 86,642 participants with 17,536 all-cause deaths, 4842 cardiovascular deaths and 5760 cancer deaths identified after a total of 1,444,068 follow-up years. After adjusting for potential confounders, dietary total fiber intake was statistically significantly inversely associated with all-cause death (Q5 vs Q1: HR 0.71, 95% CI 0.66–0.75; P for trend < 0.001), cardiovascular death (Q5 vs Q1: HR 0.73, 95% CI 0.65–0.83; P for trend < 0.001) and cancer mortality (Q5 vs Q1: HR 0.77, 95% CI 0.69–0.86; P for trend < 0.001). Similar results were observed for both insoluble and soluble fiber intake. Restricted cubic spline model analysis suggested that there was a nonlinear association of dietary fiber intake with mortality risk (all P for nonlinearity < 0.05).ConclusionsIn this large nationally representative sample of US adult population, intakes of total fiber, soluble fiber, and insoluble fiber were associated with lower risks of all-cause, cardiovascular and cancer mortality.

Association of Dietary Fiber Intake with All-Cause Mortality and Cardiovascular Disease Mortality: A 10-Year Prospective Cohort Study.

Although previous studies have established that dietary fiber (DF) intake reduces the total cardiovascular disease (CVD) mortality in general populations, limited studies have been conducted in individuals with pre-existing chronic conditions, especially in Asian countries. We aimed to investigate the association of DF intake with all-cause and CVD mortality in the general population and in the subpopulation with hypertension, diabetes, and dyslipidemia. We examined the relationship between DF intake and all-cause and CVD mortality using the Korean genome and epidemiology study. Diet was assessed using a food-frequency questionnaire at baseline. Cox proportional hazard models were used to estimate the hazard ratio (HR) and 95% confidence intervals (CIs) after adjusting for confounders. During the mean 10.1 years of follow-up, higher DF intake was significantly associated with a lower risk of all-cause mortality after adjusting for confounders (HR and 95% CIs for Q5 vs. Q1: 0.84 (0.76–0.93); p < 0.001). DF intake was inversely associated with a lower risk of CVD mortality after adjusting for the same confounders (HR and 95% CIs for Q5 vs. Q1: 0.61 (0.47–0.78); p < 0.001). Total DF intake was inversely associated with all-cause and CVD mortality in middle-aged and older adults.

Association Between Dietary Fiber Intake and Risk of Depression in Patients With or Without Type 2 Diabetes.

Depression and type 2 diabetes (T2D) are both serious public health problems, with morbidity and mortality in people increasing year by year, resulting in a heavy economic burden. A correlation between dietary fiber and both has been reported. Nevertheless, few data are available concerning dietary fiber and the risk of depression with or without T2D, which deserve further attention. We assessed the relationship between dietary fiber intake and risk of depression with or without T2D in the 2007-2014 National Health and Nutrition Examination Survey (NHANES) population. A 24-h dietary review was used to assess fiber intake. The Patient Health Questionnaire-9 was used to assess depression. Stability of the results was assessed using restricted cubic spline models and logistic regression, as well as sensitivity analyses. A total of 17,866 adults aged 20 years and older with a mean age of 49.3 ± 17.7 years were included in this study, of whom 49.5% were male. After adjusting for covariates, the association of dietary fiber intake with the risk of depression appeared to differ between non-T2D group and T2D group (OR, 0.987; 95% CI, 0.979-0.995 vs. OR, 1.003; 95% CI, 0.988-1.017). Furthermore, when dietary fiber was converted to a categorical variable, there was evidence of interaction between T2D status and fiber intake on decreasing the prevalence of depression (P-value for interaction = 0.015). Sensitivity analysis showed stable results. Our findings indicated that whether a patient has T2D may affect the relationship between dietary fiber intake and the risk of depression, which still needs to be confirmed by further randomized controlled trials.

Association of Dietary Fiber Intake With Myocardial Infarction and Stroke Events in US Adults: A Cross-Sectional Study of NHANES 2011-2018.

This study aimed to detect dietary fiber intake and its association with nonfatal cardiovascular/cerebrovascular events (myocardial infarction and stroke) in adults in the United States. This cross-sectional study obtained data from the 2011–2018 National Health and Nutrition Examination Survey database. Using multivariate logistic regression, we compared dietary fiber intake across demographics and detected an association between dietary fiber intake and patient-reported nonfatal myocardial infarction and/or stroke events. We enrolled 8,872 participants (mean dietary fiber intake, 17.38 ± 0.22 g/day). The weighted prevalence of nonfatal cardiovascular/cerebrovascular events was 5.36%, which decreased with higher dietary fiber intake (nonfatal cardiovascular/cerebrovascular events: Tertile1, 6.50%; Tertile2, 5.45%; Tertile3, 4.25%). Higher fiber intake indicated a stable negative association with nonfatal cardiovascular/cerebrovascular events in the multivariate logistic regression analysis, weighted generalized additive model, and smooth curve fitting. Interaction tests showed no significant effect of demographic, socioeconomic, and disease status on the association between dietary fiber intake and nonfatal cardiovascular/cerebrovascular events. Dietary fiber intake was far below the recommended amount. Higher dietary fiber intake was associated with a lower prevalence of nonfatal cardiovascular/cerebrovascular events.

The Association of Dietary Fiber Intake in Three Meals with All-Cause and Disease-Specific Mortality among Adults: The U.S. National Health and Nutrition Examination Survey, 2003-2014.

The timing of food intake can significantly alter the body’s metabolism of nutrient intake and affect the occurrence of chronic diseases. However, whether and how the intake time of dietary fiber could influence mortality risks is largely unknown. This study aims to reveal the association between total dietary fiber intake and fiber intake at different times with all-cause, cancer, and cardiovascular disease (CVD) mortality rates. A total of 31,164 adults who enrolled in the National Health and Nutrition Examination Survey from 2003 to 2014 are included in this study. Dietary fiber intake was measured using 2-day, 24 h dietary recall. The main exposures in this study were the intake of dietary fiber at breakfast, lunch, and dinner via regression analysis of the residual method. The main outcomes were the all-cause, cancer, and CVD mortality rates. Cox proportional hazards regression models were used to evaluate the survival relationship between dietary fiber intake at different times and mortality rates. Among the 31,164 adults, 2915 deaths, including 631 deaths due to cancer and 836 deaths due to CVD, were documented. Firstly, after adjusting for potential confounders, compared to the participants in the lowest quintile of total dietary fiber intake, the participants in the highest quintile of fiber intake had lower all-cause (HR = 0.686, 95% CI: 0.589–0.799, p for trend <0.001) and cancer (HR = 0.606, 95% CI: 0.446–0.824, p for trend = 0.015) mortality risks. Secondly, compared to the participants in the lowest quintile of dietary fiber intake at dinner, the participants in the highest quintile of fiber intake had lower all-cause (HR = 0.796, 95% CI: 0.668–0.949, p for trend = 0.009) and cancer (HR = 0.564, 95% CI: 0.388–0.822, p for trend = 0.005) mortality risks. Furthermore, equivalently replacing each standard deviation of dietary fiber consumed at breakfast with that at dinner was associated with lower cancer mortality risks (HR = 0.846, 95% CI: 0.747–0.958). In conclusion, this study demonstrates that, in the NHANES (2003–2014) cohort, to reduce all-cause and cancer mortality risks, the optimal dietary fiber intake time is in the evening.

Intake and Sources of Dietary Fiber, Inflammation, and Cardiovascular Disease in Older US Adults

Higher intake of dietary fiber has been associated with lower inflammation, but whether there are differences in this association by source of dietary fiber (ie, cereal, vegetable, or fruit) has not been studied to date. To evaluate the associations of total fiber intake and source (ie, cereal, vegetable, and fruit fiber intake) with inflammation and to evaluate whether inflammation mediates the inverse association between dietary fiber intake and cardiovascular disease (CVD). At the baseline visit (1989-1990) of 4125 adults aged 65 years or older in an ongoing US cohort study, dietary intake was assessed by a food frequency questionnaire among study participants without prevalent CVD (stroke and myocardial infarction) at enrollment. Inflammation was assessed from blood samples collected at baseline with immunoassays for markers of inflammation. Multivariable linear regression models tested the association of dietary fiber intake with inflammation. Also assessed was whether each inflammatory marker and its composite derived from principal component analysis mediated the association of baseline cereal fiber intake with development of CVD (stroke, myocardial infarction, and atherosclerotic cardiovascular death) through June 2015. Data from June 1, 1989, through June 30, 2015, were analyzed. Total fiber intake and sources of fiber (cereal, vegetable, and fruit). Systemic markers of inflammation. Cardiovascular disease was the outcome in the mediation analysis. Of 4125 individuals, 0.1% (n = 3) were Asian or Pacific Islander, 4.4% (n = 183) were Black, 0.3% (n = 12) were Native American, 95.0% (n = 3918) were White, and 0.2% (n = 9) were classified as other. Among these 4125 individuals (2473 women [60%]; mean [SD] age, 72.6 [5.5] years; 183 Black individuals [4.4%]; and 3942 individuals of other races and ethnicitites [95.6%] [ie, race and ethnicity other than Black, self-classified by participant]), an increase in total fiber intake of 5 g/d was associated with significantly lower concentrations of C-reactive protein (adjusted mean difference, -0.05 SD; 95% CI, -0.08 to -0.01 SD; P = .007) and interleukin 1 receptor antagonist (adjusted mean difference, -0.04 SD; 95% CI, -0.07 to -0.01 SD; P < .02) but with higher concentrations of soluble CD163 (adjusted mean difference, 0.05 SD; 95% CI, 0.02-0.09 SD; P = .005). Among fiber sources, only cereal fiber was consistently associated with lower inflammation. Similarly, cereal fiber intake was associated with lower CVD incidence (adjusted hazard ratio, 0.90; 95% CI, 0.81-1.00; 1941 incident cases). The proportion of the observed association of cereal fiber with CVD mediated by inflammatory markers ranged from 1.5% for interleukin 18 to 14.2% for C-reactive protein, and 16.1% for their primary principal component. Results of this study suggest that cereal fiber intake was associated with lower levels of various inflammatory markers and lower risk of CVD and that inflammation mediated approximately one-sixth of the association between cereal fiber intake and CVD.

Association between Dietary Fiber Intake and Hyperuricemia among Chinese Adults: Analysis of the China Adult Chronic Disease and Nutrition Surveillance (2015).

This study aimed to assess the association of dietary fiber intake with serum uric acid (SUA) levels and risk of hyperuricemia (HUA) among Chinese adults using the latest nationally representative data. A total of 66,427 Chinese adults aged 18 years and over from the China Adult Chronic Disease and Nutrition Surveillance in 2015 were included in this study. Dietary intakes were measured with a 3-day 24 h dietary recall and the household condiment weighing method. Mixed-effect linear and logistic regression models were used to evaluate the associations of dietary fiber intake with SUA levels and risk of HUA, respectively. Compared to the lowest intake group, the coefficient and 95% confidence in the highest intake group of total fiber were −0.06 (−0.08, −0.04) (p-trend < 0.001), −0.18 (−0.2, −0.16) (p-trend < 0.001) for cereal fiber, 0.03 (0.01, 0.04) (p-trend = 0.051) for legume fiber, 0 (−0.01, 0.02) (p-trend = 0.869) for vegetable fiber and 0.01 (−0.001, 0.04) (p-trend = 0.296) for fruit fiber. The odds ratio (OR) and 95% confidence interval (CI) of HUA for the highest vs. lowest intake group of total fiber were 0.88 (0.84, 0.91) (p-trend = 0.001), 0.67 (0.63, 0.71) (p-trend < 0.001) for cereal fiber, 1.05 (1, 1.09) (p-trend = 0.248) for legume fiber, 1.01 (0.97, 1.05) (p-trend = 0.982) for vegetable fiber and 1.06 (1, 1.12) (p-trend = 0.264) for fruit fiber. Our findings suggest that consumption of total fiber and cereal fiber were significantly inversely associated with SUA levels and HUA risk among the Chinese adult population. Developing and implementing effective public education programs are urgently needed to increase the intake of dietary fiber, especially cereal fiber among Chinese adults.

The association between dietary fiber intake and the concentrations of aldehydes in serum.

Aldehydes have been shown to be potentially carcinogenic, mutagenic, and cardiotoxic to humans. Dietary fiber reduces exposure to certain environmental pollutants and has been widely used to improve various metabolic disorders. However, the effects of dietary fiber on serum concentrations of aldehydes remain unexplored. Data was collected from the National Health and Nutrition Examination Survey (NHANES) 2013-2014. Generalized linear regression and restricted cubic spline models were performed to elucidate the association of dietary fiber intake with the serum concentration of aldehydes. After fully adjusting for age, sex, education level, race, smoking status, alcohol use, diabetes, hypertension, body mass index, energy intake, poverty-income ratio, and physical activity, dietary fiber intake had a strong negative association with serum levels of isopentanaldehyde and propanaldehyde and a positive association with serum levels of benzaldehyde. The estimated increases in the mean log2-unit (ng/mL) of aldehydes for each fold increase in dietary fiber were -0.140 (95% confidence interval [CI]: -0.195 to -0.085) for isopentanaldehyde, -0.060 (95% CI: -0.099 to -0.015) for propanaldehyde, and 0.084 (95% CI: 0.017 to 0.150) for benzaldehyde, respectively. No significant association was observed between dietary fiber intake and the concentration of any other aldehydes. These results demonstrate that dietary fiber reduces the concentration of certain aldehydes in serum.