Dietary Isoflavone Intake Research Articles

A Systematic Review and Meta-Analysis of the Effects of Dietary Isoflavones on Female Hormone-Dependent Cancers for Benefit-Risk Evaluation.

Female hormone-dependent cancers depend on estrogen for their growth. Numerous studies have explored the antitumor effect of dietary isoflavones on female hormone-dependent cancers. Still, few clinical evidence supports the use of isoflavones in female hormone-dependent cancer patients. This study was performed to examine the impact of dietary isoflavones on tumor growth of female hormone-dependent cancers and accelerate the transformation of research from bench to bedside. We searched PubMed Medline, Web of Science, and Google Scholar for relevant articles related to the effect of dietary isoflavone on tumor growth of experimental animal models of female hormone-dependent cancers from 1998 to 2024. The effects of dietary isoflavones on tumor growth were analyzed between the control and treatment groups using comprehensive meta-analysis software (CMA). We included 30 studies describing tumor growth focused on female hormone-dependent cancer types, including breast, ovarian, and uterine cancers. Overall, a pooled analysis revealed that dietary isoflavones reduced tumor volume (Hedge's g = -1.151, 95% CI = -1.717 to -0.585, p = 0.000) and tumor weight (Hedge's g = -2.584, 95% CI = -3.618 to -1.549, p = 0.000). On the other hand, dietary isoflavones increased tumor area (Hedge's g = 1.136, 95% CI = 0.752 to 1.520, p = 0.000). Dietary isoflavones have potential benefits and risks in female hormone-dependent cancers. Therefore, caution should be exercised when considering the intake of dietary isoflavones in female hormone-dependent cancer patients, particularly in the form of supplements.

Dietary Isoflavones Intake and Gastric Cancer.

Dietary isoflavones have been associated with a lower risk of gastric cancer (GC), but the evidence for this association is still limited. We investigated the association between isoflavone intake and GC risk using data from a case-control study including 230 incident, histologically confirmed GC cases and 547 controls with acute, non-neoplastic conditions. Dietary information was collected through a validated food frequency questionnaire (FFQ) and isoflavone intake was estimated using ad hoc databases. We estimated the odds ratios (OR) and the corresponding 95% confidence intervals (CI) of GC using logistic regression models, including terms for total energy intake and other major confounders. The OR for the highest versus the lowest tertile of intake was 0.65 (95%CI = 0.44-0.97, p for trend = 0.04) for daidzein, 0.75 (95%CI = 0.54-1.11, p for trend = 0.15) for genistein, and 0.66 (95%CI = 0.45-0.99, p for trend = 0.05) for total isoflavones. Stratified analyses by sex, age, education, and smoking showed no heterogeneity. These findings indicate a favorable effect of dietary isoflavones on GC.

Urinary Equol and Equol-Predicting Microbial Genera Are Favorably Associated with Body Fat Measures among Chinese Adults

BackgroundMany studies have investigated the intake of dietary isoflavones in relation to obesity risk, whereas the association using objective biomarkers of isoflavones, particularly equol (a gut-derived metabolite of daidzein with greater bioavailability than other isoflavones) has been less studied. In addition, the associations between equol and gut microbiota profile at the population level remain to be fully characterized. ObjectivesWe aimed to identify equol-predicting microbial species and to investigate the associations of equol-predicting microbial species and urinary excretion of isoflavones including glycitein, genistein, daidzein, and equol with diverse obesity markers in free living-individuals. MethodsIn this 1-y longitudinal study of 754 community-dwelling adults, urinary isoflavones, fecal microbiota, height, weight, and circumferences of waist and hip were measured at baseline and again after 1 y. Liver fat [indicated by the controlled attenuation parameter (CAP)] and other body composition were also measured after 1 y. Linear models and linear mixed-effects models were used to analyze the associations for single measure and repeated measures, respectively. ResultsAmong 305 participants (median age: 50 y, IQR, 37–59 y) including 138 males and 167 females, higher urinary excretion of equol was associated with lower CAP (β = −0.013, P < 0.001) and body fat mass (β= −0.014, P = 0.046). No association was found between any other urinary isoflavones and obesity markers (all P > 0.05). We identified 21 bacterial genera whose relative abundance were positively associated with urinary equol concentrations (all Pfalsediscovery rate < 0.05), and constructed an equol-predicting microbial score to reflect the overall equol-producing potential of host gut microbiota. This score was inversely associated with CAP (β = −0.040, P = 0.011). ConclusionsHigh urinary equol concentrations and equol-predicting microbial species could be favorably associated with liver fat and other obesity markers.

Dietary isoflavone intake is inversely associated with remnant cholesterol in US adults: A cross-sectional study

BackgroundSeveral studies have shown that dietary isoflavones are negatively correlated with total cholesterol and low-density lipoprotein cholesterol. However, few studies have investigated the link between dietary isoflavones and remnant cholesterol (RC). ObjectivesWe used the National Health and Nutrition Examination Survey (NHANES) database to explore the association between dietary isoflavone intake and RC. MethodsA cross-sectional study was conducted with 4731 participants aged ≥ 20 years from the 2007–2008, 2009–2010, and 2017–2018 NHANES databases. We adopted univariate and multiple linear regression analysis and restricted cubic spline (RCS) to assess the relationship between dietary isoflavone intake and RC. Moreover, we conducted stratified and interaction analyses to ensure the stability of the results and identify specific populations. ResultsThe weighted multifactor linear regression model showed a negative correlation between dietary isoflavone intake and remnant cholesterol (Model 2, β = -0.049, 95% CI: (-0.096, -0.002), P = 0.040). The RCS analysis indicated that there was an L-shaped negative correlation between dietary isoflavone intake and RC (P-value for non-linearity was 0.0464). Stratified analyses showed the inverse relationship between dietary isoflavone intake and RC persisted in most subgroups and there was no interaction except for the recreational activity group. ConclusionsOur study found a non-linear and negative association between dietary isoflavone intake and RC in US adults, so we hypothesized that consuming an isoflavone-rich diet may help reduce blood RC and further reduce the risk of cardiovascular disease.

Changes in the consumption of isoflavones, omega-6, and omega-3 fatty acids in women with metastatic breast cancer adopting a whole-food, plant-based diet: post-hoc analysis of nutrient intake data from an 8-week randomized controlled trial.

Diets rich in minimally processed plant-based foods are recommended to breast cancer patients, and some may have an interest in whole-food, plant-based (WFPB) diets that avoid animal-based foods, added fats, and refined sugars. Within WFPB diets, the intakes of isoflavones, omega-6 polyunsaturated fatty acids (n-6 PUFAs), and omega-3 polyunsaturated FAs (n-3 PUFAs), which have been discussed in reference to breast cancer outcomes, have not been well characterized. Women with stage IV breast cancer on stable therapy were randomized 2:1 into (1) a WFPB intervention (N = 21) or (2) usual care (N = 11) for 8 weeks. Three meals per day were provided. Outcomes presented here include dietary intake of isoflavones, n-3 and n-6- PUFAs, which were assessed using three-day food records at baseline and 8 weeks. Baseline and 8-week mean intake within groups were compared using the Wilcoxon signed-rank test and between control and intervention groups by a two-sample t-test. The WFPB intervention participants increased their daily consumption of total isoflavones from a mean of 0.8 mg/day to 14.5 mg/day (p < 0.0001) and decreased the n-6:n-3 ratio of their diet from a mean of 9.3 to 3.7 (p < 0.0001). Within the WFPB group, linoleic acid (n-6 PUFA) consumption decreased by a mean of 3.8 g (p = 0.0095), from 12.8 g/day to 9.0 g/day; total n-3 PUFA consumption increased by a mean of 1.1 g (p = 0.0005), from 1.6 g/day to 2.7 g/day. Transitioning to a WFPB diet resulted in significantly increased isoflavone intake and decreased n-6:n-3 ratio in women with breast cancer.

Dietary Flavonoid Intake and Risk of Mild Cognitive Impairment in the Elderly: A Case-Control Study

Background: This study investigates the association between dietary flavonoid intake and the incidence of mild cognitive impairment (MCI) through a matched case-control design. Methods: Dietary intake was assessed using a food frequency questionnaire, comparing the intake of flavonoids between individuals with MCI and those with normal cognitive function. Logistic regression analysis was employed to evaluate the correlation between dietary flavonoid intake and the risk of MCI. Additionally, blood concentrations of S100β, a marker of the blood-brain barrier (BBB) integrity, were measured using electrochemiluminescence immunoassay, and Pearson correlation analysis was conducted to explore the relationship between dietary flavonoid intake and blood S100β levels. Results: Compared to participants with normal cognition, those with MCI had significantly lower dietary intakes of total flavonoids, isoflavones, daidzein, glycitein, genistein, kaempferol, myricetin, flavonols, and anthocyanidins, while the intake of peonidin was significantly higher. Univariate logistic regression analysis indicated that high dietary intake of total flavonoids, isoflavones, daidzein, glycitein, genistein, kaempferol, myricetin, and flavonols was negatively correlated with MCI, whereas peonidin intake was positively correlated with MCI. Multivariate logistic regression analysis confirmed these findings. Pearson correlation analysis revealed a significant negative correlation between dietary intake of kaempferol and myricetin and blood S100β levels. Conclusion: Increasing the dietary intake of total flavonoids, isoflavones, daidzein, glycitein, genistein, and flavonols appears to be a protective factor against MCI, while higher intake of peonidin is associated with an increased risk of MCI. The protective or adverse effects of these flavonoids may not be related to the permeability of the BBB. Myricetin and kaempferol intake may protect cognitive function by maintaining BBB integrity.

Dietary Isoflavone Intake and Breast Cancer Prognosis: A Prospective Analysis and Meta-Analysis

We aimed to examine the association between dietary isoflavone intake and the risk of breast cancer recurrence and summarize evidence on the role of dietary isoflavone intake in breast cancer prognosis. This prospective study included 592 breast cancer survivors who completed a dietary assessment. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using Cox proportional hazards models. Of the studies published until May 31, 2023, that were searched in PUBMED and EMBASE databases, 14 studies were selected. Adjusted HRs were combined using fixed- or random-effects models. During the median follow-up of 4.3 years, 47 recurrences were identified. The HR (95% CI) for recurrence comparing the highest versus the lowest tertile of isoflavones intake was 1.29 (0.60–2.78). In a meta-analysis of previously published data and ours, dietary isoflavone intake was associated with a better breast cancer prognosis. The combined HRs (95% CIs) comparing the extreme categories were 0.81 (0.67–0.98) for recurrence and 0.85 (0.76–0.96) for all-cause mortality. A nonlinear inverse association was observed between isoflavone intake and the risk of recurrence and all-cause mortality. Our study suggests that dietary isoflavone intake is associated with a favorable prognosis in breast cancer survivors and warrants further investigation.

Isoflavone Consumption and Risk of Breast Cancer: An Updated Systematic Review with Meta-Analysis of Observational Studies.

Epidemiological studies that focus on the relationship between dietary isoflavone intake and the risk of breast cancer still lead to inconsistent conclusions. Herein, we conducted a meta-analysis of the latest studies to explore this issue. We performed a systematic search using Web of Science, PubMed, and Embase from inception to August 2021. The robust error meta-regression (REMR) model and generalized least squares trend (GLST) model were used to establish dose-response relationships between isoflavones and breast cancer risk. Seven cohort studies and 17 case-control studies were included in the meta-analysis, and the summary OR for breast cancer was 0.71 (95% CI 0.72-0.81) when comparing the highest to the lowest isoflavone intake. A subgroup analysis further showed that neither menopausal status nor ER status has a significant influence on the association between isoflavone intake and breast cancer risk, while the isoflavone intake doses and study design does. When the isoflavones exposure was less than 10 mg/day, no effects on breast cancer risk were detected. The inverse association was significant in the case-control studies but not in the cohort studies. In the dose-response meta-analysis of the cohort studies, we observed an inverse association between isoflavone intake and breast cancer: a 10 mg/day increase in isoflavone intake was related to reductions of 6.8% (OR = 0.932, 95% CI 0.90-0.96) and 3.2% (OR = 0.968, 95% CI 0.94-0.99) in breast cancer risk when using REMR and GLST, respectively. In the dose-response meta-analysis of the case-control studies, the inverse association for every 10 mg/day isoflavone intake was associated with breast cancer risk reductions by 11.7%. present evidence demonstrated that taking in dietary isoflavone is helpful in reducing the breast cancer risk.

Potential Protective Mechanisms of S-equol, a Metabolite of Soy Isoflavone by the Gut Microbiome, on Cognitive Decline and Dementia.

S-equol, a metabolite of soy isoflavone daidzein transformed by the gut microbiome, is the most biologically potent among all soy isoflavones and their metabolites. Soy isoflavones are phytoestrogens and exert their actions through estrogen receptor-β. Epidemiological studies in East Asia, where soy isoflavones are regularly consumed, show that dietary isoflavone intake is inversely associated with cognitive decline and dementia; however, randomized controlled trials of soy isoflavones in Western countries did not generally show their cognitive benefit. The discrepant results may be attributed to S-equol production capability; after consuming soy isoflavones, 40–70% of East Asians produce S-equol, whereas 20–30% of Westerners do. Recent observational and clinical studies in Japan show that S-equol but not soy isoflavones is inversely associated with multiple vascular pathologies, contributing to cognitive impairment and dementia, including arterial stiffness and white matter lesion volume. S-equol has better permeability to the blood–brain barrier than soy isoflavones, although their affinity to estrogen receptor-β is similar. S-equol is also the most potent antioxidant among all known soy isoflavones. Although S-equol is available as a dietary supplement, no long-term trials in humans have examined the effect of S-equol supplementation on arterial stiffness, cerebrovascular disease, cognitive decline, or dementia.

Beneficial Effects of Soy Isoflavones on Blood Pressure and Lipid Profile in Indian Postmenopausal Women

Background: The studies have suggested that dietary isoflavones intake in postmenopausal women had protective role against cardiovascular disease (CVD). Objectives: This study ascertained the effect of isoflavone in the form of soyflour on lipid profiles and blood pressure (BP) in postmenopausal women diagnosed with medium risk of CVD. Materials and Methods: It was a 16-week placebo controlled trial that was conducted on 60 postmenopausal women aged 45–55 years. Participants in the treatment group were provided with 40 g soyflour/day for 16 weeks. The participants in the control group were asked not to change their usual dietary habits and lifestyles and were instructed to avoid taking soybean and soybean products. The changes in BP and blood lipid profile were measured at baseline and at the end of the study. Results: There were non-significant differences in any of the variables between two groups at baseline. Biochemical results indicated the beneficial effect of intervention in significantly reducing systolic (6.28%) and diastolic (4.73%) BP of the treatment group. It also exhibited an effective role in significantly (P &lt; 0.05) reducing the serum cholesterol (17.29%), triglyceride (22.22%), low density lipoprotein (24.53%), very low density lipoprotein (22.21%), and significantly increasing the high density lipoprotein (13.55%) in the treatment group. Conclusion: The study indicates that daily administration of 40g soyflour for 16 weeks improved the BP and lipid profile of postmenopausal subjects.

The Inverse Correlation of Isoflavone Dietary Intake and Headache in Peri- and Post-Menopausal Women.

This study investigated the relationship between headache and dietary consumption of a variety of nutrients in middle-aged women. This cross-sectional analysis used first-visit records of 405 women aged 40–59 years. The frequency of headaches was assessed using the Menopausal Health-Related Quality of Life Questionnaire. Of the 43 major nutrient intakes surveyed using the brief-type self-administered diet history questionnaire, those that were not shared between women with and without frequent headaches were selected. Multiple logistic regression analysis was used to identify nutrients independently associated with frequent headaches. After adjusting for background factors related to frequent headache (vasomotor, insomnia, anxiety, and depression symptoms), the estimated dietary intake of isoflavones (daidzein + genistein) (mg/1000 kcal/day) was negatively associated with frequent headaches (adjusted odds, 0.974; 95% confidence interval, 0.950–0.999). Moreover, the estimated isoflavone intake was not significantly associated with headache frequency in the premenopausal group, whereas it significantly correlated with that in the peri- and post-menopausal groups. Headache in peri- and post-menopausal women was inversely correlated with the dietary intake of isoflavones. Diets rich in isoflavones may improve headaches in middle-aged women.

Phytoestrogens and lung cancer risk: a nested case-control study in never-smoking Chinese women

Since several lines of evidence suggest that estrogens may be involved in lung carcinogenesis, it has been hypothesized that intake of phytoestrogens, similar in molecular structure to mammalian estrogens, may be associated with lung cancer development. The aim was to prospectively evaluate the association between phytoestrogen exposure and lung cancer risk in never-smoking women. We conducted a nested case-control study within a population-based prospective cohort study of women. A total of 478 incident lung cancer cases and their individually matched controls were identified among never-smoking women after a mean follow-up of 15.6 years. Habitual intake of and internal exposure to phytoestrogens were assessed by repeated dietary surveys and urinary biomarkers, respectively. ORs and 95% CIs for lung cancer were estimated in conditional logistic regression models. After adjustment for potential confounders, a moderate intake of dietary isoflavones was inversely associated with lung cancer risk in never-smoking women, with the OR for the second quartile vs. the lowest quartile of intake being 0.52 (95% CI: 0.35, 0.76). Further increasing intake did not convey additional benefits, with ORs (95% CI) for the third and fourth quartiles of 0.53 (0.36, 0.78) and 0.47 (0.31, 0.72), respectively (P-overall<0.001 and P-nonlinearity=0.006). A similar association was seen when exposure to isoflavones was assessed by urinary biomarkers. ORs (95% CI) for the second, third, and fourth quartiles compared with the lowest quartile of urinary isoflavone excretion were 0.57 (0.39, 0.83), 0.64 (0.44, 0.92), and 0.60 (0.41, 0.86), respectively. The inverse association reached a plateau beyond the second quartile, with P-overall=0.04 and P-nonlinearity=0.15. Urinary excretion of gut-microbiota-derived metabolites of lignans was not related to lung cancer risk. This study suggests that moderately increasing intake of isoflavone-rich foods is associated with lower risk of lung cancer in never-smoking women.

Associations of dietary intakes of calcium, magnesium and soy isoflavones with osteoporotic fracture risk in postmenopausal women: a prospective study.

The role of dietary factors in osteoporotic fractures (OFs) in women is not fully elucidated. We investigated the associations between incidence of OF and dietary calcium, magnesium and soy isoflavone intake in a longitudinal study of 48 584 postmenopausal women. Multivariable Cox regression was applied to derive hazard ratios (HRs) and 95 % confidence intervals (CIs) to evaluate associations between dietary intake, based on the averages of two assessments that took place with a median interval of 2⋅4 years, and fracture risk. The average age of study participants is 61⋅4 years (range 43⋅3-76⋅7 years) at study entry. During a median follow-up of 10⋅1 years, 4⋅3 % participants experienced OF. Compared with daily calcium intake ≤400 mg/d, higher calcium intake (>400 mg/d) was significantly associated with about a 40-50 % reduction of OF risk among women with a calcium/magnesium (Ca/Mg) intake ratio ≥1⋅7. Among women with prior fracture history, high soy isoflavone intake was associated with reduced OF risk; the HR was 0⋅72 (95 % CI 0⋅55, 0⋅93) for the highest (>42⋅0 mg/d) v. lowest (<18⋅7 mg/d) quartile intake. This inverse association was more evident among recently menopausal women (<10 years). No significant association between magnesium intake and OF risk was observed. Our findings provide novel information suggesting that the association of OF risk with dietary calcium intake was modified by Ca/Mg ratio, and soy isoflavone intake was modified by history of fractures and time since menopause. Our findings, if confirmed, can help to guide further dietary intervention strategies for OF prevention.

Usual intake of dietary isoflavone and its major food sources in Koreans: Korea National Health and Nutrition Examination Survey 2016-2018 data.

BACKGROUND/OBJECTIVESAccumulating evidence has shown the beneficial effects of isoflavone on health. There is limited information on the usual isoflavone intake for Koreans. This study examined the usual intake of total isoflavone and its major food sources in Koreans according to age and gender.SUBJECTS/METHODSThe dietary intake data of 21,271 participants aged 1 yrs and older from the Korea National Health and Nutrition Examination Survey (KNHANES) VII 2016–2018 were analyzed. The average isoflavone intake was estimated based on the 24-h dietary recall data in KNHANES and the isoflavone database from the Korea Rural Development Administration (RDA) and literatures. The usual isoflavone intake was estimated by applying the ratio of within- and between-participant variance estimated from the 2009 KNHANES data to the 7th KNHANES (2016–2018) data. The variance of the isoflavone intake was calculated using MIXTRAN macro with intake data for two days in the 2009 KNHANES. Complex sample analysis with stratified variables and integrated weights was conducted.RESULTSThe mean total isoflavone intake in the Korean population aged 1 yrs and older (n = 21,271) was 139.27 mg/d, which was higher than the usual intake of 47.44mg/d. Legumes were a major contributing food group (91%), with arrowroot being a major individual contributor to the isoflavone intake (67.2%), followed by 21.3% of soybean, 5.4% of bean sprouts, and 2.1% of tofu. The usual isoflavone intake was highest in the participants aged 50 to 64 yrs old and increased with age until 50 to 64 yrs and then decreased with further increases in age. The usual isoflavone intake of participants aged 65 yrs and older was higher for men than for women, showing gender differences.CONCLUSIONSThe usual dietary intake of isoflavone varied according to age and gender in the Korean population. This study showed that the usual isoflavone intake was lower than the average isoflavone intake. The difference between percentiles of the usual isoflavone intake was similarly smaller than the average intake. An estimation of average intake can be hindered by the occasional consumption of foods high in isoflavones, suggesting that the usual intake estimation method can be more appropriate. Further research will be needed to establish isoflavone dietary guidelines regarding the effects of isoflavone intake on health outcomes.

Associations of Dietary Intakes of Calcium, Magnesium, and Soy Isoflavones With Bone Fracture Risk in Men: A Prospective Study.

ABSTRACTThe role of dietary factors in osteoporotic fractures in men is underinvestigated. We examined the associations of dietary intakes of calcium, magnesium, and soy isoflavones with risk of osteoporotic fractures in the Shanghai Men's Health Study. Included in this prospective study were 61,025 men aged 40 to 74 years at study enrollment (2002–2006). The cohort was followed up via in‐person surveys for occurrence of bone fractures, major diseases, and survival status. Multivariable Cox regression was applied to evaluate the associations of variables under study (ie, dietary intakes of calcium, magnesium, and soy isoflavones) with incidence of osteoporotic and non‐osteoporotic fractures, measured by hazard ratio (HR) and 95% confidence interval (CI). During a median follow‐up of 9.5 years, 1.2% and 3.4% of participants experienced osteoporotic or non‐osteoporotic fractures, respectively. Dietary calcium intake was inversely associated with risk of osteoporotic fractures with adjusted HRs of 0.78 (95% CI 0.60–1.02) and 0.27 (95% CI 0.13–0.56), respectively, for intake levels of 401 mg/d and >1000 mg/d versus ≤400 mg/d. Higher magnesium intake was associated with increased risk of osteoporotic fractures after adjusting for dietary calcium intake, with HRs of 1.27 (95% CI 0.97–1.66) and 2.21 (95% CI 1.08–4.50), respectively, for intakes of 251 mg/d and >450 mg/d versus intake ≤250 mg/d. High soy isoflavone intake was associated with a 25% reduction of osteoporotic fracture risk (HR = 0.73, 95% CI 0.56–0.97 for soy isoflavone intake >45.2 mg/d versus <21.7 mg/d). Dietary intakes of calcium, magnesium, or soy isoflavones were unrelated to the risk of non‐osteoporotic fractures. Our study added to the evidence that dietary calcium intake was inversely associated with a reduced risk of osteoporotic fractures in a dose–response fashion, while high magnesium intake was associated with an increased risk. Our study also revealed a novel association between higher soy isoflavone consumption and osteoporotic fractures in men. © 2021 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Flavonoid subclasses and CHD risk: a meta-analysis of prospective cohort studies.

Epidemiological studies have shown that higher intake of flavonoid is inversely associated with CHD risk. However, which flavonoid subclass could reduce CHD risk has remained controversial. The present meta-analysis of prospective cohort studies aimed to quantitatively assess the associations between flavonoid subclasses and CHD risk. A systematic literature search was implemented from PubMed and Web of Science databases up to March 2021, and eligible studies were identified. Multivariate-adjust relative risks (RR) with corresponding 95 % CI were pooled by using a random-effects model. A restricted cubic spline regression model was performed for non-linear dose-response analysis. A total of 19 independent prospective cohort studies with 894471 participants and 34707 events were included. The results showed that dietary intakes of anthocyanins (RR = 0·90; 95 % CI: 0·83, 0·98), proanthocyanidins (RR = 0·78; 95 % CI: 0·65, 0·94), flavonols (RR = 0·88; 95 % CI: 0·79, 0·98), flavones (RR = 0·94; 95 % CI: 0·89, 0·99) and isoflavones (RR = 0·90; 95 % CI: 0·83, 0·98) were negatively associated with CHD risk. Dose-response analysis showed that increment of 50 mg/d anthocyanins, 100 mg/d proanthocyanidins, 25 mg/d flavonols, 5 mg/d flavones and 0·5 mg/d isoflavones were associated with 5 % reduction in CHD risk, respectively. Sensitivity and subgroup analyses were used to further support these associations. The present results indicate that dietary intakes of fruits and vegetables abundant five flavonoid subclasses, namely anthocyanins, proanthocyanidins, flavonols, flavones and isoflavones, are associated with a lower risk of CHD.

Abstract 2585: Dietary isoflavone intake and lung cancer risk: an analysis using data from the prostate, lung, colorectal, and ovary (PLCO) trial

Abstract Introduction: Dietary isoflavones are mainly from soy-based foods and are widely consumed in Asian countries. Isoflavone has a similar chemical structure to estrogen and has been suggested to decrease the risk of breast cancer by acting as an estrogen antagonist. Lung cancer development was also suggested to be affected by estrogen signaling. We aim to explore isoflavone intake and lung cancer risk using the prospective PLCO trial. Methods: Data regarding dietary intake using the food frequency questionnaire, demographic and reproductive information and lung cancer diagnosis were extracted. The associations between lung cancer risk and isoflavone intake (in quartiles) overall and stratified by gender and smoking status were calculated using the Cox proportional hazard models adjusting for potential confounders. SAS 9.4 were used to perform all statistical analyses. Results: During the 1,215,948 person-year follow-up, a total of 1,706 lung cancer cases were diagnosed. Overall (Table), the highest quartile of isoflavone intake was associated with 26% reduced risk of lung cancer compared to the lowest quartile. When the analysis was stratified by gender and further by smoking status (never vs ever), the decreased risk was only observed among male ever smokers (Q4 vs Q1: HR=0.78, 95%CI: 0.64-0.96) but not their female counterparts (Q4 vs Q1: HR=0.85, 95%CI: 0.68-1.08). Discussion: This is the first prospective cohort study investigating isoflavone intake and lung cancer risk and we found a protective effect of isoflavone intake against lung cancer risk particularly among male ever smokers, despite an overall lower isoflavone intake among the US populations compared to the Asian populations. Future studies are needed to replicate these results in independent cohorts and shed a light on the potential mechanism of the protective effect of isoflavones on lung carcinogenesis and the interactions between isoflavones, smoking and endogenous estrogens. Table. Multivariate-adjusted hazard ratios (HRs) for lung cancer risk according to intake of isoflavones stratified by gender and smoking statusQuartiles of isoflavone intakeP for trendQ1Q2Q3Q4Overall No. of cases574413382337 Person-years322,453290,995302,050300,449 HR 95%CIaReference0.91 (0.80-1.03)0.88 (0.77-1.01)0.84 (0.73-0.98)0.56Men Overall No. of cases344251223194 Person-years168,817142,536138,872145,416 HR 95%CIbReference0.95 (0.81-1.13)0.94 (0.78-1.12)0.83 (0.68-1.02)0.36Never smokers No. of cases10161413 Person-years58,70954,63355,67259,906 HR 95%CIcReference1.92 (0.86-4.27)1.77 (0.76-4.09)1.69 (0.68-4.21)0.86Ever smokers No. of cases334235209181 Person-years110,10887,90383,20085,510 HR 95%CIdReference0.96 (0.81-1.14)0.96 (0.80-1.15)0.78 (0.64-0.96)0.08Womene Overall No. of cases230162159143 Person-years153,637148,459163,178155,033 HR 95%CIReference0.85 (0.69-1.04)0.82 (0.66-1.01)0.85 (0.68-1.08)0.92 Never smokers No. of cases23201728 Person-years84,77085,85896,08491,777 HR 95%CIReference0.89 (0.48-1.66)0.74 (0.38-1.42)1.37 (0.73-2.56)0.65 Ever smokers No. of cases207142142115 Person-years68,86662,60167,09563,257 HR 95%CIReference0.88 (0.71-1.10)0.83 (0.66-1.05)0.80 (0.66-1.03)0.87Abbreviations: Q1: (first) lowest quartile; Q2: second quartile; Q3: third quartile Q4: (fourth) highest quartile; HR: hazard ratioaModel = Model c + smoking status + genderbModel = Model c +smoking statuscModel adjusted for age, race, BMI, marital status, education level, alcohol use, family history of any cancer, daily energy intake, vitamin C intake, vitamin E intake and beta-carotene intake.dModel = Model c +pack-year of smokingeAll models among women additionally adjusted for age at menarche, age at menopause and use of hormonal replacement therapy (yes/no). Citation Format: Qian Wang, Meng Ru, Paolo Boffetta. Dietary isoflavone intake and lung cancer risk: an analysis using data from the prostate, lung, colorectal, and ovary (PLCO) trial [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2585.

Dietary isoflavones intake is inversely associated with non-alcoholic fatty liver disease, hyperlipidaemia and hypertension

This study investigated associations between total isoflavones and their categories (daidzein, genistein, glycitein) intake and the risks for metabolic disorders. We used the data of 6786 Chinese adults from the Nutrition Health Atlas Project. We performed multiple logistic regression and restricted cubic spline models assessing the risks for metabolic disorders (non-alcoholic fatty liver disease (NAFLD), hyperlipidaemia, hypertension, diabetes and overweight/obesity) in each category of isoflavones. Higher total isoflavones, daidzein and genistein intake were inversely associated with NAFLD (p < .05). Higher total isoflavones, daidzein, genistein and glycitein intake were also inversely associated with hyperlipidaemia (p < .01) and hypertension (p < .01). Dose-response analyses revealed that total isoflavones, daidzein, genistein and glycitein intakes were associated with the risks of metabolic disorders in a nonlinear trend. In conclusion, total isoflavones, daidzein and genistein intake were inversely associated with NAFLD, hyperlipidaemia and hypertension. Glycitein was inversely associated with hyperlipidaemia and hypertension.

Association between Soy Food and Dietary Soy Isoflavone Intake and the Risk of Cardiovascular Disease in Women: A Prospective Cohort Study in Korea.

The association between soy food and soy isoflavone intake and cardiovascular disease (CVD) risk is uncertain, especially in women. We aimed to investigate this association in Korean women. We analyzed data from the Korean Genome and Epidemiology Study, including 4713 Korean women aged 40–69 years with no CVD or cancer at baseline. Dietary information was obtained using a validated semi-quantitative food frequency questionnaire, and the incidence of CVD was assessed using biennial self-reported questionnaires on medical history. The mean follow-up time was 7.4 years, during which 82 premenopausal and 200 postmenopausal women reported CVD incidence. The highest tofu, total soy foods, and dietary soy isoflavone intake groups were significantly associated with a decreased CVD risk in premenopausal women (tofu: hazard ratio (HR) 0.39; 95% confidence interval (CI), 0.19–0.80; total soy food: HR 0.36; 95% CI, 0.18–0.70; dietary soy isoflavones: HR 0.44; 95% CI, 0.22–0.89), whereas no association was observed in postmenopausal women. Other soy foods showed no association with CVD incidence. Dietary soy isoflavones and total soy foods are associated with a decreased CVD risk in premenopausal women. Among soy foods, only tofu showed significant health benefits.

Association of dietary isoflavone consumption with subclinical cardiovascular disease in middle-aged and elderly Chinese people

Background and aimsThe association between isoflavone (ISF) consumption and cardiovascular disease (CVD) remains controversial because of limited evidence. Carotid atherosclerosis is an established indicator of subclinical CVD. The study aimed to investigate the relationship between dietary ISF intake and subclinical CVD in middle-aged and elderly adults. Methods and resultsA total of 873 subjects aged 40–70 years without CVD were enrolled in this cross-sectional study. A restricted cubic spline was used to investigate the association between ISF intake and subclinical CVD risk. The odds ratio (OR) and 95% confidence interval of the risk of subclinical CVD for ISF were estimated by two-segmented logistic regression analysis. In Model 2, there was a non-linear association between ISF intake and the risk of subclinical CVD among women (Pnon-linear = 0.002), with an inverse association below the change point. The nadir for the risk of subclinical CVD among women was 7.26 mg/day (energy-adjusted). Below the change point, an increase of 1 mg ISF/day reduced the risk of subclinical CVD by 15%. There was no significant association between ISF intake and subclinical CVD risk above the change point (OR = 1.01 [0.99, 1.04]). ISF intake was not associated with subclinical CVD risk in men (Model 2: Pnon-linear = 0.224). ConclusionsBelow the change point (7.26 mg/day), women with a higher intake of ISF had a significantly lower risk of subclinical CVD. Encouraging the consumption of ISF-rich foods may help to lower CVD risk in middle-aged and elderly women. Trial registrationThis study is registered at http://www.chictr.org.cn (ChiCTR 1900022445).