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

Validation of a food frequency questionnaire for measuring dietary intake of isoflavones and lignans using the method of triads

BACKGROUND

Emerging epidemiologic evidence suggested a protective association between dietary phytoestrogens and multiple chronic diseases, although validation studies on the 2 phytoestrogen subclasses, isoflavones and lignans, estimated from food frequency questionnaires (FFQs) are lacking.

OBJECTIVES

We evaluated the performance of the FFQ for measuring isoflavone and lignan intake among 892 free-living adults in the Anhui Lifestyle Validation Study (ALVS).

METHODS

From July 2021 to July 2022, participants from the ALVS completed a 141-item FFQ and donated fasting morning urine specimens twice, 1-year apart, and completed twelve 24-h dietary recalls (24HDRs) that consisted of 4 quarterly 3 consecutive 24-h dietary recalls (i.e. 2 weekdays and 1 weekend day in each season) between the 2 FFQ assessments. The reproducibility coefficients were assessed by the intraclass correlation coefficient between estimates from the 2 FFQs. The validity coefficients (VCs) were evaluated by the method of triads to calculate correlations between estimates from dietary assessment tools and true dietary intake using biomarkers (the mean of 2 measurements of urinary concentrations of 4 isoflavone metabolites and 4 lignan metabolites), 24HDRs, and FFQs.

RESULTS

The FFQ-derived isoflavones (median: 23.6 mg/d; IQR: 12.1-41.5 mg/d) and lignans (median: 19.7 mg/d; IQR: 11.9-30.7 mg/d) showed good reproducibility with the same intraclass correlation coefficient of 0.55 (95% confidence interval [CI]: 0.46, 0.62). Estimated VCs between the FFQs and theoretical true intake were 0.65 (95% CI: 0.31, 1.00) for isoflavones and 0.48 (95% CI: 0.24, 0.86) for lignans. Compared with FFQ-based assessments, urinary biomarkers showed the same validity in assessing dietary lignans (VC: 0.48; 95% CI: 0.21, 0.88), but dietary isoflavones showed a lower VC of 0.22 (95% CI: 0.03, 0.47).

CONCLUSIONS

FFQ shows reasonable performance in measuring habitual intake of isoflavones and lignans, although urinary isoflavones are unlikely to perform as well as FFQ-based assessment of dietary isoflavones.

Soy-derived isoflavones as chemo-preventive agents targeting multiple signalling pathways for cancer prevention and therapy

The chemopreventive and chemotherapeutic properties of soy and soy-derived compounds, especially isoflavones, have been extensively studied in recent years. However, in contrast to their anticancer effects, such as cell growth inhibition, cell cycle arrest and apoptosis induction, isoflavones have also been found to promote the growth of cancer cells. Therefore, the aim of this comprehensive review article is to present the current state of knowledge regarding the molecular mechanisms by which soy-derived isoflavones target multiple cellular signalling pathways in cancer cells. Our findings indicate that soy-derived isoflavones act as, among other things, potent modulators of HOX transcript antisense RNA (HOTAIR)/SWI/SNF-related matrix-associated actin-dependent regulator of chromatin subfamily B member 1 (SMARCB1), vascular endothelial growth factor (VEGF)/C-X-C motif chemokine ligand 12 (CXCL12)/C-X-C motif chemokine receptor type 4 (CXCR4), 17-β-oestradiol (E2)/oestrogen receptor-α (ERα)/neuroglobin (NGB) and sonic hedgehog signalling pathways, epigenetic modulatory agents (i.a. miR-155, miR-34a and miR-10a-5p) and cancer stem cells and epithelial-to-mesenchymal transition inhibitors. The paper also discusses the latest epidemiological studies and clinical trials and provides an insight into recent extensive research on the chemo-preventive and therapeutic potential of soy-derived isoflavones. LINKED ARTICLES: This article is part of a themed issue Natural Products and Cancer: From Drug Discovery to Prevention and Therapy. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v182.10/issuetoc.

Effect of red clover isoflavones on ruminal microbial composition and fermentation in dairy cows

Red clover isoflavones, particularly biochanin A and formononetin, are known for their benefits in enhancing feed efficiency and nitrogen utilization in ruminants. However, their specific effects on rumen fermentation and microbial diversity remain insufficiently explored. This study investigated the impacts of red clover isoflavones on rumen function and bacterial diversity in dairy cows, utilizing both in vivo and in vitro methodologies. In the in vivo study, 40 Holstein dairy cows were allocated to four groups, each receiving red clover isoflavones at doses of 0, 0.4, 0.8, and 1.6 g/kg. Rumen fluid was collected for analysis of fermentation parameters, enzyme activity, and microbial composition through shotgun metagenomic sequencing. Concurrently, an in vitro rumen fermentation trial was conducted to evaluate the effects of biochanin A and formononetin on urea hydrolysis. Results from the in vivo experiments showed that red clover isoflavones significantly decreased ammonia nitrogen (NH₃-N) concentrations and urease activity in the rumen (P < 0.05). Species level metagenomic analysis indicated a reduced abundance of proteolytic and ureolytic bacteria, such as Prevotella sp002317355 and Treponema_D bryantii_C, with a corresponding increase in cellulolytic bacteria, including Ruminococcus_D sp900319075 and Ruminococcus_C sp000433635 (P < 0.05). The in vitro trial further demonstrated that biochanin A and formononetin significantly reduced urea decomposition rates (P < 0.05), with biochanin A exerting a more pronounced effect. These findings align with the observed reduction in ureolytic and proteolytic bacteria, along with an increase in cellulolytic bacteria across both trials. In conclusion, biochanin A emerged as the primary active component of red clover isoflavones, modulating urea nitrogen hydrolysis and rumen fermentation. This study substantiates previous findings and highlights the potential of red clover isoflavones for enhancing rumen microbial fermentation, offering a promising strategy for future dairy industry applications. KEY POINTS: • Red clover isoflavones inhibit urease activity to decrease the abundance of urealytic bacteria. • Biochanin A reduces ammonia nitrogen and urease activity, promoting protein efficiency. • Red clover isoflavones may improve dairy cow rumen health and nitrogen utilization.

[A Prospective Cohort Study on Soy Product Intake and the Risk of Lung Cancer Based on Shanghai Suburban Adult Cohort and Biobank]

BACKGROUND

Lung cancer is one of the malignant cancers with the highest incidence rate, and it is important to identify the factors contributing to lung cancer carcinogenesis for prevention. Lifestyle and genetic factors play important roles in cancer development, however the impact of dietary factors, such as soy product intake, on lung cancer risk remains inadequately understood. This study aims to explore the associations between soy product intake, genetic risk, and lung cancer incidence, and validate the consistent effects of soy product intake in European populations, thereby providing new insights for lung cancer prevention.

METHODS

Utilizing the Shanghai Suburban Adult Cohort and Biobank (SSACB) (n=66,311), Cox proportional hazards model was adopted to assess the association between soy product intake and lung cancer incidents, followed by subgroup analyses stratified by gender, smoking status, and pathological types of lung cancer. The UK Biobank (UKB) was used for validation of the effect of soy product intake on lung cancer. To investigate the association between genetic factors and lung cancer, in addition to previously reported loci, we incorporated newly identified loci from two independent studies in Southeast China: a nested case-control population from the SSACB cohort (433 cases/650 controls) and a case-control study from the Shanghai Cancer Center-Taizhou cohort (1359 cases/1359 controls). Meta-analysis and Linkage disequilibrium clumping (LD clumping) of the association results identified 23 loci for polygenic risk score (PRS) construction. Subsequently, conditional Logistic regression model was used to assess the association between genetic risk and lung cancer.

RESULTS

In SSACB cohort, after adjusting for age, gender, smoking, chronic bronchitis, body mass index (BMI), vegetable intake and red meat intake, sufficient soy product intake was significantly associated with a reduced risk of lung cancer [hazard ratio (HR)=0.60, 95%CI: 0.47-0.77, Padj=6.69E-05], an effect that was consistent in males and females, smokers and non-smokers. In UKB, although the association did not reach statistical significance, a protective trend against lung cancer was also observed (HR=0.76, 95%CI: 0.55-1.06, Padj=0.10). In the nested case-control population within SSACB, a PRS score generated in the Chinese population was significantly correlated with lung cancer risk. After adjustment of age, gender, smoking, chronic bronchitis, and soy product intake, the high-PRS group had a 1.88 times higher risk of lung cancer compared to the low-PRS group (Padj=1.84E-03).

CONCLUSIONS

The prospective cohort study found that adequate intake of soy products was significantly associated with a reduced risk of lung cancer, while a high PRS is a risk factor for lung cancer development. Integrating soy product intake and PRS into traditional epidemiological risk factor prediction will guide personalized lung cancer prevention and high-risk population stratification.

Dietary Flavonoids and Lung Cancer: A GRADE-Assessed Systematic Review and Meta-Analysis of Observational Studies

Individual observational studies examining the association between polyphenols and the risk of lung cancer have reported mixed findings. Therefore, we performed a systematic review and meta-analysis to determine the pooled effects between polyphenol intake and lung cancer risk. A systematic search was performed on PubMed, Scopus, and Web of Science databases in April 2023. Random-effect models were used to estimate odd ratios (OR) and 95% confidence intervals (95% CI). In total, 20 studies were included in the systematic review. The pooled analyses indicated that a higher intake of flavonoids (OR = 0.81; 95% CI: 0.67,0.98; p = 0.03) and isoflavone (OR = 0.82; 95% CI: 0.74,0.92; p < 0.001) were associated with lower odds of lung cancer. In addition, the ingestion of anthocyanidin (OR = 0.80; 95% CI: 0.65,0.98; p = 0.04), kaempferol (OR = 0.78; 95% CI: 0.64,0.96; p = 0.02), quercetin (OR = 0.66; 95% CI: 0.48,0.91; p = 0.01) and flavanones (OR = 0.71; 95% CI: 0.59,0.85; p < 0.001) reduced the likelihood of developing lung cancer. Overall, our findings suggest that flavonoids, isoflavones, anthocyanidin, kaempferol, quercetin, and flavanones may protect against lung cancer.

Exploring the physiological role of the G protein-coupled estrogen receptor (GPER) and its associations with human diseases

Estrogen is a group of hormones that collaborate with the nervous system to impact the overall well-being of all genders. It influences many processes, including those occurring in the central nervous system, affecting learning and memory, and playing roles in neurodegenerative diseases and mental disorders. The hormone's action is mediated by specific receptors. Significant roles of classical estrogen receptors, ERα and ERβ, in various diseases were known since many years, but after identifying a structurally and locationally distinct receptor, the G protein-coupled estrogen receptor (GPER), its role in human physiology and pathophysiology was investigated. This review compiles GPER-related information, highlighting its impact on homeostasis and diseases, while putting special attention on functions and dysfunctions of this receptor in neurobiology and biobehavioral processes. Understanding the receptor modulation possibilities is essential for therapy, as disruptions in receptors can lead to diseases or disorders, irrespective of correct estrogen levels. We conclude that studies on the GPER receptor have the potential to develop therapies that regulate estrogen and positively impact human health.

Dietary phytoestrogen intake and ovarian cancer risk: a prospective study in the prostate, lung, colorectal and ovarian (PLCO) cohort

Estrogen plays a crucial role in ovarian tumorigenesis. Phytoestrogens (PEs) are a type of daily dietary nutrient for humans and possess a mild estrogenic characteristic. This study aimed to assess the correlation of the consumption of dietary PEs with ovarian cancer risk using data in the prostate, lung, colorectal and ovarian (PLCO) cancer screening trial. Participants were enrolled in PLCO from 1993 to 2001. Hazard ratios (HR) and 95% confidence intervals (CI) were utilized to determine the association between the intake of PEs and ovarian cancer occurrence, which were calculated by the Cox proportional hazards regression analysis. In total, 24 875 participants were identified upon completion of the initial dietary questionnaire (DQX). Furthermore, the analysis also included a total of 45 472 women who filled out the diet history questionnaire (DHQ). Overall, after adjustment for confounders, the dietary intake of total PEs was significantly associated with the risk of ovarian cancer in the DHQ group (HRQ4vsQ1 = 0.69, 95% CI: 0.50-0.95; P for trend = 0.066). Especially, individuals who consumed the highest quartile of isoflavones were found to have a decreased risk of ovarian cancer in the DHQ group (HRQ4vsQ1 = 0.68, 95% CI: 0.50-0.94; P for trend = 0.032). However, no such significant associations were observed for the DQX group. In summary, this study suggests that increased dietary intake of total PEs especially isoflavones was linked with a lower risk for developing ovarian cancer. More research is necessary to validate the findings and explore the potential mechanisms.

Recent status of sesaminol and its glucosides: Synthesis, metabolism, and biological activities

Sesamum indicum is a major and important oilseed crop that is believed to promote human health in many countries, especially in China. Sesame seeds contain two types of lignans: lipid-soluble lignans and water-soluble glucosylated lignans. The major glucosylated lignans are sesaminol glucosides (SGs). So far, four sesaminol isomers and four SGs are identified. During the naturally occurring process of SGs production, sesaminol is generated first from two molecules of E-coniferyl alcohol, and then the sugar is added to the sesaminol one by one, leading to production of SGs. Sesaminol can be prepared from SGs, from sesamolin, and through artificial synthesis. SGs are metabolized in the liver and intestine and are then transported to other tissues. They exhibit several biological activities, most of which are based on their antioxidant and anti-inflammatory activities. In this paper, we present an overview of the current status of research on sesaminol and SGs. We have also discussed their synthesis, preparation, metabolism, and biological activities. It has been suggested that sesaminol and SGs are important biological substances with strong antioxidant properties in vitro and in vivo and are widely used in the food industry, medicine, and cosmetic products. The recovery and utilization of SGs from sesame seed cake after oil processing will generate massive economic benefits.

Understanding the mechanisms and translational implications of the microbiome for cancer therapy innovation

The intersection of the microbiota and cancer and the mechanisms that define these interactions are a fascinating, rapidly evolving area of cancer biology and therapeutics. Here we present recent insights into the mechanisms by which specific bacteria or their communities contribute to carcinogenesis and discuss the bidirectional interplay between microbiota and host gene or epigenome signaling. We conclude with comments on manipulation of the microbiota for the therapeutic benefit of patients with cancer.

Isoflavone and soy food intake and risk of lung cancer in never smokers: report from prospective studies in Japan and China

PURPOSE

Evidence from several cohorts has suggested that a higher intake of isoflavone is associated with lower risk of lung cancer in never smokers, but the association has not been investigated by histologic type of lung cancer. Adenocarcinoma is a common histologic type found in never smokers. We hypothesized that a higher intake of isoflavone is associated with a lower risk of lung adenocarcinoma among never smokers. Here, we examined the associations of isoflavone and soy food intake with lung cancer and its histologic types in never smokers.

METHODS

We performed a pooled analysis using data from the Japan Public Health Center-based Prospective Study, Shanghai Women's Health Study and Shanghai Men's Study with 147,296 never smokers aged 40-74 years with no history of cancer. During 1,990,040 person-years of follow-up, 1247 lung cancer cases were documented. Dietary isoflavone and soy food intake were assessed using a food-frequency questionnaire. Multivariable Cox proportional hazards models assessed the associations between isoflavone and soy intake with incidence of lung cancer by histologic type.

RESULTS

A higher intake of dietary isoflavone and soy food were associated with reduced risk of lung adenocarcinoma. The multivariable hazard ratios (HRs) (95% CI) of risk of lung adenocarcinoma for the highest versus lowest intakes of isoflavone and soy food were 0.74 (0.60-0.92) and 0.78 (0.63-0.96), respectively. The multivariable HRs of risk of lung adenocarcinoma associated with each 10 mg/day increase in isoflavone and each 50 g/day increase in soy food intake were 0.81 (0.70-0.94) and 0.84 (0.73-0.96), respectively.

CONCLUSION

Higher intake of isoflavone and soy food was associated with lower risk of lung adenocarcinoma in never smokers.

Health Effects of Soy Isoflavones and Green Tea Catechins on Cancer and Cardiovascular Diseases Based on Urinary Biomarker Levels

Plant polyphenols have various health effects. Genistein, which is abundant in soybeans, and epigallocatechin-3-gallate, which is abundant in green tea, are major flavonoids, a subclass group of polyphenols. Several epidemiological studies have shown that these flavonoids have beneficial effects against cancer and cardiovascular diseases. However, other studies did not show such effects. Several confounding factors, including recall bias, are related to these inconsistent findings, and the determination of metabolites in the urine may be useful in reducing the number of confounding factors. Equipment, which can be used by research participants to collect samples from a portion of voided urine within 24 h without the help of medical workers, has been developed for epidemiological investigations. Previous studies, in which flavonoid metabolites in these urine samples were measured, revealed that soy intake was correlated with a reduced risk of certain types of cancer and cardiovascular diseases worldwide. Although soybeans and green tea consumption may have protective effects against cancer and cardiovascular diseases, further clinical studies that consider different confounding factors are required to provide evidence for the actual impact of dietary flavonoids on human diseases, including cancer and cardiovascular diseases. One possible mechanism involved is discussed in relation to the downregulation of reactive oxygen species and the upregulation of 5'-adenosine monophosphate-activated protein kinase elicited by these flavonoids.

Emotional and Spontaneous Locomotor Behaviors Related to cerebellar Daidzein-dependent TrkB Expression Changes in Obese Hamsters

Current evidence supports the beneficial role of phytoestrogens in metabolic diseases, but their influences on spontaneous motor and anxiety behaviors plus neuroprotective effects have still not been completely elucidated. With the present study, neuro-behavioral activities were correlated to daidzein (DZ)-dependent expression changes of a high affinity catalytic receptor for several neurotrophins, and namely tropomyosin-related kinase B receptor (TrkB) in the cerebellar cortex of high-fat diet (HFD) hamsters (Mesocricetus auratus). Indeed, these changes appear to be tightly linked to altered plasma lipid profiles as shown by reduced low-density lipoproteins plus total cholesterol levels in DZ-treated obesity hamsters accounting for increased spontaneous locomotor together with diminished anxiety activities in novel cage (NCT) and light/dark box (LDT) tests. For this latter case, the anxiolytic-like hamsters spent more time in the light compartment, which was retained the aversive area of the LDT box. As for the evaluation of the neurotrophin receptor site, significantly elevated TrkB levels were also detected, for the first time, in the cerebellum of obese hamsters treated with DZ. In this condition, such a treatment widely led to an overall improvement of HFD-induced neurodegeneration damages, above all in the Purkinje and granular layers of the cerebellum. In this context, the notably active TrkB signaling events occurring in a DZ-dependent manner may turn out to be a key neuroprotective element capable of restoring normal emotional and spontaneously linked locomotor behaviors regulated by cerebellar cortical areas especially in obesity-related conditions.

Ultra-processed food intake is associated with grip strength decline in middle-aged and older adults: a prospective analysis of the TCLSIH study

PURPOSE

Ultra-processed foods make up more than 50% of daily energy consumed in Western countries and are rapidly increasing in China. However, little is known about the association between ultra-processed food intake and muscle strength, a predictor for physical disability in senior years. We aimed to investigate the association of ultra-processed food intake with longitudinal changes in grip strength among middle-aged and older Chinese adults.

METHODS

This prospective cohort study included a total of 5409 adults aged 40 years and over (61.3% men). Ultra-processed food intake was obtained by means of a validated food frequency questionnaire and classified according to the NOVA classification system. Grip strength was measured annually using a handheld digital dynamometer. Multivariable linear regression models were used to examine the association between ultra-processed food intake and annualized change in grip strength and weight-adjusted grip strength.

RESULTS

In the fully adjusted models, annualized changes in grip strength and weight-adjusted grip strength per 10% increment in the proportion of ultra-processed foods in the diet were - 0.3708 kg (95% confidence interval - 0.5687, - 0.1730; P < 0.001) and - 0.0057 kg/kg (95% confidence interval - 0.0086, - 0.0029; P < 0.0001), respectively. In analyses stratified by age, sex, body mass index, physical activity, hypertension, hyperlipidemia, diabetes, and healthy diet score, such associations were largely consistent in most subgroups (all P for interaction > 0.05).

CONCLUSIONS

Our data indicate that higher ultra-processed food intake was associated with faster grip strength decline in middle-aged and older Chinese adults.