Association between tea consumption and risk of cancer: a prospective cohort study of 0.5 million Chinese adults

Fluorine accumulation characteristics of 85 tea tree (Camellia sinensis) varieties and its potential risk assessment

Tea tree is a fluorine (F)-enriched plant, leading to much concern about the safety of drinking tea from tea tree (Camellia sinensis (L.) Kuntze). Tea tree is a perennial leaf-harvested crop, and tea production in China is generally categorized as spring tea, summer tea and autumn tea in its annual growth rounds. However, the seasonally dynamic changes of F content and accumulation in the leaves and its drinking safety are poorly understood. In this study, 85 tea varieties cultivated under the same conditions were investigated to analyze the seasonal variation of F content and it's relationships with F accumulation, aluminum (Al), calcium (Ca) and manganese (Mn) and hazard quotient (HQ) in young leaves (one bud and two leaves, YL) and mature leaves (canopy leaves, ML). The average F contents and accumulations were 350 mg kg-1 and 203 g ha-1 in YL, and they were 2451 mg kg-1 and 2578 g ha-1 in ML, respectively, with F mainly accumulated in ML. As the growing season progresses, the F content showed a gradual increase in YL, while a decrease in ML, inferring that F may be redistributed from mature leaves to young leaves. Additionally, the F content was quite different among tea varieties which are suitable for processing oolong tea, green tea, and black tea, with higher F accumulation in oolong tea varieties than in green and black tea varieties. Moreover, F content and accumulation could be obviously affected by the geographical origin of the tea tree varieties, with significantly higher F content in the varieties from F rich fluorite belts than other regions. Furthermore, F content and accumulation showed a significant positive correlation with the content of Al and Mn (p < 0.05). Based on a daily tea consumption of 8.7 g, the HQ was investigated to show that the proportion of tea leaves with HQ<1 made from spring, summer and autumn tender leaves of 85 varieties was 100 %, 90.6 % and 50.6 %, respectively, indicating that the tea with the best drinking safety comes from spring, followed by summer, and then autumn. This result suggests that it could be necessary to avoid planting tea trees in fluorite mining areas, choose low F tea tree varieties, and control the tenderness of fresh leaves in order to ensure the safety of tea drinking.

Oral Health and Nutraceutical Agents

Oral health is essential for both overall health and quality of life. The mouth is a window into the body's health, and nutrition can strongly impact the state of general and oral health. A healthy diet involves the synergistic effect of various nutraceutical agents, potentially capable of conferring protective actions against some inflammatory and chronic-degenerative disorders. Nutraceuticals, mostly present in plant-derived products, present multiple potential clinical, preventive, and therapeutic benefits. Accordingly, preclinical and epidemiological studies suggested a protective role for these compounds, but their real preventive and therapeutic effects in humans still await confirmation. Available evidence suggests that plant extracts are more effective than individual constituents because they contain different phytochemicals with multiple pharmacological targets and additive/synergistic effects, maximizing the benefits for oral health. Moreover, nutritional recommendations for oral health should be personalized and aligned with valid suggestions for overall health. This review is aimed to: introduce the basic concepts of nutraceuticals, including their main food sources; examine the logic that supports their relationship with oral health, and summarize and critically discuss clinical trials testing the utility of nutraceuticals in the prevention and treatment of oral diseases.

Early-onset and later-onset cancer: trends, risk factors, and prevention in Northern China

The characteristics of early-onset (onset age <50 years) and later-onset (onset age ≽ 50 years) cancers differ significantly. Identifying novel risk factors for both types of cancer is crucial for increasing awareness of cancer prevention and for reducing its burden. This study aimed to analyze the trends in incidence and risk factors for early-onset and late-onset cancers. We conducted a prospective study by drawing data from the Kailuan Study. This study included 6,741 participants with cancer (624 with early-onset cancer and 6,117 with later-onset cancer) and 6,780 matched controls among the 186,249 participants who underwent Kailuan health examinations from 2006 to 2019. The primary outcomes were cancer incidence rates, and associated risk factors for early- and later-onset cancer. Weighted Cox regression was used to calculate hazard ratios and 95% confidence intervals of each exposure factor for early- and later-onset cancer by cancer type. Population-attributable risk proportions were used to estimate the number of cases that could be prevented by eliminating a risk factor from the population. Except for liver cancer, incidence rates for nearly all types of cancer increased during the study period. Smoking, alcohol consumption, lipid metabolism disorders, hypertension, diabetes mellitus, fatty liver, and inflammation were associated with a significantly increased risk of cancer at multiple sites, but risk factors for cancer incidence differed by site. Smoking, alcohol consumption, inflammation, and hypertension were the major contributors to preventable cancer. The incidence of several different types of cancer, including early-onset cancer, is increasing in northeastern China. Differences in risk factors between early-onset and later-onset malignancies may contribute to the divergence in the observed changes in incidence trends between these two specific types of cancer.

Relationship between sex differences in drinking, smoking, and exercising and the incidence of malignancies and medical procedures: a cross-sectional study of 21,916 participants in China

Objectives: The unresolved issue of the relationship between sex differences in tea, coffee, and beverage consumption and malignancy risk prompted our study in 2022. Methods: Logistic proportional hazards models were used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) in our investigation of the associations between cancer risk and tea, coffee, and beverage consumption. Results: Our findings revealed that frequent consumption of white tea significantly reduced the occurrence of malignant tumours, but this effect was detected only in the fully adjusted model for males (OR: 0.736, 95% CI: 0.095-5.704). The amount of sugar added to coffee was associated with an increased risk of malignancy in a dose-dependent manner (P for trend = 0.001), with significance observed for both men (P for trend = 0.049) and women (P for trend = 0.005) in the final model. Notably, individuals who consumed more than 2100 ml of sugary beverages daily had a statistically significant reduction in malignancy risk (OR: 0.219, 95% CI: 0.052-0.917). Interestingly, the intake of sugary beverages had a protective effect on cancer incidence, with a significant effect on males (P for trend = 0.031) but not females (P for trend = 0.096) in the final model. Conclusions: Our study highlights the substantial impact of regular white tea consumption on reducing the risk of malignant tumours in males. This study first reported that the potential protective effect of consuming sugary beverages is predominantly observed in males, and a correlation between the amount of sugar added to coffee and a heightened risk of malignancy.

Caffeine in Hepatocellular Carcinoma: Cellular Assays, Animal Experiments, and Epidemiological Investigation

The use of caffeine in treating various liver diseases has made substantial progress in the past decade owing to advances in science, technology, and medicine. However, whether caffeine has a preventive effect on hepatocellular carcinoma (HCC) and its mechanism are still worth further investigation. In this review, we summarize and analyze the efficacy and safety of caffeine in the prevention of HCC. We conducted a review of articles published in PubMed and Web of Science in the past 2 decades until December 6, 2023, which were searched for using the terms "Caffeine" and "Hepatocellular Carcinoma." Studies have found that coffee intake is negatively correlated with HCC risk, especially caffeinated coffee. Recent studies have found that caffeine has beneficial effects on liver health, decreasing levels of enzymes responsible for liver damaging and slowing the progression of hepatic fibrosis and cirrhosis. Caffeine also acts against liver fibrosis through adenosine receptors (ARs), which promote tissue remodeling by inducing fibrin and collagen production. Additionally, new studies have found that moderate consumption of caffeinated beverages can decrease various the levels of various collagens in patients with chronic hepatitis C. Furthermore, polyphenolic compounds in coffee can improve fat homeostasis, reduce oxidative stress, and prevent liver steatosis and fibrosis. Moreover, many in vitro studies have shown that caffeine can protect liver cells and inhibit the activation and proliferation of hepatic stellate cells. Taken together, we describe the benefits of caffeine for liver health and highlight its potential values as a drug to prevent various hepatic diseases. As a protective agent of liver inflammation, non-selective AR inhibitor caffeine can inhibit the growth of HCC cells by inhibiting adenosine and AR binding to initiate immune response, providing a basis for the future development of caffeine as an adjuvant drug against HCC.

Causal association between tea consumption and head and neck cancer: a Mendelian randomization study

Although evidence supports an observational association between tea consumption and susceptibility to head and neck cancer, the causal nature of this association remains unclear. We performed a two-sample Mendelian randomization (MR) analysis to determine the causal effects of tea consumption on head and neck cancer. We employed a fixed-effects inverse variance-weighted model for the MR analysis. Genome-wide association study (GWAS) summary data for tea consumption were obtained from the UK Biobank Consortium, and GWAS data for head and neck cancer were derived from two data sources and were used as the outcomes. Our MR analysis revealed limited evidence for a causal relationship between various types of tea intake and head and neck cancer. After adjustment for smoking and alcohol consumption, there was no causal relationship between tea consumption and head and neck cancer. Further experimental studies are required to confirm its potential role in these malignancies.

Tea intake and lung diseases: a Mendelian randomization study

Background

Existing studies on the relationship between tea intake and lung diseases have yielded inconsistent results, leading to an ongoing dispute on this issue. The impact of tea consumption on the respiratory system remained elucidating.

Materials and methods

We conducted a two-sample Mendelian randomization (MR) study to evaluate the associations between five distinct tea intake phenotypes and 15 different respiratory outcomes using open Genome-wide association study (GWAS) data. The inverse variance weighted (IVW) was used for preliminary screening and a variety of complementary methods were used as sensitivity analysis to validate the robustness of MR estimates. Pathway enrichment analysis was used to explore possible mechanisms.

Results

IVW found evidence for a causal effect of standard tea intake on an increased risk of lung squamous cell cancer (LSCC) (OR = 1.004; 95% CI = 1.001-1.007; P = 0.00299). No heterogeneity or pleiotropy was detected. After adjustment for potential mediators, including smoking, educational attainment, and time spent watching television, the association was still robust in multivariable MR. KEGG and GO enrichment predicted proliferation and activation of B lymphocytes may play a role in this causal relation. No causalities were observed when evaluating the effect of other kinds of tea intake on various pulmonary diseases.

Conclusion

Our MR estimates provide causal evidence of the independent effect of standard tea intake (black tea intake) on LSCC, which may be mediated by B lymphocytes. The results implied that the population preferring black tea intake should be wary of a higher risk of LSCC.

Nine dietary habits and risk of colorectal cancer: a Mendelian randomization study

BACKGROUND

Epidemiological studies have provided evidence that there is an association between diet and colorectal cancer. However, the causal relationship between dietary habits and colorectal cancer remains unknown.

METHODS

The UK Biobank provided summary-level genome-wide association study data for nine dietary habits, including alcohol consumption (n = 549,703), instant coffee consumption (n = 250,308), fruit consumption (n = 210,947), meat consumption (n = 210,947), full cream milk consumption (n = 41,306), sweets consumption (n = 25,521), tea consumption (n = 501,494), vegetable consumption (n = 210,947), and yogurt/ice cream consumption (n = 210,947). Additionally, data on colorectal cancer were collected, consisting of 5,567 cases and 372,016 controls. The MR analysis employed inverse variance weighted, weighted median, MR-Egger regression, and MR multivariate residuals tests.

RESULTS

In the predominantly European population, a positive association was observed between vegetables (OR = 1.014, 95% CI = 1.000-1.029, p = 0.048) and an increased risk of colorectal cancer. The results for vegetable did not survive correction for multiple comparisons. However, no strong evidence was found for other dietary factors, such as alcohol (OR = 1.012, 95% CI = 0.974-1.051, p = 0.556), fruit (OR = 1.007, 95% CI = 0.986-1.029, p = 0.512), meat (OR = 1.000, 95% CI = 0.987-1.026, p = 0.968), full cream milk (OR = 1.019, 95% CI = 0.979-1.061, p = 0.357), sweets (OR = 0.998, 95% CI = 0.991-1.004, p = 0.524), and tea (OR = 1.002, 95% CI = 0.994-1.009, p = 0.672), with regards to colorectal cancer risk in the European population.

CONCLUSIONS

Our study highlights the need for a more nuanced approach to dietary recommendations for CRC prevention, with greater emphasis adherence to the Mediterranean dietary pattern.

Associations between tea-drinking habits and health-related quality of life in Chinese adults: a mediation analysis based on sleep quality

BACKGROUND

The aim of this study was to explore the association between tea-drinking habits and health-related quality of life (HRQoL) in Chinese adults and the mediating effect of sleep quality in this association.

METHODS

Data were derived from the 2020 Survey of Social Factors for Chronic Disease Prevention and Control among adults in Lishui District, Nanjing, Jiangsu Province, China. Tea-drinking habits were measured by participants' self-report. The HRQoL was measured using the 12-item Short Form Health Survey. Multiple linear regression modelling and mediating effects modelling were used for analyses.

RESULTS

Habitual tea drinking, frequent tea drinking (drinking tea 6-7 days per week), tea concentration and <10 g of tea per day were strongly associated with an increase in HRQoL among Chinese adults (all p<0.05). The association between tea-drinking habits and HRQoL among Chinese adults was more pronounced in the male population and in those ≥45 y of age (all p<0.05). Tea drinking habits may improve HRQoL in Chinese adults by enhancing sleep quality (all p<0.05).

CONCLUSIONS

Maintaining the habit of habitual tea drinking (6-7 days per week), in small amounts (<10 g tea per day) was conducive to improving HRQoL of Chinese adults by improving sleep quality.

Biological Potential and Mechanisms of Tea's Bioactive Compounds in Tea: An Updated Review

BACKGROUND

Tea (Camellia sinensis) has a rich history and is widely consumed across many countries, and is categorized into green tea, white tea, oolong tea, yellow tea, black tea, and dark tea based on the level of fermentation. Based on a review of previous literature, the commonly recognized bioactive substances in tea include tea polyphenols, amino acids, polysaccharides, alkaloids, terpenoids, macro minerals, trace elements, and vitamins, which have been known to have various potential health benefits, such as anticancer, antioxidant, anti-inflammatory, anti-diabetes, and anti-obesity properties, cardiovascular protection, immune regulation, and control of the intestinal microbiota. Most studies have only pointed out the characteristics of tea's bioactivities, so a comprehensive summary of the pharmacological characteristics and mechanisms of tea's bioactivities and their use risks are vital.

AIM

of Review The aim of this paper is to summarize the bioactive substances of tea and their pharmacological characteristics and mechanisms, providing a scientific basis for the application of bioactive substances in tea and outlining future research directions for the study of bioactive substances in tea. Key Scientific Concepts of Review This review summarizes the main biologically active substances, pharmacological effects, and mechanisms and discusses the potential risks. It may help researchers to grasp more comprehensive progress in the study of tea bioactive substances to further promote the application of tea as a natural bioactive substance in the medical field.

Associations of dietary, sociodemographic, and anthropometric factors with anemia among the Zhuang ethnic adults: a cross-sectional study in Guangxi Zhuang Autonomous Region, China

BACKGROUND

After decades of rapid economic development, anemia remains a significant public health challenge globally. This study aimed to estimate the associations of sociodemographic, dietary, and body composition factors with anemia among the Zhuang in Guangxi Zhuang Autonomous Region, China.

METHODS

Our study population from the baseline survey of the Guangxi ethnic minority Cohort Study of Chronic Diseases consisted of 13,465 adults (6,779 women and 6,686 men) aged 24-82 years. A validated interviewer-administered laptop-based questionnaire system was used to collect information on participants' sociodemographic, lifestyle, and dietary factors. Each participant underwent a physical examination, and hematological indices were measured. Least absolute shrinkage and selection operator (LASSO) regression was used to select the variables, and logistic regression was applied to estimate the associations of independent risk factors with anemia.

RESULTS

The overall prevalences of anemia in men and women were 9.63% (95% CI: 8.94-10.36%) and 18.33% (95% CI: 17.42─19.28%), respectively. LASSO and logistic regression analyses showed that age was positively associated with anemia for both women and men. For diet in women, red meat consumption for 5-7 days/week (OR = 0.79, 95% CI: 0.65-0.98, p = 0.0290) and corn/sweet potato consumption for 5-7 days/week (OR = 0.73, 95% CI: 0.55-0.96, p = 0.0281) were negatively associated with anemia. For men, fruit consumption for 5-7 days/week (OR = 0.75, 95% CI: 0.60-0.94, p = 0.0130) and corn/sweet potato consumption for 5-7 days/week (OR = 0.66, 95% CI: 0.46-0.91, p = 0.0136) were negatively correlated with anemia. Compared with a normal body water percentage (55-65%), a body water percentage below normal (< 55%) was negatively related to anemia (OR = 0.68, 95% CI: 0.53-0.86, p = 0.0014). Conversely, a body water percentage above normal (> 65%) was positively correlated with anemia in men (OR = 1.73, 95% CI: 1.38-2.17, p < 0.0001).

CONCLUSIONS

Anemia remains a moderate public health problem for premenopausal women and the elderly population in the Guangxi Zhuang minority region. The prevention of anemia at the population level requires multifaceted intervention measures according to sex and age, with a focus on dietary factors and the control of body composition.

Association between tea consumption and colorectal cancer: a systematic review and meta-analysis of a population-based study

PURPOSE

A meta-analysis study was performed to systematically assess the association between tea consumption and CRC risk.

METHODS

Cochrane Library, Embase, PubMed, and Web of Science were retrieved to collect articles in English since 24 July 2023. Databases were searched and evaluated by two reviewers independently.We screened the literature based on inclusion and exclusion criteria. After determining the random effect model or fixed utility model based on a heterogeneity test, odds ratios (ORs) and 95% confidence intervals (CIs) were calculated.

RESULTS

We included fourteen articles in this meta-analysis. We analyzed the data using a random effect model to explore the association between tea consumption and CRC because of apparent heterogeneity (P < 0.001, I2 = 99.5%). The combined results of all tests showed that there is no statistically significant association between tea consumption and CRC risk (OR = 0.756, 95%CI = 0.470-1.215, P = 0.247). Subsequently, subgroup analysis and sensitivity analysis were performed. Excluding any single study, the overall results ranged from 0.73 (95%CI = 0.44-1.20) to 0.86 (95%CI = 0.53-1.40). It was determined that there was no significant publication bias between tea consumption and CRC risk (P = 0.064) by Egger's tests.

CONCLUSIONS

The results indicated that tea consumption may not be significantly associated with the development of CRC.

IMPLICATIONS OF KEY FINDINGS

Tea reduces colon cancer risk by 24%, but the estimate is uncertain. The actual effect on risk can range from a reduction of 51% to an increase of 18%, but regional and population differences may cause differences.

Coffee, Green Tea Intake, and the Risk of Hepatocellular Carcinoma: A Systematic Review and Meta-Analysis of Observational Studies

Several studies suggest an inverse relationship between coffee intake and risk of hepatocellular carcinoma (HCC), but the association between green tea intake and the risk of HCC is still inconclusive. We performed a meta-analysis of observational studies to clarify the association. We identified eligible studies published from January 1, 1992, to February 28, 2022, by searching PubMed, Web of Science, and EMBASE. A total of 32 studies were included in the meta-analysis. Among them, 21 studies involving 2,492,625 participants and 5980 cases of HCC reported coffee intake, 18 studies involving 1,481,647 participants and 6985 cases of HCC reported green tea intake, and seven studies reported both coffee intake and green tea intake. The results showed that a higher coffee (RR = 0.53; 95% CI: 0.47-0.59; I2 = 0.0%; Pheterogeneity = 0.634) or green tea (RR = 0.80; 95% CI: 0.67-0.95; I2 = 72.30%; Pheterogeneity < 0.001) intake may be associated with a lower risk of HCC. The same results were observed in both cohort and case-control subgroups. Our findings suggest that drinking coffee or green tea may be a potentially effective approach for the prevention or mitigation of HCC, but this still needs to be confirmed by further well-designed observational studies and clinical experimental research.

Self-Reported Primary Cooking Fuels Use and Risk of Chronic Digestive Diseases: A Prospective Cohort Study of 0.5 Million Chinese Adults

BACKGROUND

Household air pollution (HAP) from inefficient combustion of solid fuels is a major health concern worldwide. However, prospective evidence on the health impacts of solid cooking fuels and risks of chronic digestive diseases remains scarce.

OBJECTIVES

We explored the effects of self-reported primary cooking fuels on the incidence of chronic digestive diseases.

METHODS

The China Kadoorie Biobank recruited 512,726 participants 30-79 years of age from 10 regions across China. Information on primary cooking fuels at the current and previous two residences was collected via self-reporting at baseline. Incidence of chronic digestive diseases was identified through electronic linkage and active follow-up. Cox proportional hazards regression models were used to estimate adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for the associations of self-reported long-term cooking fuel patterns and weighted duration of self-reported solid cooking fuel use with chronic digestive diseases incidence. Linear trend was tested by assigning the medians of weighted duration in each group and then taking those as continuous variables in the models. Subgroup analyses were undertaken across the baseline characteristics of participants.

RESULTS

During 9.1 ± 1.6 y of follow-up, 16,810 new cases of chronic digestive diseases were documented, among which 6,460 were diagnosed as cancers. Compared with long-term cleaner fuel use, self-reported long-term use of solid cooking fuels (i.e., coal, wood) was associated with elevated risks of chronic digestive diseases (HR = 1.08 ; 95% CI: 1.02, 1.13), including nonalcoholic fatty liver disease (NAFLD) (HR = 1.43 ; 95% CI: 1.10, 1.87), hepatic fibrosis/cirrhosis (HR = 1.35 ; 95% CI: 1.05, 1.73), cholecystitis (HR = 1.19 ; 95% CI: 1.07, 1.32), and peptic ulcers (HR = 1.15 ; 95% CI: 1.00, 1.33). The longer the weighted duration of self-reported solid cooking fuel use, the higher the risks of chronic digestive diseases, hepatic fibrosis/cirrhosis, peptic ulcers, and esophageal cancer (p Trend < 0.05 ). The aforementioned associations were modified by sex and body mass index (BMI). Positive associations of always solid cooking fuel use with chronic digestive disease, hepatic fibrosis/cirrhosis, NAFLD, and cholecystitis were observed among women but not men. The longer the weighted duration of self-reported solid cooking fuel use, the higher the risk of NAFLD among those with a BMI ≥ 28   kg / m 2 .

DISCUSSION

Long-term self-reported solid cooking fuels use was associated with higher risks of chronic digestive diseases. The positive association of HAP from solid cooking fuels with chronic digestive diseases indicates for an imminent promotion of cleaner fuels as public health interventions. https://doi.org/10.1289/EHP10486.

Cumulative consumption of tea is associated with lower risk of liver cancer: Updated results from the Shanghai Women's Health Study

Prospective epidemiological studies have provided limited evidence for an association between tea consumption and liver cancer risk. Based on a population-based prospective cohort study in middle-aged Chinese women, we investigated the association between tea consumption and the risk of primary liver cancer. Detailed information on tea drinking habits and other potential confounders was obtained at the baseline interview. Incident liver cancer cases were identified through record linkage with the population-based cancer registry and verified through home visits and review of medical charts by medical experts. Multiple aspects of tea drinking habits including starting age, duration, intensity and cumulative consumption of any type of tea and green tea were considered. Multivariable-adjusted hazard ratios (aHRs) and their 95% confidence intervals (CIs) were derived from the Cox regression models. After a median follow-up time of 18.12 (interquartile range = 1.59) years, 253 incident liver cancer cases were identified from 71 841 cohort members. Compared with never tea drinkers, the risk of liver cancer for participants who have consumed over 30 kg of dried tea leaves cumulatively was 0.56 (95% CI: 0.32-0.97). For those who drank green tea only, the aHR was 0.54 (95% CI: 0.30-0.98). This updated study suggested an inverse association between cumulative consumption of tea, especially green tea and the risk of primary liver cancer.

Association between Different Types of Tea Consumption and Risk of Gynecologic Cancer: A Meta-Analysis of Cohort Studies

Plenty of studies have shown that tea has an effect of inhibiting gynecologic tumors. However, there still remained controversy of the association between tea and gynecologic tumors in epidemiological studies. In this study, PubMed, Embase, and Cochrane Database were used to search the literature from 1 January 1960 to 26 December 2022 to investigate the association between tea intake and gynecologic cancer risk. In total, 19 cohort studies with 2,020,980 subjects and 12,155 gynecological tumor cases were retrieved. The pooled relative risk (RR) of gynecologic tumor for tea intake was 1.00 (95% CI: 0.96-1.04). RRs were 0.94 (95% CI: 0.88-1.01) for ovarian cancer, 1.02 (95% CI: 0.97-1.07) for endometrial cancer, and 1.06 (95% CI: 0.91-1.23) for cervical cancer. Subgroup analyses were adopted based on the tea type and geographic location. Interestingly, significant preventive impact of non-herbal tea on ovarian cancer (pooled relative risk: 0.67; 95% CI: 0.55-0.81) was found, especially for black tea (pooled relative risk: 0.64; 95% CI: 0.51-0.80). Dose-response analysis indicated that although it is not statistically significant, a decreasing trend of ovarian cancer risk could be observed when the tea consumption was 1.40 to 3.12 cups/day. In conclusion, our findings suggested that ovarian cancer, but not other gynecologic cancers, could possibly be prevented by drinking non-herbal tea. In addition, the preventive impact of green tea on gynecologic cancer seemed to be relatively weak and needs further cohorts to validate it.

Preventive and therapeutic effects of green tea on lung cancer: a narrative review of evidence from clinical and basic research

Background and Objective

Green tea is a popular beverage worldwide and has numerous health-promoting properties. Accumulating evidence indicates that green tea has preventive and therapeutic effects on lung cancer. This study aimed to investigate the association between green tea consumption and lung cancer.

Methods

We performed a narrative review to summarized the association between green tea consumption and lung cancer.

Key Content and Findings

Green tea consumption is known to decrease lung cancer risk in the general population, as indicated by meta-analyses of observational studies. Two active components of green tea, theabrownin and (-)-epigallocatechin gallate (EGCG), mediate the antitumor activity of green tea. Theabrownin promotes apoptosis, induces cell cycle arrest, and inhibits the migration, clone formation, and proliferation of lung cancer cell lines in vitro and in vivo. EGCG inhibits lung cancer cell proliferation and promotes apoptosis, agenesis, and epithelial-mesenchymal transition (EMT). In addition, EGCG sensitizes lung cancer cells to cisplatin and tyrosine kinase inhibitors (TKIs). The possible molecular mechanisms underlying the antitumor activity of EGCG and theabrownin were reviewed.

Conclusions

Observational studies have indicated that green tea has preventive effects on lung cancer. In vitro and animal studies have indicated that green tea has therapeutic effects on lung cancer. Further clinical trials are needed to illustrate the therapeutic effects of green tea or its active components (i.e., theabrownin, EGCG) on lung cancer.

Risk factors and protective factors for alcohol-related liver disease: A systematic review and meta-analysis

BACKGROUND

Although alcohol-related liver disease (ALD) is a global health threat, there are no specific effective treatments for it. Thus, efforts at preventing ALD are important and could be enhanced by using strategies based on validated risk and protective factors for the disease.

METHODS

The literature on factors influencing the risk for ALD was systematically searched from PubMed, Embase, and the Cochrane library databases from inception to June 2022. Factors suitable for quantitative analysis were submitted to meta-analysis using fixed-effects and random-effects models to calculate each factor's risk ratio (RR) and 95% confidence interval (CI).

RESULTS

Ten cohort studies (covering 1,005,339 subjects) that reported a clear causal relationship were included in the analysis, involving 11 potential risk factors (sex, race, education level, body mass index, alcohol consumption, types of alcoholic beverage, duration of drinking, drinking frequency, smoking, coffee consumption, and tea consumption). Three of these factors (sex, alcohol consumption, and smoking) were subjected to meta-analysis, and the results showed that male sex (RR = 2.84, 95% CI = 1.86-4.36), alcohol consumption ≥280 g/week (RR = 4.96, 95% CI = 2.71-9.07), and smoking (RR = 2.39, 95% CI = 1.97-2.89) were risk factors for ALD.

CONCLUSIONS

Many factors are likely to influence the incidence of ALD, and male sex, heavy alcohol consumption, and smoking increase the risk of ALD. The relationship between other factors and ALD risk needs further evaluation.

Inflammatory potential of diet and risk of nonalcoholic fatty liver disease: a prospective cohort study

BACKGROUND/OBJECTIVES

Diet is an important factor that can exacerbate or ameliorate chronic inflammation, which has been implicated in the pathogenesis of nonalcoholic fatty liver disease (NAFLD). However, no prospective study has yet investigated the relation between the inflammatory potential of diet and NAFLD. The aim of this study was to investigate the association between the inflammatory potential of the diet and the risk of NAFLD.

SUBJECT/METHODS

The study included 12,877 participants aged over 18 years (mean [standard deviation]: 39.4 [11.5] years). Dietary intake was assessed at baseline through food frequency questionnaires. Using white blood cell count as the inflammatory marker, we newly created a dietary inflammatory potential score by reduced rank regression and stepwise linear regression. NAFLD was identified by abdominal ultrasound during yearly health checkups. Cox proportional hazards regression models were used to estimate the association between the dietary inflammatory potential score and the risk of NAFLD.

RESULTS

During a median follow-up period of 4.2 years, 2744 first incident cases of NAFLD occurred. After adjustment for potential confounders, the multivariable hazards ratios (95% confidence intervals) for NAFLD across increasing quartiles of the dietary inflammatory potential score were 1.00 (reference), 1.01 (0.90, 1.13), 1.15 (1.03, 1.29), and 1.26 (1.13, 1.41), with P for trend <0.0001. This positive association appeared greater in men than in women (P for interaction = 0.02).

CONCLUSIONS

Our results indicate that a dietary pattern with high inflammatory potential is associated with a higher risk of NAFLD. Such findings provide the support that inflammation may be a potential mechanism linking diet to the risk of NAFLD.

Involvement of microRNA modifications in anticancer effects of major polyphenols from green tea, coffee, wine, and curry

Epidemiological studies have shown that consumption of green tea, coffee, wine, and curry may contribute to a reduced risk of various cancers. However, there are some cancer site-specific differences in their effects; for example, the consumption of tea or wine may reduce bladder cancer risk, whereas coffee consumption may increase the risk. Animal and cell-based experiments have been used to elucidate the anticancer mechanisms of these compounds, with reactive oxygen species (ROS)-based mechanisms emerging as likely candidates. Chlorogenic acid (CGA), curcumin (CUR), epigallocatechin gallate (EGCG), and resveratrol (RSV) can act as antioxidants that activate AMP-activated protein kinase (AMPK) to downregulate ROS, and as prooxidants to generate ROS, leading to the downregulation of NF-κB. Polyphenols can modulate miRNA (miR) expression, with these dietary polyphenols shown to downregulate tumor-promoting miR-21. CUR, EGCG, and RSV can upregulate tumor-suppressing miR-16, 34a, 145, and 200c, but downregulate tumor-promoting miR-25a. CGA, EGCG, and RSV downregulate tumor-suppressing miR-20a, 93, and 106b. The effects of miRs may combine with ROS-mediated pathways, enhancing the anticancer effects of these polyphenols. More precise analysis is needed to determine how the different modulations of miRs by polyphenols relate to the cancer site-specific differences found in epidemiological studies related to the consumption of foods containing these polyphenols.

A Primary Screening Method for Liver Cancer in Chronic Hepatitis B Carriers: A Prospective Community-Based Cohort Study

Background

Patients with hepatitis B virus (HBV) were invited to receive ultrasound and alpha-protein examination directly in China. However, not all HBV carriers need to be subjected to further tests. This study aimed to develop a feasible primary screening method to narrow down potential high-risk individuals of liver cancer among populations with HBV.

Methods

Based on a prospective community-based cohort, potential risk factors were selected as the predictors, including age, sex, smoking, alcohol consumption, diabetes, liver cancer family history, liver diseases in mothers, source of water, body mass index (BMI), and psychological trauma. Cox proportional regression model was applied to predict the 3-year absolute risk of liver cancer and derive risk scores. The area under receiver operating characteristic curve (AUROC) and calibration plot were used to assess the performance of the model. Bootstrap resampling was used for internal validation.

Results

Age, sex, BMI, alcohol consumption, liver diseases in mothers, and psychological trauma were independent risks of liver cancer. The 1- to 3-year AUROC of the prediction model was 71.15% (95% CI, 66.88–75.42), 71.16% (95% CI, 67.42–74.90), and 72.95% (95% CI, 64.20–81.70), respectively. The predicted risk was calibrated well with the observed liver cancer risk. Bootstrap resampling showed that C-index was 0.70 (0.67–0.74). A 32-point risk score was also developed and a score over 5 was identified for patients at extremely high risk.

Conclusions

A user-friendly primary screening method was created that could estimate the 3-year absolute risk of liver cancer and identify extremely high-risk individuals among the population with HBV.

Nutrition and melanoma prevention

There has been considerable research in recent years on dietary factors and/or nutritional elements that might impact melanoma risk. A wide variety of dietary compounds have been studied, but only a selected group will be discussed in this review. Many have promising in vitro evidence supporting their potential, and some have been associated with decreased melanoma risk in epidemiologic studies; however, data from randomized controlled trials in humans are lacking. Future studies may be able to clarify the potential role of dietary components in melanoma risk reduction.

Associations of tea consumption with blood pressure progression and hypertension incidence

BACKGROUND

Association between tea consumption and incident hypertension remains uncertain. This study conducted to examine the health effects of tea consumption on blood pressure progression and hypertension incidence.

METHODS

A population-based cohort of 38,913 Chinese participants without hypertension at baseline were included in the current study. Information on tea consumption was collected through standardized questionnaires. Associations of tea consumption with blood pressure progression and incident hypertension were analyzed using logistic regression models and Cox proportional hazards regression models, respectively.

RESULTS

During a median follow-up of 5.9 years, 17,657 individuals had experienced progression to a higher blood pressure stage and 5,935 individuals had developed hypertension. In multivariate analyses, habitual tea drinkers (≥ 3 times/week for at least six months) had a 17% lower risk for blood pressure progression [odds ratio (OR) = 0.83, 95% CI: 0.79–0.88] and a 14% decreased risk for incident hypertension [hazard ratio (HR) = 0.86, 95% CI: 0.80–0.91] compared with non-habitual tea drinkers. Individuals in different baseline blood pressure groups could obtain similar benefit from habitual tea drinking. In terms of tea consumption amount, an inverse, linear dose-response relation between monthly consumption of tea leaves and risk of blood pressure progression was observed, while the risk of incident hypertension did not reduce further after consuming around 100 g of tea leaves per month.

CONCLUSIONS

Our study demonstrated that habitual tea consumption could provide preventive effect against blood pressure progression and hypertension incidence.

Household Air Pollution From Solid Cooking Fuel Combustion and Female Breast Cancer

Background: Women bear a large share of disease burden caused by household air pollution due to their great involvement in domestic activities. Pollutant emissions are believed to vary by exposure patterns such as cooking and space heating. Little is known about the independent effect of solid cooking fuel combustion on breast cancer risk. We aimed to examine the association of indoor coal and wood combustion for cooking with breast cancer risk. Methods: During June 2004-July 2008, participants aged 30-79 from 10 diverse regions across China were enrolled in the China Kadoorie Biobank. Primary cooking fuel use information in up to three residences was self-reported at baseline. Multivariable logistic regression models yielded adjusted odds ratios (ORs) and 95% confidence intervals (CIs). Results: A total of 290,396 female participants aged 30-79 were included in the main analysis. Compared with long-term clean fuel users, the fully adjusted ORs were 2.07 (95%CI: 1.37-3.13) for long-term coal users, 1.12 (95% CI: 0.72-1.76) for long-term wood users, and 0.98 (95% CI: 0.55-1.74) for those who used mixed solid fuels to cook. Those who had switched from solid to clean fuels did not have an excess risk of breast cancer (OR: 0.88, 95%CI 0.71-1.10). Conclusion: Long-term solid fuel combustion for cooking may increase the risk of breast cancer. The strength of association is stronger among coal users than wood users. Targeted interventions are needed to accelerate the access to clean and affordable energy.

Association between alcohol consumption and oesophageal microbiota in oesophageal squamous cell carcinoma

BACKGROUND

Microbiota has been reported to play a role in cancer patients. Nevertheless, little is known about the association between alcohol consumption and resultant changes in the diversity and composition of oesophageal microbiota in oesophageal squamous cell carcinoma (ESCC).

METHODS

We performed a hospital-based retrospective study of 120 patients with pathologically diagnosed primary ESCC. The relevant information for all study participants were collected through a detailed questionnaire. The differences in adjacent tissues between non-drinkers and drinkers were explored using 16S rRNA gene sequencing. Raw sequencing data were imported into QIIME 2 to analyse the diversity and abundance of microbiota. Linear discriminant analysis effect size (LEfSe) and unconditional logistic regression were performed to determine the bacterial taxa that were associated with drinking.

RESULTS

The Shannon diversity index and Bray-Curtis distance of oesophageal microbiota were significantly different among drinkers(P < 0.05). The alcohol-related bacteria were primarily from the orders Clostridiales, Gemellales and Pasteurellales, family Clostridiaceae, Lanchnospiraceae, Helicobacteraceae, Alcaligenaceae, Bacteroidaceae, Pasteurellaceae and Gemellaceae; genus Clostridium, Helicobacter, Catonella, Bacteroides, Bacillus, Moraxella, and Bulleidia; and species B. moorei and longum (genus Bifidobacterium). In addition, the diversity and abundance of these microbiota were observed to be affected by the age, residential districts of the patients, and sampling seasons. Moreover, the higher the frequency and years of alcohol consumption, the lower was the relative abundance of genus Catonella that was observed.

CONCLUSION

Alcohol consumption is associated with alterations in both the diversity and composition the of the oesophageal microbiota in ESCC patients.

Diet and cancer of the esophagus and stomach

PURPOSE OF REVIEW

Dietary factors have been linked to cancers. This review focuses on several nutrients, which have strong evidence showing increase in cancer risks in the esophagus and stomach.

RECENT FINDINGS

Obesity is an important risk factor in upper gastrointestinal cancers. High sugar content in food and sugary drinks are the main drivers of obesity. Proinflammatory diet is another dietary factor, which is increasingly recognized as being associated with esophageal and gastric cancer.

SUMMARY

Cancer has been predicted to be the leading cause of death in this century. Cancers of the esophagus and stomach are the six and third most common cause of death worldwide. Although Helicobacter pylori infection is a known cause of gastric cancer, obesity is a leading contributor to esophageal adenocarcinoma. Epidemiological data have shown that dietary factors are associated with the two cancers. Observational, case control, animal and recent large cohort studies have identified associations between dietary factors and upper gastrointestinal cancer. Data are also emerging from studies, which look at dietary patterns, such as reduction in the Dietary Inflammatory Index, as well as adherence to a modified Mediterranean diet, and its association with the incidence of esophageal and gastric cancer.

Tea Consumption and the Risk of Endometrial Cancer: An Updated Meta-Analysis

Although the relationship between tea consumption and the risk of endometrial cancer has been previously analyzed in certain studies, the resulting information is still conflicting, and a previous meta-analysis yielded inconsistent results. Therefore, here, we aimed to perform an updated meta-analysis of studies on this subject in order to elucidate this relationship.We searched the literature on the PubMed, Web of Science, Scopus, and Chinese National Knowledge Infrastructure databases for studies that were published prior to September 25, 2019, and all the relevant references were examined. Ultimately, we included eight studies, and seven of them were on black tea. We used the overall relative risk values (RR) and 95% confidence intervals (CI) to evaluate the risk. The synthetic RR of the eight eligible studies demonstrated that tea consumption was not relevant to the incidence rate of endometrial cancer (RR 1.06, 95% CI 0.96, 1.18). No publication bias was found. We detected significant heterogeneity among the studies (Q = 15.84, p = 0.027, I² = 55.8%). In conclusion, the results of this meta-analysis indicate that tea consumption is not relevant to the incidence of endometrial cancer. Further research and cohort studies should be conducted to validate our result.

Association of tea consumption and the risk of gastric cancer in Japanese adults: the Japan Collaborative Cohort Study

OBJECTIVE

To examine the possible relationship between tea consumption and risk of gastric cancer (GC) among Japanese men and women included in a large Japanese population-based study titled the Japan Collaborative Cohort (JACC) Study.

DESIGN

Prospective cohort study.

SETTING

A population-based cohort included subjects who were recruited from 24 areas of JACC Study, in which data regarding the incidence of cancer were available.

PARTICIPANTS

63 848 participants (26 025 men and 37 823 women), aged 40-79, were included in the analyses and underwent follow-up (median 13.3 years) prospectively in research on cancer incidence.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcome variable was the risk of GC according to the frequency intakes of total tea, green tea, black tea and oolong tea. The adjusted HRs for the risk of GC associated with tea consumption were calculated using the Cox proportional hazards model.

RESULTS

1494 cases of GC were detected (960 men and 534 women) during the follow-up period. The multivariable-adjusted HRs for the risk of GC in the highest versus lowest quintiles of total tea intake were 1.05 (0.83-1.33); p trend=0.50 in men, and 0.82 (0.60-1.12); p trend=0.45 in women. There was no association found between the consumption of green tea, black tea or oolong tea with the risk for GC in either gender.

CONCLUSIONS

In this large community-based prospective cohort study, tea consumption was not associated with the risk of GC in either gender.

Objectives, design and main findings until 2020 from the Rotterdam Study

The Rotterdam Study is an ongoing prospective cohort study that started in 1990 in the city of Rotterdam, The Netherlands. The study aims to unravel etiology, preclinical course, natural history and potential targets for intervention for chronic diseases in mid-life and late-life. The study focuses on cardiovascular, endocrine, hepatic, neurological, ophthalmic, psychiatric, dermatological, otolaryngological, locomotor, and respiratory diseases. As of 2008, 14,926 subjects aged 45 years or over comprise the Rotterdam Study cohort. Since 2016, the cohort is being expanded by persons aged 40 years and over. The findings of the Rotterdam Study have been presented in over 1700 research articles and reports. This article provides an update on the rationale and design of the study. It also presents a summary of the major findings from the preceding 3 years and outlines developments for the coming period.

Tea consumption and colorectal cancer risk: a meta-analysis of prospective cohort studies

PURPOSE

Data from in vitro and animal studies support the preventive effect of tea (Camellia sinensis) against colorectal cancer. Further, many epidemiologic studies evaluated the association between tea consumption and colorectal cancer risk, but the results were inconsistent. We conducted a meta-analysis of prospective cohort studies to systematically assess the association between tea consumption and colorectal cancer risk.

METHODS

A comprehensive literature review was conducted to identify the related articles by searching PubMed and Embase up to June, 2019. Summary relative risks (RRs) and 95% confidence intervals (CIs) were calculated using a fixed effect model.

RESULTS

Twenty cohort articles were included in the present meta-analysis involving 2,068,137 participants and 21,437 cases. The combined RR of colorectal cancer for the highest vs. lowest tea consumption was determined to 0.97 (95% CI 0.94-1.01) with marginal heterogeneity (I² = 24.0%, P = 0.093) among all studies. This indicated that tea consumption had no significant association with colorectal cancer risk. Stratified analysis showed that no significant differences were found in all subgroups. We further conducted the gender-specific meta-analysis for deriving a more precise estimation. No significant association was observed between tea consumption and colorectal cancer risk in male (combined RR = 0.97; 95% CI 0.90-1.04). However, tea consumption had a marginal significant inverse impact on colorectal cancer risk in female (combined RR = 0.93; 95% CI 0.86-1.00). Further, we found a stronger inverse association between tea consumption and risk of colorectal cancer among the female studies with no adjustment of coffee intake (RR: 0.90; 95% CI 0.82-1.00, P < 0.05) compared to the female studies that adjusted for coffee intake (RR = 0.97; 95% CI 0.87-1.09, P > 0.05).

CONCLUSIONS

Our finding indicates that tea consumption has no significant impact on the colorectal cancer risk in both genders combined, but gender-specific meta-analysis shows that tea consumption has a marginal significant inverse impact on colorectal cancer risk in female.