Associations between tea and coffee beverage consumption and the risk of lung cancer in the Singaporean Chinese population

The impact of coffee consumption on human health

Coffee consumption is a key aspect of modern lifestyle. Caffeine, the major component of coffee, has an impact on various human tissues and organs after being absorbed in the gastrointestinal tract. Its beneficial effects on reducing both the incidence of many diseases, including cancer, and overall mortality has been described. According to most cohort studies, coffee has a positive impact on cardiovascular diseases as it lowers the risk of cardiovascular diseases and does not increase blood pressure. Meta-analyses suggest a protective effect of caffeine contained in coffee on neurological disorders such as migraines, dementia, and slowing the progression of Alzheimer’s disease and Parkinson’s disease. However, research on malignant tumour development in humans is inconsistent. On the one hand, caffeine contained in coffee has been shown to significantly reduce the risk of breast cancer, endometrial cancer and prostate cancer. On the other hand, most meta-analyses have shown an association between coffee intake and an increased prevalence of lung cancer. In some cases, it can even lead to significant rise in morbidity. The positive impact of chlorogenic acid (a polyphenol in coffee) administered with doxorubicin has been described in in vitro and in vivo lung cancer studies.

A systematic review and dose-response meta-analysis of prospective cohort studies on coffee consumption and risk of lung cancer

Studies on the association between coffee consumption and risk of lung cancer have been conflicting. The aim of this study was to systematically review the current evidence on the association between coffee consumption and risk of lung cancer and to quantify this association by performing a meta-analysis. A comprehensive systematic search was performed on online databases up to July 2023 investigating the association between coffee consumption and risk of lung cancer. All prospective cohort studies reporting odds ratios (ORs), rate or risk ratios (RRs), or hazard ratios (HRs) and 95% confidence intervals (CIs) in this context were included. The overall effect size was calculated using the random-effects model and statistical between-studies heterogeneity was examined using Cochrane's Q test and I2. A total of 14 prospective cohort studies were included in this systematic review and meta-analysis. We found a significant positive association between coffee consumption and risk of lung cancer (RR: 1.28; 95% CI: 1.12, 1.47). This association remained significant when we included a pooled analysis paper and excluded 5 cohort studies (RR: 1.37; 95% CI: 1.12, 1.66). We observed no proof of significant publication bias using Egger's test (P = 0.58). Moreover, dose-response analysis showed that each one cup/day increase in coffee consumption was related with a 6% higher lung cancer risk (RR: 1.06; 95% CI: 1.03, 1.09). In conclusion, we found a significant positive association between coffee consumption and risk of lung cancer.

Functional Tea Extract Inhibits Cell Growth, Induces Apoptosis, and Causes G0/G1 Arrest in Human Hepatocellular Carcinoma Cell Line Possibly through Reduction in Telomerase Activity

The functional tea CFT-1 has been introduced into China as a nutraceutical beverage according to the "Healthy China" national project. The effects on human hepatocellular carcinoma (HCC) cells remain unclear and were investigated with the functional tea extract (purity > 98%). The morphological changes in the cells were observed with microscopes. Cell proliferation, migration, cycle distribution, and apoptotic effects were assessed by MTT, Transwell assays, and flow cytometry, respectively, while telomerase inhibition was evaluated with telomerase PCR ELISA assay kits. The CFT-1 treatment resulted in cell shrinkage, nuclear pyknosis, and chromatin condensation. CFT-1 suppressed the growth of Hep3B cells with IC50 of 143 μg/mL by inducing apoptosis and G0/G1 arrest in Hep3B cells. As for the molecular mechanism, CFT-1 treatment can effectively reduce the telomerase activity. The functional tea extract inhibits cell growth in human HCC by inducing apoptosis and G0/G1 arrest, possibly through a reduction in telomerase activity. These results indicate that CFT-1 extract exhibited in vitro anticancer activities and provided insights into the future development and utilization of CFT-1 as functional foods to inhibit the proliferation of HCC cells.

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.

Lung Cancer and Lifestyle Factors: Umbrella Review

This review explores the effect of common everyday factors, such as alcohol, tea and coffee consumption, on the risk for lung cancer. We performed an umbrella review of current systematic reviews. The risk for lung cancer was increased with alcohol or coffee intake and decreased with tea intake. While evidence for alcohol is of low quality, the effect of coffee may be confounded by the smoking effect. The protective effect of tea intake is present, but the evidence is also of low quality.

Possible Mechanisms of Dark Tea in Cancer Prevention and Management: A Comprehensive Review

Tea is one of the most popular drinks in the world. Dark tea is a kind of post-fermented tea with unique sensory characteristics that is produced by the special fermentation of microorganisms. It contains many bioactive substances, such as tea polyphenols, theabrownin, tea polysaccharides, etc., which have been reported to be beneficial to human health. This paper reviewed the latest research on dark tea's potential in preventing and managing cancer, and the mechanisms mainly involved anti-oxidation, anti-inflammation, inhibiting cancer cell proliferation, inducing cancer cell apoptosis, inhibiting tumor metastasis, and regulating intestinal flora. The purpose of this review is to accumulate evidence on the anti-cancer effects of dark tea, the corresponding mechanisms and limitations of dark tea for cancer prevention and management, the future prospects, and demanding questions about dark tea's possible contributions as an anti-cancer adjuvant.

Dietary Heat-Treatment Contaminants Exposure and Cancer: A Case Study from Turkey

In this study, the 10-year dietary habits of patients diagnosed with cancer (n = 1155) were retrospectively analyzed, and the relationships between dietary (red meat, white meat, fish meat, French fries, bread, instant coffee, ready-to-drink coffee, Turkish coffee, and black tea) heterocyclic amines, polycyclic aromatic hydrocarbons, acrylamide, and N-nitrosamine-based risk scores and cancer types were statistically evaluated. The foods with the highest and lowest mean dietary heat-treatment contaminant risk scores were red meat and ready-to-drink coffee, respectively. There were statistically significant differences in the dietary heat-treatment contamination risk scores based on the cancer patients' demographic characteristics (sex, age, smoking, and body mass index) (p < 0.05). According to the cancer types, the systems with the highest and lowest dietary heat-treatment contaminant risk scores were determined as other (brain, thyroid, lymphatic malignancies, skin, oro- and hypopharynx, and hematology) and the reproductive (breast, uterus, and ovary) system, respectively. The relationship between instant coffee consumption and respiratory system cancer types, the frequency of consumption of French fries and urinary system cancer types and the consumption of meat products and gastrointestinal system cancer types were determined. It is thought that this study contains important findings regarding the relationship between dietary habits and cancer and will be a good source for other studies to be conducted in this context.

Health Benefits of Coffee Consumption for Cancer and Other Diseases and Mechanisms of Action

Coffee is one of the most widely consumed beverages worldwide, and epidemiology studies associate higher coffee consumption with decreased rates of mortality and decreased rates of neurological and metabolic diseases, including Parkinson's disease and type 2 diabetes. In addition, there is also evidence that higher coffee consumption is associated with lower rates of colon and rectal cancer, as well as breast, endometrial, and other cancers, although for some of these cancers, the results are conflicting. These studies reflect the chemopreventive effects of coffee; there is also evidence that coffee consumption may be therapeutic for some forms of breast and colon cancer, and this needs to be further investigated. The mechanisms associated with the chemopreventive or chemotherapeutic effects of over 1000 individual compounds in roasted coffee are complex and may vary with different diseases. Some of these mechanisms may be related to nuclear factor erythroid 2 (Nrf2)-regulated pathways that target oxidative stress or pathways that induce reactive oxygen species to kill diseased cells (primarily therapeutic). There is evidence for the involvement of receptors which include the aryl hydrocarbon receptor (AhR) and orphan nuclear receptor 4A1 (NR4A1), as well as contributions from epigenetic pathways and the gut microbiome. Further elucidation of the mechanisms will facilitate the potential future clinical applications of coffee extracts for treating cancer and other inflammatory diseases.

Tea consumption and risk of bladder cancer in the Bladder Cancer Epidemiology and Nutritional Determinants (BLEND) Study: Pooled analysis of 12 international cohort studies

BACKGROUND & AIMS

Tea has been shown to be associated with reduced risk of several diseases including cardiovascular diseases, stroke, metabolic syndrome, and obesity. However, the results on the relationship between tea consumption and bladder cancer are conflicting. This research aimed to assess the association between tea consumption and risk of bladder cancer using a pooled analysis of prospective cohort data.

METHODS

Individual data from 532,949 participants in 12 cohort studies, were pooled for analyses. Cox regression models stratified by study centre was used to estimate hazard ratios (HR) and corresponding 95% CIs. Fractional polynomial regression models were used to examine the dose-response relationship.

RESULTS

A higher level of tea consumption was associated with lower risk of bladder cancer incidence (compared with no tea consumption: HR = 0.87, 95% C.I. = 0.77-0.98 for low consumption; HR = 0.86, 95% C.I. = 0.77-0.96 for moderate consumption; HR = 0.84, 95% C.I. = 0.75-0.95 for high consumption). When stratified by sex and smoking status, this reduced risk was statistically significant among men and current and former smokers. In addition, dose-response analyses showed a lower bladder cancer risk with increment of 100 ml of tea consumption per day (HR-increment = 0.97; 95% CI = 0.96-0.98). A similar inverse association was found among males, current and former smokers while never smokers and females showed non-significant results, suggesting potential sex-dependent effect.

CONCLUSIONS

Higher consumption of tea is associated with reduced risk of bladder cancer with potential interaction with sex and smoking status. Further studies are needed to clarify the mechanisms for a protective effect of tea (e.g. inhibition of the survival and proliferation of cancer cells and anti-inflammatory mechanisms) and its interaction with smoking and sex.

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.

Tea combats circadian rhythm disorder syndrome via the gut-liver-brain axis: potential mechanisms speculated

Circadian rhythm is an intrinsic mechanism developed by organisms to adapt to external environmental signals. Nowadays, owing to the job and after-work entertainment, staying up late - Circadian rhythm disorders (CRD) are common. CRD is linked to the development of fatty liver, type 2 diabetes, and chronic gastroenteritis, which affecting the body's metabolic and inflammatory responses via multi-organ crosstalk (gut-liver-brain axis, etc.). However, studies on the mechanisms of multi-organ interactions by CRD are still weak. Current studies on therapeutic agents for CRD remain inadequate, and phytochemicals have been shown to alleviate CRD-induced syndromes that may be used for CRD-therapy in the future. Tea, a popular phytochemical-rich beverage, reduces glucolipid metabolism and inflammation. But it is immature and unclear in the mechanisms of alleviation of CRD-mediated syndrome. Here, we have analyzed the threat of CRD to hosts and their offspring' health from the perspective of the "gut-liver-brain" axis. The potential mechanisms of tea in alleviating CRD were further explored. It might be by interfering with bile acid metabolism, tryptophan metabolism, and G protein-coupled receptors, with FXR, AHR, and GPCR as potential targets. We hope to provide new perspectives on the role of tea in the prevention and mitigation of CRD.HighlightsThe review highlights the health challenges of CRD via the gut-liver-brain axis.CRD research should focus on the health effects on healthy models and its offspring.Tea may prevent CRD by regulating bile acid, tryptophan, and GPCR.Potential targets for tea prevention and mitigation of CRD include FXR, AHR and GPCR.A comprehensive assessment mechanism for tea in improving CRD should be established.

Black Tea Alleviates Particulate Matter-Induced Lung Injury via the Gut-Lung Axis in Mice

Black tea, as the most consumed kind of tea, is shown to have beneficial effects on human health. However, its impact on particulate matter (PM) induced lung injury and the mechanisms involved have been sparsely addressed. Here, we show that PM-exposed mice exhibited oxidative stress and inflammation in the lungs, which was significantly alleviated by a daily intake of black tea infusion (TI) in a concentration-dependent manner. Interestingly, both the ethanol-soluble fraction (ES) and the ethanol precipitate fraction (EP) exhibited better effects than those of TI; moreover, EP tended to have stronger protection than ES in some indicators, implying that EP played a dominant role in the prevention effects. Furthermore, fecal microbiota transplantation (FMT) revealed that the gut microbiota was differentially reshaped by TI and its fractions were able to directly alleviate the injury induced by PMs. These results indicate that daily intake of black tea and its fractions, especially EP, may alleviate particulate matter-induced lung injury via the gut-lung axis in mice. In addition, the Lachnospiraceae_NK4A136_group could be the core gut microbe contributing to the protection of EP and thus should be further studied in the future.

Association between Coffee Consumption/Physical Exercise and Gastric, Hepatic, Colon, Breast, Uterine Cervix, Lung, Thyroid, Prostate, and Bladder Cancer

Although the effects of coffee consumption and physical exercise on the risk of cancer have been suggested, their interactions have not been investigated. The present cross-sectional study aimed to investigate the correlation of coffee consumption and physical exercise with cancer. Participants ≥40 years old in the Korean Genome and Epidemiology Study 2004–2016 were included (n = 162,220). Histories of gastric cancer, hepatic cancer, colon cancer, breast cancer, uterine cervix cancer, lung cancer, thyroid cancer, prostate cancer, and bladder cancer were analyzed according to the coffee consumption groups using logistic regression models. The odds among individuals in the >60 cups/month coffee group were lower for gastric cancer (adjusted odds ratio (aOR) = 0.80 (95% confidence intervals = 0.65–0.98)), hepatic cancer (0.32 (0.18–0.58)), colon cancer (0.53 (0.39–0.72)), breast cancer (0.56 (0.45–0.70)), and thyroid cancer (0.71 (0.59–0.85)) than for individuals in the no coffee group. Physical exercise of ≥150 min/week was correlated with higher odds for gastric cancer (1.18 (1.03–1.36)), colon cancer (1.52 (1.26–1.83)), breast cancer (1.53 (1.35–1.74)), thyroid cancer (1.42 (1.27–1.59)), and prostate cancer (1.61 (1.13–2.28)) compared to no exercise. Coffee consumption and physical exercise showed an interaction in thyroid cancer (p = 0.002). Coffee consumption was related to a decreased risk of gastric cancer, hepatic cancer, colon cancer, breast cancer, and thyroid cancer in the adult population. Physical exercise was positively correlated with gastric cancer, colon cancer, breast cancer, thyroid cancer, and prostate cancer.

Low frequency variants associated with leukocyte telomere length in the Singapore Chinese population

The role of low frequency variants associated with telomere length homeostasis in chronic diseases and mortalities is relatively understudied in the East-Asian population. Here we evaluated low frequency variants, including 1,915,154 Asian specific variants, for leukocyte telomere length (LTL) associations among 25,533 Singapore Chinese samples. Three East Asian specific variants in/near POT1, TERF1 and STN1 genes are associated with LTL (Meta-analysis P 2.49×10-14-6.94×10-10). Rs79314063, a missense variant (p.Asp410His) at POT1, shows effect 5.3 fold higher and independent of a previous common index SNP. TERF1 (rs79617270) and STN1 (rs139620151) are linked to LTL-associated common index SNPs at these loci. Rs79617270 is associated with cancer mortality [HR95%CI = 1.544 (1.173, 2.032), PAdj = 0.018] and 4.76% of the association between the rs79617270 and colon cancer is mediated through LTL. Overall, genetically determined LTL is particularly associated with lung adenocarcinoma [HR95%CI = 1.123 (1.051, 1.201), Padj = 0.007]. Ethnicity-specific low frequency variants may affect LTL homeostasis and associate with certain cancers.

The association between dietary vitamin B12 and lung cancer risk: findings from a prospective cohort study

BACKGROUND

Since previous epidemiological studies reported inconsistent associations between dietary vitamin B12 intake and lung cancer risk, more studies are warranted to clarify this association in different populations.

METHODS

The association between dietary B12 intake and lung cancer risk was examined in the Singapore Chinese Health Study, an ongoing prospective cohort study of 63 257 Singaporean Chinese men and women, 45-74 years of age at enrollment during 1993-1998 and were followed up for incidence of lung cancer for up to 25 years. Dietary vitamin B12 intake was derived from a validated food frequency questionnaire. Cox proportional hazard regression method was used to estimate hazard ratio and 95% confidence interval (CI) of lung cancer associated with dietary vitamin B12 intake with adjustment for multiple potential confounders.

RESULTS

After a mean follow-up of 17.64 years, 2001 study participants developed lung cancer. High levels of vitamin B12 intake were associated with significantly increased risk of lung cancer (Ptrend = 0.03). Compared with the lowest quintile, hazard ratios (95% CIs) of lung cancer for quintile 2, 3, 4, and 5 of vitamin B12 intake were 1.09 (0.95-1.25), 1.11 (0.96-1.28), 1.11 (0.97-1.29) and 1.18 (1.03-1.35), respectively. This positive association was more apparent in men than in women, in adenocarcinoma patients, or in participants with equal or less than 2 years follow-up than those with longer duration of follow-up.

CONCLUSION

Higher intake of dietary vitamin B12 was associated with increased risk of lung cancer. This highlights the potential harmful effect of vitamin B12 supplementation for lung cancer.

Anti-Cancer Effects of Green Tea Epigallocatchin-3-Gallate and Coffee Chlorogenic Acid

Tea and coffee are consumed worldwide and epidemiological and clinical studies have shown their health beneficial effects, including anti-cancer effects. Epigallocatechin gallate (EGCG) and chlorogenic acid (CGA) are the major components of green tea polyphenols and coffee polyphenols, respectively, and believed to be responsible for most of these effects. Although a large number of cell-based and animal experiments have provided convincing evidence to support the anti-cancer effects of green tea, coffee, EGCG, and CGA, human studies are still controversial and some studies have suggested even an increased risk for certain types of cancers such as esophageal and gynecological cancers with green tea consumption and bladder and lung cancers with coffee consumption. The reason for these inconsistent results may have been arisen from various confounding factors. Cell-based and animal studies have proposed several mechanisms whereby EGCG and CGA exert their anti-cancer effects. These components appear to share the common mechanisms, among which one related to reactive oxygen species is perhaps the most attractive. Meanwhile, EGCG and CGA have also different target molecules which might explain the site-specific differences of anti-cancer effects found in human studies. Further studies will be necessary to clarify what is the mechanism to cause such differences between green tea and coffee.