Coffee consumption and reduced risk of hepatocellular carcinoma: findings from the Singapore Chinese Health Study

Low-Carbohydrate Diet Score and Risk of Hepatocellular Carcinoma: Findings from a Prospective Cohort Study

Limited data are reported on the association between low-carbohydrate diet (LCD) score, a comprehensive measure of dietary pattern according to sources of carbohydrate, fat, and protein, and risk of hepatocellular carcinoma (HCC). We evaluated this score with HCC risk in the Singapore Chinese Health Study, a prospective cohort of 63,275 middle-aged and elderly Chinese living in Singapore and recruited during 1993-1998 period. LCD scores were derived from the semi-quantitative food frequency questionnaire at baseline. A nested case-control study involved 197 HCC cases and 465 controls was also constructed among 28,346 participants who provided blood samples. Cox proportional hazard regression method was used to calculate HRs and 95% confidence intervals (CI) for HCC with different levels of LCD scores. Conditional logistic regression was performed for the case-control study analysis. After 17.6 years of follow-up with 819,573 person-years, 561 participants developed primary HCC. Although there was a null association between total LCD score and HCC risk (HRper-SD increment = 1.07; 95% CI, 0.98-1.16; Ptrend = 0.06), there was a positive association between animal-based LCD and the risk of HCC (HRper-SD increment = 1.11; 95% CI, 1.02-1.21; Ptrend = 0.01). Furthermore, this association was present in both HBsAg-negative and HBsAg-positive individuals in the case-control study. In stratified analysis for the entire cohort, this positive association was only present in those who consumed alcoholic beverages monthly or less frequent but not in weekly or daily drinker (Pinteraction = 0.79). In summary, a diet with lower carbohydrate, higher animal fat and protein was significantly associated with higher risk of HCC among Chinese Singaporeans.

PREVENTION RELEVANCE

In a large cohort study of more than 63,000 Chinese Singaporeans, we found that a diet with lower carbohydrate and higher animal fat and protein was associated with increased risk of HCC, suggesting that dietary modification could be an effective strategy in primary prevention to reduce the HCC burden.

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.

Consumption of Coffee, Tea, and Caffeine at Midlife, and the Risk of Physical Frailty in Late Life

OBJECTIVES

Our study evaluated the prospective association between the consumption of caffeine-containing beverages at midlife and the risk of physical frailty at late life within a population-based cohort of Chinese adults living in Singapore over a follow-up period of 20 years.

DESIGN

Prospective cohort study.

SETTING AND PARTICIPANTS

We used data from 12,583 participants from the baseline and third follow-up interviews of the Singapore Chinese Health Study (SCHS). Participants had a mean age of 53 years at baseline (1993-1998), and a mean age of 73 years during the third follow-up (2014-2017).

METHODS

At baseline, habitual consumption of caffeine-containing beverages was evaluated using a validated semi-quantitative food-frequency questionnaire. During the third follow-up, physical frailty was assessed using the modified Cardiovascular Health Study phenotype.

RESULTS

Compared with non-daily drinkers, those who drank 4 or more cups of coffee daily had reduced odds of physical frailty [odds ratio (OR), 0.54; 95% CI, 0.38-0.76]. Similarly, compared with those who hardly drank tea, participants who drank tea everyday also had reduced odds (OR, 0.82; 95% CI, 0.71-0.95). Total daily caffeine intake at midlife was associated with reduced likelihood of frailty at late life in a dose-response relationship (Ptrend < .001). Relative to their counterparts in the lowest quartile of daily caffeine intake (0-67.6 mg/d), participants in the highest quartile (223.0-910.4 mg/d) had an OR of 0.77 (95% CI, 0.66-0.91). Higher caffeine consumption was associated with lower likelihood of being in the slowest quintile for timed up-and-go (TUG) and weakest quintile for handgrip strength.

CONCLUSIONS AND IMPLICATIONS

In this cohort of Chinese adults, higher consumption of caffeine at midlife, via coffee and tea, was associated with a reduced likelihood of physical frailty in late life.

Dietary Patterns, Foods, and Nutrients to Ameliorate Non-Alcoholic Fatty Liver Disease: A Scoping Review

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease without pharmacological treatment yet. There is also a lack of specific dietary recommendations and strategies to treat the negative health impacts derived from NAFLD.

OBJECTIVE

This scoping review aimed to compile dietary patterns, foods, and nutrients to ameliorate NAFLD.

METHODS

A literature search was performed through MEDLINE, Scopus, Web of Science, and Google Scholar.

RESULTS

Several guidelines are available through the literature. Hypocaloric Mediterranean diet is the most accepted dietary pattern to tackle NAFLD. Coffee consumption (sugar free) may have a protective effect for NAFLD. Microbiota also plays a role in NAFLD; hence, fibre intake should be guaranteed.

CONCLUSIONS

A high-quality diet could improve liver steatosis. Weight loss through hypocaloric diet together with physical activity and limited sugar intake are good strategies for managing NAFLD. Specific dietary recommendations and a Mediterranean plate have been proposed to ameliorate NAFLD.

Effects of coffee intake on airway hypersensitivity and immunomodulation: an in vivo murine study

BACKGROUND/OBJECTIVES

Coffee is a complex chemical mixture, with caffeine being the most well-known bioactive substance. The immunomodulatory and anti-inflammatory properties of coffee and caffeine impact health in various aspects, including the respiratory system. The objective is to investigate the effects of coffee and caffeine on airway hyperresponsiveness and allergic reactions, as well as to analyze and compare associated cytokine profiles.

MATERIALS/METHODS

BALB/c mice were intraperitoneally sensitized with ovalbumin (OVA) and given OVA inhalation to induce airway hypersensitivity. Two weeks after sensitization, they were intragastrically gavaged with coffee or caffeine, both containing 0.3125 mg caffeine, daily for 4 weeks. Control mice were fed with double-distilled water. Serum OVA-specific antibody levels were measured beforehand and 5 weeks after the first gavage. Airway hyperresponsiveness was detected by whole body plethysmography after gavage. Cytokine levels of bronchoalveolar lavage and cultured splenocytes were analyzed.

RESULTS

Coffee effectively suppressed T helper 2-mediated specific antibody response. Airway responsiveness was reduced in mice treated with either coffee or caffeine. Compared to the control, coffee significantly reduced OVA-specific immunoglobulin (Ig) G, IgG1 and IgE antibody responses (P < 0.05). Caffeine also attenuated specific IgG and IgG1 levels, though IgE level was unaffected. Coffee significantly reduced interleukin (IL)-4 and increased IL-10 concentration in spleen cells and bronchoalveolar lavage fluid (P < 0.05).

CONCLUSIONS

Coffee effectively attenuated airway hyperresponsiveness and systemic allergic responses induced by OVA food allergen in mice. As a complex composition of bioactive substances, coffee displayed enhanced immunomodulatory and anti-inflammatory effects than caffeine.

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.

Targeted and Non-Targeted HPLC Analysis of Coffee-Based Products as Effective Tools for Evaluating the Coffee Authenticity

Coffee is a very popular beverage worldwide. However, its composition and characteristics are affected by a number of factors, such as geographical and botanical origin, harvesting and roasting conditions, and brewing method used. As coffee consumption rises, the demands on its high quality and authenticity naturally grows as well. Unfortunately, at the same time, various tricks of coffee adulteration occur more frequently, with the intention of quick economic profit. Many analytical methods have already been developed to verify the coffee authenticity, in which the high-performance liquid chromatography (HPLC) plays a crucial role, especially thanks to its high selectivity and sensitivity. Thus, this review summarizes the results of targeted and non-targeted HPLC analysis of coffee-based products over the last 10 years as an effective tool for determining coffee composition, which can help to reveal potential forgeries and non-compliance with good manufacturing practice, and subsequently protects consumers from buying overpriced low-quality product. The advantages and drawbacks of the targeted analysis are specified and contrasted with those of the non-targeted HPLC fingerprints, which simply consider the chemical profile of the sample, regardless of the determination of individual compounds present.

Caffeine in liver diseases: Pharmacology and toxicology

We have previously shown that adenosine A1AR antagonists, adenosine A2aAR antagonists, and caffeine have significant inhibitory effects on the activation and proliferation of hepatic stellate cells in alcoholic liver fibrosis. Many recent studies have found that moderate coffee consumption is beneficial for various liver diseases. The main active ingredient of coffee is caffeine, which is a natural non-selective adenosine receptor antagonist. Moreover, numerous preclinical epidemiological studies and clinical trials have examined the association between frequent coffee consumption and the risk of developing different liver diseases. In this review, we summarize and analyze the prophylactic and therapeutic effects of caffeine on various liver diseases, with an emphasis on cellular assays, animal experiments, and clinical trials. To review the prevention and treatment effects of caffeine on different liver diseases, we searched all literature before 19 July 2022, using “caffeine” and “liver disease” as keywords from the PubMed and ScienceDirect databases. We found that moderate coffee consumption has beneficial effects on various liver diseases, possibly by inhibiting adenosine binding to its receptors. Caffeine is a potential drug for the prevention and treatment of various liver diseases.

The role of dietary factors in nonalcoholic fatty liver disease to hepatocellular carcinoma progression: A systematic review

BACKGROUND AND AIMS

Dietary factors play an important role in promoting nonalcoholic fatty liver disease (NAFLD)-related hepatocellular carcinoma (HCC) development through regulation of metabolism and inflammation. However, so far there was no evidence regarding how dietary factors may influence different disease outcomes in the NAFLD to HCC progression. Our study aimed to comprehensively evaluate the role of dietary factors on the risk of progression from NAFLD to HCC.

METHODS

A comprehensive literature research was conducted in PubMed, Web of Science and Embase databases to identify case-control and cohort studies published up to March 15, 2022 in English. We included studies investigating associations of food and beverage items (excluding alcohol), food groups, dietary patterns, and dietary habits with incidence risk of four main chronic liver diseases involved in the NAFLD-to-HCC progression (i.e., NAFLD, liver fibrosis, liver cirrhosis, and HCC). Three researchers independently performed the literature search, selected eligible articles, performed data abstraction and evaluated study quality. After evaluating adequacy and credibility of the associations reported for each dietary factor and each liver disease outcome, we summarized and evaluated the consistency of associations based on a priori determined criteria considering study design and the proportion of significant associations.

RESULTS

There were 109 studies included in this review (47 on NAFLD, 1 on liver fibrosis, 6 on liver cirrhosis, and 55 on HCC). Consistent evidence suggested that higher dietary inflammatory potential was associated with increased risk of both NAFLD and HCC whereas Mediterranean diet was associated with lower risk of both diseases. Additionally, greater conformity to the Healthy Eating Index, Dietary Approaches to Stop Hypertension score, and Mediterranean Diet Score, and dietary patterns with high dietary antioxidant capacity reduced NAFLD risk. Some specific foods including soft drinks and red and/or processed meat were associated with increased NAFLD risk while total vegetables and spinach were associated with reduced NAFLD risk. Coffee and white meat consumption were inversely related to HCC risk.

CONCLUSIONS

Dietary patterns or individual foods representing a more anti-inflammatory potential were associated with reduced risk of both NAFLD and HCC, which implied diet-induced inflammation may impact NAFLD progression towards HCC.

Caffeine and EGCG Alleviate High-Trans Fatty Acid and High-Carbohydrate Diet-Induced NASH in Mice: Commonality and Specificity

Caffeine and epigallocatechin-3-gallate (EGCG), which respectively, are the main functional extracts from coffee and green tea, and present protective effects against non-alcoholic fatty liver diseases (NAFLD). These two beverages and their functional extracts are highly recommended as potential treatments for obesity and NAFLD in clinics; however, their pharmacodynamic effects and pharmacological mechanisms in non-alcoholic steatohepatitis (NASH) remain unclear. Therefore, the aim of this study was to explore the commonality and specificity of the pharmacodynamic effects and pharmacological mechanisms of caffeine and EGCG on NASH mice, which were fed with a high-trans fatty acid/high-carbohydrate (HFHC) diet. C57BL/6J mice were fed a normal diet (control group) or an HFHC diet (HFHC group) for 24 weeks. HFHC group mice were additionally treated with caffeine (75 mg/kg) or EGCG (100 mg/kg) for 6 weeks, using obeticholic acid (OCA,10 mg/kg) as a positive control group. The pharmacological effects of the drugs, including effects on glucose and lipid metabolism and liver inflammation and fibrosis, were evaluated. Gene expression in liver tissue samples from the different groups were assessed. Both caffeine and EGCG significantly reduced the liver manifestations of NASH induced by HFHC. The pathological aspects of liver lipid deposition, inflammation, and liver fibrosis in both groups were strongly ameliorated. Of note, most indexes were strongly reversed in the caffeine group, although AST activity, fasting blood glucose, and the HOMA-IR index were improved in the ECGC group. There were 714 differentially expressed genes between the caffeine and HFHC groups and 268 differentially expressed genes between the EGCG and HFHC groups. Twenty and 17 NASH-related KEGG signaling pathways were enriched by caffeine and EGCG. This study confirmed that 75 mg/kg caffeine and 100 mg/kg EGCG could significantly improve liver lipid deposition, glucose metabolism, inflammation, and fibrosis in a mouse model of NASH induced by HFHC. The bioinformatics platform we built for caffeine and EGCG in NASH disease found that the two drugs may greatly overlap in improving the mechanism related to NASH inflammation. However, caffeine may have better potential in regulating glucose metabolism and EGCG may have better potential in regulating lipid metabolism.

Coffee Consumption and Cancer Risk: An Assessment of the Health Implications Based on Recent Knowledge

A significant number of studies suggest that coffee consumption reduces cancer risk. This beneficial effect is usually ascribed to the presence of polyphenolic antioxidants and anti-inflammatory agents, including caffeine, cafestol, kahweol, and chlorogenic acids. To summarize recent literature on this subject, we performed a bibliographic search in PubMed and Embase over the period January 2005 to December 2020 to identify cohort studies and meta-analysis (with data collection ensuring quality of selected reports) that could provide quantitative data on the relationship between coffee consumption and common cancers. The totality of eligible scientific articles supports the evidence that coffee intake is inversely associated with risk of hepatocellular cancer and, to a slight extent, risk of breast cancer among postmenopausal women. As to the association with other organs, including the esophagus, pancreas, colorectum, kidneys, bladder, ovaries, and prostate, the results are less clear as reports reveal conflicting results or statistically nonsignificant data. Therefore, this overview does not provide broad-based conclusions. Important uncertainties include general study design, inhomogeneous patient sampling, different statistical analysis (deliberate), misreporting of socioeconomic status, education, coffee-brewing methods, consumption of caffeinated or decaffeinated coffee, smoking habits, and alcohol intake. Clearly, more epidemiologic research needs to be conducted before solid science-based recommendations can be made with regard to coffee consumption.

Effect of green coffee bean extract supplementation on liver function and inflammatory biomarkers: A meta-analysis of randomized clinical trials

Inflammation is considered a major contributor to non-alcoholic fatty liver disease (NAFLD) and several chronic diseases such as, cardiovascular disease and type two diabetes. Green coffee bean extract (GCBE) supplementation has been suggested to enhancing antioxidant capacity in people with obesity but results across studies are mixed. We conducted a meta-analysis of randomized controlled trials of GCBE supplementation in overweight/obese with normal liver function and NAFLD adults with ALT, AST, γ-GTP, ALP, LDH, CRP, IL-6, and TNF-α as outcomes by searching PubMed and other databases. Eight studies were included, totaling 330 participants randomized to GCBE supplementation or placebo ranging from 50 mg/day to 1200 mg/day for 8-12 weeks. GCBE supplementation resulted in lower levels of TNF-α (mean difference = 1.37 pg/mL [95% CI = 0.97-1.76]; p < 0.00001). No significant difference was found in the remaining markers. In conclusion, GCBE supplementation attenuated TNF-α, a circulating inflammatory marker mediator which may be linked with lower systemic inflammation. However, potential cellular and molecular mechanisms by which GCBE exerts this positive effect warrants further investigations in human model studies.

Composite Score of Healthy Lifestyle Factors and Risk of Hepatocellular Carcinoma: Findings from a Prospective Cohort Study

BACKGROUND

While the associations between individual lifestyle factors and risk of hepatocellular carcinoma (HCC) have been described previously, their combined impact on HCC risk is unknown.

METHODS

The association of a composite score of healthy lifestyle factors, including body mass index, alcohol consumption, cigarette smoking, alternative Mediterranean diet, and sleep duration, and HCC risk was examined in the Singapore Chinese Health Study, an ongoing prospective cohort study of 63,257 Chinese men and women. Cox proportional hazard regression method was used to estimate HR and its 95% confidence interval (CI). Conditional logistic regression method was used to evaluate this composite lifestyle score-HCC risk association among a subset of individuals who tested negative for hepatitis B surface antigen (HBsAg) and anti-hepatitis C antibody.

RESULTS

After a mean follow-up of 17.7 years, 561 participants developed HCC. Individuals with higher composite scores representing healthier lifestyles (range 0-8) were at significantly lower risk of HCC. Compared with the lowest composite score category (0-4), the HRs (95% CIs) for the composite scores of 5, 6, 7, and 8 were 0.67 (0.62-0.85), 0.61 (0.48-0.77), 0.49 (0.37-0.65), and 0.13 (0.06-0.30), respectively (P trend < 0.0001). A similar inverse association was observed in participants with negative HBsAg and anti-hepatitis C virus (HCV)-negative serology (HR, 0.38; 95% CI, 0.19-0.79; for the highest vs. the lowest category of the composite scores; P trend = 0.001).

CONCLUSIONS

Healthy lifestyles protect against HCC development, especially for individuals without hepatitis B virus and HCV infections.

IMPACT

This study highlights the importance of a comprehensive lifestyle modification strategy for HCC primary prevention.

The Association between Diet and Hepatocellular Carcinoma: A Systematic Review

Globally, liver cancer is the sixth most common cause of cancer mortality, with hepatocellular carcinoma (HCC) being the most common type of primary liver cancer. Emerging evidence states that diet is recognised as a potential lifestyle-related risk factor for the development of HCC. The aim of this systematic review is to determine whether there is an association between diet and the development of HCC. Using the PRISMA guidelines, three databases (MEDLINE Complete, CINAHL and Embase) were systematically searched, and studies published until July 2020 were included. Thirty observational studies were selected. The protocol was registered with PROSPERO (CRD42019135240). Higher adherence to the Mediterranean dietary pattern, Alternative Healthy Eating Index-2010, the Urban Prudent Dietary Pattern, the Traditional Cantonese Dietary Pattern, intake of vegetables, wholegrains, fish, poultry, coffee, macronutrients such as monounsaturated fats and micronutrients such as vitamin E, vitamin B9, β-carotene, manganese and potassium were associated with a reduced risk of HCC. The results suggest a potential role of diet in the development of HCC. Further quantitative research needs to be undertaken within a range of populations to investigate diet and the relationship with HCC risk.

Effects of coffee roasting technologies on cup quality and bioactive compounds of specialty coffee beans

The effects of drum, fluidized bed, and traditional type of coffee roasting technologies on the cup quality and bioactive compounds of Yirgacheffe, Harar, and Sidama variety specialty coffee beans grown in Ethiopia were investigated at light, medium, and dark degree of roast from 150°C to 200°C for 7 to 15 min. No significant differences in cup quality were detected among the roasted coffee varieties disregard of the type of roasters. Varietal difference was found to have significant (p < .05) effect on caffeine content of the coffee beans. A significant reduction in trigonelline and total chlorogenic acids content of the coffee beans was observed during roasting process, with darker roasts attaining the least values. Drum roaster was found to be the best type of coffee roaster for specialty coffee beans at medium degree of roast with the highest cup quality, optimum bioactive compounds content, and minimum acrylamide formation. However, traditional roaster resulted at the least average cup score of 80% among the three coffee samples and the highest acrylamide content of 2.306 mg/L for Yirgacheffe coffee sample at light degree of roast. There are still some bottlenecks that need to be addressed via advancements using novel food processing technologies in order to devise the next generation of coffee processing.

Association between Dietary Tomato Intake and the Risk of Hepatocellular Carcinoma: The Singapore Chinese Health Study

BACKGROUND

Intake of tomato and/or lycopene has been associated with reduced risk of several cancers, but there is no report on the association with risk of hepatocellular carcinoma (HCC).

METHODS

The associations of tomato and lycopene consumption with risk of HCC were examined in the Singapore Chinese Health Study, a prospective cohort of 63,257 Chinese ages 45 to 74 years at enrollment. Diet was assessed using a validated semiquantitative food frequency questionnaire. Cox proportional hazard regression models were used to estimate HR and its 95% confidence interval (CI) of HCC with the consumption of tomato and lycopene among all cohort participants, and unconditional logistic regression was used to assess the association by hepatitis B surface antigen (HBsAg) positivity in a nested case-control study.

RESULTS

After a mean follow-up of 17.6 years, 561 incident HCC cases were identified. Higher tomato intake was associated with lower risk of HCC after adjustment for potential confounders (P _trend < 0.001). Compared with the lowest quartile, HRs (95% CIs) of HCC for the second, third, and fourth quartile of tomato intake were 0.70 (0.56-0.88), 0.73 (0.58-0.92), and 0.63 (0.49-0.81). Among HBsAg-negative individuals, the inverse association remained (P _trend = 0.03). There was no association between lycopene intake and HCC risk (P _trend = 0.54).

CONCLUSIONS

Tomato intake may offer protection against the development of HCC, particularly among individuals without chronic infection with hepatitis B virus.

IMPACT

Tomato intake is a low-cost preventative measure against HCC that may help reduce risk due to increasing rates of nonalcoholic fatty liver disease.

Green tea (Camellia sinensis) for the prevention of cancer

BACKGROUND

This review is an update of a previously published review in the Cochrane Database of Systematic Reviews (2009, Issue 3).Tea is one of the most commonly consumed beverages worldwide. Teas from the plant Camellia sinensis can be grouped into green, black and oolong tea, and drinking habits vary cross-culturally. C sinensis contains polyphenols, one subgroup being catechins. Catechins are powerful antioxidants, and laboratory studies have suggested that these compounds may inhibit cancer cell proliferation. Some experimental and nonexperimental epidemiological studies have suggested that green tea may have cancer-preventative effects.

OBJECTIVES

To assess possible associations between green tea consumption and the risk of cancer incidence and mortality as primary outcomes, and safety data and quality of life as secondary outcomes.

SEARCH METHODS

We searched eligible studies up to January 2019 in CENTRAL, MEDLINE, Embase, ClinicalTrials.gov, and reference lists of previous reviews and included studies.

SELECTION CRITERIA

We included all epidemiological studies, experimental (i.e. randomised controlled trials (RCTs)) and nonexperimental (non-randomised studies, i.e. observational studies with both cohort and case-control design) that investigated the association of green tea consumption with cancer risk or quality of life, or both.

DATA COLLECTION AND ANALYSIS

Two or more review authors independently applied the study criteria, extracted data and assessed methodological quality of studies. We summarised the results according to diagnosis of cancer type.

MAIN RESULTS

In this review update, we included in total 142 completed studies (11 experimental and 131 nonexperimental) and two ongoing studies. This is an additional 10 experimental and 85 nonexperimental studies from those included in the previous version of the review. Eleven experimental studies allocated a total of 1795 participants to either green tea extract or placebo, all demonstrating an overall high methodological quality based on 'Risk of bias' assessment. For incident prostate cancer, the summary risk ratio (RR) in the green tea-supplemented participants was 0.50 (95% confidence interval (CI) 0.18 to 1.36), based on three studies and involving 201 participants (low-certainty evidence). The summary RR for gynaecological cancer was 1.50 (95% CI 0.41 to 5.48; 2 studies, 1157 participants; low-certainty evidence). No evidence of effect of non-melanoma skin cancer emerged (summary RR 1.00, 95% CI 0.06 to 15.92; 1 study, 1075 participants; low-certainty evidence). In addition, adverse effects of green tea extract intake were reported, including gastrointestinal disorders, elevation of liver enzymes, and, more rarely, insomnia, raised blood pressure and skin/subcutaneous reactions. Consumption of green tea extracts induced a slight improvement in quality of life, compared with placebo, based on three experimental studies. In nonexperimental studies, we included over 1,100,000 participants from 46 cohort studies and 85 case-control studies, which were on average of intermediate to high methodological quality based on Newcastle-Ottawa Scale 'Risk of bias' assessment. When comparing the highest intake of green tea with the lowest, we found a lower overall cancer incidence (summary RR 0.83, 95% CI 0.65 to 1.07), based on three studies, involving 52,479 participants (low-certainty evidence). Conversely, we found no association between green tea consumption and cancer-related mortality (summary RR 0.99, 95% CI 0.91 to 1.07), based on eight studies and 504,366 participants (low-certainty evidence). For most of the site-specific cancers we observed a decreased RR in the highest category of green tea consumption compared with the lowest one. After stratifying the analysis according to study design, we found strongly conflicting results for some cancer sites: oesophageal, prostate and urinary tract cancer, and leukaemia showed an increased RR in cohort studies and a decreased RR or no difference in case-control studies.

AUTHORS' CONCLUSIONS

Overall, findings from experimental and nonexperimental epidemiological studies yielded inconsistent results, thus providing limited evidence for the beneficial effect of green tea consumption on the overall risk of cancer or on specific cancer sites. Some evidence of a beneficial effect of green tea at some cancer sites emerged from the RCTs and from case-control studies, but their methodological limitations, such as the low number and size of the studies, and the inconsistencies with the results of cohort studies, limit the interpretability of the RR estimates. The studies also indicated the occurrence of several side effects associated with high intakes of green tea. In addition, the majority of included studies were carried out in Asian populations characterised by a high intake of green tea, thus limiting the generalisability of the findings to other populations. Well conducted and adequately powered RCTs would be needed to draw conclusions on the possible beneficial effects of green tea consumption on cancer risk.

Coffee, green tea and liver cancer risk: an evaluation based on a systematic review of epidemiologic evidence among the Japanese population

BACKGROUND

Coffee and green tea, two popular drinks in the Japanese, have recently drawn much attention as potential protective factors against the occurrence of liver cancer.

METHODS

We systematically reviewed epidemiologic studies on coffee, green tea and liver cancer among Japanese populations. Original data were obtained by searching the MEDLINE (PubMed) and Ichushi databases, complemented with manual searches. The evaluation was performed in terms of the magnitude of association in each study and the strength of evidence ('convincing', 'probable', 'possible', or 'insufficient'), together with biological plausibility.

RESULTS

We identified four cohort and four case-control studies on coffee and liver cancer and six cohort and one case-control studies on green tea and liver cancer. All cohort and case-control studies on coffee reported a weak to strong inverse association, with a summary relative risk (RR) for one cup increase being 0.72 (95% confidence interval [CI] 0.66-0.79). Conversely, all studies but two cohort studies on green tea reported no association, with a corresponding summary RR of 0.99 (95% CI 0.97-1.01, P = 0.37).

CONCLUSION

Coffee drinking 'probably' decreases the risk of primary liver cancer among the Japanese population whereas the evidence on an association between green tea and liver cancer is 'insufficient' in this population.

Increased Coffee Intake Reduces Circulating HBV DNA and HBsAg Levels in HBeAg-Negative Infection: A Cohort Study

Coffee is hepatoprotective and potentially antiviral; however, its anti-hepatitis B virus (anti-HBV) property is not known in humans. This study investigated the influence of coffee drinking behaviour as well as clinical and biochemical profiles of hepatitis B e antigen (HBeAg) negative participants on circulating HBV DNA and hepatitis B surface antigen (HBsAg) levels at a 24-week interval. Exactly 114 chronically HBV-infected adult participants were enrolled from the University of Malaya Medical Centre (UMMC), Malaysia. A significant reduction of HBV DNA level was observed in those drinking three or more cups of coffee per day, with a median reduction of 523 IU/mL (P = 0.003). Reduction of HBsAg level was observed in those drinking two cups per day, with a median reduction of 37 IU/mL (P < 0.001). Multivariate analysis showed that increased coffee intake (P = 0.015) and lower ALT level (P = 0.033) were the significant predictors for a lower HBV DNA level, whereas increased coffee intake (P = 0.002) and having a family history of HBV infection (P = 0.021) were the significant predictors for a lower HBsAg level. These data suggest that drinking three cups or more coffee per day reduces circulating HBV DNA and HBsAg levels.

Impact of Nutritional Changes on Nonalcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD) is a major global health threat due to its growing incidence and prevalence. It is becoming the leading cause of liver disease in addition to its strong association with cardio-metabolic disease. Therefore, its prevention and treatment are of strong public interest. Therapeutic approaches emphasize lifestyle modifications including physical activity and the adoption of healthy eating habits that intend to mainly control body weight and cardio-metabolic risk factors associated with the metabolic syndrome. Lifestyle interventions may be reinforced by pharmacological treatment in advanced stages, though there is still no registered drug for the specific treatment of NAFLD. The purpose of this review is to assess the evidence available regarding the impact of dietary recommendations against NAFLD, highlighting the effect of macronutrient diet composition and dietary patterns in the management of NAFLD.

Synergistic cytotoxicity and mechanism of caffeine and lysozyme on hepatoma cell line HepG2

The influences of caffeine, lysozyme and the joint application of them on the hepatoma cell line HepG2 proliferation inhibition and cell apoptosis were observed by 3-(4, 5-dimethyl-2-thiazyl)-2, 5-diphenyl-2H-tetrazolium bromide assay and Hoechst 33342, which showed the proliferation inhibition rate of the joint application on HepG2 cells was 47.21%, significantly higher than caffeine or lysozyme, and the joint application promoted the apoptosis of HepG2 cells obviously. Van't Hoff classical thermodynamics formula, the Föster theory of non-radiation energy transfer and fluorescence phase diagram were used to manifest that the process of lysozyme binding to caffeine followed a two-state model, which was spontaneous at low temperature driven by enthalpy change, and the predominant intermolecular force was hydrogen bonding or Van der Waals force to stabilize caffeine-lysozyme complex with the distance 5.86nm. The attenuated total reflection-Fourier transform infrared spectra indicated that caffeine decreased the relative contents of α-helix and β-turn, which inferred the structure of lysozyme tended to be "loose". Synchronous fluorescence spectra and ultraviolet spectra supported the above conclusion. The amino acid residues in the cleft of lysozyme were exposed and electropositivity was increased attributing to the loose structure, which were conducive to increasing caffeine concentration on the HepG2 cell surface by electrostatic interaction to show synergistic effect.

Coffee consumption and disease correlations

Coffee is one of the most widely consumed beverages in the world. It has primarily consumed due to its stimulant effect and unique taste since the ancient times. Afterwards, its consumption has been historically associated with a lower risk of some diseases such as type 2 diabetes mellitus, obesity, cardiovascular disease and some type of cancer and thus it has also consumed due to health benefits. It contains many bioactive compounds such as caffeine, chlorogenic acids and diterpenoid alcohols which have so far been associated with many potential health benefits. For example, caffeine reduces risk of developing neurodegenerative disease and chlorogenic acids (CGA) and diterpene alcohols have many health benefits such as antioxidant and chemo-preventive. Coffee also have harmful effects. For example, diterpenoid alcohols increases serum homocysteine and cholesterol levels and thus it has adverse effects on cardiovascular system. Overall, the study that supports the health benefits of coffee is increasing. But, it is thought-provoking that the association with health benefits of coffee consumption and frequency at different levels in each study. For this reason, we aimed to examine the health effect of the coffee and how much consumption is to investigate whether it meets the claimed health benefits.

Coffee Consumption and Risk of Biliary Tract Cancers and Liver Cancer: A Dose-Response Meta-Analysis of Prospective Cohort Studies

Background: A meta-analysis was conducted to summarize the evidence from prospective cohort and case-control studies regarding the association between coffee intake and biliary tract cancer (BTC) and liver cancer risk. Methods: Eligible studies were identified by searches of PubMed and EMBASE databases from the earliest available online indexing year to March 2017. The dose–response relationship was assessed by a restricted cubic spline model and multivariate random-effect meta-regression. A stratified and subgroup analysis by smoking status and hepatitis was performed to identify potential confounding factors. Results: We identified five studies on BTC risk and 13 on liver cancer risk eligible for meta-analysis. A linear dose–response meta-analysis did not show a significant association between coffee consumption and BTC risk. However, there was evidence of inverse correlation between coffee consumption and liver cancer risk. The association was consistent throughout the various potential confounding factors explored including smoking status, hepatitis, etc. Increasing coffee consumption by one cup per day was associated with a 15% reduction in liver cancer risk (RR 0.85; 95% CI 0.82 to 0.88). Conclusions: The findings suggest that increased coffee consumption is associated with decreased risk of liver cancer, but not BTC.

Coffee, including caffeinated and decaffeinated coffee, and the risk of hepatocellular carcinoma: a systematic review and dose-response meta-analysis

OBJECTIVES

To examine the association between coffee, including caffeinated and decaffeinated coffee, with hepatocellular carcinoma (HCC) and assess the influence of HCC aetiology and pre-existing liver disease.

DESIGN

We performed a systematic review and meta-analysis. We calculated relative risks (RRs) of HCC according to caffeinated and decaffeinated coffee consumption using a random-effects dose-response meta-analysis. We tested for modification of the effect estimate by HCC aetiology and pre-existing liver disease. We judged the quality of evidence using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) criteria.

RESULTS

We found 18 cohorts, involving 2 272 642 participants and 2905 cases, and 8 case-control studies, involving 1825 cases and 4652 controls. An extra two cups per day of coffee was associated with a 35% reduction in the risk of HCC (RR 0.65, 95% CI 0.59 to 0.72). The inverse association was weaker for cohorts (RR 0.71, 95% CI 0.65 to 0.77), which were generally of higher quality than case-control studies (RR 0.53, 95% CI 0.41 to 0.69). There was evidence that the association was not significantly altered by stage of liver disease or the presence/absence of high alcohol consumption, high body mass index, type 2 diabetes mellitus, smoking, or hepatitis B and C viruses. An extra two cups of caffeinated and decaffeinated coffee (2 and 3 cohort studies, respectively) were associated with reductions of 27% (RR 0.73, 95% CI 0.63 to 0.85) and 14% (RR 0.86, 95% CI 0.74 to 1.00) in the risk of HCC. However, due to a lack of randomised controlled trials, potential publication bias and there being no accepted definition of coffee, the quality of evidence under the GRADE criteria was 'very low'.

CONCLUSIONS

Increased consumption of caffeinated coffee and, to a lesser extent, decaffeinated coffee are associated with reduced risk of HCC, including in pre-existing liver disease. These findings are important given the increasing incidence of HCC globally and its poor prognosis.

Daily Coffee Intake Inhibits Pancreatic Beta Cell Damage and Nonalcoholic Steatohepatitis in a Mouse Model of Spontaneous Metabolic Syndrome, Tsumura-Suzuki Obese Diabetic Mice

BACKGROUND

Metabolic syndrome is one of the most important health issues worldwide. Obesity causes insulin resistance, hyperlipidemia, diabetes, and various diseases throughout the body. The liver phenotype, which is called nonalcoholic steatohepatitis (NASH), frequently progresses to hepatocellular carcinoma. We recently established a new animal model, Tsumura-Suzuki obese diabetic (TSOD) mice, which spontaneously exhibit obesity, diabetes, hyperlipidemia, and NASH with liver nodules.

METHODS

We examined the effects of coffee intake on various conditions of the metabolic syndrome using TSOD mice. The daily volume of coffee administered was limited so that it reflected the appropriate quantities consumed in humans. To clarify the effects of the specific components, animals were divided into two coffee-intake groups that included with and without caffeine.

RESULTS

Coffee intake did not significantly affect obesity and hyperlipidemia in TSOD mice. In contrast, coffee intake caused various degrees of improvement in the pancreatic beta cell damage and steatohepatitis with liver carcinogenesis. Most of the effects were believed to be caused by a synergistic effect of caffeine with other components such as polyphenols. However, the antifibrotic effects of coffee appeared to be due to the polyphenols rather than the caffeine.

CONCLUSIONS

A daily habit of drinking coffee could possibly play a role in the prevention of metabolic syndrome.

An updated dose-response meta-analysis of coffee consumption and liver cancer risk

Prospective cohort studies of the relationship between coffee consumption and liver cancer risk have drawn different conclusions. Therefore, a dose-response meta-analysis of prospective cohort studies was performed to disentangle this causal relationship. Prospective cohort studies of the association between coffee consumption and liver cancer risk published prior to Jan 9, 2016 were identified by searching in the PubMed and EMBASE databases. Extracted data were analyzed using a random-effects model. Of the 2892 records identified using the search strategy, a total of twenty cohort studies from ten publications were included in the final meta-analysis. The pooled estimate of relative risk (RR) with 95% confidence interval (CI) for highest vs. non/occasional coffee drinkers was 0.55(0.44–0.67). No evidence of publication bias was observed (p for Egger’s test = 0.229). Sensitivity analysis indicated the results were robust. Dose-response analysis revealed a significant linear dose-response relationship between coffee consumption and liver cancer risk (p = 0.36). Subgroup analyses stratified by pre-specified variables (gender, geographic region, and adjusted factors) indicated similar results within individual subgroups. Our meta-analysis suggested that coffee consumption is inversely associated with liver cancer risk.

Coffee and cancer risk: A meta-analysis of prospective observational studies

Meta-analyses on coffee and cancer incidence mainly restricted to limited cancers. We carried out a more comprehensive meta-analysis of cohort studies to explore association between coffee and most cancer types. We conducted comprehensive search and summarized relative risk (RR) and 95% confidence intervals for the highest versus lowest coffee intake and cancer using STATA12. We conducted dose-analysis if result suggested significant association. The publication bias was evaluated with begg's and egger's test. Finally, 105 individual prospective studies were included. Inverse associations were observed on oral, pharyngeal, colon, liver, prostate, endometrial cancer and melanoma, with RR 0.69 (95% CI = 0.48-0.99, I² = 73.4%, P = 0.044), 0.87 (95% CI = 0.78-0.96, I² = 28.4%, P = 0.007), 0.46 (95% CI = 0.37-0.57, I² = 0%, P = 0), 0.89 (95% CI = 0.84-0.93, I² = 30.3%, P = 0.003), 0.73 (95% CI = 0.67-0.80, I²  = 0%, P = 0) and 0.89 (95% CI = 0.80-0.99, I²  = 0%, P = 0.031) respectively. However, the relative risk for lung cancer is 2.18 (95% CI = 1.26-3.75, I²  = 63.3%, P = 0.005). The summary relative risk for increment of 2 cups of coffee were RR = 0.73, 95% CI = 0.67-0.79 for liver cancer, RR = 0.97, 95% CI = 0.96-0.98 for prostate cancer and RR = 0.88, 95% CI = 0.85-0.92 for endometrial cancer. Accordingly, coffee intake was associated with reduced risk of oral, pharynx, liver, colon, prostate, endometrial cancer and melanoma and increased lung cancer risk.

Exercise and diet in the management of nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is the most prevalent chronic liver condition worldwide, and is projected to become the leading cause for liver transplantation in the United States as early as 2020. The mainstay of treatment remains lifestyle modification with diet and exercise recommendations, as although some pharmacological treatments such as glitazones and Vitamin E have shown benefit, there are concerns regarding long term safety. The evidence base for dietary interventions in NAFLD such as the Mediterranean diet, omega-3 polyunsaturated fatty acids and coffee is mainly derived from observational data with questionable validity. Where trials exist, they have shown benefit for surrogate outcomes such as hepatic steatosis and insulin resistance, but no trials have been conducted with salient clinical outcomes such as reduction in progression to chronic liver disease. Benefit in surrogate outcomes has also been seen for aerobic, anaerobic and combined modality exercise but it remains unclear if one type is superior. Furthermore, a reduction in sedentary time appears equally important. To provide a sound evidence base for lifestyle recommendations to people with NAFLD, longer duration trials of standardized dietary or exercise interventions, and testing various doses, types and with liver related outcomes, are essential.

Coffee consumption and risk of hepatocellular carcinoma: a meta-analysis of eleven epidemiological studies

Growing evidence has shown that coffee consumption is inversely related with the risk of hepatocellular carcinoma. It is suggested that caffeine maintains strong antioxidative activity. With this property, coffee intake may lead to the inhibition of cell proliferation of liver cancer cells; also, some compounds contained in coffee can reduce the genotoxicity of aflatoxin B1 in vitro and lower the damage caused by some carcinogens. A computerized search was performed in PubMed to identify relevant articles published before August 2015. Eleven relevant studies were included with a total of 2,795 cases and 340,749 control subjects. According to the meta-analysis we performed, the pooled odds ratio (OR) from all included studies was 0.49 (95% confidence interval [CI] =0.46–0.52). The subgroup analysis indicated that the pooled ORs for Asian studies and other populations were 0.27 (95% CI =0.23–0.31) and 0.82 (95% CI =0.77–0.87), respectively. The overall pooled OR for high consumption was decreased to 0.21 (95% CI =0.18–0.25) and significance was observed. Among other populations, the pooled OR of subjects with high coffee consumption was 0.65 (95% CI =0.56–0.73) compared to the nondrinker. The corresponding OR of five Asian studies was 0.13 (95% CI =0.09–0.17). The findings from this meta-analysis further confirmed the inverse association between the coffee consumption and hepatocellular carcinoma risk with quantitative evidence. The protective effect can be detected among healthy population and patients with chronic liver diseases, and the consumption can also prevent the development of liver cirrhosis.

Lifestyle and Dietary Interventions in the Management of Nonalcoholic Fatty Liver Disease

NAFLD is the leading cause of chronic liver disease in the Western world with an estimated prevalence of 20-30 %. Lifestyle interventions targeted at weight loss through dietary interventions and exercise are the most effective treatment, but only a minority of patients are able to achieve and sustain the necessary intervention targets. Weight loss of 3-5 % has been associated with a reduction of hepatic steatosis while weight loss of ≥5-7 % has correlated with resolution of NASH in some studies. Greater reductions in weight loss (≥10 %) may improve hepatic fibrosis. In the absence of weight loss, no specific diet has demonstrated superiority. Physical activity can improve hepatic steatosis and metabolic indices even without weight loss. Diet coupled with exercise can produce significant weight loss and may improve histologic components of the NAFLD activity score. While formal guidelines for diet and exercise in NAFLD are lacking, adherence to diet and exercise recommendations similar to those from the American Diabetes Association for diabetic care seems reasonable. Dietary supplementation with vitamin E in non-diabetics with biopsy-proven NASH has been shown to improve NAFLD activity score. The role for other macronutrients, micronutrients, antioxidants, and probiotics in the treatment of NAFLD remains limited.

Management of NAFLD: a stage-based approach

NAFLD is the most prevalent form of liver disease in the USA, affecting an estimated 30% of the population. The condition is associated with increased mortality related to cardiovascular disease, malignancy and liver disease. Identification of patients who might be at increased risk of adverse outcomes is critical as it is not feasible to screen all patients with suspected NAFLD. Patients with NASH, the progressive subtype of NAFLD, should be targeted for treatment, especially if they have concomitant fibrosis because such patients are more likely than those without fibrosis to have adverse outcomes. Treatment goals in patients with NAFLD vary depending on the disease stage owing to differential risk of progression and the particularities of an individual's comorbid disease. Lifestyle intervention is important for all patients irrespective of disease stage, but other therapies should be targeted to those most likely to benefit. In this Review, we highlight risk factors for disease progression and offer a stage-based treatment approach for patients with NAFLD.

Natural antioxidants for non-alcoholic fatty liver disease: molecular targets and clinical perspectives

Non-alcoholic steatohepatitis (NASH), the progressive form of non-alcoholic fatty liver disease (NAFLD), is emerging as a main health problem in industrialized countries. Lifestyle modifications are effective in the treatment of NAFLD; however, the long-term compliance is low. Therefore, several pharmacological treatments have been proposed but none has shown significant efficacy or long-term safety. Natural polyphenols are a heterogeneous class of polyphenolic compounds contained in vegetables, which are being proposed for the treatment of different metabolic disorders. Although the beneficial effect of these compounds has traditionally related to their antioxidant properties, they also exert several beneficial effects on hepatic and extra-hepatic glucose and lipid homeostasis. Furthermore, natural polyphenols exert antifibrogenic and antitumoural effects in animal models, which appear relevant from a clinical point of view because of the association of NASH with cirrhosis and hepatocellular carcinoma. Several polyphenols, such anthocyanins, curcumin and resveratrol and those present in coffee, tea, soy are available in the diet and their consumption can be proposed as part of a healthy diet for the treatment of NAFLD. Other phenolic compounds, such as silymarin, are commonly consumed worldwide as nutraceuticals or food supplements. Natural antioxidants are reported to have beneficial effects in preclinical models of NAFLD and in pilot clinical trials, and thus need clinical evaluation. In this review, we summarize the existing evidence regarding the potential role of natural antioxidants in the treatment of NAFLD and examine possible future clinical applications.

Caffeine reduces hepatic lipid accumulation through regulation of lipogenesis and ER stress in zebrafish larvae

BACKGROUND

Caffeine, the main component of coffee, has showed its protective effect on non-alcoholic fatty liver disease (NAFLD) in many studies. However, the hepatoprotection of caffeine and its mechanisms in zebrafish were unexplored. Thus, this study's intentions are to establish a NAFLD model of zebrafish larvae and to examine the role of caffeine on fatty liver with the model.

RESULTS

Growth and the incidence of fatty liver of zebrafish larvae increased with the increased amount of feeding in a dose-dependent manner. The degree of hepatic steatosis of larvae also gradually aggravated with the increased quantity and duration of feeding. Triglyceride contents of zebrafish fed for 20 days significantly increased in model group (180 mg/d) compared with control group (30 mg/d) (P < 0.001). Significant decreases in body weight and hepatic steatosis rate were observed in 2.5, 5, 8 % caffeine treatment group compared with model group (P < 0.05). Hepatic lipid accumulation was also significantly reduced in caffeine treatment larvae. Moreover, caffeine treatment was associated with upregulation of lipid β-oxidation gene ACO and downregulation of lipogenesis-associated genes (SREBP1, ACC1, CD36 and UCP2), ER stress-associated genes (PERK, IRE1, ATF6 and BIP), the inflammatory cytokine genes (IL-1beta and TNF-alpha) and autophagy associated genes (ATG12 and Beclin-1). Protein expression of CHOP, BIP and IL-1beta remarkably reduced in caffeine treatment group compared with model group.

CONCLUSIONS

We induced hepatoteatosis in zebrafish by overfeeding regimen and demonstrated caffeine have a role in suppression of hepatosteatosis by downregulation of genes associated with lipogenesis, ER stress, inflammatory response and enhancement of lipid oxidation, indicating zebrafish model may be used to identify putative pharmacological targets and to test novel drugs for human NAFLD treatment.

Downregulation of mPGES-1 Expression via EGR1 Plays an Important Role in Inhibition of Caffeine on PGE2 Synthesis of HBx(+) Hepatocytes

We investigated the mechanism of caffeine in influencing HBx(+) hepatocytes to synthesize PGE₂. The inhibitory effect of caffeine on hepatocyte proliferation increased with increasing caffeine concentrations (200–800 μM) and treatment times (1–7 days), which was first observed at the second test time point (caffeine treatment for 4 days). The inhibition of caffeine on the growth of HL7702-HBx and HepG2-HBx cells was most obvious at 800 μM caffeine and at caffeine treatment for 7 days. The PGE₂ secretion and the expression of mPGES-1 and EGR1 were downregulated, whereas PPARγ expression was upregulated. The mPGES-1 promoter activity of HBx(+) hepatocytes decreased more significantly than that of HBx(−) hepatocytes. Moreover, the expression of EGR1 and PPARγ changed more significantly in HBx(+) hepatocytes cultured for 12 to 24 hours in the presence of 5 mM caffeine. This limited success may be attributed to caffeine releasing the binding of HBx and PPARγ and furthermore affecting the mPGES-1 expression by EGR1 in HBx(+) hepatocytes. The results indicate that caffeine could effectively reduce PGE₂ synthesis in HBx(+) hepatocytes by specifically blocking the PPARγ-EGR1-mPGES-1 pathway, thereby providing a new evidence of molecular biology for the hypothesis that drinking coffee is beneficial to HBV-infected patients.

Green tea and liver cancer risk: A meta-analysis of prospective cohort studies in Asian populations

OBJECTIVES

The aim of this meta-analysis was to investigate whether an association existed between green tea consumption and the risk for liver cancer in prospective cohort studies in Asian populations.

METHODS

Relevant studies were identified by searching PubMed, EMBASE, ISI Web of Science, and the Chinese Bio-medicine Database published before April 2015. Study-specific risk estimates for the highest versus non- or lowest and increment of daily cup of green tea consumption levels were combined based on fixed- or random-effects models. STATA 11.0 (Stata Corporation, College Station, TX, USA) software was used for statistical analysis.

RESULTS

Nine prospective cohort articles involving 465,274 participants and 3694 cases of liver cancer from China, Japan, and Singapore were included. The summary relative risk (RR) indicated a significant association between the highest green tea consumption and reduced risk for liver cancer (summary RR, 0.88; 95% confidence interval [CI], 0.81-0.97). However, no statistically significant association was observed when analyzing daily consumption of one cup (summary RR, 0.97; 95% CI, 0.95-1.00). When stratified by sex, the protective effect of green tea consumption on risk for liver cancer was observed only in the group of women (summary RR, 0.78; 95% CI, 0.64-0.96), but not in men (summary RR, 0.89; 95% CI, 0.79-1.00).

CONCLUSIONS

The present analysis indicated the preventive effects of green tea intake on the risk for liver cancer in female Asian populations. However, additional studies are needed to make a convincing case for this association.

Oxidation of olive oil fortified with quercetin, caffeic acid, tyrosol and hydroxytyrosol

Purpose

– This paper aims to evaluate effects of the fortification of polyphenolic compound mixtures of quercetin, caffeic acid, tryrosol and hydroxytyrosol in olive oil oxidation.

Design/methodology/approach

– The authors measured olive oxidation initiated by copper using thiobarbituric acid reactive substance, as an indicator of lipid peroxidation.

Findings

– Overall, most mixture combinations exhibited oxidation similar to olive oil alone. Some mixture combinations of polyphenolic compounds acted as antioxidants; however, as the concentrations were changed, they became prooxidant in nature.

Research limitations/implications

– In vitro studies have limitations for extrapolation to in vivo and clinical studies.

Practical implications

– Such information will be useful in determining optimal concentrations and combinations of antioxidants for reducing rancidity and perhaps as models that could be used to modulate various chronic diseases that are associated with oxidative stress.

Originality/value

– Olive oil, along with fruits, vegetables and fish, are important constituents of health promoting diets, such as the Mediterranean diet. Active ingredients include monounsaturated fatty acids, oleic acid and a variety of antioxidants including various polyphenolic compounds.

Coffee, tea and decaffeinated coffee in relation to hepatocellular carcinoma in a European population: multicentre, prospective cohort study

Inverse associations of coffee and/or tea in relation to hepatocellular carcinoma (HCC) risk have been consistently identified in studies conducted mostly in Asia where consumption patterns of such beverages differ from Europe. In the European Prospective Investigation into Cancer and nutrition (EPIC), we identified 201 HCC cases among 486,799 men/women, after a median follow-up of 11 years. We calculated adjusted hazard ratios (HRs) for HCC incidence in relation to quintiles/categories of coffee/tea intakes. We found that increased coffee and tea intakes were consistently associated with lower HCC risk. The inverse associations were substantial, monotonic and statistically significant. Coffee consumers in the highest compared to the lowest quintile had lower HCC risk by 72% [HR: 0.28; 95% confidence intervals (CIs): 0.16-0.50, p-trend < 0.001]. The corresponding association of tea with HCC risk was 0.41 (95% CI: 0.22-0.78, p-trend = 0.003). There was no compelling evidence of heterogeneity of these associations across strata of important HCC risk factors, including hepatitis B or hepatitis C status (available in a nested case-control study). The inverse, monotonic associations of coffee intake with HCC were apparent for caffeinated (p-trend = 0.009), but not decaffeinated (p-trend = 0.45) coffee for which, however, data were available for a fraction of subjects. Results from this multicentre, European cohort study strengthen the existing evidence regarding the inverse association between coffee/tea and HCC risk. Given the apparent lack of heterogeneity of these associations by HCC risk factors and that coffee/tea are universal exposures, our results could have important implications for high HCC risk subjects.

Levels of caffeine and its metabolites among U.S. smokers and nonsmokers

Data from National Health and Nutrition Examination Survey for the years 2009-2010 were used to estimate the levels of caffeine and 14 of its metabolite among U.S. smokers and nonsmokers after adjustments were made for other factors that affect observed caffeine levels. In this study, when adjusted for daily caffeine intake, adjusted levels (AGM) of caffeine and its metabolites were not found to be statistically significantly different between smokers and nonsmokers. AGMs for caffeine and all of its metabolites were found to be statistically significantly higher (p < 0.01) among females aged ≥ 12 years than males. For caffeine, 1,3-dimethylxanthine, and 1,7-dimethylxanthine, those aged ≥ 20 years had statistically significantly higher (p < 0.01) AGM than those aged 12-19 years but the reverse was true for 7-methylxanthine and 3,7-dimethylxanthine (p ≤ 0.02). The order of the AGMs by race/ethnicity was non-Hispanic whites > Hispanics > non-Hispanic blacks and most of the differences were statistically significant, at least between non-Hispanic whites and non-Hispanic blacks (p < 0.01). In general, there was a statistically significant positive association between the levels of caffeine and its metabolites and body mass index as well as daily caffeine intake. However, the levels of 7-methylxanthine were negatively associated with body mass index.

Inhibitory Effects of Caffeic Acid, a Coffee-Related Organic Acid, on the Propagation of Hepatitis C Virus

Multipurpose cohort studies have demonstrated that coffee consumption reduces the risk of hepatocellular carcinoma (HCC). Given that one of the main causes of HCC is hepatitis C virus (HCV) infection, we examined the effect of caffeic acid, a major organic acid derived from coffee, on the propagation of HCV using an in vitro naïve HCV particle-infection and production system within human hepatoma-derived Huh-7.5.1-8 cells. When cells were treated with 1% coffee extract or 0.1% caffeic acid for 1-h post HCV infection, the amount of HCV particles released into the medium at 3 and 4 days post-infection considerably decreased. In addition, HCV-infected cells cultured with 0.001% caffeic acid for 4 days, also released less HCV particles into the medium. Caffeic acid treatment inhibited the initial stage of HCV infection (i.e., between virion entry and the translation of the RNA genome) in both HCV genotypes 1b and 2a. These results suggest that the treatment of cells with caffeic acid may inhibit HCV propagation.

Hepatocellular carcinoma epidemiology

Primary liver cancer (namely hepatocellular carcinoma, HCC) is worldwide the fifth most common cancer in men and the seventh one in women, and it represents the third most frequent cause of cancer death. HCC rates are particularly high in eastern/south-eastern Asia and in Africa, intermediate in Southern Europe, and low in most high-income countries. Persistent infections by HBV or HCV are the main recognized risk factors for HCC. Aflatoxin exposure is also an important risk factor for HCC development in Africa and eastern Asia. In high-income countries heavy alcohol drinking, tobacco smoking, overweight, diabetes, familial/genetic factors, and selected dietary aspects, have a relevant role. Updated geographic patterns and time trends in mortality from HCC in Europe, USA, Japan, and Australia are provided in the present review, together with an overview of relevant etiologic factors for HCC and main measures for the prevention of this neoplasm.

The impact of diet and nutrition in the prevention and progression of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the third leading cause of cancer mortality worldwide. There is growing evidence for a chemopreventive role of nutrition in the development of HCC in at risk populations. Bibliographical searches were performed in PubMed for the terms 'nutrition and hepatocellular carcinoma', 'nutrition and liver cancer', 'nutrition and hepatic cancer', 'diet and hepatocellular carcinoma', 'diet and liver cancer'. High dietary sugar intake should be discouraged in at risk populations. Coffee, polyphenols, vanadium, dietary fibre, fruits and vegetables show encouraging results in terms of chemoprevention. Red meat intake may be associated with increased risk of HCC. The evidence for fatty acids is inconclusive, but they might exert anti-cancer effects. Inconclusive results are available on vitamins, selenium probiotics and prebiotics. There is increasing evidence that diet may play an important role in the development of HCC, and may also have a chemopreventive role in at risk populations.