Caffeine is protective in patients with non-alcoholic fatty liver disease

Glucagon-induced extracellular cAMP regulates hepatic lipid metabolism

Hormonal signals help to maintain glucose and lipid homeostasis in the liver during the periods of fasting. Glucagon, a pancreas-derived hormone induced by fasting, promotes gluconeogenesis through induction of intracellular cAMP production. Glucagon also stimulates hepatic fatty acid oxidation but the underlying mechanism is poorly characterized. Here we report that following the acute induction of gluconeogenic genes Glucose 6 phosphatase (G6Pase) and Phosphoenolpyruvate carboxykinase (Pepck) expression through cAMP-response element-binding protein (CREB), glucagon triggers a second delayed phase of fatty acid oxidation genes Acyl-coenzyme A oxidase (Aox) and Carnitine palmitoyltransferase 1a (Cpt1a) expression via extracellular cAMP. Increase in extracellular cAMP promotes PPARα activity through direct phosphorylation by AMP-activated protein kinase (AMPK), while inhibition of cAMP efflux greatly attenuates Aox and Cpt1a expression. Importantly, cAMP injection improves lipid homeostasis in fasted mice and obese mice, while inhibition of cAMP efflux deteriorates hepatic steatosis in fasted mice. Collectively, our results demonstrate the vital role of glucagon-stimulated extracellular cAMP in the regulation of hepatic lipid metabolism through AMPK-mediated PPARα activation. Therefore, strategies to improve cAMP efflux could serve as potential new tools to prevent obesity-associated hepatic steatosis.

Nonalcoholic steatohepatitis in morbid obese patients: coffee consumption vs. disease severity

INTRODUCTION

Obesity correlates with nonalcoholic fatty liver disease (NAFLD) and occurs in 90 to 100% of severely obese individuals (body mass index [BMI] > 35 kg/m2). Coffee consumption (CC) has been associated with reduced progression of fibrosis in both hepatitis C infection and NAFLD; however, this topic is still under discussion when this liver disease affects severely obese individuals.

OBJECTIVE

To assess the association between CC, insulin resistance (IR) and histological NAFLD morbid obese patients.

MATERIAL AND METHODS

Cross-sectional study, including obese individuals undergoing bariatric surgery, liver biopsy and histological diagnosis between September 2013 and August 2014. The patients were classified into 3 groups according to their weekly CC: 0- 239.9 mL; 240-2099.9 mL and ≥ 2100 mL.

RESULTS

A total of 112 obese individuals were included (BMI = 41.9 ± 4.3 kg/m2), with a mean age of 34.7 ± 7.4 years; 68.6% were women. CC was reported by 72.3% of patients. There were no statistical significant differences between groups regarding the presence of IR (84.8% vs. 74.2% vs. 75.9%; p = 0.536). Progressively higher percentages of individuals with normal liver histology were observed (14.7% vs. 21.9% vs. 24.3%). NASH (65.7% vs. 70.3% vs. 57.5%) were observed among those who consumed greater coffee volumes (p = 0.812). In conclusion, obese individuals with elevated CC exhibited lower frequencies of NASH, although with no statistical significance in this sample.

Nutrition Interventions for Chronic Liver Diseases and Nonalcoholic Fatty Liver Disease

The progressively increasing rates of obesity have led to a worldwide epidemic of nonalcoholic fatty liver disease (NAFLD), the hepatic manifestation of the metabolic syndrome. It is currently the most common cause of liver disease worldwide and projected to be the leading indication for liver transplantation in the United States by 2020. NAFLD is associated with both liver-related and overall mortality. Undoubtedly, nutrition interventions are key in the treatment of NAFLD, to reverse the disease, and prevent disease progression, complications, and associated comorbidities, including cardiovascular disease and diabetes.

Coffee consumption protects against progression in liver cirrhosis and increases long-term survival after liver transplantation

BACKGROUND

Therapeutic options to treat progression of end-stage liver disease (ESLD) or improve long-term survival after liver transplantation remain scarce. We investigated the impact of coffee consumption under these conditions.

METHODS

We recorded coffee consumption habits of 379 patients with ESLD awaiting liver transplantation and 260 patients after liver transplantation. Survival was analyzed based on coffee intake.

RESULTS

One hundred ninety-five patients with ESLD consumed coffee on a daily basis, while 184 patients did not. Actuarial survival was impaired (P = 0.041) in non-coffee drinkers (40.4 ± 4.3 months, 95% confidence interval [CI]: 32.0-48.9) compared with coffee drinkers (54.9 ± 5.5 months, 95% CI: 44.0-65.7). In subgroup analysis, the survival of patients with alcoholic liver disease (ALD; P = 0.020) and primary sclerosing cholangitis (PSC; P = 0.017) was increased with coffee intake while unaffected in patients with chronic viral hepatitis (P = 0.517) or other liver disease entities (P = 0.652). Multivariate analysis showed that coffee consumption of PSC and ALD patients retained as an independent risk factor (odds ratio [OR]: 1.94; 95% CI: 1.15-3.28; P = 0.013) along with MELD score (OR: 1.13; 95% CI: 1.09-1.17; P = 0.000). Following liver transplantation, long-term survival was longer in coffee drinkers (coffee: 61.8 ± 2.0 months, 95% CI: 57.9-65.8) than non-drinkers (52.3 ± 3.5 months, 95% CI: 45.4-59.3; P = 0.001).

CONCLUSIONS

Coffee consumption delayed disease progression in ALD and PSC patients with ESLD and increased long-term survival after liver transplantation. We conclude that regular coffee intake might be recommended for these patients.

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.

Beneficial Role of Coffee and Caffeine in Neurodegenerative Diseases: A Minireview

Coffee is among the most widespread and healthiest beverages in the world. Coffee typically contains more caffeine than most other beverages, and is widely and frequently consumed. Thus, it contributes significantly to the overall caffeine consumption within the general population, particularly in adults. Controversies regarding its benefits and risks still exist as reliable evidence is becoming available supporting its health-promoting potential. Several lines of evidence have highlighted the beneficial effects towards several disease conditions including Type II diabetes, hepatitis C virus, hepatocellular carcinoma, nonalcoholic fatty liver disease and neurodegenerative disorders such as Alzheimer's disease (AD), Parkinson's disease (PD) and Amyotrophic Lateral Sclerosis (ALS). The health-promoting properties of coffee are largely attributed to its rich phytochemistry, including caffeine, chlorogenic acid, caffeic acid, and hydroxy hydroquinone. In this minireview, an attempt has been made to discuss the various evidences which are mainly derived from animal and cell models. Various mechanisms chiefly responsible for the beneficial effects of caffeine have also been briefly outlined. A short note on the undesirable effects of excessive coffee intakes is also presented.

Perspectives on Treatment for Nonalcoholic Steatohepatitis

It is important to provide treatment to patients with nonalcoholic steatohepatitis (NASH) because one third of patients with the metabolic syndrome die of liver disease. Basic research studies have elucidated mechanisms of NASH pathogenesis, which could lead to therapeutic targets. Health agencies have confirmed strategies for the optimal management of NASH and approved new drugs and treatments, which urgently are needed. The US Food and Drug Administration recently endorsed end points for NASH therapy. The reversal of NASH with no evidence of progression to advanced fibrosis has been defined as the end point for phase 2b and phase 3 trials in patients with NASH and early stage fibrosis. Although a decrease in the nonalcoholic fatty liver disease activity score could serve as an end point in clinical trials, it is not clear whether patients with lower scores have a lower risk of progression to advanced fibrosis. End points for clinical trials of patients with NASH cirrhosis currently are based on model for end-stage liver disease and Child-Pugh-Turcotte scores, as well as the hepatic venous pressure gradient. Different strategies are being explored to reduce liver diseases that are linked to a sedentary lifestyle, overeating, and genetic factors. In association with insulin resistance and deregulation of the lipid metabolism (accumulation of lipotoxins that promote hepatic lipogenesis, adipose tissue lipolysis, and impaired β-oxidation), these factors could increase the risk of liver steatosis with necroinflammatory lesions and fibrosis. We review the pathogenic mechanisms of NASH and therapeutic options, as well as strategies that are being developed for the treatment of injury to the liver and other organs.

Coffee and tea consumption in relation with non-alcoholic fatty liver and metabolic syndrome: A systematic review and meta-analysis of observational studies

BACKGROUND & AIMS

Diet plays a role in the onset and progression of metabolic disorders, including non-alcoholic fatty liver disease (NAFLD) and metabolic syndrome (MetS). We aimed to systematically review and perform quantitative analyses of results from observational studies on coffee/tea consumption and NAFLD or MetS.

METHODS

A Medline and Embase search was performed to retrieve articles published up to March 2015. We used a combination of the keywords "coffee", "caffeine", "tea", "non-alcoholic fatty liver disease", "non-alcoholic steatohepatitis", "metabolic syndrome". Pooled risk ratios (RRs) and 95% confidence intervals (CIs) were calculated by random-effects model.

RESULTS

Seven studies assessed coffee consumption in NAFLD patients. Fibrosis scores were reported in four out of seven; all four studies revealed an inverse association of coffee intake with fibrosis severity, although the lack of comparable exposure and outcomes did not allow to perform pooled analysis. Seven studies met the inclusion criteria to be included in the meta-analysis on coffee consumption and MetS. Individuals consuming higher quantities of coffee were less like to have MetS (RR = 0.87, 95% CI: 0.79-0.96). However, the association of coffee and individual components of MetS was not consistent across the studies. Pooled analysis of six studies exploring the association between tea consumption and MetS resulted in decreased odds of MetS for individuals consuming more tea (RR = 0.83, 95% CI: 0.73-0.95).

CONCLUSIONS

Studies on coffee and NAFLD suggest that coffee consumption could have a protective role on fibrosis. Both coffee and tea consumption are associated with less likelihood of having MetS but further research with better designed studies is needed.

Coffee and Liver Disease

Coffee is the most popular beverage in the world. Consumption of coffee has been shown to benefit health in general, and liver health in particular. This article reviews the effects of coffee intake on development and progression of liver disease due to various causes. We also describe the putative mechanisms by which coffee exerts the protective effect. The clinical evidence of benefit of coffee consumption in Hepatitis B and C, as well as nonalcoholic fatty liver disease and alcoholic liver disease, has also been presented. Coffee consumption is associated with improvement in liver enzymes (ALT, AST, and GGTP), especially in individuals with risk for liver disease. Coffee intake more than 2 cups per day in patients with preexisting liver disease has been shown to be associated with lower incidence of fibrosis and cirrhosis, lower hepatocellular carcinoma rates, as well as decreased mortality.

Fatty liver disease and lifestyle in youngsters: diet, food intake frequency, exercise, sleep shortage and fashion

BACKGROUND & AIMS

Fatty liver is associated with alcohol habits and/or overweight/obesity. We challenged several lifestyle features associated with fatty liver and, particularly, with non-alcoholic fatty liver disease (NAFLD). Among them, sleep shortage as a result of nightlife habits and a preference for plus-size fashion were assessed. The latter consists of fashionable plus-sized clothing for actual individuals' size and reflects a frequent attitude of some social or age groups, conceivably indicating more global and widespread trend and behaviour.

METHODS

We studied a group of 708 non-diabetic youngsters, 458 women and 250 men, 21.72 ± 3.71 years old (range 15-35 years), referred for minor digestive ailments for clinical assessment, ultrasound detection of fatty liver and nutritional counselling. Details of personal history regarding lifestyle, food intake frequency and alcohol intake, dietary and physical exercise profile, sleep duration and clothing preferences were recorded.

RESULTS

The prevalence of NAFLD in this cohort of youngsters is 67/708 (9.4%). Even if it is quantitatively very low in both groups, the average alcohol intake, always below 20 g/day, is greater in NAFLD subjects (5.83 ± 4.32 g) vs. subjects with normal liver (2.02 ± 3.20 g). The number of meals/day and adherence to a Mediterranean diet profile are smaller in NAFLD subjects. By multiple regression, BMI, sedentary life, plus-sized clothing for their actual size, sleep shortage and lower frequency of daily food intake are associated with the presence of NAFLD.

CONCLUSIONS

Onset and continuation of fatty liver disease, beyond food and exercise quantity and quality, with their effects on obesity, may also be associated with other aspects of lifestyle.

Association between caffeine consumption and nonalcoholic fatty liver disease: a systemic review and meta-analysis

OBJECTIVES

Caffeine consumption is reported to be associated with reduced hepatic fibrosis in patients with chronic liver diseases. We performed a systematic review and meta-analysis to assess the association between caffeine consumption and prevalence or hepatic fibrosis of nonalcoholic fatty liver disease (NAFLD) in observational studies.

METHODS

We searched the literature of all languages from PubMed, EMBASE, and the Cochrane library from 1 January 1980 through 10 January 2015. Total caffeine consumption was defined as the daily intake of caffeine (mg/day) from all caffeine-containing products. Combined and subgroup analyses stratified by study designs, study locations, and type of caffeine intake were performed.

RESULTS

Four cross-sectional and two case control studies with a total of 20,064 subjects were included in the meta-analysis. Among these, three studies with 18,990 subjects were included in the analysis for prevalence of NAFLD while the other three studies with 1074 subjects were for hepatic fibrosis. Total caffeine consumption (mg/day) was not significantly associated with either the prevalence [pooled mean difference (MD) 2.36; 95% confidence interval (CI) -35.92 to 40.64] or hepatic fibrosis (higher versus lower stages; pooled MD -39.95; 95% CI -132.72 to 52.82) of NAFLD. Subgroup analyses stratified by study designs and locations were also not significant. However, after stratifying by type of caffeine intake, regular coffee caffeine intake (mg/day) was significantly associated with reduced hepatic fibrosis of NAFLD (pooled MD -91.35; 95% CI -139.42 to -43.27; n = 2 studies).

CONCLUSION

Although total caffeine intake is not associated with the prevalence or hepatic fibrosis of NAFLD, regular coffee caffeine consumption may significantly reduce hepatic fibrosis in patients with NAFLD.

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.

Coffee consumption and NAFLD: a community based study on 1223 subjects

Background

Objective of the present cross-sectional study was to investigate the impact of caffeine consumption on fatty liver and serum alanine aminotransferase (ALT) concentrations in a random population sample.

Methods

All subjects (n = 1452; 789 women, 663 men; average age 42.3 ± 12.8 years) underwent ultrasonographic examination of the liver and completed a standardized questionnaire regarding personal and lifestyle data, in particular relating to coffee consumption and past medical history. In addition, anthropometric data were documented and laboratory examinations performed. Statistical interpretation of the data was performed descriptively and by means of bivariate and multivariate analysis.

Results

Data of the present study demonstrated a significant association between hepatic steatosis male gender (p < 0.0001), advanced age (p < 0.0001) and elevated body-mass index (BMI; p < 0.0001). No association between caffeine consumption and fatty liver was identified. An association between caffeine consumption and elevated serum ALT concentrations was not identified.

Conclusions

The findings of the present study provide no evidence for an association between caffeine consumption and either the prevalence of hepatic steatosis or serum ALT concentrations.

Nonalcoholic Fatty Liver Disease Review: Diagnosis, Treatment, and Outcomes

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of abnormal serum aminotransferase levels in both developed and developing countries. Patients with nonalcoholic steatohepatitis (NASH), a subset of NAFLD, are at risk for progressive liver disease and in need of effective treatment options. A practical approach may be pursued by identifying patients with NAFLD with the highest likelihood for histologic evidence of NASH. Despite decades of clinical trials, no single treatment can be recommended to all patients with NASH. Importantly, there is no evidence that pioglitazone or vitamin E improves fibrosis. Bariatric surgeries may improve hepatic histology in morbidly obese patients with NASH, although randomized clinical trials are lacking. Currently, NASH is the second leading etiology of liver disease among adults awaiting liver transplantation in the United States. The primary and secondary prevention of NAFLD may require aggressive strategies for managing obesity, diabetes, and metabolic syndrome.

Oily fish, coffee and walnuts: Dietary treatment for nonalcoholic fatty liver disease

Rates of non-alcoholic fatty liver disease (NAFLD) are increasing worldwide in tandem with the metabolic syndrome, with the progressive form of disease, non-alcoholic steatohepatitis (NASH) likely to become the most common cause of end stage liver disease in the not too distant future. Lifestyle modification and weight loss remain the main focus of management in NAFLD and NASH, however, there has been growing interest in the benefit of specific foods and dietary components on disease progression, with some foods showing protective properties. This article provides an overview of the foods that show the most promise and their potential benefits in NAFLD/NASH, specifically; oily fish/ fish oil, coffee, nuts, tea, red wine, avocado and olive oil. Furthermore, it summarises results from animal and human trials and highlights potential areas for future research.

Coffee and Caffeine Are Associated With Decreased Risk of Advanced Hepatic Fibrosis Among Patients With Hepatitis C

BACKGROUND & AIMS

Coffee or caffeine has been proposed to protect against hepatic fibrosis, but few data are available on their effects in patients with chronic hepatitis C virus (HCV) infection.

METHODS

We conducted a cross-sectional study of veterans with chronic HCV infection to evaluate the association between daily intake of caffeinated and decaffeinated coffee, tea, and soda, and level of hepatic fibrosis, based on the FibroSURE test (BioPredictive, Paris, France) (F0-F3, mild [controls] vs. F3/F4-F4, advanced). Models were adjusted for multiple potential confounders including age, alcohol abuse, and obesity.

RESULTS

Among 910 patients with chronic HCV infection, 98% were male and 38% had advanced hepatic fibrosis. Daily intake of caffeinated coffee was higher among controls than patients with advanced fibrosis (1.37 vs. 1.05 cups/d; P = .038). In contrast, daily intake of caffeinated tea (0.61 vs. 0.56 cups/d; P = .651) or soda (1.14 vs. 0.95 cans/d; P = .106) did not differ between the groups. A higher percentage of controls (66.0%) than patients with advanced fibrosis (57.9%) consumed 100 mg or more of caffeine daily from all sources (P = .014); controls also received a larger proportion of their caffeine from coffee (50.2% vs. 43.0%; P = .035). Hepatoprotective effects of an average daily intake of 100 mg or more of caffeine (adjusted odds ratio, 0.71; 95% confidence interval, 0.53-0.95; P = .020) and 1 cup or more of caffeinated tea by non-coffee drinkers (adjusted odds ratio, 0.56; 95% confidence interval, 0.34-0.94; P = .028) persisted after adjustment for confounders, including insulin resistance.

CONCLUSIONS

A modest daily caffeine intake (as little as 100 mg) may protect against advanced hepatic fibrosis in men with chronic HCV infection. Additional research is needed to confirm these findings in women and in people with other chronic liver diseases.

Associations of coffee consumption with markers of liver injury in the insulin resistance atherosclerosis study

Background

Coffee consumption has been associated with reduced risk of developing type 2 diabetes mellitus (T2DM) however, the mechanism for this association has yet to be elucidated. Non-alcoholic fatty liver disease (NAFLD) characterizes and predicts T2DM yet the relationship of coffee with this disorder remains unclear. Our aim was to investigate the associations of coffee with markers of liver injury in 1005 multi-ethnic, non-diabetic adults in the Insulin Resistance Atherosclerosis Study.

Methods

Dietary intake was assessed using a validated 114-item food frequency questionnaire. Alanine aminotransferase (ALT), aspartate aminotransferase (AST) and fetuin-A were determined in fasting blood samples and the validated NAFLD liver fat score was calculated. Multivariate linear regression assessed the contribution of coffee to variation in markers of liver injury.

Results

Caffeinated coffee showed significant inverse associations with ALT (β = −0.08, p = 0.0111), AST (β = −0.05, p = 0.0155) and NAFLD liver fat score (β = −0.05, p = 0.0293) but not with fetuin-A (β = 0.04, p = 0.17). When the highest alcohol consumers were excluded, these associations remained (ALT β = −0.11, p = 0.0037; AST β = −0.05, p = 0.0330; NAFLD liver fat score β = −0.06, p = 0.0298). With additional adjustment for insulin sensitivity, the relationship with ALT remained significant (ALT β = −0.08, p = 0.0400; AST β = −0.03, p = 0.20; NAFLD liver fat score β = −0.03, p = 0.27). There were no significant associations of decaffeinated coffee with liver markers.

Conclusions

These analyses indicate a beneficial impact of caffeinated coffee on liver morphology and/or function, and suggest that this relationship may mediate the well-established inverse association of coffee with risk of T2DM.

Electronic supplementary material

The online version of this article (doi:10.1186/s12876-015-0321-3) contains supplementary material, which is available to authorized users.

Nonalcoholic fatty liver disease: a precursor of the metabolic syndrome

The conventional paradigm of nonalcoholic fatty liver disease representing the "hepatic manifestation of the metabolic syndrome" is outdated. We identified and summarized longitudinal studies that, supporting the association of nonalcoholic fatty liver disease with either type 2 diabetes mellitus or metabolic syndrome, suggest that nonalcoholic fatty liver disease precedes the development of both conditions. Online Medical databases were searched, relevant articles were identified, their references were further assessed and tabulated data were checked. Although several cross-sectional studies linked nonalcoholic fatty liver disease to either diabetes and other components of the metabolic syndrome, we focused on 28 longitudinal studies which provided evidence for nonalcoholic fatty liver disease as a risk factor for the future development of diabetes. Moreover, additional 19 longitudinal reported that nonalcoholic fatty liver disease precedes and is a risk factor for the future development of the metabolic syndrome. Finally, molecular and genetic studies are discussed supporting the view that aetiology of steatosis and lipid intra-hepatocytic compartmentation are a major determinant of whether fatty liver is/is not associated with insulin resistance and metabolic syndrome. Data support the novel paradigm of nonalcoholic fatty liver disease as a strong determinant for the development of the metabolic syndrome, which has potentially relevant clinical implications for diagnosing, preventing and treating metabolic syndrome.

Recent advances in dietary supplementation, in treating non-alcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is currently known as the most common liver problem, characterized by excessive lipid accumulation in hepatocytes, which may progress to other liver diseases such as nonalcoholic steatohepatitis, hepatic tissue fibrosis, liver cirrhosis, and failure or hepatocellular carcinoma. Since NAFLD is positively associated with the development of obesity, insulin resistance, and ultimately type 2 diabetes mellitus, it is often regarded as the hepatic manifestation of the metabolic syndrome. No pharmacologic treatment has yet been proven for this disease. For most patients with presumed or confirmed NAFLD, the only proven strategy is to offer lifestyle advice that can lead to sustained weight loss. Since insulin resistance, oxidative stress, inflammation, and necro-apoptosis are involved in NAFLD pathogenesis, it seems that every potential therapeutic agent should target one or some of these pathologic events. There are many well known anti-oxidants, anti-inflammatory, and insulin sensitizer dietary supplements which have shown beneficial effects on NAFLD improvement in animal and human studies. The purpose of this review is to explore the existing evidences on dietary supplements considered to have hepatoprotective properties, and to present some proposed mechanisms by which they may protect against NAFLD.

Caffeine ameliorates high energy diet-induced hepatic steatosis: sirtuin 3 acts as a bridge in the lipid metabolism pathway

We demonstrate that caffeine could improve HED-induced hepatic steatosis by promoting lipid metabolism via the cAMP/CREB/SIRT3/AMPK/ACC pathway. SIRT3 acts as a molecular bridge connecting caffeine and lipid metabolism.

4Ps medicine of the fatty liver: the research model of predictive, preventive, personalized and participatory medicine-recommendations for facing obesity, fatty liver and fibrosis epidemics

Relationship between adipose tissue and fatty liver, and its possible evolution in fibrosis, is supported by clinical and research experience. Given the multifactorial pathogenesis of non-alcoholic fatty liver disease (NAFLD), treatments for various contributory risk factors have been proposed; however, there is no single validated therapy or drug association recommended for all cases which can stand alone. Mechanisms, diagnostics, prevention and treatment of obesity, fatty liver and insulin resistance are displayed along with recommendations and position points. Evidences and practice can get sustainable and cost-benefit valuable outcomes by participatory interventions. These recommendations can be enhanced by comprehensive research projects, addressed to societal issues and innovation, market appeal and industry development, cultural acceptance and sustainability. The basis of participatory medicine is a greater widespread awareness of a condition which is both a disease and an easy documented and inclusive clue for associated diseases and unhealthy lifestyle. This model is suitable for addressing prevention and useful for monitoring improvement, worsening and adherence with non-invasive imaging tools which allow targeted approaches. The latter include health psychology and nutritional and physical exercise prescription expertise disseminated by continuous medical education but, more important, by concrete curricula for training undergraduate and postgraduate students. It is possible and recommended to do it by early formal teaching of ultrasound imaging procedures and of practical lifestyle intervention strategies, including approaches aimed to healthier fashion suggestions. Guidelines and requirements of research project funding calls should be addressed also to NAFLD and allied conditions and should encompass the goal of training by research and the inclusion of participatory medicine topics. A deeper awareness of ethics of competences in health professionals and the articulation of knowledge, expertise and skills of medical doctors, dieticians, health psychologists and sport and physical exercise graduates are the necessary strategy for detectin a suboptimal health status and achieving realistically beneficial lifestyle changes. “The devil has put a penalty on all things we enjoy in life. Either we suffer in health or we suffer in soul or we get fat” (Albert Einstein); the task of medical research and intervention is to make possible to enjoy life also without things that make sufferance in health and souls and which excessively increase body fat.

The influence of roasting and additional processing on the content of bioactive components in special purpose coffees

ABSTRACT

Coffee being the beverage consumed worldwide is also a very competitive commodity. Consequently, producers seek ways of attracting consumers by proposing e.g. novel ingredient combinations usually without evaluating their health quality. In this study, variations in health-promoting determinants for five special purpose coffee brews were characterized. The major bioactive components - chlorogenic acids (CAs) - detected by HPLC-DAD-MS included caffeoyl-, feruloyl- and dicaffeoylquinic acids. Roasting declined CAs content by 50 %, while caffeine content increased by about 30 % during this process. In roasted coffee brews studied, CAs content varied from 14.1 to 26.6 mg/g; smaller variations were seen in antioxidant potential (determined by spectrophotometric and cyclic voltammetry assays). Profiles generated by HPLC with post-column on-line antioxidant detection revealed that caffeoylquinic acids were the most abundant antioxidants in samples studied. The highest antioxidative potential exhibited coffee enriched with green coffee extract confirming the soundness of such an approach to obtain healthier products.

HIGHLIGHTS

• Special purpose coffees are equivalent to regular ones as regards antioxidant potential. • Caffeoylquinic acids are the most abundant antioxidants in coffee samples studied. • Roasting process causes some degradation of chlorogenic acids but not caffeine. • Special purpose coffees retain health benefits while being more attractive to consumers.

Coffee and liver health

Coffee is one of the most widely used beverages in the world. It includes a wide array of components that can have potential implications for health. Several epidemiological studies associate coffee consumption with a reduced incidence of various chronic diseases such as diabetes, cardiovascular diseases, and neurodegenerative diseases. Over the past 20 years, an increasing number of epidemiological and experimental studies have demonstrated the positive effects of coffee on chronic liver diseases. Coffee consumption has been inversely associated with the activity of liver enzymes in subjects at risk, including heavy drinkers. Coffee favours an improvement in hepatic steatosis and fibrosis, and a reduction in cirrhosis and the risk of hepatocellular carcinoma. The mechanisms of action through which it exerts its beneficial effects are not fully understood. Experimental studies show that coffee consumption reduces fat accumulation and collagen deposition in the liver and promotes antioxidant capacity through an increase in glutathione as well as modulation of the gene and protein expression of several inflammatory mediators. Animal and in vitro studies indicate that cafestol and kahweol, 2 diterpens, can operate by modulating multiple enzymes involved in the detoxification process of carcinogens causing hepatocellular carcinoma. It is unclear whether the benefits are significant enough to "treat" patients with chronic liver disease. While we await clarification, moderate daily unsweetened coffee use is a reasonable adjuvant to therapy for these patients.

Non-alcoholic fatty liver disease: What has changed in the treatment since the beginning?

Non-alcoholic fatty liver disease (NAFLD) is an umbrella term to describe the entire spectrum of this common liver disease. In patients with NAFLD, especially those with non-alcoholic steatohepatitis (NASH), most often have one or more components of the metabolic syndrome, but this is not universal. Although most patients with NAFLD share many clinical features, only a subset of patients develops significant liver inflammation and progressive fibrosis. On the other hand, not all patients with NASH exhibit insulin resistance. NASH can be seen in patients who are lean and have no identifiable risk factors. Many clinical studies have tried numerous drugs and alternative medicine, however, investigators have failed to identify a safe and effective therapy for patients with NASH. As summarized, the heterogeneity of pathogenic pathways in individual patients with NASH may warrant the development of an individualized treatment according to the underlying pathogenic pathway. The differentiation of pathogenetic targets may require the development of diagnostic and prognostic biomarkers, and the identification of genetic susceptibilities. At present, evidence-based medicine provides only a few options including life-style modifications targeting weight loss, pioglitazone and vitamin E in non-diabetic patients with biopsy-proven NASH.

Non-alcoholic fatty liver disease: what the clinician needs to know

Non-alcoholic fatty liver disease (NAFLD) is the most frequent cause of liver disease in the Western world. Furthermore, it is increasing worldwide, paralleling the obesity pandemic. Though highly frequent, only about one fifth of affected subjects are at risk of developing the progressive form of the disease, non-alcoholic steatohepatitis with fibrosis. Even in the latter, liver disease is slowly progressive, though, since it is so prevalent, it is already the third cause of liver transplantation in the United States, and it is predicted to get to the top of the ranking in few years. Of relevance, fatty liver is also associated with increased overall mortality and particularly increased cardiovascular mortality. The literature and amount of published papers on NAFLD is increasing as fast as its prevalence, which makes it difficult to keep updated in this topic. This review aims to summarize the latest knowledge on NAFLD, in order to help clinicians understanding its pathogenesis and advances on diagnosis and treatment.

Nonalcoholic fatty liver disease: A comprehensive review of a growing epidemic

Nonalcoholic fatty liver disease (NAFLD) is quickly becoming one of the most prominent causes of liver disease worldwide. The increasing incidence of NAFLD is tied to the obesity epidemic and the subsequent metabolic derangements brought along with it. Current efforts to elucidate the mechanism and causes of the disease have answered some questions, but much remains unknown about NAFLD. The aim of this article is to discuss the current knowledge regarding the pathogenesis of the disease, as well as the current and future diagnostic, preventative, and therapeutic options available to clinicians for the management of NAFLD.

Coffee consumption in NAFLD patients with lower insulin resistance is associated with lower risk of severe fibrosis

BACKGROUND & AIMS

Coffee has inverse relationships with both type 2 diabetes and hepatic fibrosis in patients with nonalcoholic fatty liver disease (NAFLD). Relationships were explored between coffee intake and insulin resistance (IR) with respect to NAFLD histologic severity.

METHODS

We analyzed data from 782 adults (≥18 years) in the Nonalcoholic Steatohepatitis Clinical Research Network (NASH CRN) from 2004 to 2008. IR was assessed using the HOMA-IR. We modeled associations between coffee intake and NAFLD histologic severity using multiple logistic regression; and interactions between coffee and IR on NAFLD histology were explored.

RESULTS

Among 782 participants, 38% (n = 295) were men, 12% (n = 97) were Latino, mean age (± standard deviation) was 48 ± 12 years. Median BMI was 33.5 kg/m(2) [interquartile range, 29.7-38.3] and median HOMA-IR was 4.3 [2.7-7.2]. Diabetes was present in 24% (n = 189). NASH was present in 79% (n = 616), and 25% (n = 199) had advanced fibrosis. The frequency of coffee intake (cups/day, cpd) was as follows: 0 cpd, n = 230 (29%); <1 cpd, n = 219 (28%); 1 to <2 cpd, n = 116 (15%); ≥2 cpd, n = 217 (28%). The effect of coffee on fibrosis varied with degree of IR (interaction P = 0.001). Coffee consumers with less IR, defined as HOMA-IR<4.3, had a lower odds of advanced fibrosis [OR = 0.64; 95% CI, (0.46-0.88), P = 0.001]. There was no protective effect of coffee on advanced fibrosis among individuals with higher HOMA-IR [OR = 1.06, 95% CI (0.87-1.28), P = 0.6].

CONCLUSIONS

Coffee intake is inversely associated with advanced fibrosis among NAFLD patients with lower HOMA-IR. Our findings warrant further investigation given the worldwide ubiquity of coffee intake.

Management of fatty liver disease with the metabolic syndrome

Non-alcoholic fatty liver disease (NAFLD) is the liver disease of this century, increasing in parallel with obesity, insulin resistance and the metabolic syndrome. NAFLD can be seen as a component of the metabolic syndrome, and as such, contributing as a risk factor for cardiovascular disease. In fact, these patients die more often from cardiovascular disease than from direct consequences of liver disease. In this review, we will summarize the data that link NAFLD as a central player in this dysmetabolism, as well as the evidence for appropriate therapy, in order to improve not only liver disease prognosis, but also the overall prognosis and risk of mortality, with particular focus on cardiovascular risk.

Caffeine stimulates hepatic lipid metabolism by the autophagy-lysosomal pathway in mice

Caffeine is one of the world's most consumed drugs. Recently, several studies showed that its consumption is associated with lower risk for nonalcoholic fatty liver disease (NAFLD), an obesity-related condition that recently has become the major cause of liver disease worldwide. Although caffeine is known to stimulate hepatic fat oxidation, its mechanism of action on lipid metabolism is still not clear. Here, we show that caffeine surprisingly is a potent stimulator of hepatic autophagic flux. Using genetic, pharmacological, and metabolomic approaches, we demonstrate that caffeine reduces intrahepatic lipid content and stimulates β-oxidation in hepatic cells and liver by an autophagy-lysosomal pathway. Furthermore, caffeine-induced autophagy involved down-regulation of mammalian target of rapamycin signaling and alteration in hepatic amino acids and sphingolipid levels. In mice fed a high-fat diet, caffeine markedly reduces hepatosteatosis and concomitantly increases autophagy and lipid uptake in lysosomes.

CONCLUSION

These results provide novel insight into caffeine's lipolytic actions through autophagy in mammalian liver and its potential beneficial effects in NAFLD.

Impact of coffee on liver diseases: a systematic review

Coffee is one of the most commonly consumed beverages in the world. Its health benefits including improved overall survival have been demonstrated in a variety of disease states. To examine the association of coffee consumption with liver disease, a systematic review of studies on the effects of coffee on liver associated laboratory tests, viral hepatitis, nonalcoholic fatty liver disease (NAFLD), cirrhosis and hepatocellular carcinoma (HCC) was performed. Coffee consumption was associated with improved serum gamma glutamyltransferase, aspartate aminotransferase and alanine aminotransferase values in a dose dependent manner in individuals at risk for liver disease. In chronic liver disease patients who consume coffee, a decreased risk of progression to cirrhosis, a lowered mortality rate in cirrhosis patients, and a lowered rate of HCC development were observed. In chronic hepatitis C patients, coffee was associated with improved virologic responses to antiviral therapy. Moreover, coffee consumption was inversely related to the severity of steatohepatitis in patients with non-alcoholic fatty liver disease. Therefore, in patients with chronic liver disease, daily coffee consumption should be encouraged.

Coffee and non-alcoholic fatty liver disease: brewing evidence for hepatoprotection?

Coffee is one of the most popular beverages in the world. Several studies consistently show that coffee drinkers with chronic liver disease have a reduced risk of cirrhosis and a lower incidence of hepatocellular carcinoma regardless of primary etiology. With the increasing prevalence of non-alcoholic fatty liver disease (NAFLD) worldwide, there is renewed interest in the effect of coffee intake on NAFLD severity and positive clinical outcomes. This review gives an overview of growing epidemiological and clinical evidence which indicate that coffee consumption reduces severity of NAFLD. These studies vary in methodology, and potential confounding factors have not always been completely excluded. However, it does appear that coffee, and particular components other than caffeine, reduce NAFLD prevalence and inflammation of non-alcoholic steatohepatitis. Several possible mechanisms underlying coffee's hepatoprotective effects in NAFLD include antioxidative, anti-inflammatory, and antifibrotic effects, while a chemopreventive effect against hepatocarcinogenesis seems likely. The so-far limited data supporting such effects will be discussed, and the need for further study is highlighted.

Hepatic steatosis and steatohepatitis: Are they really two distinct entities?

Non-alcoholic fatty liver disease affects nearly 30% of Americans. A histopathological spectrum exists from simple steatosis to NASH which may progress to cirrhosis and HCC. NASH is currently the third most common indication for liver transplant with increasing incidence. Steatosis can be considered the hepatic manifestation of the metabolic syndrome as insulin resistance is a major risk factor for its development. While liver biopsy is the gold standard for diagnosis, non-invasive methods are currently being developed to appropriately determine who needs histologic evaluation. Management focuses on mitigation of risk factors, since targeted therapies to halt progression of fibrosis have not been validated. Simple steatosis does not affect overall survival, but NASH conveys increased mortality. Because of this, non-invasive strategies to diagnose patients and management algorithms are needed. This review supports the definitions of simple steatosis and NASH as two distinct entities based on pathophysiology, diagnosis, management, and prognosis.

Pathophysiology of NASH: perspectives for a targeted treatment

Non alcoholic steatohepatitis (NASH) is the more severe form of nonalcoholic fatty liver disease. In NASH, fatty liver, hepatic inflammation, hepatocyte injury and fibrogenesis are associated, and this condition may eventually lead to cirrhosis. Current treatment of NASH relies on the reduction of body weight and increase in physical activity, but there is no pharmacologic treatment approved as yet. Emerging data indicate that NASH progression results from parallel events originating from the liver as well as from the adipose tissue, the gut and the gastrointestinal tract. Thus, dysfunction of the adipose tissue through enhanced flow of free fatty acids and release of adipocytokines, and alterations in the gut microbiome generate proinflammatory signals that underlie NASH progression. Additional 'extrahepatic hits' include dietary factors and gastrointestinal hormones. Within the liver, hepatocyte apoptosis, ER stress and oxidative stress are key contributors to hepatocellular injury. In addition, lipotoxic mediators and danger signals activate Kupffer cells which initiate and perpetuate the inflammatory response by releasing inflammatory mediators that contribute to inflammatory cell recruitment and development of fibrosis. Inflammatory and fibrogenic mediators include chemokines, the cannabinoid system, the inflammasome and activation of pattern-recognition receptors. Here we review the major mechanisms leading to appearance and progression of NASH, focusing on both extrahepatic signals and local inflammatory mechanisms, in an effort to identify the most promising molecular targets for the treatment of this condition.

Pathophysiology of NASH: perspectives for a targeted treatment

Non alcoholic steatohepatitis (NASH) is the more severe form of nonalcoholic fatty liver disease. In NASH, fatty liver, hepatic inflammation, hepatocyte injury and fibrogenesis are associated, and this condition may eventually lead to cirrhosis. Current treatment of NASH relies on the reduction of body weight and increase in physical activity, but there is no pharmacologic treatment approved as yet. Emerging data indicate that NASH progression results from parallel events originating from the liver as well as from the adipose tissue, the gut and the gastrointestinal tract. Thus, dysfunction of the adipose tissue through enhanced flow of free fatty acids and release of adipocytokines, and alterations in the gut microbiome generate proinflammatory signals that underlie NASH progression. Additional 'extrahepatic hits' include dietary factors and gastrointestinal hormones. Within the liver, hepatocyte apoptosis, ER stress and oxidative stress are key contributors to hepatocellular injury. In addition, lipotoxic mediators and danger signals activate Kupffer cells which initiate and perpetuate the inflammatory response by releasing inflammatory mediators that contribute to inflammatory cell recruitment and development of fibrosis. Inflammatory and fibrogenic mediators include chemokines, the cannabinoid system, the inflammasome and activation of pattern-recognition receptors. Here we review the major mechanisms leading to appearance and progression of NASH, focusing on both extrahepatic signals and local inflammatory mechanisms, in an effort to identify the most promising molecular targets for the treatment of this condition.

Role of exercise in optimizing the functional status of patients with nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is frequently concomitant with obesity. This article discusses factors that influence health and functional outcomes of people who develop NAFLD, including increased burden of illness, whole body function, performance, and perception of self-efficacy. Changes in macronutrients, amount of calories consumed, and decreased physical activity all negatively influence patient outcome. The benefits of exercise in this population are also discussed. To be effective, exercise must be performed, regularly and in conjunction with dietary and other behavioral change. Therefore, a lifelong commitment to exercise, activity, and diet are needed if NAFLD is to be successfully treated.

The role of diet and nutritional intervention for the management of patients with NAFLD

During the last few decades, the prevalence of obesity, insulin resistance and non-alcoholic fatty liver disease (NAFLD) have dramatically increased. Nutrition and modern lifestyle habits are intimately involved in this epidemiological change. Although lifestyle intervention can theoretically revert the metabolic disturbances and prevent the long term complications of NAFLD, its efficacy is diminished in clinical practice by poor implementation and reduced adherence to lifestyle intervention programs. In this article we summarize the main elements of dietary interventions for NAFLD, describe practical strategies to optimize efficacy and review potential nutritional strategies under development that hopefully will improve outcomes in the future.

Systematic review with meta-analysis: non-alcoholic steatohepatitis - a case for personalised treatment based on pathogenic targets

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is an umbrella term, which encompasses simple steatosis and non-alcoholic steatohepatitis (NASH). The entire spectrum of NAFLD has been associated with metabolic syndrome. NASH is associated with increased mortality compared with that of the general population. Many therapeutic options for NASH have been studied. However, there is very little evidence supporting the efficacy of most regimens for the treatment of NASH.

AIM

To provide a review focusing on the current therapeutic options available for patients with NASH as well as to briefly introduce possible future interventions.

METHODS

A MEDLINE, Pubmed and Cochrane Review database search using a combination of keywords, which included non-alcoholic fatty liver disease, non-alcoholic hepatic steatosis, NAFLD, NASH, treatment, therapeutics, vitamin E, orlistat and bariatric surgery. An overall summary of the articles was developed for each section of discussion in this review.

RESULTS

NASH associated with metabolic syndrome can progress advanced fibrosis and cirrhosis. Weight loss and lifestyle modification have been shown to improve NASH. Other medications used for weight loss and metabolic syndrome have been evaluated, such as orlistat, metformin and thiazolidinediones. Alternative regimens using ursodeoxycholic acid, statins and probiotics as well as bariatric surgery have been evaluated, but have not been recommended as first-line treatment for NASH. Vitamin E for NASH patients without diabetes seems to be promising. The lack of effective treatment for NASH suggests the heterogeneity of patients presenting with the NASH phenotype. The best treatment strategy for these patients may be to identify their pathogenic target and develop personalised treatment protocols.

CONCLUSIONS

Currently, there are few options available for the management of NASH. Future targeted treatment strategies based on the pathogenic pathways may be needed to develop effective treatment for patients with NASH.

Role of diet and nutritional management in non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) encompasses a spectrum ranging from simple steatosis to non-alcoholic steatohepatitis, which causes an increased risk of cirrhosis, type 2 diabetes, and cardiovascular complications. With the worldwide growing incidence of obesity, sedentary lifestyle, and unhealthy dietary pattern, NAFLD has currently been recognized as a major health burden. Dietary patterns and nutrients are the important contributors to the development, progression, and treatment of NAFLD and associated metabolic comorbidities. Generally, hypercaloric diet, especially rich in trans/saturated fat and cholesterol, and fructose-sweetened beverages seem to increase visceral adiposity and stimulate hepatic lipid accumulation and progression into non-alcoholic steatohepatitis, whereas reducing caloric intake, increasing soy protein and whey consumption, and supplement of monounsaturated fatty acids, omega-3 fatty acids, and probiotics have preventive and therapeutic effects. In addition, choline, fiber, coffee, green tea, and light alcohol drinking might be protective factors for NAFLD. Based on available data, at least 3-5% of weight loss, achieved by hypocaloric diet alone or in conjunction with exercise and behavioral modification, generally reduces hepatic steatosis, and up to 10% weight loss may be needed to improve hepatic necroinflammation. A sustained adherence to diet rather than the actual diet type is a major predictor of successful weight loss. Moreover, a healthy diet has benefits beyond weight reduction on NAFLD patients whether obese or of normal weight. Therefore, nutrition serves as a major route of prevention and treatment of NAFLD, and patients with NAFLD should have an individualized diet recommendation.

[The role of diet in non-alcoholic fatty liver disease]

Prevalence of non-alcoholic fatty liver disease (NAFLD) is about 20-25% in Korean adults population. Obesity is strongly associated with NAFLD and the prevention of obesity is a major public issue. Unfortunately, pharmacological treatment of obesity and NAFLD remains uncertain. Only weight loss by dietary changes been shown to lead to histological improvement in fatty liver. So the nutrition therapy is a cornerstone of treatment for NAFLD. Epidemiologic studies show that saturated fat, trans-fatty acid, carbohydrate, and simple sugar have strong correlation with intrahepatic fat accumulation. But, true associations with specific nutrients still remain unclear. Recently, fructose consumption has been rising in many countries and several epidemiologic studies show that fructose consumption has strong correlation with metabolic diseases. The consumption of excessively added sugar in the pathogenesis of steatohepatitis has received attention. Most clinicians agree with lifestyle modification are effective in histologic improvement. Total energy intake restriction is the most important action to reduce intrahepatic fat accumulation. Macronutrient composition may also have correlation with the development of NAFLD. To reduce the incidence of NAFLD, public statements on optimal dietary education program have been issused. Various specific dietary programs are suggested. Among them low fat diet and low carbohydrate diet are suggested in patients with NAFLD. However, there is no ideal diet to obtain the histological improvement in NAFLD. Further randomised controlled studies about specific diet are needed to determine the long-term benefit and histological improvement by ideal diet. Tailoring diet therapy to a patient's lifestyle is more important than universal specific dietary program.

Current management of patients with nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) and its progressive form, nonalcoholic steatohepatitis (NASH) are the most common causes of chronic liver disease in industrialized countries. NAFLD has also been strongly associated with type II diabetes and cardiovascular diseases. This study was a multipurposed review, which included discussion of recent studies investigating the cellular and genetic basis of these diseases, the pathogenesis of NAFLD and the current treatment and management of nonalcoholic steatohepatitis. Currently, maintaining a healthy weight through dietary changes and exercise, the use of insulin-modulating pharmacologic agents for diabetes control and the use of lipid-lowering, anti-oxidants have been the most widely recommended treatments. Inclusion of pathogenic mechanisms in treatment design will allow future therapies to target-specific pathways involved in NAFLD pathogenesis.

Review article: coffee consumption, the metabolic syndrome and non-alcoholic fatty liver disease

BACKGROUND

Coffee consumption may modulate the risk of the metabolic syndrome (MetS) and non-alcoholic fatty liver disease (NAFLD).

AIM

To review the experimental, epidemiological and clinical studies investigating the association between coffee consumption and the risk of MetS and NAFLD.

METHODS

A literature search was conducted with the aim of finding original experimental, epidemiological and clinical articles on the association between coffee consumption, MetS and NAFLD. The following databases were used: PubMed, Embase, Scopus and Science Direct. We included articles written in English and published up to July 2013.

RESULTS

Three experimental animal studies investigated the effects of coffee in the MetS, whereas five examined whether experimental coffee intake may modulate the risk of fatty liver infiltration. All of the animal studies showed a protective effect of coffee towards the development of MetS and NAFLD. Moreover, we identified eleven epidemiological and clinical studies that met the inclusion criteria. Of them, six were carried out on the risk of the MetS and five on the risk of NAFLD. Four of the six studies reported an inverse association between coffee consumption and the risk of MetS. The two studies showing negative results were from the same study cohort consisting of young persons with a low prevalence of the MetS. All of the epidemiological and clinical studies on NAFLD reported a protective effect of coffee intake.

CONCLUSIONS

Coffee intake can reduce the risk of NAFLD. Whether this effect may be mediated by certain components of the MetS deserves further investigation.

Current concepts and management approaches in nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of liver dysfunction worldwide. NAFLD may progress to nonalcoholic steatohepatitis (NASH) and in turn cirrhosis. Importantly, hepatic cancer can occur in NASH in the absence of cirrhosis. The cardinal histologic feature of NAFLD is the presence of an excessive accumulation of triacylglycerols and diacylglycerols in hepatocytes. The presence of obesity and insulin resistance lead to an increased hepatic-free fatty acid (FFA) flux creating an environment appropriate for the development of NAFLD. The generation of toxic reactive oxygen species with the production of hepatic injury and inflammation as a consequence of FFA oxidation will ultimately lead to the initiation and progression of fibrosis. Lifestyle modifications specifically weight loss, physical exercise, and cognitive behavior therapy have been recommended as treatments for NASH. Dietary fructose is an independent risk factor for the development of NAFLD. Pioglitazone can be used to treat biopsy-proven NASH; however, its safety risks should be considered carefully. Greater consumption for coffee, independent of its caffeine component, has been associated with a significant reduced risk of advanced fibrosis in NASH. Additional data are needed before recommending bariatric surgery as an established option for the specific treatment of NASH.

Regular coffee but not espresso drinking is protective against fibrosis in a cohort mainly composed of morbidly obese European women with NAFLD undergoing bariatric surgery

BACKGROUND & AIMS

The aim of this study was to determine the influence of coffee and other caffeinated drinks on liver fibrosis of severely obese European patients.

METHODS

A specific questionnaire exploring various types of coffee (regular filtrated coffee and espresso), caffeinated drinks, and chocolate was filled in by 195 severely obese patients. All patients had liver biopsies that were analyzed according to the NASH Clinical Research Network Scoring System. Univariate and multivariate analyses of significant fibrosis were performed.

RESULTS

Caffeine came mainly from coffee-containing beverages (77.5%). Regular coffee and espresso were consumed in 30.8% and 50.2% of the patients, respectively. Regular coffee, espresso, and total caffeine consumption was similar between patients with and without NASH. While consumption of espresso, caffeinated soft drinks, and chocolate was similar among patients, with respect to the level of fibrosis, regular coffee consumption was lower in patients with significant fibrosis (F ≥2). According to logistic regression analysis, consumption of regular coffee was an independent protective factor for fibrosis (OR: 0.752 [0.578-0.980], p=0.035) in a model including level of AST (OR: 1.04 [1.004-1.076], p=0.029), presence of NASH (OR: 2.41 [1.007-5.782], p=0.048), presence of the metabolic syndrome (NS), and level of HOMA-IR (NS). Espresso, but not regular coffee consumption was higher in patients with lower HDL cholesterol level, higher triglyceride level, and the metabolic syndrome.

CONCLUSIONS

Consumption of regular coffee but not espresso is an independent protective factor for liver fibrosis in severely obese European patients.