Dietary vitamin E and C intake is inversely associated with the severity of nonalcoholic fatty liver disease

Antioxidants and the risk of metabolic dysfunction-associated steatotic liver disease: results of National Health and Nutrition Examination Survey and two-sample Mendelian randomization analyses

BACKGROUND

The link between antioxidants and metabolic dysfunction-associated steatotic liver disease (MASLD) is a topic of considerable discussion in the field of observational studies, with the exact causal connections still being unclear.

METHODS

In this investigation, a cohort consisting of 17 061 participants from the National Health and Nutrition Examination Surveys was studied. Initially, a cross-sectional analysis was carried out to examine the relationship between the CDAI and MASLD. Further, Mendelian randomization (MR) was utilized to assess the possible causal links between antioxidant levels in the bloodstream and MASLD.

RESULTS

The association between the CDAI and MASLD was found to be significant in the fully adjusted logistic regression model, showing an OR of 0.95 [95% confidence interval (CI): 0.94-0.97; P  < 0.001]. The use of restricted cubic spline regression revealed no significant nonlinear association between the CDAI and the occurrence of MASLD ( Pnonlinearity  = 0.321). Additionally, MR findings did not suggest any causal connections between circulating levels of various antioxidants and MASLD. These antioxidants included vitamin A (retinol) (IVW: OR: 0.67, 95% CI: 0.33-1.36, P  = 0.272), vitamin C (ascorbate) (IVW: OR: 0.61, 95% CI: 0.34-1.09, P  = 0.094), vitamin E (α-tocopherol) (IVW: OR: 0.55, 95% CI: 0.13-2.25, P  = 0.407), vitamin E (γ-tocopherol) (IVW: OR: 0.89, 95% CI: 0.36-2.23, P  = 0.806), zinc (IVW: OR: 0.95, 95% CI: 0.82-1.09, P  = 0.449), selenium (IVW: OR: 0.98, 95% CI: 0.84-1.16, P  = 0.855), and carotene (IVW: OR: 0.80, 95% CI: 0.36-1.81, P  = 0.596).

CONCLUSION

The findings highlight a significant negative linear relationship between CDAI and MASLD prevalence in the observational component of the study. However, the MR analysis did not indicate any causal effects of circulating antioxidant levels on MASLD.

Exploring the application of dietary antioxidant index for disease risk assessment: a comprehensive review

Oxidative stress contributes to the development of cardiometabolic diseases and cancers. Numerous studies have highlighted the adverse effects of high reactive oxygen species (ROS) levels in the progression of chronic noncommunicable diseases and also during infections. On the other hand, antioxidants play a crucial role in preventing oxidative stress or postponing cell damage via the direct scavenging of free radicals or indirectly via the Keap1/Nrf2/ARE pathway, among others. Dietary antioxidants can be obtained from various sources, mainly through a plant-based diet, including fruits and vegetables. The dietary antioxidant index (DAI) has been developed to assess total antioxidant intake from diet. This review delineated the performance of DAI in the risk assessment of different diseases. It is suggested that a high DAI score prevents obesity-related diseases, including diabetes mellitus, hyperuricemia, dyslipidemia, and metabolic (dysfunction)-associated steatotic liver disease (MASLD). Additionally, DAI is negatively associated with Helicobacter pylori and Human papillomavirus infection, thus reducing the risk of gastric and cervical cancer. Also, a high intake of antioxidants prevents the development of osteoporosis, miscarriage, infertility, and mental illnesses. However, further prospective observations and clinical trials are warranted to confirm the application of DAI in preventing diseases that have been studied.

Synergistic impact of Composite Dietary Antioxidant Index and physical activity on fatty liver disease

Background

The relationship between dietary antioxidants and fatty liver disease remains a topic of debate. This study aimed to examine the association between the Composite Dietary Antioxidant Index (CDAI) and nonalcoholic fatty liver disease (NAFLD)/metabolic-associated fatty liver disease (MAFLD).

Methods

The study analyzed data from the 2003-2018 cycles of the National Health and Nutrition Examination Survey. The study included 16,321 individuals aged 20-85 years. Food and nutrient intake data were based on the 24-h recall method. Multivariate logistic regression models were employed to examine the relationship between CDAI and NAFLD/MAFLD.

Results

In the fully adjusted multivariate logistic regression model, CDAI demonstrated a significant negative correlation with NAFLD and MAFLD. Mediation analysis showed that inflammatory factors partially mediated the relationship between CDAI and NAFLD/MAFLD prevalence. The combination of high CDAI levels with effective physical activity was associated with a greater reduction in NAFLD/MAFLD prevalence than high CDAI levels alone.

Conclusion

Our study highlighted a negative association between CDAI and NAFLD/MAFLD, mediated by inflammatory factors. Additionally, participants with characteristics of active physical activity and high levels of CDAI were more strongly correlated with the reduced prevalence of NAFLD/MAFLD. Further research in clinical cohorts should be conducted to comprehensively investigate the impact of CDAI on NAFLD/MAFLD prevalence.

Association between composite dietary antioxidant index and fatty liver index among US adults

Background

The potential beneficial health effects of dietary antioxidants have been reported. However, the association of a composite dietary antioxidant index (CDAI) with fatty liver index (FLI) remains unclear. This study aims to assess whether CDAI (including its components) is associated with FLI among US adults.

Methods

This population-based cross-sectional study used data on US adults from the National Health and Nutrition Examination Survey (NHANES) 2007-2018 cycles. Weighted generalized linear regression models were used to analyze the association between CDAI (including vitamin A, C, E, zinc, selenium, and carotenoids) and FLI, which was calculated by using body mass index (BMI), waist circumference and levels of γ-glutamyl transferase and triglycerides.

Results

Weighted generalized linear regression models showed an inverse association between CDAI and FLI in the total population (β, -0.40; 95% CI, -0.59, -0.21), in women (β, -0.56; 95% CI, -0.94, -0.18), and in men (β, -0.32; 95% CI, -0.54, -0.10) after adjusting for various confounders. The restricted cubic splines showed the negative linear dose-response associations between CDAI and FLI (all P non_linear >0.05). The dietary selenium intake in women has an inverse U-shaped relationship with FLI, with an inflection point value of 110 μg. In model 3, intake of dietary antioxidants Vitamins A, C, E, and carotenoids were significantly negatively associated with FLI in female but only were vitamins A and E negatively associated with FLI in male. In subgroup analysis, CDAI showed a significantly negative relation to FLI among those aged 60 years or older (β, -0.57; 95% CI, -0.81, -0.33), among those who engaged in active physical activity (β, -0.46; 95% CI, -0.63, -0.29), among those without metabolic syndrome (β, -0.43; 95% CI, -0.62, -0.24), and those without hyperuricemia (β, -0.43; 95% CI, -0.60, -0.26). Additionally, CDAI was significantly negatively associated with male FLI, regardless of whether they had diabetes or not.

Conclusion

In conclusion, our results indicate that higher CDAI may be associated with a lower FLI.

The Interplay between Liver and Adipose Tissue in the Onset of Liver Diseases: Exploring the Role of Vitamin Deficiency

The deficiency of vitamins, a condition known as "hidden hunger", causes comprehensive pathological states. Research over the years has identified a relationship between liver diseases and hypovitaminosis or defects in vitamin metabolism. The exact mechanisms remain elusive; however, the crucial involvement of specific vitamins in metabolic functions, alongside the reclassification of liver disease as metabolic dysfunction-associated steatotic liver disease (MASLD), has prompted researchers to investigate the potential cause-effect dynamics between vitamin deficiency and liver disease. Moreover, scientists are increasingly investigating how the deficiency of vitamins might disrupt specific organ crosstalk, potentially contributing to liver disease. Although the concept of a dysmetabolic circuit linking adipose tissue and the liver, leading to liver disease, has been discussed, the possible involvement of vitamin deficiency in this axis is a relatively recent area of study, with numerous critical aspects yet to be fully understood. In this review, we examine research from 2019 to July 2024 focusing on the possible link between liver-adipose tissue crosstalk and vitamin deficiency involved in the onset and progression of non-alcoholic fatty liver disease (NAFLD). Studies report that vitamin deficiency can affect the liver-adipose tissue axis, mainly affecting the regulation of systemic energy balance and inflammation.

Association between Dietary Potassium Intake and Nonalcoholic Fatty Liver Disease and Advanced Hepatic Fibrosis in U.S. Adults

Introduction

The correlation between potassium and nonalcoholic fatty liver disease (NAFLD) is currently still poorly understood. We conducted this study to explore the correlation between dietary potassium intake and NAFLD, as well as advanced hepatic fibrosis (AHF). The study also sought to identify any potential interactions.

Methods

The data employed in this study were obtained from the National Health and Nutrition Examination Survey (NHANES) program, encompassing a period from 2007 to 2018. Employing the multiple logistic regression analysis, we evaluated the association of dietary potassium intake with NAFLD and AHF. Subsequently, stratification analysis, based on demographic variables, was constructed so as to assess the stability of the results. In addition, potential interaction effects were assessed by interaction tests.

Results

A total of 9443 participants were included in the analysis. The mean age of the participants was 50.4 years, and their daily mean dietary potassium and vitamin C intake was 2556.49 mg and 82.93 mg, respectively. Following comprehensive statistical analyses, the findings indicated a negative correlation between dietary potassium intake and both NAFLD and AHF. Participants in Q4 group with dietary potassium intake exhibited a 31% and 42% reduction in the odds of developing NAFLD and AHF, respectively, in comparison to Q1 group. An interaction effect of dietary vitamin C intake was observed in the association between dietary potassium intake and NAFLD. The results imply that high dietary vitamin C intake augment the inverse relationship between dietary potassium intake and NAFLD.

Conclusion

Dietary potassium intake was found to have an inverse association with the odds of both NAFLD and AHF. The association between dietary potassium intake and NAFLD was amplified by the presence of vitamin C in the diet.

Daily intake of baru (Dipteryx alata Vog.), a Cerrado native almond, promotes changes in the intestinal microbiota of individuals with obesity: A pilot study

The Brazilian Cerrado biome is rich in plant biodiversity, with fruits that have unique sensory characteristics and high nutritional quality. Among the various fruits, baru (Dipteryx alata Vog.) has attracted the attention of researchers because of its high lipid, protein, carbohydrate, fiber, and micronutrient (minerals and vitamins) contents. The present study evaluated the effects of regular consumption of baru almonds for over 60 days on the biochemical and anthropometric profiles and fecal microbiota of obese individuals. A pilot study was conducted on 15 individuals with obesity who were instructed to consume a 20-gram portion of baru almonds throughout the day. The body composition was assessed using anthropometric measurements. Blood pressure, glucose levels, lipid profile, serum insulin and iron contents, and fecal microbiota composition were determined at baseline (day 0) and after 60 days. Baru almond consumption contributed to changes in biochemical parameters, improved HDL cholesterol levels, and reduced total and LDL cholesterol levels. Some positive changes in the microbiota composition after consuming baru almonds include a decrease in the Faecalibacterium family and an increase in the Provotella genus. Therefore, ingesting baru almonds can modulate gut microbiota of individuals with obesity.

Can Nutraceuticals Support the Treatment of MASLD/MASH, and thus Affect the Process of Liver Fibrosis?

Currently, metabolic dysfunction-associated steatotic liver disease (MASLD) and metabolic dysfunction-associated steatohepatitis (MASH) are considered to be the main causes of fibrosis. In turn, fibrosis may lead to the development of hepatocellular carcinoma or advanced cirrhosis, i.e., potentially life-threatening conditions. It is likely that therapy aimed at reducing the risk of developing hepatic steatosis and inflammation could be helpful in minimizing the threat/probability of organ fibrosis. In recent years, increasing attention has been paid to the influence of nutraceuticals in the prevention and treatment of liver diseases. Therefore, the aim of this review was to describe the precise role of selected ingredients such as vitamin C, beta-carotene, omega-3 fatty acids, and curcumin. It is likely that the use of these ingredients in the treatment of patients with MASLD/MASH, along with behavioral and pharmacological therapy, may have a beneficial effect on combating inflammation, reducing oxidative stress, and thereby preventing liver damage.

Dietary macro and micronutrients associated with MASLD: Analysis of a national US cohort database

INTRODUCTION AND OBJECTIVES

Our objective was to measure and compare the intake of macro and micronutrients in a cohort of individuals with Metabolic Syndrome Associated Steatotic Liver Disease (MASLD) compared with matched controls to identify areas of further research in this area; we identified nutrition-associated associations with MASLD in the United States general population.

MATERIALS AND METHODS

We used the 2017 - 2018 NHANES dataset. Elastography Controlled Attenuation Parameter (CAP score>280) in the absence of other liver disease was defined as MASLD in adults (>18). Advanced fibrosis was defined by transient elastography >10 kPa. Controls were adults without liver disease.

RESULTS

1648 MASLD cases (11.4 % advanced fibrosis) and 2527 controls were identified. MASLD cases were older (P<0.001), more likely males (P = 0.01), less likely to have a college education (P = 0.04) and more likely married (P = 0.002). MASLD cases were more likely to be of Mexican American or Hispanic ethnicity (P = 0.002), have higher BMI, and have higher prevalence of diabetes, hyperlipidemia and hypertension (P<0.001 for all). MASLD cases had higher hs-CRP (P = 0.02) and ferritin (P = 0.02). MASLD cases had lower total (P = 0.004) and added vitamin E in their diet (P = 0.002), lower vitamin K intake (P = 0.005), and higher selenium intake (P = 0.03). Caloric intake (P = 0.04), carbohydrate intake (P = 0.02), cholesterol intake (P = 0.03) and saturated fatty acid intake (P = 0.05) were higher in MASLD. Individuals with MASLD were more likely to be on a diet (P<0.001), sedentary (P = 0.008) and less likely to participate in moderate or vigorous recreational activities (P<0.001).

CONCLUSIONS

The deficiencies of micronutrients and excess of macronutrients point to oxidative stress, pro-inflammatory state, and lipotoxicity as pathways linking the US diet to MASLD. MASLD patients are more often on special diets, which may reflect prior provider counseling on diet changes to improve health.

Serum vitamins and homocysteine levels in autoimmune liver disease: A systematic review and meta-analysis

OBJECTIVE

Vitamins and homocysteine (Hcy) are involved in liver metabolism and related to the pathogenesis of autoimmune liver disease (AILD), but consensus is lacking. This study aims to systematically summarize relevant evidence to clarify the association of serum vitamins and Hcy levels with AILD.

METHODS

The English and Chinese literature was searched until August 29, 2023. Studies were included if they were observational studies of investigating serum vitamins and Hcy levels in patients with AILD and their healthy comparisons. Quality assessment was performed by using the Newcastle-Ottawa Scale, and a meta-analysis was conducted using ReviewManager 5.3. The protocol was registered in the international prospective register of systematic reviews (PROSPERO), with registration number CRD42023455367.

RESULTS

A total of 25 case-control studies comprising 3487 patients (1673 patients and 1814 healthy controls) were included for analysis. There were 548 autoimmune hepatitis (AIH) cases, 1106 primary biliary cholangitis (PBC) cases, and 19 primary sclerosing cholangitis (PSC) cases. We found that serum A and E were decreased in both AIH and PBC/PSC; but vitamin C was reduced only in patients with PBC, not AIH. In addition, decreased content of 25(OH)D3 was found in both AIH and PBC. However, levels of 25(OH)D did not differ between the patients and controls, and were independent of disease types and the country. Only one study that met the inclusion criteria reported vitamin B6, B9, B12, and Hcy changes, and found that vitamin B6 and B9 were significantly decreased in patients with PBC, while serum vitamin B12 and Hcy levels were significantly elevated in them. One eligible study each confirmed a reduction in plasma vitamin K1 and 1,25(OH)2D3 in patients with PBC.

CONCLUSION

Most vitamins are deficient in AILD, so appropriate vitamin supplementation should be necessary. Further studies with larger sample sizes are needed to validate these findings.

Dietary inflammatory index is associated with metabolic dysfunction-associated fatty liver disease among United States adults

Background

Metabolic dysfunction-associated fatty liver disease (MAFLD) is presently the most prevalent chronic liver disorder globally that is closely linked to obesity, dyslipidemia metabolic syndrome, and type 2 diabetes mellitus (T2DM). Its pathogenesis is strongly associated with inflammation, and diet is a major factor in reducing inflammation. However, current research has focused primarily on exploring the relationship between diet and NAFLD, with less research on its link to MAFLD.

Methods

In this research, using dietary inflammatory index (DII) as a measure to assess dietary quality, we analyzed the relationship between diet and MAFLD. Data from the National Health and Nutrition Examination Survey (NHANES) 2017-2018, including 3,633 adults with complete DII and MAFLD, were used to develop cross-sectional analyses. Logistic regression analysis was adapted for investigating the relationship between DII and MAFLD development. Additionally, subgroup analysis and threshold effect analysis were carried out.

Results

A positive link between DII and MAFLD was found in the fully adjusted model (OR = 1.05; 95%CI, 1.00-1.11, p < 0.05). Subgroup analysis indicated that there was no significant dependence for the connection between DII and MAFLD except for the subgroup stratified by age. Compared with other age groups, people with MAFLD had 20% higher DII scores than non-MAFLD participants in those aged 20-41 years old (OR = 1.20; 95%CI, 1.08-1.33, p < 0.001). Furthermore, we found a U-shaped curve with an inflection point of 3.06 illustrating the non-linear connection between DII and MAFLD.

Conclusion

As a result, our research indicates that pro-inflammatory diet may increase the chance of MAFLD development, thus improved dietary patterns as a lifestyle intervention is an important strategy to decrease the incidence of MAFLD.

Vitamin E intake is inversely associated with NAFLD measured by liver ultrasound transient elastography

Non-alcoholic fatty liver disease (NAFLD) is one of the most common chronic liver diseases, whose severe form is associated with oxidative stress. Vitamin E as an antioxidant has a protective potential in NAFLD. Whether dietary intake of vitamin E, supplementary vitamin E use, and total vitamin E have a preventive effect on NAFLD requires investigation. A cross-sectional study used data from the National Health and Nutrition Examination Survey (2017-2020) was conducted. Vitamin E intake, including dietary vitamin E, supplementary vitamin E use, and total vitamin E, was obtained from the average of two 24-h dietary recall interviews. The extent of hepatic steatosis was measured by liver ultrasound transient elastography and presented as controlled attenuated parameter (CAP) scores. Participants were diagnosed with NAFLD based on CAP threshold values of 288 dB/m and 263 dB/m. The statistical software R and survey-weighted statistical models were used to examine the association between vitamin E intake and hepatic steatosis and NAFLD. Overall, 6122 participants were included for NAFLD analysis. After adjusting for age, gender, race, poverty level index, alcohol consumption, smoking status, vigorous recreational activity, body mass index, abdominal circumference, hyperlipidemia, hypertension, diabetes, and supplementary vitamin E use, dietary vitamin E was inversely associated with NAFLD. The corresponding odds ratios (OR) and 95% confidence intervals (CI) of NAFLD for dietary vitamin E intake as continuous and the highest quartile were 0.9592 (0.9340-0.9851, P = 0.0039) and 0.5983 (0.4136-0.8654, P = 0.0091) (Ptrend = 0.0056). Supplementary vitamin E was significantly inversely associated with NAFLD (fully adjusted model: OR = 0.6565 95% CI 0.4569-0.9432, P = 0.0249). A marginal improvement in total vitamin E for NAFLD was identified. The ORs (95% CIs, P) for the total vitamin E intake as continuous and the highest quartile in the fully adjusted model were 0.9669 (0.9471-0.9871, P = 0.0029) and 0.6743 (0.4515-1.0071, P = 0.0538). Sensitivity analysis indicated these findings were robust. The protective effects of vitamin E significantly differed in the stratum of hyperlipidemia (Pinteraction < 0.05). However, no statistically significant results were identified when the threshold value was set as 263 dB/m. Vitamin E intake, encompassing both dietary and supplemental forms, as well as total vitamin E intake, demonstrated a protective association with NAFLD. Augmenting dietary intake of vitamin E proves advantageous in the prevention of NAFLD, particularly among individuals devoid of hyperlipidemia.

Dietary pattern in women with polycystic ovary syndrome with and without associated non-alcoholic fatty liver disease: A cross-sectional study

INTRODUCTION

Women with Polycystic Ovary Syndrome (PCOS) have a higher prevalence of Nonalcoholic Fatty Liver Disease (NAFLD) than the general population. PCOS and NAFLD have common metabolic risk factors, however, the role of diet in NAFLD development is still uncertain in PCOS women.

OBJECTIVE

To evaluate and compare the dietary patterns and nutritional intake in patients with PCOS with and without NAFLD.

METHOD

Cross-sectional study that included patients with PCOS diagnosed according to Rotterdam criteria. All participants were submitted to abdominal ultrasound to investigate liver steatosis. Dietary profile was assessed by 24-hour food recall (24hR), and Food Frequency Questionnaire (FFQ). Diet quality was assessed by the Healthy Eating Index (HEI) adapted for the Brazilian population. Physical activity practice was also assessed.

RESULTS

87 participants were included (average age 35.2 ± 5.7 years), among whom, 67 (77%) had NAFLD. The group with PCOS and NAFLD presented higher body mass index (BMI) (34.9 ± 4.5 vs. 30.4 ± 4.9 kg/m2; p = 0.001), Waist Circumference (WC) (103 [97‒113] vs. 95 [87.5‒100] cm; p < 0.001) and were considered physically active less frequently than those without NAFLD (34.3% vs. 60%; p = 0.04). Food intake and dietary patterns assessed by 24hR, FFQ and HEI presented no difference between the groups.

CONCLUSIONS

PCOS women with coexistent NAFLD had higher BMI, WC and were less physically active than those without NAFLD. Dietary evaluation showed that PCOS women with NAFLD had no significant difference in macro and micronutrients or food group intake and diet quality in comparison to those without NAFLD.

Lifestyle interventions in nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is a dynamic chronic liver disease that develops in close association with metabolic irregularities. Between 2016 and 2019, the global prevalence among adults was reported as 38% and among children and adolescents it was about 10%. NAFLD can be progressive and is associated with increased mortality from cardiovascular disease, extrahepatic cancers and liver complications. Despite these numerous adverse outcomes, no pharmacological treatments currently exist to treat nonalcoholic steatohepatitis, the progressive form of NAFLD. Therefore, the main treatment is the pursuit of a healthy lifestyle for both children and adults, which includes a diet rich in fruits, nuts, seeds, whole grains, fish and chicken and avoiding overconsumption of ultra-processed food, red meat, sugar-sweetened beverages and foods cooked at high heat. Physical activity at a level where one can talk but not sing is also recommended, including leisure-time activities and structured exercise. Avoidance of smoking and alcohol is also recommended. Policy-makers, community and school leaders need to work together to make their environments healthy by developing walkable and safe spaces with food stores stocked with culturally appropriate and healthy food items at affordable prices as well as providing age-appropriate and safe play areas in both schools and neighbourhoods.

Association between dietary intakes of B vitamins and nonalcoholic fatty liver disease in postmenopausal women: a cross-sectional study

Background

Non-alcoholic fatty liver disease (NAFLD) is increasingly common globally, particularly among postmenopausal women. Diet plays a fundamental role in the treatment of NAFLD. However, clinical research on the dietary intakes of B vitamins, specifically in postmenopausal women, is scant. Hence, it is imperative to study the impact of B vitamin dietary intake in postmenopausal women.

Methods

This study utilized National Health and Nutrition Examination Survey (NHANES) data for 668 postmenopausal women. Logistic regression analysis was conducted to investigate the association of the intakes of B vitamins with hepatic steatosis and liver fibrosis prevalence. The analysis accounted for various covariates and employed restricted cubic spline analysis to examine potential nonlinear relationships. Additionally, interactions among age, diabetes, and B-vitamin intakes, as well as the interaction between folate and vitamin B12 intake, were explored.

Results

Higher intakes of folate [0.30 (0.10-0.88)], choline [0.26 (0.07-0.95)], vitamin B1, and vitamin B2 were associated with a reduced risk of hepatic steatosis in postmenopausal women. The associations of niacin (P-nonlinear = 0.0003), vitamin B1 (P-nonlinear = 0.036), and vitamin B2 (P-nonlinear<0.0001) intakes with hepatic steatosis showed a nonlinear pattern. However, no significant associations were observed between the intakes of niacin, vitamin B6 and vitamin B12 and hepatic steatosis. Furthermore, there were no significant associations between B-vitamin intakes and liver fibrosis. No interaction effects were observed.

Conclusion

Dietary intakes of folate, choline, vitamin B1, and vitamin B2 may be associated with liver steatosis in postmenopausal women, these results suggest that optimizing the intake of these specific B vitamins may have a protective effect against liver steatosis in postmenopausal women, offering valuable insights into potential dietary strategies to promote their well-being.

Diets with Higher Anti-inflammatory Potential Associated with Lower Risk of Development of Nonalcoholic Fatty Liver Disease and Early-Stage of Fibrosis Among US Adults

BACKGROUND

There is limited evidence of how dietary inflammatory potential influences nonalcoholic fatty liver disease (NAFLD) progression.

AIMS

Our study aims to evaluate the association of dietary inflammatory index (DII) with liver fibrosis, a hallmark feature of NAFLD, among US adults.

METHODS

Cross-sectional data consisting of 5,506 participants in the National Health and Nutrition Examination Survey from 2011 to 2018 were used. Energy adjusted-DII (E-DII) scores were calculated using 2 days of 24-h dietary recall data. We used a partial proportional odds model to determine risk at each stage of fibrosis according to the E-DII score.

RESULTS

The weighted prevalence of NAFLD (assessed by US fatty liver index) was 34.5%, with 23.2% (assessed by NAFLD Fibrosis Score) having mild fibrosis, 10.4% intermediate fibrosis, and 0.9% advanced fibrosis. When comparing the most pro-inflammatory diets to the most anti-inflammatory diets (AIDs) in the multivariable model, the marginal probability effect (MPE) of NAFLD, mild fibrosis and intermediate fibrosis increased by 11.7% (95% CI 6.6%, 16.9%), 7.0% (95% CI 3.5%, 10.4%) and 4.0% (95% CI 0.3%, 7.5%), respectively. The MPE of advanced fibrosis was not significant (MPE = 0.7%; 95% CI - 1.1%, 2.8%). Similar associations were observed when applying Fibrosis-4 and transient elastography as fibrosis diagnostic measurements.

CONCLUSIONS

An AID was associated with lower risk of development of NAFLD and early-stage of fibrosis among US adults. But the associations became attenuated and dissipated as the fibrogenesis became severe. Further studies are needed to re-confirm our observations.

Dietary strategies in non-alcoholic fatty liver disease patients: From evidence to daily clinical practice, a systematic review

Lifestyle modification comprising calorie restriction (CR) and increased physical activity enabling weight loss is the first-line of treatment for non-alcoholic fatty liver disease (NAFLD). However, CR alone is not optimal and evidence suggests that dietary pattern and composition are also critical in NAFLD management. Accordingly, high consumption of red and processed meat, saturated fat, added sugar, and sweetened beverages are associated with an increased risk of developing NAFLD and hepatocellular carcinoma, while other foods and compounds such as fish, olive oil, and polyphenols are, in contrast, beneficial for metabolic disorders. Therefore, several dietary interventions have been studied in order to determine which strategy would be the most beneficial for NAFLD. The evidence regarding the effectiveness of different dietary interventions such as low carbohydrate/low-fat diet, time-restricted eating diet, CR, and the well-studied Mediterranean diet is summarized.

Oxidative balance score is inversely associated with the incidence of non-alcoholic fatty liver disease

BACKGROUND & AIMS

The contribution of the balance between overall oxidative stress and antioxidant status in non-alcoholic fatty liver disease (NAFLD) is unclear. The oxidative balance score (OBS) comprises dietary and lifestyle pro- and antioxidant components that indicate the overall oxidative stress burden. We investigated the association between OBS and the incidence of NAFLD in middle-aged and older Korean adults.

METHODS

Among the 10,030 participants of the Korean Genome and Epidemiology Study_Ansan and Ansung cohort, 5065 without NAFLD at baseline were selected for secondary analysis. OBS was categorized into quartiles. Multiple Cox proportional hazard regression analyses were performed to estimate the hazard ratio (HR) and 95% confidence interval (CI) for NAFLD incidence by sex-specific OBS quartile groups after adjusting for confounders.

RESULTS

During the follow-up period (median 13.4 years), 913 (43.2%) men and 1288 (43.9%) women were newly diagnosed with NAFLD. Compared with that of the lowest quartile (Q1) group, the adjusted HR (95% CI) for NAFLD incidence in Q2, Q3, and Q4 groups was 0.85 (0.71-1.00), 0.65 (0.54-0.78), and 0.50 (0.40-0.62) in men, and 0.85 (0.73-0.99), 0.66 (0.56-0.77), and 0.48 (0.40-0.59) in women, respectively, and for NAFLD incidence, per incremental change in OBS, was 0.90 (0.87-0.92) in men and 0.88 (0.86-0.90) in women.

CONCLUSIONS

A higher OBS was significantly associated with a lower risk for NAFLD incidence. Maintaining a healthy lifestyle and an antioxidant-rich diet is a potentially viable strategy for preventing NAFLD.

Vitamin E supplementation in the treatment on nonalcoholic fatty liver disease (NAFLD): Evidence from an umbrella review of meta-analysis on randomized controlled trials

OBJECTIVE

We conducted this umbrella review of meta-analysis on randomized controlled trials to clarify the effects of vitamin E administration on alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma-glutamyl transferase (GGT), degrees of steatosis and fibrosis in patients with nonalcoholic fatty liver disease (NAFLD).

METHODS

PubMed, MEDLINE, SCOPUS, EMBASE, and Web of Science were searched to identify pertinent articles published up to June 2023. To calculate the overall effect size (ES) and confidence intervals (CI), random-effects model was used.

RESULTS

Six meta-analyses were included in the umbrella review. By pooling ES based on the random-effects model, we found that vitamin E supplementation significantly decreased ALT (ES -6.47, 95% CI -11.73 to -1.22, P = 0.01), AST (ES -5.35, 95% CI -9.78 to -0.93, P = 0.01), degrees of fibrosis (ES -0.24, 95% CI -0.36 to -0.12, P < 0.001) and steatosis (ES -0.67, 95% CI -0.88 to -0.45, P < 0.001) in NAFLD patients, but had no effect on GGT. In the subgroup analyses, we detected that fibrosis scores notably decreased when vitamin E dosage was >600 IU/day (ES -0.25, 95% CI -0.41 to -0.10, P = 0.002) and when the treatment duration was ≥12 months (ES -0.24, 95% CI -0.37 to -0.12, P < 0.001).

CONCLUSION

Vitamin E administration improves ALT, AST, fibrosis, and steatosis in NAFLD subjects. Fibrosis scores were significantly reduced when vitamin E dosage exceeded 600 IU/day or with a treatment duration of at least 12 months.

Serum vitamin C levels and risk of non-alcoholic fatty liver disease: results from a cross-sectional study and Mendelian randomization analysis

Background and aims

Vitamin C, as an antioxidant, may play a role in the treatment of NAFLD. This research aimed to investigate the association of serum vitamin C levels with the risk of NAFLD and to further examine the causal relationship by Mendelian randomization (MR) method.

Methods

The cross-sectional study selected 5,578 participants of the National Health and Nutrition Examination Survey (NHANES), 2005-2006 and 2017-2018. The association of serum vitamin C levels with NAFLD risk was evaluated under a multivariable logistic regression model. A two-sample MR study, using genetic data from large-scale genome-wide association studies (GWAS) of serum vitamin C levels (52,014 individuals) and NAFLD (primary analysis: 1,483 cases /17,781 controls; secondary analysis: 1,908 cases/340,591 controls), was conducted to infer causality between them. The inverse-variance-weighted (IVW) was applied as the main method of MR analysis. A series of sensitivity analyzes were used to evaluate the pleiotropy.

Results

In the cross-sectional study, results showed that Tertile 3 group (Tertile 3: ≥1.06 mg/dl) had a significantly lower risk (OR = 0.59, 95% CI: 0.48 ~ 0.74, p < 0.001) of NAFLD than Tertile 1 group (Tertile 1: ≤0.69 mg/dl) after full adjustments. In regard to gender, serum vitamin C was protective against NAFLD in both women (OR = 0.63, 95% CI: 0.49 ~ 0.80, p < 0.001) and men (OR = 0.73, 95% CI: 0.55 ~ 0.97, p = 0.029) but was stronger among women. However, in the IVW of MR analyzes, no causal relationship between serum vitamin C levels and NAFLD risk was observed in the primary analysis (OR = 0.82, 95% CI: 0.47 ~ 1.45, p = 0.502) and secondary analysis (OR = 0.80, 95% CI: 0.53 ~ 1.22, p = 0.308). MR sensitivity analyzes yielded consistent results.

Conclusion

Our MR study did not support a causal association between serum vitamin C levels and NAFLD risk. Further studies with greater cases are warranted to confirm our findings.

Targeting ferroptosis, a novel programmed cell death, for the potential of alcohol-related liver disease therapy

Ferroptosis is a new iron-dependent cell death mode, which is different from the other types of programmed cell death, such as apoptosis, necrosis, and autophagy. Ferroptosis is characterized by a process in which fatal lipids from lipid peroxidation accumulate in cells and eventually lead to cell death. Alcohol-related liver disease (ALD) is a type of liver injury caused by excessive alcohol intake. Alcohol-related liver disease is a broad-spectrum disease category, which includes fatty liver, steatohepatitis, hepatitis, cirrhosis, and hepatocellular tumors. Recent studies have found that ferroptosis is involved in the pathological development of non-viral liver diseases. Therefore, ferroptosis may be an ideal target for the treatment of non-viral liver diseases. In this review article, we will elaborate the molecular mechanism and regulatory mechanism of ferroptosis, explore the key role of ferroptosis in the Alcohol-related liver disease process, and summarize the existing targeted ferroptosis drugs and their feasibility for the treatment of Alcohol-related liver disease.

Effects of COVID-19 Pandemic on Metabolic Status and Psychological Correlates of a Cohort of Italian NAFLD Outpatients

Non-alcoholic fatty liver disease (NAFLD) is a potentially progressive condition characterized by the presence of fat in more than 5% of hepatocytes, representing the hepatic expression of metabolic syndrome (MetS). A reduction of at least 5–7% in initial body weight improves the metabolic profile underlying NAFLD. The aim of our study was to evaluate the effects of the COVID-19 lockdown on a cohort of non-advanced NAFLD Italian outpatients. We identified 43 patients with 3 available time point visits in our center: first visit (T0) when behavioral indications aimed at controlling MetS were provided, a pre-COVID visit (T1) and a post-COVID visit (T2). During the lockdown, an online compilation of validated psychological tests (SRQ-20, EQ5D, SF-12 and STAI) and a specifically formulated questionnaire for NAFLD was presented to our cohort and completed by 14 consenting patients. Patients who had lost more than 5% of the initial weight at T1 (9 subjects, 21%) maintained the results even at T2, with an overall reduction in BMI and liver stiffness; patients who had not lost the desired weight at T1 (34 subjects, 79%) displayed a further increase in BMI and visceral adiposity at T2. Of interest is that patients in the latter group reported signs of psychological suffering. Our data demonstrated that the setting of good counseling was effective in controlling the metabolic disorder underlying NAFLD in our cohort of outpatients. Given the need for patients to play an active role in the behavioral therapy for NAFLD, we advocate that a multidisciplinary approach be adopted, including a psychological support to obtain the best results over time.

Study on the correlation between B vitamins and breast cancer

BACKGROUND

Relevant studies suggest that serum vitamin level is related to the risk of breast cancer, and dietary pattern and drug supplementation can significantly affect the level of vitamin in the body. Therefore, intervention of vitamin level in the body is expected to be a potential strategy to reduce the risk of breast cancer. However, the current epidemiological findings of serum vitamin levels and breast cancer risk are inconsistent, and the relationship between serum vitamin and breast cancer is still controversial. In this study, we compared the serum vitamin expression levels of healthy people, benign breast patients, and breast cancer patients, and evaluated the relationship between B vitamin levels and breast cancer risk.

METHODS

The study used liquid chromatography-tandem mass spectrometry to determine the serum vitamin levels of 520 people who attended Yunnan Cancer Hospital from September 2020 to December 2020. After screening by exclusion criteria, 38 patients with benign breast diseases, 87 patients with breast cancer and 91 healthy controls were finally included. The kruskal-wallis H test was used to compare the differences in serum vitamin levels of subjects. Χ² test was used to evaluate the relationship between B vitamin level and age,BMI,TNM staging,Ki-67,Her-2,surgery and chemotherapy, and other baseline characteristics and through binary logistic regression analysis, calculating odds ratio and 95% confidence interval (CI) to evaluate the relationship between B vitamins and breast cancer risk.

CONCLUSION

The levels of VitB1 and VitB5 in the serum of breast cancer patients and patients with benign breast diseases were higher than those in the healthy control group, while the expression levels of VitB3 in breast cancer patients were lower than those in the healthy control group and the breast benign disease groups. The level of VitB1 was positively correlated with breast cancer risk. The VitB3 level was negatively correlated with breast cancer risk. The VitB5 level is not significantly related to the risk of breast cancer.

Nutritional intervention in the management of non-alcoholic fatty liver disease

Lifestyle modification is the primary intervention to control NAFLD progression, but despite evidence-based effectiveness it is difficult to distinguish the benefits of nutrition from physical activity and the optimal diet composition is not established. Macronutrients as saturated fatty acids, sugars and animal proteins are harmful in NAFLD and the Mediterranean Diet reducing sugar, red meat and refined carbohydrates and increasing unsaturated-fatty-acids was reported to be beneficial. However one size cannot fit all since NAFLD is a multifaceted syndrome encompassing many diseases of unknown etiologies, different clinical severity and outcomes. Studies of the intestinal metagenome, provided new insights into the physio-pathological interplay between intestinal microbiota and NAFLD. How much the microbiota heterogeneity can influence response to diet remains unknown. New knowledge indicates that AI guided personalized nutrition based on clinic-pathologic and genetic data combined with pre/post nutritional intervention gut metagenomics/metabolomics will be part of the future management of NAFLD.

The association between vitamin C dietary intake and its serum levels with anthropometric indices: A systematic review and meta-analysis

BACKGROUND

studies showed inflammatory background of overweight and obesity. Prevalence of weight disorders has dramatically increased over the past few decades. Vitamin C is an antioxidant and may be associated with weight disorders. This study aims to systematically review the relationship between dietary and serum vitamin C levels with anthropometric indices.

METHODS

A systematic search was conducted in Medline database (PubMed), Scopus, Embase, Web of Science, Cochrane library and Google Scholar up to the end of August 2021. All observational studies that assessed the relationship between dietary or circulating vitamin C levels and body mass index (BMI) and waist circumference (WC) on adults were included. The quality of included studies was assessed using the National Institute of Health quality assessment tool.

RESULTS

Among 11,689 studies, 47 and 37 articles were included in the systematic review and meta-analysis, respectively. There was an inverse significant correlation between WC and serum vitamin C levels (r = -0.28, 95% CI: -0.35,-0.21, I² = 14.2%) and between BMI and serum vitamin C levels (r = -0.17, 95% CI: -0.25, -0.09, I² = 72.8%). Higher vitamin C consumption was significantly associated with lower BMI. There were no significant differences in serum vitamin C levels between normal-weight and overweight subjects, but serum vitamin C levels were significantly higher in obese subjects in comparison with normal-weight subjects.

CONCLUSION

Results showed that both dietary and serum vitamin C levels were inversely associated with BMI and WC. More well-designed clinical trials are needed to assess the effect of vitamin C supplementation in prevention and treatment of obesity.

Association between Diet Quality and Index of Non-Alcoholic Steatohepatitis in a Large Population of People with Type 2 Diabetes: Data from the TOSCA.IT Study

Background: There are still open questions with respect to the optimal dietary treatment in patients with type 2 diabetes (T2D) and coexisting non-alcoholic steatohepatitis (NASH). The aim of this study is to investigate, in patients with T2D, the association between NASH, dietary component intake, food groups and adherence to the Mediterranean diet. Methods: Cross-sectional analysis of 2026 people with T2D (1136 men and 890 women). The dietary habits were assessed with the European Prospective Investigation into Cancer and Nutrition (EPIC) questionnaire. NASH was identified by the Index Of NASH (ION). Based on the cluster analysis two dietary patterns were identified: the NASH and the NO-NASH pattern. Results: The macronutrient composition of the diet was similar in the two patterns. However, the NASH pattern compared with the NO-NASH pattern was characterized by a significantly lower content of fibre (p < 0.001), β-carotene (p < 0.001), vitamin C (p < 0.001), vitamin E (p < 0.001), polyphenols (p = 0.026) and antioxidant capacity (p < 0.001). With regard to food consumption, the NASH pattern compared with NO-NASH pattern was characterized by higher intake of rice (p = 0.021), potatoes (p = 0.013), red (p = 0.004) and processed meat (p = 0.003), and a lower intake of wholegrain bread (p = 0.019), legumes and nuts (p = 0.049), vegetables (p = 0.047), fruits (p = 0.002), white meat (p = 0.001), fatty fish (p = 0.005), milk and yogurt (p < 0.001). Conclusions: NO-NASH dietary pattern was characterized by a food consumption close to the Mediterranean dietary model, resulting in a higher content of polyphenols, vitamins, and fibre. These finding highlight the potential for dietary components in the prevention/treatment of NASH in people with T2D.

Macronutrient and Micronutrient Intake in Adolescents With Non-alcoholic Fatty Liver Disease: The Association With Disease Severity

OBJECTIVES

While dietary changes are recommended to treat pediatric non-alcoholic fatty liver disease (NAFLD), the role of specific nutrients in disease progression is unclear. The objective of this study is to (1) assess the macronutrient and micronutrient intake in adolescents with liver biopsy proven NAFLD [with and without non-alcoholic steatohepatitis (NASH)] and lean controls; (2) determine nutritional predictors of disease severity amongst these groups.

METHODS

Adolescents with biopsy-proven NAFLD and lean controls completed the Harvard Food Frequency Questionnaire.

RESULTS

Twenty-eight NAFLD and 15 lean controls were studied. NAFLD with (n = 20) and without NASH (n = 8) had similar total calorie, protein, fat, and carbohydrate intake. Subjects with NASH had higher total sugar (122.3 ± 48.3 vs 83.1 ± 38.8 g), glucose (24.3 ± 9.3 vs 15.2 ± 7.5 g), sucrose (42.3 ± 16.9 vs 28.8 ± 11.7 g), and fructose (29.4 ± 12.5 vs 18.1 ± 8.0 g) intake than those with NAFLD but without NASH ( P < 0.05). Both NAFLD groups had similar micronutrient intake. Alanine aminotransferase (ALT) correlated with total caloric intake ( ρ = 0.4; P = 0.04). Total carbohydrate calories correlated with a higher NAS summary score ( ρ = 0.38; P = 0.04) and lobular inflammation ( ρ = 0.50; P = 0.007). Percent calories from added sugar and glucose correlated with worsening NAS summary score ( ρ = 0.44, P = 0.02; ρ = 0.48, P = 0.009) and lobular inflammation ( ρ = 0.51, P = 0.006; ρ = 0.53, P = 0.004). Percent calories from fructose correlated with lobular inflammation ( ρ = 0.56; P = 0.002). Total daily calories, protein, fat, carbohydrate, and micronutrient intake were similar between NAFLD and lean controls.

CONCLUSIONS

NASH patients consume similar total calories, protein, and fat as those without NASH, but have significantly higher sugar intake. NAFLD and lean children, however, have similar macro/micronutrient intake. Histologic disease severity correlates with total carbohydrate and added sugar intake, supporting a role for simple sugar intake in NAFLD progression.

Associations of serum folate and vitamin C levels with metabolic dysfunction-associated fatty liver disease in US adults: A nationwide cross-sectional study

Background

Clinical research results on the relationship between folate and non-alcoholic fatty liver disease are contradictory. Metabolic dysfunction-associated fatty liver disease (MAFLD) is a recently proposed concept. Evidence about the relationship between serum folate and MAFLD, especially considering the status of serum vitamin C, is scarce. This study was aimed to investigate the association of serum folate levels with the prevalence of MAFLD, and further to analyze the potential impact of serum vitamin C status on their association.

Methods

Totally 2,797 participants from National Health and Nutrition Examination Survey (NHANES) 2017-2018 were included. Vibration-controlled transient elastography was used to detect liver steatosis and fibrosis. Participants were divided in groups based on the tertiles of serum folate or vitamin C, and the serum folate or vitamin C level in T1 was low. Logistic regression analysis in the complex sample module was performed to illustrate the association of serum folate levels with the prevalence of MAFLD. Stratification analysis by serum vitamin C status was performed as well.

Results

Compared with the serum folate levels of T1 group, participants in the T3 group had 47.9% lower risk of MAFLD [OR = 0.521 (95% CI: 0.401-0.677)]. However, when participants were stratified by serum vitamin C levels, there was no association between the serum folate levels and MAFLD in the T1 or T2 group. Among participants in the T3 group of vitamin C status, participants in the T3 group of serum folate had a 63.6% lower risk of MAFLD compared with the T1 group [OR = 0.364 (95% CI: 0.147-0.903)].

Conclusions

High serum folate level is associated with lower prevalence of MAFLD, especially in participants with sufficient vitamin C.

Iron metabolism mediates the relationship between Vitamin C and hepatic steatosis and fibrosis in NAFLD

Vitamin C (Vit C) and iron metabolism are closely related to metabolic disorders. However, the relation between iron storage protein ferritin and Vit C has not been elucidated. We aimed to investigate the crosstalk between Vit C and ferritin and its implications on non-alcoholic fatty liver disease (NAFLD). Clinical information of 3,614 subjects was obtained from the NHANES Public Data 2017–2018. FibroScan data, which estimates liver steatosis and fibrosis and Vit C, were selected to assess factors influencing NAFLD in this cross-sectional study. Ferritin and Vit C among different categories of liver steatosis and fibrosis were assessed by CAP and E value. Logistic regression and RCS models were used to analyze the correlations. In vitro study in hepG2 were conducted to validate the regulations. Ferritin increased while Vit C decreased with more severe hepatic steatosis and hepatic fibrosis (all P < 0.001). Logistic regression models indicated that increased serum ferritin was a risk factor for NAFLD while increased Vit C was a protective factor for NAFLD and hepatic fibrosis after adjusting the continuous and categorical variables. Vitamin C was negatively associated with ferritin. Further mediation analysis identified that ferritin mediates the impact of Vit C on NAFLD (P < 0.05) and cirrhosis (P < 0.001). The experiments on cellular level suggested Vit C alleviated PA/OA induced steatosis and maintains iron homeostasis through inhibiting PA/OA induced upregulation of iron bound protein ferritin and labile iron pool (LIP) induction in hepG2 cells. In conclusion, Vit C was a protective factor, whereas ferritin was a risk factor for hepatic steatosis and fibrosis. Vitamin C alleviated NAFLD and maintained iron homeostasis via ferritin suppression and LIP induction.

One size does not fit all; practical, personal tailoring of the diet to NAFLD patients

Different dietary regimens for weight loss have developed over the years. Since the most evidenced treatment for non-alcoholic fatty liver disease (NAFLD) is weight reduction, it is not surprising that more diets targeting obesity are also utilized for NAFLD treatment. However, beyond the desired weight loss effects, one should not ignore the dietary composition of each diet, which may not necessarily be healthy or safe over the long term for hepatic and extrahepatic outcomes, especially cardiometabolic outcomes. Some of these diets are rich in saturated fat and red meat, are very strict, and require close medical supervision. Some may also be very difficult to adhere to for long periods, thus reducing the patient's motivation. The evidence for a direct benefit to NAFLD by restrictive diets such as very-low-carb, ketogenic, very-low-calorie diets, and intermittent fasting is scarce, and the long-term safety has not been tested. Nowadays, the approach is that the diet should be tailored to the patient's cultural and personal preferences. There is strong evidence for the independent protective association of NAFLD with a diet based on healthy eating patterns of minimally-processed foods, low in sugar and saturated fat, high in polyphenols, and healthy types of fats. This leads to the conclusion that a Mediterranean diet should serve as a basis that can be restructured into other kinds of diets. This review will elaborate on the different diets and their role in NAFLD. It will provide a practical guide to tailor the diet to the patients without compromising its composition and safety.

Association of serum vitamin C with liver fibrosis in adults with nonalcoholic fatty liver disease

OBJECTIVE

This study aimed to investigate the association between serum vitamin C and liver fibrosis in patients with NAFLD in the US adults.

METHODS

We conducted a cross-sectional analysis of data from the 2017 to 2018 cycle of National Health and Nutrition Examination Survey (NHANES). Serum vitamin C and transient elastography (TE)-accessed liver stiffness was taken as independent and dependent variables, respectively. Liver steatosis and fibrosis were detected by controlling attenuation parameter (CAP) and TE. NAFLD was defined by a CAP score of ≥248 dB/m without any indication of other causes of chronic liver disease. The median liver stiffness of ≥8.2 kPa was used to identify significant fibrosis (≥F2) among NAFLD patients. We calculated the adjusted odds ratio (OR) and 95% confidential intervals (CIs) for associations with significant NAFLD fibrosis using multivariable logistic regression models.

RESULTS

Overall, 1926 individuals with NAFLD were included in the analysis and 267 subjects met the definition of significant fibrosis. Serum vitamin C was associated with lower odds of liver fibrosis in NAFLD after adjusting for potential confounders (OR = 0.60, 95% CI, 0.43-0.84), while in the subgroup analysis stratified by gender and body mass index (BMI), this association showed a difference after adjusting for confounders (males: OR = 0.43, 95% CI, 0.26-0.71; females: OR = 0.78, 95% CI, 0.49-1.24). There were no significant associations of serum vitamin C with liver fibrosis in NAFLD with underweight or normal (OR = 1.34, 95% CI, 0.19-9.34).

CONCLUSIONS

This cross-sectional study indicated an association of serum vitamin C with significant fibrosis in men and overweight or obese patients with NAFLD.

Toxicological effects of traffic-related air pollution on the lungs: Evidence, biomarkers and intervention

BACKGROUND

Numerous epidemiological studies have recently observed that exposure to traffic-related air pollution (TRAP) is associated with increased risk of various respiratory diseases. Major gaps in knowledge remain regarding the toxicological effects.

OBJECTIVES

We examined the toxicological effects of the gasoline exhaust particles (GEP), a paradigm of TRAP, in rats, with an objective to provide the evidence, obtain the biomarkers, and suggest effective intervention measure.

METHODS

We measured the airway hyperresponsiveness (AHR), inflammatory cells in the bronchoalveolar lavage (BAL) fluid, histological changes in the lung tissues, and the biomarkers so as to systematically examine the toxicological effects of GEPs at different dose levels (0.5, 2.5, 5 mg/kg BW). The intervention of vitamin E (VE), a natural antioxidant, on the toxicological effects was investigated.

RESULTS

The lung injury caused by GEP exposure was first indicated by the airway hyperresponsiveness (AHR). Compared with the control group, GEP exposure significantly increased the airway resistances and decreased the lung compliance; the higher the dose of GEP, the more serious the lung injury. Lung injury was also revealed by the increase of inflammatory cells, including the lymphocytes and neutrophils, in the BAL fluid. With the increase of GEP dose, histological changes in the lung tissues were further observed: inflammatory cell infiltration increased and alveolar wall thickened. The toxicology of GEP was demonstrated by the increase of the biomarkers of the oxidative stress, the pro-inflammatory cytokines and the apoptosis cytokine. However, administration of VE was found to be effective in restoring airway injury.

CONCLUSION

The toxicological effects of traffic-related air pollution (TRAP) on rat lungs are supported by evidence and biomarkers, and vitamin E intervention is feasible.

A Molecular Insight into the Role of Antioxidants in Nonalcoholic Fatty Liver Diseases

Nonalcoholic fatty liver disease (NAFLD) defines fat accumulation in the liver, and it is commonly associated with metabolic syndromes like diabetes and obesity. Progressive NAFLD leads to nonalcoholic steatohepatitis (NASH) and ultimately causes cirrhosis and hepatocellular carcinoma, and NASH is currently a frequent cause of liver transplantation. Oxidative stress is often contributed to the progression of NAFLD, and hence, antioxidants such as silymarin, silybin, or silibinin, pentoxifylline, resveratrol, and vitamins A, C, and E are used in clinical trials against NAFLD. Silymarin induces the peroxisome proliferator-activated receptor α (PPARα), a fatty acid sensor, which promotes the transcription of genes that are required for the enzymes involved in lipid oxidation in hepatocytes. Silybin inhibits sterol regulatory element-binding protein 1 and carbohydrate response element-binding protein to downregulate the expression of genes responsible for de novo lipogenesis by activating AMP-activated protein kinase phosphorylation. Pentoxifylline inhibits TNF-α expression and endoplasmic reticulum stress-mediated inflammatory nuclear factor kappa B (NF-κB) activation. Thus, it prevents NAFLD to NASH progression. Resveratrol inhibits methylation at Nrf-2 promoters and NF-κB activity via SIRT1 activation in NAFLD conditions. However, clinically, resveratrol has not shown promising beneficial effects. Vitamin C is beneficial in NAFLD patients. Vitamin E is not effectively regressing hepatic fibrosis. Hence, its combination with antifibrotic agents is used as an adjuvant to produce a synergistic antifibrotic effect. However, to date, none of these antioxidants have been used as a definite therapeutic agent in NAFLD patients. Further, these antioxidants should be studied in NAFLD patients with larger populations and multiple endpoints in the future.

Mitochondria homeostasis: Biology and involvement in hepatic steatosis to NASH

Mitochondrial biology and behavior are central to the physiology of liver. Multiple mitochondrial quality control mechanisms remodel mitochondrial homeostasis under physiological and pathological conditions. Mitochondrial dysfunction and damage induced by overnutrition lead to oxidative stress, inflammation, liver cell death, and collagen production, which advance hepatic steatosis to nonalcoholic steatohepatitis (NASH). Accumulating evidence suggests that specific interventions that target mitochondrial homeostasis, including energy metabolism, antioxidant effects, and mitochondrial quality control, have emerged as promising strategies for NASH treatment. However, clinical translation of these findings is challenging due to the complex and unclear mechanisms of mitochondrial homeostasis in the pathophysiology of NASH.

Oxidative Stress and Redox Signaling in the Pathophysiology of Liver Diseases

The increased production of derivatives of molecular oxygen and nitrogen in the form of reactive oxygen species (ROS) and reactive nitrogen species (RNS) lead to molecular damage called oxidative stress. Under normal physiological conditions, the ROS generation is tightly regulated in different cells and cellular compartments. Any disturbance in the balance between the cellular generation of ROS and antioxidant balance leads to oxidative stress. In this article, we discuss the sources of ROS (endogenous and exogenous) and antioxidant mechanisms. We also focus on the pathophysiological significance of oxidative stress in various cell types of the liver. Oxidative stress is implicated in the development and progression of various liver diseases. We narrate the master regulators of ROS-mediated signaling and their contribution to liver diseases. Nonalcoholic fatty liver diseases (NAFLD) are influenced by a "multiple parallel-hit model" in which oxidative stress plays a central role. We highlight the recent findings on the role of oxidative stress in the spectrum of NAFLD, including fibrosis and liver cancer. Finally, we provide a brief overview of oxidative stress biomarkers and their therapeutic applications in various liver-related disorders. Overall, the article sheds light on the significance of oxidative stress in the pathophysiology of the liver. © 2022 American Physiological Society. Compr Physiol 12:3167-3192, 2022.

SGLT2 Inhibitors as the Most Promising Influencers on the Outcome of Non-Alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD), the most frequent liver disease in the Western world, is a common hepatic manifestation of metabolic syndrome (MetS). A specific cure has not yet been identified, and its treatment is currently based on risk factor therapy. Given that the initial accumulation of triglycerides in the liver parenchyma, in the presence of inflammatory processes, mitochondrial dysfunction, lipotoxicity, glucotoxicity, and oxidative stress, can evolve into non-alcoholic steatohepatitis (NASH). The main goal is to identify the factors contributing to this evolution because, once established, untreated NASH can progress through fibrosis to cirrhosis and, ultimately, be complicated by hepatocellular carcinoma (HCC). Several drugs have been tested in clinical trials for use as specific therapy for NAFLD; most of them are molecules used to cure type 2 diabetes mellitus (T2DM), which is one of the main risk factors for NAFLD. Among the most studied is pioglitazone, either alone or in combination with vitamin E, glucagon-like peptide-1 (GLP-1) receptor agonists, dipeptidyl peptidase-4 (DPP-4) inhibitors. Actually, the most promising category seems to be sodium-glucose cotransporter (SGLT2) inhibitors. Their action is carried out by inhibiting glucose reabsorption in the proximal renal tubule, leading to its increased excretion in urine and decreased levels in plasma. Experimental studies in animal models have suggested that SGLT2 inhibitors may have beneficial modulatory effects on NAFLD/NASH, and several trials in patients have proven their beneficial effects on liver enzymes, BMI, blood lipids, blood glucose, and insulin resistance in NAFLD patients, thus creating strong expectations for their possible use in preventing the evolution of liver damage in these patients. We will review the main pathogenetic mechanisms, diagnostic modalities, and recent therapies of NAFLD, with particular attention to the use of SGLT2 inhibitors.

Association of Serum Vitamin C With NAFLD and MAFLD Among Adults in the United States

Background and Aims

Despite the remarkable progress of metabolic dysfunction-associated fatty liver disease (MAFLD), formerly named non-alcoholic fatty liver disease (NAFLD), the disease remains poorly improved. Since increased oxidative stress and inflammation contribute to the initiation and progression of fatty liver disorders, vitamin C (VC), an antioxidant agent, might be a suitable treatment option for MAFLD. However, the lack of clinically confirmed benefits makes clinicians challenging to recommend antioxidant supplements for MAFLD individuals.

Methods

Herein, the nationally representative National Health and Nutrition Examination Survey 2017–2018 data were collected to evaluate the potential association between the serum VC levels with the risk of different categories of NALFD and the newly proposed MAFLD terminology. Hepatic steatosis was defined as controlled attenuated parameter scores ≥ 263 dB/m, whereas liver fibrosis (LF) status was defined as F0–F4, with the cutoff values of median liver stiffness being 6.3, 8.3, 10.5, and 12.5 (KPa), respectively. A cross-sectional analysis was performed to calculate the odds rate and determine the potential beneficial effects of VC.

Results

A total of 4,494 participants aged more than 18 years and conducted transient elastography examinations were included. Our findings demonstrated that participants with increased serum VC status were more likely to be female predominant, more educated, and moderate drinkers. Interestingly, female participants tended to have a lower prevalence of NAFLD, MAFLD, LF, and liver cirrhosis (LC) after stratification by gender. Moreover, our results revealed that participants from the quartile three group (quartile 3: 50.5–67.0 μmol/L) experienced a slightly lower risk of MAFLD than the risk of NAFLD. Of note, the serum concentration of VC (quartile 2: 30.9–50.5 μmol/L) inversely associated with LF and LC was lower than the serum VC level (quartile 3) associated with NAFLD and MAFLD. Notably, individuals from the quartile 3 group experienced a statistically significant 32.5, 42.0, 45.7, and 71% decrease in risk of NAFLD, MAFLD, LF, and LC, respectively.

Conclusion

In summary, our findings suggested an inverse association between serum VC levels and NAFLD, MAFLD, LF, or LC. Additionally, adjustment of VC supplementation according to age, gender, and ethnicity may be a promising candidate for these diseases.

Oxidative Stress in Non-Alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD) is a challenging disease caused by multiple factors, which may partly explain why it still remains an orphan of adequate therapies. This review highlights the interaction between oxidative stress (OS) and disturbed lipid metabolism. Several reactive oxygen species generators, including those produced in the gastrointestinal tract, contribute to the lipotoxic hepatic (and extrahepatic) damage by fatty acids and a great variety of their biologically active metabolites in a “multiple parallel-hit model”. This leads to inflammation and fibrogenesis and contributes to NAFLD progression. The alterations of the oxidant/antioxidant balance affect also metabolism-related organelles, leading to lipid peroxidation, mitochondrial dysfunction, and endoplasmic reticulum stress. This OS-induced damage is at least partially counteracted by the physiological antioxidant response. Therefore, modulation of this defense system emerges as an interesting target to prevent NAFLD development and progression. For instance, probiotics, prebiotics, diet, and fecal microbiota transplantation represent new therapeutic approaches targeting the gut microbiota dysbiosis. The OS and its counter-regulation are under the influence of individual genetic and epigenetic factors as well. In the near future, precision medicine taking into consideration genetic or environmental epigenetic risk factors, coupled with new OS biomarkers, will likely assist in noninvasive diagnosis and monitoring of NAFLD progression and in further personalizing treatments.

Effects of Oral Vitamin C Supplementation on Liver Health and Associated Parameters in Patients With Non-Alcoholic Fatty Liver Disease: A Randomized Clinical Trial

Non-alcoholic fatty liver disease (NAFLD) is now recognized as the most prevalent hepatic disorder worldwide, and an unhealthy lifestyle is the leading risk factor for its occurrence. Vitamin C (VC) has been suggested to protect NAFLD, whereas evidence from randomized controlled trials (RCTs) is sparse. In this study, we aimed to investigate the potential benefits of VC supplementation daily on liver health and associated parameters in patients with NAFLD. In this double-blind, RCT, 84 patients with NAFLD, aged 18-60 years old, were assigned to 12 weeks of oral treatment with either low (250 mg/day, n = 26), medium (1,000 mg/day, n = 30), or high (2,000 mg/day, n = 28) doses of VC supplements. After the intervention, the Medium group had a more significant decrease in aspartate aminotransferase [Medium, -5.00 (-10.25, -1.75) vs. High, -2.50 (-7.75, 0.00), P = 0.02] and alanine aminotransferase [Medium, -8.00 (-18.00, -1.75) vs. High, -3.50 (-13.75, 4.25), P = 0.05; Medium vs. Low, -3.00 (-9.00, 5.50), P = 0.031]. The levels of other indicators of liver health, such as gamma-glutamyl transferase, alkaline phosphatase, total bilirubin, and direct bilirubin were decreased after the intervention but comparable among the three groups and so did the parameters of glucose metabolism, such as fasting insulin, fasting glucose, and homeostasis model assessment for insulin resistance. The plasma level of VC in patients and total adiponectin and high molecular weight (HMW) adiponectin levels were also elevated but not in a dose-dependent manner. Meanwhile, analysis of fecal microbiota composition showed an increase in the alpha diversity (Abundance-based Coverage Estimator (ACE), Shannon, chao1, and Simpson) both in the Low and the Medium groups. A total of 12 weeks of VC supplementation, especially 1,000 mg/day, improved liver health and glucose metabolism in patients with NAFLD. The elevated plasma levels of VC, total and HMW adiponectin, and the improvement of intestinal microbiota may have made some contributions.

Non-alcoholic fatty liver disease: A patient guideline

This patient guideline is intended for all patients at risk of or living with non-alcoholic fatty liver disease (NAFLD). NAFLD is the most frequent chronic liver disease worldwide and comes with a high disease burden. Yet, there is a lot of unawareness. Furthermore, many aspects of the disease are still to be unravelled, which has an important impact on the information that is given (or not) to patients. Its management requires a close interaction between patients and their many healthcare providers. It is important for patients to develop a full understanding of NAFLD in order to enable them to take an active role in their disease management. This guide summarises the current knowledge relevant to NAFLD and its management. It has been developed by patients, patient representatives, clinicians and scientists and is based on current scientific recommendations, intended to support patients in making informed decisions.

Diet and Liver Adiposity in Older Adults: The Multiethnic Cohort Adiposity Phenotype Study

BACKGROUND

Diet plays a key role in the pathogenesis of nonalcoholic fatty liver disease. Limited data exist regarding specific nutrients and food groups and liver fat continuously, particularly among different ethnicities.

OBJECTIVES

We aimed to determine the relationship between usual dietary intake and accurately measured liver fat content in a multiethnic population.

METHODS

Participants from the Multiethnic Cohort were recruited into the cross-sectional Adiposity Phenotype Study including women and men aged 60-77 y and 5 race/ethnic groups (African American, Japanese American, Latino, Native Hawaiian, and white). They filled out a detailed FFQ and underwent abdominal MRI for liver fat quantification and whole-body DXA for total adiposity. Intake of a priori-selected dietary factors (total and macronutrient energy, specific micronutrients, and food groups) was analyzed in relation to liver fat by estimating the mean percentage liver fat for quartiles of each dietary factor in a general linear model that adjusted for age, sex, race/ethnicity, percentage body fat, and daily energy intake (kcal/d).

RESULTS

In total, 1682 participants (mean age: 69.2 y; 51% female) were included. Mean ± SD liver fat percentage was 5.7 ± 4.6. A significant positive association with liver fat was found across quartiles of percentage energy from fat, saturated fat, cholesterol, total red meat, red meat excluding processed red meat, and coffee (Bonferroni-adjusted P-trend < 0.05). A significant inverse association was observed for dietary fiber, vitamin C, and vitamin E (Bonferroni-adjusted P-trend < 0.05).

CONCLUSIONS

This study of ethnically diverse older adults shows that certain dietary factors, in particular red meat and saturated fat from red meat, were strongly associated with liver fat, whereas dietary fiber was inversely associated with liver fat, replicating some of the previous studies conducted mostly in whites.

Associations of Dietary Lipid-Soluble Micronutrients with Hepatic Steatosis among Adults in the United States

Lipid-soluble micronutrients may be beneficial to non-alcoholic fatty liver disease due to their important roles in metabolism and maintaining tissue functions. Utilizing 2017-2018 National Health and Nutrition Examination Survey, this study examined the potential overall and race/ethnicity-specific (black, Hispanic and white) associations of dietary lipid-soluble micronutrients (α-tocopherol, retinol, vitamin D, β-carotene and total carotenoids) with hepatic steatosis. The analysis included 4376 adults (1037 blacks, 981 Hispanics, 1549 whites) aged ≥20 years who completed the transient elastography examination with dietary data available. Odds ratios (OR) and 95% confidence intervals (95%CI) were estimated using logistic regressions. The age-adjusted prevalence of steatosis was 20.9% for blacks, 34.0% for Hispanics and 28.7% for whites. Overall, dietary α-tocopherol was inversely associated with steatosis (highest vs. lowest quartile: OR = 0.51, 95%CI = 0.35-0.74, P_trend = 0.0003). The associations remained significant among blacks (highest vs. lowest tertile: OR = 0.45, 95%CI = 0.26-0.77, P_trend = 0.002) and whites (highest vs. lowest tertile: OR = 0.56, 95%CI = 0.33-0.94, P_trend = 0.02). Higher α-tocopherol intake was associated with lower odds of steatosis among all (P_trend = 0.016) and black participants (P_trend = 0.003) classified as never/rare/occasional alcohol drinkers. There was a trend suggesting higher β-carotene intake with lower odds of steatosis (P_trend = 0.01). Our results suggest potential protective effects of dietary vitamin E as α-tocopherol on steatosis particularly among blacks.

Dietary Treatment for NAFLD: New Clinical and Epidemiological Evidence and Updated Recommendations

The key factor in preventing and treating nonalcoholic fatty liver disease (NAFLD) is a holistic lifestyle modification approach, encompassing diet based on healthy eating patterns of unprocessed foods, exercise, balanced drinking, and smoking habits. The Mediterranean diet and other healthy dietary patterns can reduce liver fat and may be related with lower disease progression. The type of diet should be tailored to the patient's cultural and personal preferences. Changing dietary composition without reducing caloric intake may offer an additional and sometimes more feasible alternative, so that the nutritional treatment incorporates, but is not focused on, weight reduction goals. The growing global consumption of ultra-processed foods, which is the polar opposite of the Mediterranean diet and its concept of home-based cooking, poses a great challenge in the prevention of NAFLD and probably hepatocellular carcinoma.This review will cover the most updated clinical and epidemiological evidence for lifestyle treatment in NAFLD and provide practical treatment tools.

Nutritional Evaluation and Treatment of the Cirrhotic Patient

Malnutrition and sarcopenia that lead to functional deterioration, frailty, and increased risk for complications and mortality are common in cirrhosis. Sarcopenic obesity, which is associated with worse outcomes than either condition alone, may be overlooked. Lifestyle intervention aiming for moderate weight reduction can be offered to obese compensated cirrhotic patients, with diet consisting of reduced caloric intake, achieved by reduction of carbohydrate and fat intake, while maintaining high protein intake. Dietary and moderate exercise interventions in patients with cirrhosis are beneficial. Cirrhotic patients with malnutrition should have nutritional counseling, and all patients should be encouraged to avoid a sedentary lifestyle.

Role of Oxidative Stress in the Pathogenesis of Non-Alcoholic Fatty Liver Disease: Implications for Prevention and Therapy

Oxidative stress (OxS) is considered a major factor in the pathophysiology of inflammatory chronic liver diseases, including non-alcoholic liver disease (NAFLD). Chronic impairment of lipid metabolism is closely related to alterations of the oxidant/antioxidant balance, which affect metabolism-related organelles, leading to cellular lipotoxicity, lipid peroxidation, chronic endoplasmic reticulum (ER) stress, and mitochondrial dysfunction. Increased OxS also triggers hepatocytes stress pathways, leading to inflammation and fibrogenesis, contributing to the progression of non-alcoholic steatohepatitis (NASH). The antioxidant response, regulated by the Nrf2/ARE pathway, is a key component in this process and counteracts oxidative stress-induced damage, contributing to the restoration of normal lipid metabolism. Therefore, modulation of the antioxidant response emerges as an interesting target to prevent NAFLD development and progression. This review highlights the link between disturbed lipid metabolism and oxidative stress in the context of NAFLD. In addition, emerging potential therapies based on antioxidant effects and their likely molecular targets are discussed.

Associations between dietary total antioxidant capacity and odds of non-alcoholic fatty liver disease (NAFLD) in adults: a case-control study

The relationships between the total antioxidant capacity (TAC) of the diet and the risk of non-alcoholic fatty liver disease (NAFLD) have not previously been assessed. The aim of this study was to assess relationships between DTAC and odds of NAFLD in a case-control study. This case-control study was carried out in 158 patients with NAFLD and 357 healthy individuals aged 18-55 years. Dietary data were collected using validated 168-item quantitative food frequency questionnaires. Triacylglycerols (TAGs), total cholesterol (TC), high-density lipoprotein (HDL-C), low-density lipoprotein (LDL-C) and fasting blood glucose (FBS) concentrations were assessed using enzymatic methods and commercial kits. The DTAC was calculated based on the oxygen radical absorbance capacity of each food reported by the U.S. Department of Agriculture. The mean ± sd (standard deviation) for age and body mass index (BMI) of the study participants were 43⋅9 years ±5⋅9 and had 30⋅5 kg/m2 ±2⋅6. The NAFLD patients included higher BMI and female proportion, compared with the control group. The NAFLD patients included higher smoking rates, biochemical parameters (TG, TC, LDL-C and FBS) and DTAC scores, compared with control groups (P-value < 0⋅05). However, patients with NAFLD had lower HDL levels and physical activities, compared with the control group. The highest tertile of DTAC showed lower odds of NAFLD, compared with the lowest tertile. This association was significant after adjustment for potential confounders (OR, 0⋅19; 95 % CI, 0⋅9-0⋅34; P for trend 0⋅001). Findings suggest that the promotion of naturally increased antioxidant capacities may help prevent odds of NAFLD.

Negative association between antioxidant vitamin intake and non-alcoholic fatty liver disease in Chinese non-diabetic adults: mediation models involving superoxide dismutase

We aimed to explore the association between antioxidant vitamin intake, oxidative stress related markers and non-alcoholic fatty liver disease (NAFLD) by a cross-sectional analysis. A total of 241 non-diabetic participants from a Chinese rural cohort were included. NAFLD was diagnosed by abdominal ultrasound (NAFLD, n = 71; Non-NAFLD, n = 171). Dietary intake was assessed by a 24-h food recall. Plasma oxidative stress related markers superoxide dismutase (SOD), glutathione reductase (GR) and 8-oxo-2'-deoxyguanosine(8-oxo-dG) were measured. The association between dietary antioxidant vitamin intake, oxidative stress related markers and NAFLD were analysed by Spearman correlation analysis and multiple logistic regression analysis. Mediation models were established to examine whether SOD mediated the association between dietary vitamin A or α-tocopherol intake and NAFLD. Spearman correlation analysis indicated that dietary vitamin A and α-tocopherol intake were positively correlated with SOD (p < .05). Multiple logistic regression analysis found plasma SOD, dietary vitamin A and α-tocopherol intake were inversely associated with NAFLD (all p < .05). Mediation analysis indicated that SOD significantly mediated the indirect effect of dietary α-tocopherol (mediated effect = 13.21% total effect) or vitamin A (mediated effect = 3.12% total effect) intake on NAFLD. Our study indicated that dietary vitamin A and α-tocopherol intake may contribute to protect from NAFLD in Chinese non-diabetics, and the associations were partly mediated by SOD. However, SOD only accounted for a minor percentage of the association between vitamin A intake and NAFLD. Thus, other mechanisms underlying antioxidant vitamin' protective effect on NAFLD need further exploration.

New Insights into the Pathogenesis of Non-Alcoholic Fatty Liver Disease: Gut-Derived Lipopolysaccharides and Oxidative Stress

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease worldwide. The intricate NAFLD pathogenesis is summarized by the multiple-hits hypothesis, which combines all the environmental and genetic factors that promote the development of NAFLD into a single scenario. Among these, bacterial lipopolysaccharides (LPS) are derived from the overgrowth of Gram-negative bacteria and translocated mainly as a consequence of enhanced intestinal permeability. Furthermore, oxidative stress is increased in NAFLD as a consequence of reactive oxygen species (ROS) overproduction and a shortage of endogenous antioxidant molecules, and it is promoted by the interaction between LPS and the Toll-like receptor 4 system. Interestingly, oxidative stress, which has previously been described as being overexpressed in cardiovascular disease, could represent the link between LPS and the increased cardiovascular risk in NAFLD subjects. To date, the only effective strategy for the treatment of NAFLD and non-alcoholic steatohepatitis (NASH) is the loss of at least 5% body weight in overweight and/or obese subjects. However, the dose-dependent effects of multispecies probiotic supplementation on the serum LPS level and cardiometabolic profile in obese postmenopausal women were demonstrated. In addition, many antibiotics have regulatory effects on intestinal microbiota and were able to reduce serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), and tumor necrosis factor alpha (TNF-α) in NASH animal models. Regarding the oxidant status, a Mediterranean diet has been reported to reduce oxidant stress, while vitamin E at high daily dosages induced the resolution of NASH in 36% of treated patients. Silymarin had the positive effect of reducing transaminase levels in NAFLD patients and long-term treatment may also decrease fibrosis and slow liver disease progression in NASH. Finally, the influence of nutraceuticals on gut microbiota and oxidant stress in NAFLD patients has not yet been well elucidated and there are insufficient data either to support or refuse their use in these subjects.

Association between consumption frequency of honey and non-alcoholic fatty liver disease: results from a cross-sectional analysis based on the Tianjin Chronic Low-grade Systemic Inflammation and Health (TCLSIH) Cohort Study

Non-alcoholic fatty liver disease (NAFLD) is the hepatic manifestation of the metabolic syndrome. Recent evidence has suggested the protective effects of honey consumption against the metabolic syndrome, but the association between honey intake and NAFLD is still unclear. We investigated how the consumption frequency of honey was associated with NAFLD in the general population. This was a cross-sectional study of 21 979 adults aged 20-90 years. NAFLD was diagnosed based on the ultrasound-diagnosed fatty liver without significant alcohol intake and other liver diseases. Diet information, including consumption frequency of honey, was assessed by a validated 100-item FFQ. OR with 95 % CI were calculated by the binary logistic regression model, adjusting for confounding factors identified by the directed acyclic graph. Overall, 6513 adults (29·6 %) had NAFLD. Compared with participants consuming ≤1 time/week of honey, the multivariable OR of NAFLD were 0·86 (95 % CI 0·77, 0·97) for 2-6 times/week and 1·10 (95 % CI 0·95, 1·27) for ≥1 times/d (Pfor trend = 0·90). The results were generally similar in subgroups of BMI at a cut-point of 24·0 kg/m2 (Pfor interaction = 0·10). In this large-scale study, consuming honey 2-6 times/week was inversely associated with NAFLD, whereas consuming honey ≥1 times/d had no association with NAFLD. These results need replication in other large-scale prospective studies.