Association between Dietary Vitamin C Intake and Non-Alcoholic Fatty Liver Disease: A Cross-Sectional Study among Middle-Aged and Older Adults

Evaluation of the role of some non-enzymatic antioxidants among Iraqi patients with non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD), characterized by hepatic fat accumulation in individuals consuming little or no alcohol, has become highly prevalent globally. Oxidative stress plays a central role in instigating inflammation and cell death pathways driving NAFLD progression. This case-control study aimed to elucidate the association between circulating levels of the pivotal non-enzymatic antioxidants - coenzyme Q10 and vitamins E and C - and liver injury parameters among 60 Iraqi NAFLD patients versus 30 healthy controls. NAFLD diagnosis entailed over 5% hepatic steatosis on ultrasound excluding other etiologies. Patients spanned three age groups: 20-29, 30-39, and 40-49. Substantially diminished antioxidant levels concurrent with elevated alkaline phosphatase enzyme were unveiled in NAFLD patients relative to controls (all p < 0.001). Age-based analysis reinforced widespread antioxidant depletion and liver enzyme augmentation across NAFLD patients. Significant correlations also emerged between antioxidants and liver parameters. Our novel observations confirm an antioxidant inadequacy likely perpetuating pathogenic oxidative reactions in NAFLD. Restoring such deficits through lifestyle or therapeutic interventions may confer preventative and disease-modifying value.

Supplementation of Micro- and Macronutrients-A Role of Nutritional Status in Non-Alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD) is a condition in which the pathological cumulation of fat with coexisting inflammation and damage of hepatic cells leads to progressive dysfunctions of the liver. Except for the commonly well-known major causes of NAFLD such as obesity, dyslipidemia, insulin resistance, or diabetes, an unbalanced diet and imbalanced nutritional status should also be taken into consideration. In this narrative review, we summarized the current knowledge regarding the micro- and macronutrient status of patients suffering from NAFLD considering various diets and supplementation of chosen supplements. We aimed to summarize the knowledge indicating which nutritional impairments may be associated with the onset and progression of NAFLD at the same time evaluating the potential therapy targets that could facilitate the healing process. Except for the above-mentioned objectives, one of the most important aspects of this review was to highlight the possible strategies for taking care of NAFLD patients taking into account the challenges and opportunities associated with the micronutrient status of the patients. The current research indicates that a supplementation of chosen vitamins (e.g., vitamin A, B complex, C, or D) as well as chosen elements such as zinc may alleviate the symptoms of NAFLD. However, there is still a lack of sufficient data regarding healthy ranges of dosages; thus, further research is of high importance in this matter.

Potassium affects the association between dietary intake of vitamin C and NAFLD among adults in the United States

INTRODUCTION

Although the association between nonalcoholic fatty liver disease (NAFLD) and vitamin C has been well studied, the effects of dietary potassium intake on this relationship are still unclear. Thus, this study aimed to determine the effects of dietary potassium intake on the association between vitamin C and NAFLD.

METHODS

We performed a cross-sectional learn about with 9443 contributors the usage of 2007-2018 NHANES data. Multiple logistic regression evaluation has been utilized to check out the affiliation of dietary vitamin C intake with NAFLD and advanced hepatic fibrosis (AHF). Subsequently, we plotted a smoothed match curve to visualize the association. Especially, the analysis of AHF was conducted among the NAFLD population. In addition, stratified evaluation used to be developed primarily based on demographic variables to verify the steadiness of the results. Effect amendment by way of dietary potassium intake used to be assessed via interplay checks between vitamin C and NAFLD in the multivariable linear regression.

RESULTS

In this cross-sectional study, we found that vitamin C was negatively related to NAFLD and AHF. The relationship between vitamin C and NAFLD was different in the low, middle and high potassium intake groups. Furthermore, potassium intake significantly modified the negative relationship between vitamin C and NAFLD in most of the models.

CONCLUSION

Our research showed that potassium and vitamin C have an interactive effect in reducing NAFLD, which may have great importance for clinical medication.

The association of the healthy food diversity index with the risk of non-alcoholic fatty liver disease among the adult population

BACKGROUND AND AIM

Dietary diversity index is a useful evaluation index for examining the role of dietary pattern in predicting chronic diseases risk, including non-alcoholic fatty liver disease(NAFLD). In the present study, we aimed to examine the possible association of dietary diversity using US Healthy Food Diversity(US HFD) index and the NAFLD risk in Iranian adults.

METHODS

A total of 675 individuals (225 patients with NAFLD and 450 controls) aged 20-60 years were recruited for the current case-control study. Data on dietary intakes were determined using a validated food frequency questionnaire, and dietary diversity was calculated using the US HFD index. In patients with NAFLD, an ultrasound scan of the liver was used to detect NAFLD. Logistic regression models were used to estimate the odds ratios(ORs) and 95 % confidence interval(CI) of NAFLD across tertiles of the US HFD index.

RESULTS

Mean ± SD age of the study population were 38.13 ± 8.85 years. The median (interquartile) score of the US HFD index in patients with NAFLD and healthy subjects was 0.08(0.07-0.09) and 0.09(0.08-0.10), respectively. In the age and sex-adjusted model, the odds of NAFLD were considerably reduced across tertiles of the US HFD index (OR:0.48; 95%CI:0.32-0.72, Ptrend<0.001). Also, in the final model, after adjusting for age, sex, waist-to-hip ratio, smoking, physical activity, marital status, socioeconomic status, and energy intake, the odds of NAFLD were significantly reduced across tertiles US HFD index (OR:0.55; 95%CI:0.31-0.97, Ptrend<0.001). Furthermore, for each SD increase in the US HFD index, the odds of NAFLD are reduced by 23 % (OR:0.77;95%CI:0.60-0.97,P-Value<0.001).

CONCLUSIONS

Our findings revealed that greater adherence to dietary pattern with a high US HFD score, defined by higher intakes of fruits, vegetables, whole grains, legumes, nuts, low-fat dairy, seeds, soya products, and plant oils may be related to reducing the odds of NAFLD.

Association between dietary vitamin A intake from different sources and non-alcoholic fatty liver disease among adults

Non-alcoholic fatty liver disease (NAFLD) has become an urgent public health issue with high global prevalence, but data on NAFLD are inconsistent. The association of total dietary vitamin A intake with the NAFLD risk was not well documented in previous studies. To explore the relationship between dietary vitamin A intake from different sources and NAFLD risk among American adults. Data were collected from the National Health and Nutrition Examination Survey (NHANES) from 2007 to 2014. Logistic regression and restricted cubic spline models were used to estimate the relationship between total dietary vitamin A intake and NAFLD risk. 6,613 adult participants were included. After adjusting potential confounders, the odds ratios (ORs) with 95% confidence intervals (CIs) of NAFLD for the highest quartile intake of total vitamin A, preformed vitamin A, provitamin A carotenoids were respectively 0.86 (0.69-1.06), 0.97 (0.74-1.28), and 0.78 (0.61-0.99), compared to the lowest quartile. Stratifying gender and age, provitamin A carotenoids intake was inversely associated with NAFLD risk in females and participants aged < 45 years. Dose-response analysis indicated a linear negative relationship between provitamin A carotenoids intake and NAFLD risk. Provitamin A carotenoids intake was inversely associated with NAFLD, especially in women and those aged < 45 years among adult American.

Swimming exercise ameliorates insulin resistance and nonalcoholic fatty liver by negatively regulating PPARγ transcriptional network in mice fed high fat diet

BACKGROUND

Recent findings elucidated hepatic PPARγ functions as a steatogenic-inducer gene that activates de novo lipogenesis, and is involved in regulation of glucose homeostasis, lipid accumulation, and inflammation response. This study delved into a comprehensive analysis of how PPARγ signaling affects the exercise-induced improvement of insulin resistance (IR) and non-alcoholic fatty liver disease (NAFLD), along with its underlying mechanism.

METHODS

Chronic and acute swimming exercise intervention were conducted in each group mice. IR status was assessed by GTT and ITT assays. Serum inflammatory cytokines were detected by Elisa assays. PPARγ and its target genes expression were detected by qPCR assay. Relative protein levels were quantified via Western blotting. ChIP-qPCR assays were used to detect the enrichment of PPARγ on its target genes promoter.

RESULTS

Through an exploration of a high-fat diet (HFD)-induced IR and NAFLD model, both chronic and acute swimming exercise training led to significant reductions in body weight and visceral fat mass, as well as hepatic lipid accumulation. The exercise interventions also demonstrated a significant amelioration in IR and the inflammatory response. Meanwhile, swimming exercise significantly inhibited PPARγ and its target genes expression induced by HFD, containing CD36, SCD1 and PLIN2. Furthermore, swimming exercise presented significant modulation on regulatory factors of PPARγ expression and transcriptional activity.

CONCLUSION

The findings suggest that swimming exercise can improve lipid metabolism in IR and NAFLD, possibly through PPARγ signaling in the liver of mice.

Association between use of vitamin and mineral supplement and non-alcoholic fatty liver disease in hypertensive adults

Non-alcoholic fatty liver disease (NAFLD) is the most common hepatic metabolic disorder in hypertensive adults. Impaired metabolism of micronutrients may increase NAFLD risk by exacerbating oxidative stress, insulin resistance, and inflammation among hypertensive adults. In this first cross-sectional analysis of 7,376 hypertensive adults with 2,015 NAFLD cases in the Korea National Health and Nutrition Examination Survey, vitamin and mineral supplements (VMS) use was identified via questionnaire. NAFLD was defined by a hepatic steatosis index > 36. Multivariable-adjusted odds ratios (MVOR) and 95% confidence intervals (CIs) were calculated using logistic regression models. In our study, 18.6% were current users of VMS; of these, 76.7% used multi-vitamin/mineral supplements. Current VMS users had significantly lower odds of NAFLD, compared with non-users (MVOR [95% CI]: 0.73 [0.58-0.92]). The inverse association became attenuated and non-significant among those consuming VMS at higher frequency (≥ 2 times/day), for longer duration (> 16 months), and taking ≥ 2 VMS products. The inverse association with current use of VMS was only evident in those aged < 56 years (MVOR [95% CI]: 0.54 [0.40-0.72]) and men (MVOR [95% CI]: 0.56 [0.40-0.80])(Pinteraction ≤ 0.04). Our results suggest that VMS use may lower NAFLD risk, particularly among younger or male hypertensive adults, if taken in moderation.

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.

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.

The Effect of Bioactive Aliment Compounds and Micronutrients on Non-Alcoholic Fatty Liver Disease

In the current review, we focused on identifying aliment compounds and micronutrients, as well as addressed promising bioactive nutrients that may interfere with NAFLD advance and ultimately affect this disease progress. In this regard, we targeted: 1. Potential bioactive nutrients that may interfere with NAFLD, specifically dark chocolate, cocoa butter, and peanut butter which may be involved in decreasing cholesterol concentrations. 2. The role of sweeteners used in coffee and other frequent beverages; in this sense, stevia has proven to be adequate for improving carbohydrate metabolism, liver steatosis, and liver fibrosis. 3. Additional compounds were shown to exert a beneficial action on NAFLD, namely glutathione, soy lecithin, silymarin, Aquamin, and cannabinoids which were shown to lower the serum concentration of triglycerides. 4. The effects of micronutrients, especially vitamins, on NAFLD. Even if most studies demonstrate the beneficial role of vitamins in this pathology, there are exceptions. 5. We provide information regarding the modulation of the activity of some enzymes related to NAFLD and their effect on this disease. We conclude that NAFLD can be prevented or improved by different factors through their involvement in the signaling, genetic, and biochemical pathways that underlie NAFLD. Therefore, exposing this vast knowledge to the public is particularly important.

Vitamin C and vitamin D3 alleviate metabolic-associated fatty liver disease by regulating the gut microbiota and bile acid metabolism via the gut-liver axis

Background: Previous studies have demonstrated that both vitamin C (VC) and vitamin D3 (VD3) have therapeutic potential against metabolic disorders, including obesity, diabetes, and metabolic-associated fatty liver disease (MAFLD). However, it is unclear whether VC supplementation is associated with improving the intestinal flora and regulating the metabolism of bile acids via the gut-liver axis in MAFLD. There is still no direct comparison or combination study of these two vitamins on these effects.

Methods: In this study, we employed biochemical, histological, 16S rDNA-based microbiological, non-targeted liver metabolomic, and quantitative real-time polymerase chain reaction analyses to explore the intervening effect and mechanism of VC and VD3 on MAFLD by using a high-fat diet (HFD)-induced obese mouse model.

Results: Treatment of mice with VC and VD3 efficiently reversed the characteristics of MAFLD, such as obesity, dyslipidemia, insulin resistance, hepatic steatosis, and inflammation. VC and VD3 showed similar beneficial effects as mentioned above in HFD-induced obese mice. Interestingly, VC and VD3 reshaped the gut microbiota composition; improved gut barrier integrity; ameliorated oxidative stress and inflammation in the gut-liver axis; inhibited bile acid salt reflux-related ASBT; activated bile acid synthesis-related CYP7A1, bile acid receptor FXR, and bile acid transportation-related BSEP in the gut-liver axis; and improved bile secretion, thus decreasing the expression of FAS in the liver and efficiently ameliorating MAFLD in mice.

Conclusion: Together, the results indicate that the anti-MAFLD activities of VC and VD3 are linked to improved gut-liver interactions via regulation of the gut microbiota and bile acid metabolism, and they may therefore prove useful in treating MAFLD clinically.

Dietary phytochemical index and the risk of non-alcoholic fatty liver disease: A case-control study among Iranian adults

BACKGROUNDS

Dietary phytochemical index (DPI) is an inexpensive method for estimating the amounts of phytochemicals in foods. No study has investigated the association between DPI and non-alcoholic fatty liver disease (NAFLD). Our study aimed to compare DPI in patients with NAFLD and the control group.

METHODS

This is a case-control study of 250 subjects with NAFLD and 450 healthy subjects attending the Metabolic Liver Disease Research Center as a referral center affiliated to Isfahan University of Medical Sciences. DPI was calculated based on data collected from a 168-item validated food frequency questionnaire. Sociodemographic data, physical activity, and anthropometric measures such as body weight, height, and waist circumference were determined.

RESULTS

In the final adjusted model, the odds ratio (OR) of NAFLD across the DPI tertiles decreased significantly (OR = 0.55, 95 %CI = 0.31-0.95) (P-trend = 0.03). The highest vs. lowest tertiles of vegetable and olives PI were significantly associated with a lower risk of NAFLD (OR and 95 % CI = 0.26 (0.14-0.47); OR and 95 % CI = 0.51 (0.29-0.90), p for trend < 0.001, respectively), however, there was no significant relation between other PI components and NAFLD.

CONCLUSION

This case-control study suggested that a higher PI score is associated with a reduced chance of NAFLD after adjusting for confounding variables. In addition, the highest tertile of vegetable and olives PI was significantly associated with a lower risk of NAFLD.

The effect of a fruit-rich diet on liver biomarkers, insulin resistance, and lipid profile in patients with non-alcoholic fatty liver disease: a randomized clinical trial

BACKGROUND

Despite confirmed dietary approaches to improve the Non-Alcoholic Fatty Liver Disease (NAFLD), the effect of fruits on NAFLD is not clear. The present study aimed to investigate the effect of a fruit rich diet (FRD) on liver steatosis, liver enzymes, Insulin resistance, and lipid profile in patients with NAFLD.

METHODS

Eighty adults with NAFLD participated in this randomized controlled trial. The participants were randomly assigned to the FRD group with consumption of at least 4 servings of fruits daily or the control group with fruits consumption of less than 2 servings/day. The grade of steatosis, serum levels of liver enzymes including alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), and gamma-glutamyl transferase (GGT), total cholesterol (TC), triglyceride (TG), low-density lipoprotein (LDL), high-density lipoprotein (HDL), glucose, and homeostatic model assessment for insulin resistance (HOMA-IR) were measured at the baseline and at the end of the study.

RESULTS

After 6 months of intervention, the FRD group had significantly higher BMI (31.40 ± 2.61 vs. 25.68 ± 2.54, p < .001), WC (113.5 ± 10.7 vs. 100.5 ± 7.5, p < .001), the grade of steatosis, ALT (89.1 ± 92.9 vs. 32.0 ± 19.2, p < .001), AST (74.5 ± 107.8 vs. 24.0 ± 8.5, p < .001), ALP (273.4 ± 128.5 vs. 155.0 ± 43.9, p < .001), GGT (92.7 ± 16.2 vs. 21.2 ± 7.7, p < .001), TC (206.1 ± 40.5 vs. 172.7 ± 42.4, p < .01), LDL (126.9 ± 32.3 vs. 99.8 ± 29.8, p < .001), glucose (115.5 ± 30.0 vs. 97.7 ± 19.0, p < .01), and insulin resistance (7.36 ± 4.37 vs. 2.66 ± 1.27, p < .001), and lower HDL (41.4 ± 8.9 vs. 53.8 ± 15.1, p < .001) compared to the control group. Adjusting for BMI and calorie intake did not change the results.

CONCLUSION

The results of the present study indicated that consumption of fruits more than 4 servings/day exacerbates steatosis, dyslipidemia, and glycemic control in NAFLD patients. Further studies are needed to identify the underlying mechanisms of the effects of fruits on NAFLD.

CLINICAL TRIAL REGISTRATION

This trial was registered at Iranian randomized clinical trial website with IRCT registration no. IRCT20201010048982N1on October 15, 2020.

Associations of serum multivitamin levels with the risk of non-alcoholic fatty liver disease: A population-based cross-sectional study in U.S. adults

Vitamins were closely associated with non-alcoholic fatty liver disease (NAFLD) development, but no study had explored the association of serum multivitamin levels with NAFLD risk. We assessed the association between serum levels of both single-vitamin and multivitamins (VA, VB6, VB9, VB12, VC, VD, and VE) and the risk of NAFLD, using the database of National Health and Nutrition Examination Survey (NHANES) (cycles 2003–2004 and 2005–2006). We employed multivariable logistic regression and weighted quantile sum (WQS) regression models to explore the association of serum multivitamin levels with NAFLD. Among all 2,294 participants, 969 participants with NAFLD were more likely to be male, older, less educated, or have hypertension/high cholesterol/diabetes. After adjustment of covariates, serum VC/VD/VB6/VB9 levels were negatively correlated with NAFLD risk, while serum VA/VE levels were positively correlated with NAFLD risk. In the WQS model, elevated serum VA/VE levels and lowered serum VC/VD/VB6 levels were linearly associated with increased NAFLD risk. There was a non-linear relationship between serum VB9/VB12 levels and NAFLD risk. There were evident associations between serum multivitamin levels and reduced NAFLD risk, which was mainly driven by VD/VB9/VC. In conclusion, our findings suggested that serum multivitamin levels were significantly associated with the risk of NAFLD.

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.

Nutrient patterns and non-alcoholic fatty liver disease in Iranian Adul: A case-control study

Backgrounds

The current literature boasts the importance of diet in preventing or managing liver complications. However, there is limited evidence on the association of nutrient patterns (NP) with these complications. In this case-control study, we aimed to examine the possible relationship between nutrient patterns and the risk of non-alcoholic fatty liver disease (NAFLD) amongst the adult Iranian population.

Methods

This case-control study is being conducted at the Metabolic Liver Disease Research Center at Isfahan University of Medical Sciences in 2019. The study included 225 newly diagnosed cases of NAFLD and 450 controls. A validated semi-quantitative food frequency questionnaire (FFQ) assessed dietary intake. Principal component analysis using Varimax rotation obtained nutrient patterns. Logistic regression was performed to estimate NAFLD risk.

Results

We identified four major nutrient patterns. The first nutrient pattern was high in consumption of lactose, animal protein, vitamin D, riboflavin, pantothenic acid, vitamin B12, calcium, phosphorus, zinc, and potassium. The second nutrient pattern included fiber, plant protein, vitamin A, thiamine, niacin, copper, and selenium, while the third featured plant protein, zinc, copper, magnesium, manganese, chromium, and selenium. The fourth was characterized by fructose, vitamin A, pyridoxine, vitamin C, and potassium. After adjusting for confounders, individuals in the highest tertile of NP4 had lower odds of NAFLD (OR: 0.56, 95% CI: 0.32–0.98, P_trend = 0.042); compared to those who were in the lowest tertile.

Conclusion

High compliance to a nutrient pattern characterized by fructose, vitamin C, vitamin A, pyridoxine, and potassium mainly supplied from fruits, vegetables, and nuts is inversely proportional to the odds of NAFLD. Also our findings indicate a very high fiber intake, a relatively optimal dietary fat profile, and a pretty low sugar intake for cases and controls, unseen in western countries. However, these initial findings need to be approved with further studies to confirm the relationship between nutrient patterns and NAFLD.

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.

The association between Dietary Diversity Score and odds of nonalcoholic fatty liver disease: a case-control study

OBJECTIVE

There is no previous study that investigated the association between Dietary Diversity Score (DSS) and odds of nonalcoholic fatty liver disease (NAFLD). The present study aimed to examine the association between DDS and its components and NAFLD among Iranian adults.

METHODS

In the case-control study, we enrolled 121 newly diagnosed cases of NAFLD and 122 with age, BMI and sex-matched controls. All NAFLD patients were diagnosed through ultrasonography methods by gastroenterologists. Anthropometric parameters of participants including weight, height, hip circumference and waist circumference were measured. A validated 147-item semi-quantitative food frequency questionnaire was applied to assess the usual dietary intakes of participants. Binary logistic regression was conducted to estimate the risk of NAFLD in relation to DDS and its components, including refined grains, vegetables, fruits, dairy and meats.

RESULTS

The mean age of study participants was 42.7 years of them 53.1% were male. Higher adherence to DDS [odds ratio (OR) = 0.48; 95% confidence interval (CI), 0.25-0.95] and vegetable group (OR = 0.34; 95% CI, 0.16-0.71) were remarkably associated with lower risk of NAFLD, after adjusting for several confounders including age, BMI, physical activity, energy intake, job, education, and antihypertensive drugs usage. Contrastingly, greater adherence to the refined grain (OR = 3.36; 95% CI, 1.44-7.87) and meat group (OR = 3.27; 95% CI, 1.25-6.90) was significantly associated with increased risk of NAFLD.

CONCLUSION

High DDS is inversely correlated with the risk of NAFLD. Hence, increasing the diversity score of diet by emphasizing the higher diversity scores for vegetables and less for meat and refined grains may be profitable for the management of NAFLD.

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.

Association Between Korean-Style Balanced Diet and Risk of Abdominal Obesity in Korean Adults: An Analysis Using KNHANES-VI (2013-2016)

Abdominal obesity is a critical factor for metabolic diseases, and specific eating patterns such as the Mediterranean diet help prevent metabolic diseases. This study aimed to investigate the association between the modified Korean health eating index (MKHEI), including a Korean-balanced diet, and abdominal obesity risk according to genders in adults aged 20-64 years (4,886 males and 7,431 females), using the Korea National Health and Nutrition Examination Survey VI (2013-2016). Adjusted means and 95% confidence intervals of MKHEI scores and nutrient intake estimated using the 24-h recall method were calculated according to abdominal obesity (waist circumference ≥90 cm for men and ≥85 cm for women) after adjusting for age, residence area, region, education, income, drinking status, smoking status, marital status, and exercise. Adjusted odds ratios (ORs) for abdominal obesity were measured according to MKHEI tertiles using logistic regression analysis while controlling for covariates. Individuals aged >50 years, married, below high school, lower-income, heavy alcohol drinkers, past and current smokers, and males living in the southern areas had a higher risk of abdominal obesity. In both genders, the scores of all MKHEI components were lower in the abdominal obesity group (n = 2,895) than in the control group (n = 9,422). Further, the scores of fruits with and without fruit juice and those of beans, including fermented beans, were lower in the abdominal obesity group only in females but not in males. Further, the scores of fast foods were higher in the abdominal obesity group than in the control group only in females. After adjusting for covariates, the adjusted OR for abdominal obesity was inversely associated with Korean balanced diet (KBD) related to KHEI scores. Unlike KBD, MKHEI of Western-style diet was not associated with abdominal obesity in either gender. In conclusion, KBD can lower the risk of abdominal obesity in females and should thus be recommended to prevent abdominal obesity.

A nutritional intervention that promotes increased vegetable intake in Japanese with non-alcoholic fatty liver disease: a six-month trial

The aim of this study was to investigate whether a nutritional intervention motivating increased vegetable consumption would be an effective treatment and diet therapy for patients with non-alcoholic fatty liver disease. We examined 15 patients with this disease (5 men and 10 women). During the 6-month intervention period, all participants received a small amount of vegetables twice a month as a nutritional education tool aimed at increasing vegetable consumption. They also received nutritional counseling and underwent ultrasound and blood biochemical examinations at baseline and 3 and 6 months after initiation of the intervention. Moreover, they were requested to submit dietary records for any 2 days. Green, white, and total vegetable intakes were significantly higher at 3 and 6 months than at baseline in 8 patients. These patients had significantly lower alanine amino­transferase and triglyceride concentrations than those whose vegetable intake did not increase. Additionally, green vegetable intake significantly negatively correlated with weight at 3 and 6 months (r = −0.617, p = 0.032 and r = −0.848, p = 0.008, respectively). These results suggest that our nutritional approach effectively increased vegetable consumption in at least some patients with non-alcoholic fatty liver disease, consequently improving their condition.

Streamlined three step total vitamin C analysis by HILIC-UV for laboratory testing

OBJECTIVES

In the clinical setting, the analysis and quantification of vitamin C (ascorbic acid) poses several challenges including analyte instability and poor retention by reverse phase HPLC systems. In this article we describe a rapid hydrophilic interaction chromatography ultraviolet method for the measurement of total vitamin C in plasma which overcomes these issues.

METHODS

Ascorbic acid and the internal standard were separated under isocratic conditions using a Waters BEH-Amide column and a mobile phase containing 0.005 M potassium phosphate in 80% acetonitrile.

RESULTS

The proposed method was validated and showed good precision (coefficient of variation <5%), accuracy (>99%), and analyte stability after extraction (>24 h).

CONCLUSIONS

The simple sample preparation allows full automation and rapid analytical run times of the assay and is therefore suitable for a high-throughput clinical chromatography laboratory.

The Role of Vitamin Deficiency in Liver Disease: To Supplement or Not Supplement?

Over the past few years, growing interest has been shown for the impact of dietary requirements and nutritional factors on chronic diseases. As a result, nutritional programs have been reinforced by public health policies. The precise role of micronutrients in chronic liver disease is currently receiving particular attention since abnormalities in vitamin levels are often detected. At present, treatment programs are focused on correcting vitamin deficiencies, which are frequently correlated to higher rates of comorbidities with poor outcomes. The literature reviewed here indicates that liver diseases are often related to vitamin disorders, due to both liver impairment and abnormal intake. More specific knowledge about the role of vitamins in liver disease is currently emerging from various results and recent evidence. The most significant benefits in this area may be observed when improved vitamin intake is combined with a pharmacological treatment that may also affect the progression of the liver disease, especially in the case of liver tumors. However, further studies are needed.

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.

The Role of Vitamins in Non-Alcoholic Fatty Liver Disease: A Systematic Review

Non-Alcoholic Fatty Liver Disease (NAFLD) emerged as the most prevalent liver disorder contributing significantly to disease burden worldwide. It manifests as a broad spectrum of hepatic damage with varying severity ranging from less serious steatosis to a more severe Non-Alcoholic Steatohepatitis (NASH), with or without fibrosis, cirrhosis, and hepatocellular carcinoma. Vitamins, on the other hand, are micronutrients that are vital for healthy well-being. Some studies have linked liver diseases with hypovitaminosis; however, there are still some gaps about the basis of their correlation. Hence, this systematic review aims to discuss the role of vitamins in the pathogenesis of NAFLD and explore their hepatoprotective potential that may benefit clinicians in managing this condition.

This systematic review searched for studies indexed in the PubMed, PubMed Central, Medline, Google Scholar, and ScienceDirect databases. Inclusion and exclusion criteria were applied, duplicates were removed, and meticulous screening of articles was done systematically. Out of 729 unique studies generated using the search strategy, 17 were finally included after thorough review and quality appraisal. 

NAFLD is not simply an outcome of insulin resistance and metabolic derangements; instead, it is a disease with complex underlying pathogenesis. Moreover, vitamin deficiency has been associated with NAFLD development and increased susceptibility to more severe liver damage. Derangement in vitamins correlates to the lipotoxic hepatic environment, altered immune system, unwarranted inflammation, oxidative stress, gene mutations, epigenetic modification, and gut dysbiosis seen in NAFLD. As they influence several pathophysiologic processes in the liver, vitamins A, B3, B6, B9, B12, C, D, and E are promising potential options that can impact NAFLD management. However, more well-designed studies conducted in the human population are still necessary to establish their efficacy and safety as therapeutic agents.

Effects of stocking density and dietary vitamin C on performance, meat quality, intestinal permeability, and stress indicators in broiler chickens

The objective of the current study was to investigate the effects of stocking density (SD) and dietary supplementation of vitamin C on growth performance, meat quality, intestinal permeability, and stress indicators in broiler chickens. The study was conducted using a completely randomized design with a 2 × 2 factorial arrangement consisting of 2 different SD and 2 supplemental levels of dietary vitamin C. A total of 1,368 Ross 308 broiler chickens of 21 days of age with similar body weights (BW) were randomly allotted to 1 of 4 treatments with 6 replicates each. Different numbers of birds per identical floor pen (2.0 m × 2.4 m) were used to create 2 different SD levels of low SD (9 birds/m²) and high SD (18 birds/m²). The basal diet was formulated with no supplemental vitamin C to meet or exceed nutrient recommendations of the Ross 308 manual. The other diet was prepared by supplementing 200 mg/kg vitamin C in the basal diet. The study lasted for 14 days. At the end of the study, 3 male birds per replicate were selected to analyze meat quality, intestinal permeability, and stress indicators such as blood heterophil:lymphocyte (H:L) and feather corticosterone (CORT) concentrations. Results indicated that there were no interactions between different SD and dietary supplementation of vitamin C for all measurements. For the main effects of SD, birds raised at high SD had less (p < 0.01) BW, BW gain, and feed intake with increasing stress responses including greater blood H:L and feather CORT concentrations (p < 0.01) than those raised at low SD. Transepithelial electrical resistance in the jejunal mucosa was decreased (p < 0.05) at high SD, indicating an increase in intestinal permeability. However, the main effects of dietary supplementation of 200 mg/kg vitamin C were insignificant for all measurements. In conclusion, high SD of broiler chickens impairs growth performance and intestinal barrier function with increasing stress responses. However, dietary supplementation of vitamin C may have little beneficial effects on broiler chickens raised at the high SD condition used in the present study.

Vitamin C Inhibits the Metabolic Changes Induced by Tet1 Insufficiency Under High Fat Diet Stress

SCOPE

DNA methylation contributes to obesity, but the role of the DNA demethylase ten-eleven translocation protein 1 (Tet1) in obesity remains unclear. Vitamin C is a cofactor for the Tet family of proteins, but whether vitamin C can be used to treat obesity via Tet1 awaits clarification.

METHODS AND RESULTS

Tet1^+/+ and Tet1^+/- mice are fed a high fat diet (HFD). Higher weight gain and more severe hepatic steatosis, accompanied by reduced 5-hydromethylcytosine (5hmC) levels, are found in the white adipose tissue and liver of Tet1^+/- mice. Accumulated lipids are observed in palmitic acid or oleic acid treated primary hepatocytes derived from Tet1^+/- mice, which are rescued by Tet1 overexpression or vitamin C treatment. Bisulfite sequencing reveals higher DNA methylation levels on lipolysis related genes in the liver of Tet1^+/- mice. Notably, oral intake of vitamin C normalizes DNA methylation levels, promotes lipolysis, and decreases obesity in HFD-fed Tet1^+/- mice.

CONCLUSIONS

The results reveal a novel function of Tet1 in obesity and provide a new mechanism for the beneficial role of vitamin C in metabolic diseases through enhanced Tet1 activity.

Vitamins and non-alcoholic fatty liver disease: A Molecular Insight⋆

The incidence of non-alcoholic fatty liver disease (NAFLD) is rising rapidly across the globe. NAFLD pathogenesis is largely driven by an imbalance in hepatic energy metabolism and at present, there is no approved drug for its treatment. The liver plays a crucial role in micronutrient metabolism and deregulation of this micronutrient metabolism may contribute to the pathogenesis of NAFLD. Vitamins regulate several enzymatic processes in the liver, and derangement in vitamin metabolism is believed to play a critical role in NAFLD progression. The anti-oxidant activities of vitamin C and E have been attributed to mitigate hepatocyte injury, and alterations in the serum levels of vitamin D, vitamin B12 and folate have shown a strong correlation with NAFLD severity. This review aims to highlight the role of these vitamins, which represent promising therapeutic targets for the management of NAFLD.

The Impact of Dietary Patterns and Nutrition in Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) has become one of the most common causes of chronic liver disease worldwide. The prevalence of NAFLD has grown proportionally with the rise in obesity, sedentary lifestyle, unhealthy dietary patterns, and metabolic syndrome. Currently, in the absence of approved pharmacologic treatment, the keystone of treatment is lifestyle modification focused on achieving a weight loss of 7%-10%, cardiovascular exercise, and improving insulin sensitivity. The primary aim of this review is to outline the effect of different dietetic approaches against NAFLD and highlight the important micronutrient components in the management of NAFLD.

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.

The Effect of Curcumin Phytosome on the Treatment of Patients with Non-alcoholic Fatty Liver Disease: A Double-Blind, Randomized, Placebo-Controlled Trial

Non-alcoholic fatty liver disease (NAFLD) is a global health problem with increasing prevalence among overweight and obese patients. It is strongly associated with conditions of insulin resistance including type 2 diabetes mellitus (T2DM) and obesity. It has detrimental consequences ranged from simple steatosis to irreversible hepatic fibrosis and cirrhosis. Curcumin is a dietary polyphenol with potential effect in improving NAFLD. Therefore, the aim of this trial was to examine the effect of curcumin supplementation on various aspects of NAFLD. In this trial, a total number of 80 patients were randomised to receive either curcumin at 250 mg daily or placebo for 2 months. Lipid profiles, hepatic enzymes, anthropometric indices and hepatic fat mass were assessed at the baseline and the end of the trial, and compared within the groups. The grade of hepatic steatosis, and serum aspartate aminotransferase (AST) levels were significantly reduced in the curcumin group (p = 0.015 and p = 0.007, respectively) compared to the placebo. There was also a significant reduction in high density lipoprotein (HDL) levels and anthropometric indices in both groups with no significant differences between the two groups. Low dose phospholipid curcumin supplementation each day for 2 months showed significant reduction in hepatic steatosis and enzymes in patients with NAFLD compared to placebo. Further studies of longer duration and higher dosages are needed to assess its effect on other parameters of NAFLD including cardiovascular risk.

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.

Serum Malondialdehyde is Associated with Non-Alcoholic Fatty Liver and Related Liver Damage Differentially in Men and Women

Background: Non-alcoholic fatty liver disease (NAFLD) and steatohepatitis (NASH) are associated with increased oxidative stress and lipid peroxidation, but large studies are lacking. The aim was to test the association of malondialdehyde (MDA), as a marker of oxidative damage of lipids, with NAFLD and liver damage markers, and to test the association between dietary vitamins E and C intake and MDA levels. Methods: A cross-sectional study was carried out among subjects who underwent blood tests including FibroMax for non-invasive assessment of NASH and fibrosis. MDA was evaluated by reaction with Thiobarbituric acid and HPLC-fluorescence detection method. NAFLD was diagnosed by abdominal ultrasound. Findings: MDA measurements were available for 394 subjects. In multivariate analysis, the odds for NAFLD were higher with the rise of MDA levels in a dose–response manner, adjusting for age, gender, BMI, and lifestyle factors. Only among men, higher serum MDA was associated of higher odds for NAFLD and NASH and/or fibrosis (OR = 2.59, 95% CI 1.33–5.07, P = 0.005; OR = 2.04, 1.02–4.06, P = 0.043, respectively). Higher vitamin E intake was associated with lower odds of high serum MDA level (OR = 0.28 95% CI 0.13–0.62, P = 0.002). In conclusion, serum MDA is associated with NAFLD and markers of NASH or fibrosis among men. Dietary vitamin E may be protective among women.

Oxidative Stress Management in Chronic Liver Diseases and Hepatocellular Carcinoma

Chronic viral hepatitis B and C and non-alcoholic fatty liver disease (NAFLD) have been widely acknowledged to be the leading causes of liver cirrhosis and hepatocellular carcinoma. As anti-viral treatment progresses, the impact of NAFLD is increasing. NAFLD can coexist with chronic viral hepatitis and exacerbate its progression. Oxidative stress has been recognized as a chronic liver disease progression-related and cancer-initiating stress response. However, there are still many unresolved issues concerning oxidative stress, such as the correlation between the natural history of the disease and promising treatment protocols. Recent findings indicate that oxidative stress is also an anti-cancer response that is necessary to kill cancer cells. Oxidative stress might therefore be a cancer-initiating response that should be down regulated in the pre-cancerous stage in patients with risk factors for cancer, while it is an anti-cancer cell response that should not be down regulated in the post-cancerous stage, especially in patients using anti-cancer agents. Antioxidant nutrients should be administered carefully according to the patients’ disease status. In this review, we will highlight these paradoxical effects of oxidative stress in chronic liver diseases, pre- and post-carcinogenesis.

Ascorbate protects liver from metabolic disorder through inhibition of lipogenesis and suppressor of cytokine signaling 3 (SOCS3)

Background

Fatty liver is a reversible status, but also an origin stage to develop to other metabolic syndromes, such as diabetes and heart disease that threatens public health worldwide. Ascorbate deficiency is reported to be correlated with increasing risks for metabolic syndromes, but whether ascorbate has a therapeutic effect is unknown. Here, we investigated if ascorbate treatment alone could work on protecting from the development of steatosis and mechanisms beyond.

Methods

Guinea pigs were fed with a chow diet or a high palm oil diet (HPD) respectively. HPD induced animals were administered different concentrations of ascorbate in different time intervals through water. Besides, hepatocyte-like cells derived from human embryonic stem cells and HepG2 cells were treated with palmitic acid (PA) to induce lipid accumulation for molecular mechanism study.

Results

We find that ascorbate rescues HPD and PA induced steatosis and insulin tolerance in vivo and in vitro. We demonstrate that ascorbate changes cellular lipid profiles via inhibits lipogenesis, and inhibits the expression of SOCS3 via STAT3, thus enhances insulin signal transduction. Overexpression of SOCS3 abolishes the ascorbate rescue effects on insulin signal and lipid accumulation in hepatic cells.

Conclusions

Ascorbate ameliorates hepatic steatosis and improves insulin sensitivity through inhibiting lipogenesis and SOCS3.

Fat and Sugar-A Dangerous Duet. A Comparative Review on Metabolic Remodeling in Rodent Models of Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is a common disease in Western society and ranges from steatosis to steatohepatitis to end-stage liver disease such as cirrhosis and hepatocellular carcinoma. The molecular mechanisms that are involved in the progression of steatosis to more severe liver damage in patients are not fully understood. A deeper investigation of NAFLD pathogenesis is possible due to the many different animal models developed recently. In this review, we present a comparative overview of the most common dietary NAFLD rodent models with respect to their metabolic phenotype and morphological manifestation. Moreover, we describe similarities and controversies concerning the effect of NAFLD-inducing diets on mitochondria as well as mitochondria-derived oxidative stress in the progression of NAFLD.

Multiple genome analyses reveal key genes in Vitamin C and Vitamin D synthesis and transport pathways are shared

Vitamin C (VC) and vitamin D (VD) have been widely used as the dietary supplements and in treatment of diseases both independently and in combination. Whether there is a connection between their pathways is critical for their therapeutic applications. Using whole-genome expression profiles, we performed multiple measures of associations, networks, eQTL mappings and expressions of key genes of interest in VC and VD functions. Several key genes in their pathways were found to be associated. Gc and Rgn play important roles connecting VC and VD pathways in mice. The r values of expression levels between Gc and Rgn in mouse spleen, liver, lung, and kidney are 0.937, 0.558, 0.901, and 0.617, respectively. The expression QTLs of Gc and Rgn are mapped onto the same locations, i.e., 68-76 MB in chromosome 7 and 26-36 MB in chromosome 9. In humans, there are positive correlations between CYP27B1 and SLC23A1 expression levels in kidney (r = 0.733) and spleen (r = 0.424). SLC23A2 and RXRA are minimally associated in both mouse and human. These data indicate that pathways of VC and VD are not independent but affect each other, and this effect is different between mice and humans during VC and VD synthesis and transportation.

The relationship between dietary antioxidant intake and physical activity rate with nonalcoholic fatty liver disease (NAFLD): A case - Control study

INTRODUCTION

Although dietary intakes, especially micronutrients, can be associated with the severity of nonalcoholic fatty liver disease (NAFLD), investigations on the amount of vitamins and antioxidants consumption and their relationship with NAFLD are very limited and incomplete. Therefore, we decided to investigate the relationship between antioxidant compounds intake and physical activity rate with NAFLD.

METHODS

In this study, 200 patients with NAFLD for the case group and 400 healthy subjects for the control group were selected. Patients were diagnosed as NAFLD after giving blood tests and performing Ultrasonography by a radiology specialist. Dietary intakes were evaluated through a validated 168-items semi-quantitative food frequency questionnaire (FFQ). Physical activity rate was estimated by a validated short form of International Physical Activity Questionnaire (Short IPAQ).

RESULTS

The study population was between 20 and 60 years old and 46% of them were women. Weight, waist circumference, hip circumference, WHR, and BMI in the cases were higher than the controls. Physical activity comparisons showed that controls had higher physical activity rate than cases. Mean consumption of vitamins C, A, D and alpha-tocopherol in case group was less than the other group. After adjustment for all potential confounder, subjects who were in highest tertile of vitamin A intake -in comparison to those in the lowest tertile of intake-decreased risk of NAFLD (OR = 0.40, 95%CI: 0.30-0.55). The same finding was obtained for vitamin D; [Top category vs. bottom category of vitamin D of intake (OR = 0.35, 95%CI: 0.20-0.61)].

CONCLUSIONS

We found that more intakes of vitamins A and D are related to lower risk of NAFLD in this group of Iranian adults. Physical activity rate in cases was less than the controls. Further prospective studies are required to confirm causal association between antioxidant compounds intake and NAFLD.

Association of alcohol consumption with prevalence of fatty liver after adjustment for dietary patterns: Cross-sectional analysis of Japanese middle-aged adults

Background & aims

Moderate alcohol intake is associated with reduced prevalence or incidence of fatty liver. However, whether or not the association is independent of dietary patterns remains unclear. We aimed to evaluate the cross-sectional association of alcohol intake with fatty liver after accounting for dietary patterns and obesity.

Methods

We assessed 4579 adults aged 30–79 years who participated in routine clinical examinations in St. Luke's International Hospital, Japan (January to March, 2015). We assessed their habitual diet using diet-history questionnaire, estimated alcohol intake, and derived dietary pattern variables using factor analysis. Fatty liver was ascertained using ultrasonography. Linear and U-shaped associations of alcohol intake with fatty liver were evaluated using Poisson regression, and a post hoc analysis was conducted after detecting potential outliers for alcohol intake and excluding them using sex-specific statistics (median plus 2 × interquartile range).

Results

Fatty liver was ascertained in 1120 participants (24.5%). Whereas no significant association of alcohol intake with fatty liver was observed when potential outliers of alcohol intake were included (p = 0.25), a significant U-shaped association was observed after excluding the outliers with and without adjustment for dietary patterns (p = 0.003 and 0.02, respectively). The lowest prevalence was estimated when alcohol consumption was approximately 7% of energy, with a prevalence ratio of 0.72 (95% confidence interval = 0.59–0.86) compared to non-drinkers. The association became imprecise and attenuated toward the null after further adjustment for body mass index (p = 0.06).

Conclusions

Alcohol intake showed a U-shaped association with fatty liver prevalence. This association was independent of underlying dietary patterns, while it was sensitive to excessive alcohol intake and obesity status, providing clinical implications for the prevention of fatty liver.

Pathophysiological, Molecular and Therapeutic Issues of Nonalcoholic Fatty Liver Disease: An Overview

Nonalcoholic Fatty Liver Disease (NAFLD) represents the leading cause of liver disease in developed countries but its diffusion is currently also emerging in Asian countries, in South America and in other developing countries. It is progressively becoming one of the main diseases responsible for hepatic insufficiency, hepatocarcinoma and the need for orthotopic liver transplantation. NAFLD is linked with metabolic syndrome in a close and bidirectional relationship. To date, NAFLD is a diagnosis of exclusion, and liver biopsy is the gold standard for diagnosis. NAFLD pathogenesis is complex and multifactorial, mainly involving genetic, metabolic and environmental factors. New concepts are constantly arising in the literature promising new diagnostic and therapeutic tools. One of the challenges will be to better characterize not only NAFLD development but overall NAFLD progression, in order to better identify NAFLD patients at higher risk of metabolic, cardiovascular and neoplastic complications. This review analyses NAFLD epidemiology and the different prevalence of the disease in distinct groups, particularly according to sex, age, body mass index, type 2 diabetes and dyslipidemia. Furthermore, the work expands on the pathophysiology of NAFLD, examining multiple-hit pathogenesis and the role of different factors in hepatic steatosis development and progression: genetics, metabolic factors and insulin resistance, diet, adipose tissue, gut microbiota, iron deposits, bile acids and circadian clock. In conclusion, the current available therapies for NAFLD will be discussed.

Concurrent exercise improves insulin resistance and nonalcoholic fatty liver disease by upregulating PPAR-γ and genes involved in the beta-oxidation of fatty acids in ApoE-KO mice fed a high-fat diet

Objective

To emphasize the mechanism of concurrent exercise effect on lipid disorders in insulin resistance (IR) and nonalcoholic fatty liver disease (NAFLD).

Materials and methods

Twenty male ApoE knockout mice were randomly divided into two groups: HFD group (n = 10) fed a high fat diet, and HFDE group (n = 10) with high-fat diet intervention for 12 weeks and swimming exercise. Other ten healthy male C57BL/6 J mice were fed a normal diet, and included as control group. Retro-orbital blood samples were collected for biochemical analysis. Oil red O staining of liver tissues was performed to confirm the exercise effect. Western blotting was performed to evaluate the expressions of PPAR-γ, CPT-1, MCAD.

Results

The levels of TG, TC, LDL, FFA, FIN, FPG and Homa-IRI in the HFD group were significantly higher than ND group, while these were markedly decreased in the HFDE group compared with HFD group. The Oil Red O staining of liver samples further confirmed the exercise effect on the change of lipid deposition in the liver. Western blotting showed increased expressions of PPAR-γ, CPT-1, MCAD induced by high fat diet were significantly downregulated by exercise.

Conclusion

A concurrent 12-week exercise protocol alleviated the lipid metabolism disorders of IR and NAFLD, probably via PPAR-γ/CPT-1/MCAD signaling.

The relationship between vitamin C status, the gut-liver axis, and metabolic syndrome

Metabolic syndrome (MetS) is a constellation of cardiometabolic risk factors, which together predict increased risk of more serious chronic diseases. We propose that one consequence of dietary overnutrition is increased abundance of Gram-negative bacteria in the gut that cause increased inflammation, impaired gut function, and endotoxemia that further dysregulate the already compromised antioxidant vitamin status in MetS. This discussion is timely because "healthy" individuals are no longer the societal norm and specialized dietary requirements are needed for the growing prevalence of MetS. Further, these lines of evidence provide the foundational basis for investigation that poor vitamin C status promotes endotoxemia, leading to metabolic dysfunction that impairs vitamin E trafficking through a mechanism involving the gut-liver axis. This report will establish a critical need for translational research aimed at validating therapeutic approaches to manage endotoxemia-an early, but inflammation-inducing phenomenon, which not only occurs in MetS, but is also prognostic of more advanced metabolic disorders including type 2 diabetes mellitus, as well as the increasing severity of nonalcoholic fatty liver diseases.

The Role of Vitamin E in the Treatment of NAFLD

There has been a growing interest in the role of vitamin E supplementation in the treatment and/or prevention of nonalcoholic fatty liver (NAFLD). We performed a systematic review of the medical literature from inception through 15 June 2018 by utilizing PubMed and searching for key terms such as NAFLD, vitamin E, alpha-tocopherol, and nonalcoholic steatohepatitis (NASH). Data from studies and medical literature focusing on the role of vitamin E therapy in patients with NAFLD and nonalcoholic steatohepatitis (NASH) were reviewed. Most studies assessing the impact of vitamin E in NAFLD were designed to evaluate patients with NASH with documented biochemical and histological abnormalities. These studies demonstrated improvement in biochemical profiles, with a decline in or normalization of liver enzymes. Furthermore, histological assessment showed favorable outcomes in lobular inflammation and hepatic steatosis following treatment with vitamin E. Current guidelines regarding the use of vitamin E in the setting of NAFLD recommend that vitamin E-based treatment be restricted to biopsy-proven nondiabetic patients with NASH only. However, some concerns have been raised regarding the use of vitamin E in patients with NASH due to its adverse effects profile and lack of significant improvement in hepatic fibrosis. In conclusion, the antioxidant, anti-inflammatory, and anti-apoptotic properties of vitamin E accompanied by ease-of-use and exceptional tolerability have made vitamin E a pragmatic therapeutic choice in non-diabetic patients with histologic evidence of NASH. Future clinical trials with study design to assess vitamin E in combination with other anti-fibrotic agents may yield an additive or synergistic therapeutic effect.

Tomato Powder Inhibits Hepatic Steatosis and Inflammation Potentially Through Restoring SIRT1 Activity and Adiponectin Function Independent of Carotenoid Cleavage Enzymes in Mice

SCOPE

Beta-carotene-15,15'-oxygenase (BCO1) and beta-carotene-9',10'-oxygenase (BCO2) metabolize lycopene to biologically active metabolites, which can ameliorate nonalcoholic fatty liver disease (NAFLD). We investigate the effects of tomato powder (TP containing substantial lycopene (2.3 mg/g)) on NAFLD development and gut microbiome in the absence of both BCO1 and BCO2 in mice.

METHOD AND RESULTS

BCO1^-/- /BCO2^-/- double knockout mice were fed a high fat diet (HFD) alone (n = 9) or with TP feeding (n = 9) for 24 weeks. TP feeding significantly reduced pathological severity of steatosis and hepatic triglyceride levels in BCO1^-/- /BCO2^-/- mice (p < 0.04 vs HFD alone). This was associated with increased SIRT1 activity, nicotinamide phosphoribosyltransferase expression and AMP-activated protein kinase phosphorylation, and subsequently decreased lipogenesis, hepatic fatty acid uptake, and increasing fatty acid β-oxidation (p < 0.05). TP feeding significantly decreased mRNA expression of proinflammatory genes (tnf-α, il-1β, and il-6) in both liver and mesenteric adipose tissue, which were associated with increased plasma adiponectin and hepatic adiponectin receptor-2. Multiplexed 16S rRNA gene sequencing was performed using DNA extracted from cecum fecal samples. TP feeding increased microbial richness and decreased relative abundance of the genus Clostridium.

CONCLUSION

Dietary TP can inhibit NAFLD independent of carotenoid cleavage enzymes, potentially through increasing SIRT1 activity and adiponectin production and decreasing Clostridium abundance.

Non-alcoholic fatty liver and advanced fibrosis in the elderly: Results from a community-based Polish survey

BACKGROUND & AIMS

Development of non-alcoholic fatty liver (NAFL) is dependent on metabolic factors occurring at an increased frequency with advancing age. Until now, few studies have explored the prevalence of NAFL in aged populations. Our study aimed to determine the prevalence of NAFL and advanced fibrosis in the elderly population participating in a national survey of a community-based elderly cohort.

METHODS

A total of 3003 participants (mean age 79.6 years, 46.8% male) were enrolled in the study, after applying the following exclusion criteria: individuals younger than 65 years old (n=829) and those with positive serological biomarkers of HBV or HCV infection (n=391), chronic alcohol ingestion (n=727) or incomplete data records (n=745). Based on the fatty liver index (FLI), the participants were classified into three categories: FLI<30 (no NAFL), 30≤FLI<60 (borderline) and FLI≥60 (NAFL). According to the non-alcoholic fatty liver disease (NAFLD) fibrosis score (NFS), the participants were divided into three advanced fibrosis risk categories: NFS<-1.455 (low risk), -1.455≤NFS≤0.676 (intermediate risk) and NFS>0.676 (high risk).

RESULTS

The prevalence of NAFL in the general population was 37.2%; the prevalence reached 51.4% in participants 65-70 years of age and decreased with advancing age (P<.0001). The prevalence of advanced fibrosis was 7.79% (14.8% in the NAFL population) and increased with advancing age (P<.005).

CONCLUSIONS

The prevalence of NAFL and metabolically driven advanced fibrosis are relatively common in the elderly population, and these hepatic conditions run in adverse directions with advancing age.

Treatment of NAFLD with diet, physical activity and exercise

Lifestyle intervention can be effective when treating non-alcoholic fatty liver diseases (NAFLD) patients. Weight loss decreases cardiovascular and diabetes risk and can also regress liver disease. Weight reductions of ⩾10% can induce a near universal non-alcoholic steatohepatitis resolution and fibrosis improvement by at least one stage. However, modest weight loss (>5%) can also produce important benefits on the components of the NAFLD activity score (NAS). Additionally, we need to explore the role of total calories and type of weight loss diet, micro- and macronutrients, evidence-based benefits of physical activity and exercise and finally support these modifications through established behavioural change models and techniques for long-term maintenance of lifestyle modifications. Following a Mediterranean diet can reduce liver fat even without weight loss and is the most recommended dietary pattern for NAFLD. The Mediterranean diet is characterised by reduced carbohydrate intake, especially sugars and refined carbohydrates (40% of the calories vs. 50-60% in a typical low fat diet), and increased monounsaturated and omega-3 fatty acid intake (40% of the calories as fat vs. up-to 30% in a typical low fat diet). Both TV sitting (a reliable marker of overall sedentary behaviour) and physical activity are associated with cardio-metabolic health, NAFLD and overall mortality. A 'triple hit behavioural phenotype' of: i) sedentary behaviour, ii) low physical activity, and iii) poor diet have been defined. Clinical evidence strongly supports the role of lifestyle modification as a primary therapy for the management of NAFLD and NASH. This should be accompanied by the implementation of strategies to avoid relapse and weight regain.

Qualitative and Quantitative Evaluation of Dietary Intake in Patients with Non-Alcoholic Steatohepatitis

There are very few reports about the intake of nutrients for the development or progression of non-alcoholic steatohepatitis (NASH). The aim of this study was to identify the dietary habits and the nutrient intake in patients with NASH, in comparison to chronic hepatitis C (HCV)-related patients. We prospectively evaluated the intake of macronutrients and micronutrients in 124 NAFLD and 162 HCV patients, compared to 2326 subjects as a control group. We noticed major differences in macro- and micronutrients intakes in NASH and HCV patients compared to controls. Proteins, carbohydrate (glucose, fructose, sucrose, maltose and amide), saturated fatty acid (SFA), monounsaturated fatty acid (MUFA), folic acid, vitamin A and C (p < 0.0001), and thiamine (p < 0.0003) ingestion was found to be higher in patients with NASH, while total lipids, polyunsaturated fatty acid (PUFA), riboflavin and vitamin B6 daily intake were lower compared to controls (p < 0.0001). Similarly, NASH patients had significantly reduced carbohydrate intake (p < 0.0001) and an increased intake of calcium (p < 0.0001) compared to HCV positive patients. Finally, we showed in NASH males an increase in the intake of SFA, PUFA, soluble carbohydrates (p < 0.0001) and a decrease in the amount of fiber (p < 0.0001) compared to control males. In NASH female population, we showed an increase of daily total calories, SFA, MUFA, soluble carbohydrates, starch and vitamin D ingested (p < 0.0001) with a reduction of fibers and calcium (p < 0.0001) compared to control females. This study showed how NASH patients’ diets, in both male and females, is affected by a profound alteration in macro- and micronutrients intake.

Association between homocysteine and non-alcoholic fatty liver disease in Chinese adults: a cross-sectional study

Background

Non-alcoholic fatty liver disease (NAFLD) is the most common liver disease worldwide, and its prevalence is likely to rise even further. To help understand the pathogenesis and early prevention of progressive NAFLD, this large-scale study was designed to explore the potential association between homocysteine and the prevalence of NAFLD.

Methods

A total of 7203 subjects aged 18 years or older were enrolled in this cross-sectional study. The association of homocysteine with the prevalence of NAFLD, in the total sample and stratified by subgroups, was examined using multiple logistic regression analyses.

Results

Subjects in the higher quartiles of homocysteine had a higher prevalence of NAFLD. After multivariate adjustment, the odds ratio (OR) for NAFLD in the highest compared with the lowest quartile of homocysteine was 2.08 (95% confidence interval [CI] 1.61, 2.67). Moreover, in the subgroup analyses, we found an effect modification by gender, body mass index (BMI) and smoking status on the association between homocysteine and the prevalence of NAFLD (P for interaction: 0.001, 0.002 and <0.001, respectively). A stronger association was observed in female, obese and non-smoking adults than in male, normal weight and smoking subjects.

Conclusion

Homocysteine was significantly associated with the prevalence of NAFLD, particularly in female, obese or non-smoking adults.