An observational study on the association between major dietary patterns and non-alcoholic fatty liver disease in Chinese adolescents

Fruit and vegetable intake and the risk of non-alcoholic fatty liver disease: a meta-analysis of observational studies

Purpose

This systematic review and meta-analysis of clinical observational studies aims to clarify the correlation between the intake levels of fruits and vegetables and non-alcoholic fatty liver disease (NAFLD).

Materials and methods

PubMed, Embase, Web of Science, and the Cochrane Library were searched for studies on the association between vegetable or fruit intake with the risk of NAFLD from the foundation of each database up until September 2023. The relative risk (OR) and the 95% confidence interval (CI) were pooled for both the highest and lowest consumption levels of vegetables and fruits to explore their association with the incidence of NAFLD.

Results

The meta-analysis encompassed 11 studies with a total of 493,682 patients. A higher consumption of vegetables (OR = 0.78, 95% CI = 0.67-0.91) and fruits (OR = 0.88, 95% CI = 0.83-0.93) was found to have a negative correlation with the risk of NAFLD, denoting an inverse association. This correlation, however, varied among different ethnic groups and gender.

Conclusions

Our results indicate that increased consumption of vegetables and fruits is associated with a reduced likelihood of developing NAFLD.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/#searchadvanced, identifier: CRD42023460430.

Food co-consumption network as a new approach to dietary pattern in non-alcoholic fatty liver disease

Dietary patterns strongly correlate with non-alcoholic fatty liver disease (NAFLD), which is a leading cause of chronic liver disease in developed societies. In this study, we introduce a new definition, the co-consumption network (CCN), which depicts the common consumption patterns of food groups through network analysis. We then examine the relationship between dietary patterns and NAFLD by analyzing this network. We selected 1500 individuals living in Tehran, Iran, cross-sectionally. They completed a food frequency questionnaire and underwent scanning via the FibroScan for liver stiffness, using the CAP score. The food items were categorized into 40 food groups. We reconstructed the CCN using the Spearman correlation-based connection. We then created healthy and unhealthy clusters using the label propagation algorithm. Participants were assigned to two clusters using the hypergeometric distribution. Finally, we classified participants into two healthy NAFLD networks, and reconstructed the gender and disease differential CCNs. We found that the sweet food group was the hub of the proposed CCN, with the largest cliques of size 5 associated with the unhealthy cluster. The unhealthy module members had a significantly higher CAP score (253.7 ± 47.8) compared to the healthy module members (218.0 ± 46.4) (P < 0.001). The disease differential CCN showed that in the case of NAFLD, processed meat had been co-consumed with mayonnaise and soft drinks, in contrast to the healthy participants, who had co-consumed fruits with green leafy and yellow vegetables. The CCN is a powerful method for presenting food groups, their consumption quantity, and their interactions efficiently. Moreover, it facilitates the examination of the relationship between dietary patterns and NAFLD.

Dietary and Nutritional Interventions in Nonalcoholic Fatty Liver Disease in Pediatrics

Nonalcoholic fatty liver disease (NAFLD) is pediatrics' most common chronic liver disease. The incidence is high in children and adolescents with obesity, which is associated with an increased risk of disease progression. Currently, there is no effective drug therapy in pediatrics; therefore, lifestyle interventions remain the first line of treatment. This review aims to present an updated compilation of the scientific evidence for treating this pathology, including lifestyle modifications, such as exercise and dietary changes, highlighting specific nutritional strategies. The bibliographic review was carried out in different databases, including studies within the pediatric population where dietary and/or nutritional interventions were used to treat NAFLD. Main interventions include diets low in carbohydrates, free sugars, fructose, and lipids, in addition to healthy eating patterns and possible nutritional interventions with n-3 polyunsaturated fatty acids (EPA and DHA), amino acids (cysteine, L-carnitine), cysteamine, vitamins, and probiotics (one strain or multi-strain). Lifestyle changes remain the main recommendation for children with NAFLD. Nevertheless, more studies are required to elucidate the effectiveness of specific nutrients and bioactive compounds in this population.

A systematic review on factors associated with non-alcoholic fatty liver disease (NAFLD) among adolescents

BACKGROUND & AIMS

Non-Alcoholic Fatty Liver Disease (NAFLD) is a global public health risk. The occurrence of adolescent NAFLD coincides with high rates of overweight and obesity, with an unhealthy lifestyle also playing a role. Data on prevalence and factors contributing to NAFLD among Asian adolescents is lacking as most studies focus on adults. This systematic review aims to determine the prevalence and factors contributing to NAFLD among adolescents.

METHODS

A systematic search was conducted using five (Goh et al., 2013) [5] databases: Cochrane, PubMed, Scopus, Science Direct, EBSCO and grey literature. Two reviewers independently screened studies using predefined inclusion and exclusion criteria and performed data extraction. Assessment of methodological quality was completed using the Newcastle-Ottawa checklist.

RESULTS

The quality of most studies were of high quality, with the majority reporting no association between lifestyle factors and NAFLD. A total of 6 studies were included in this systematic review. The prevalence of NAFLD among adolescents varied between 8.0% (Fraser et al., 2007) in a study on 5586 adolescents aged 12-19 and 16.0% (Chen et al., 2009) in another survey of 1724 adolescents aged 12-13 years old. Snacking habits and lack of physical activity had potential associations with adolescent NAFLD. Current evidence shows that lifestyle factor (Western dietary pattern) is associated with a higher risk of developing NAFLD among adolescents.

CONCLUSIONS

Lifestyle factors, including snacking habits and lack of physical activity, were associated with a higher risk of developing NAFLD among adolescents from high-income countries. The difference in the prevalence of NAFLD between countries with different incomes requires further investigation.

Higher Overall Intakes Are the Defining Feature of Dietary Intakes in NAFLD and Compared to the General Population

We aimed to compare the dietary intakes of Australian patients with non-alcoholic fatty liver disease (NAFLD) to general Australian population intake data and determine whether the intake of any nutrient or food group was able to predict the degree of steatosis. Dietary data from fifty adult patients with NAFLD were compared to intake data from the Australian Health Survey for energy, macronutrients, fat sub-types, alcohol, iron, folate, sugar, fibre, sodium and caffeine. Linear regression models adjusting for potential confounders (age, sex, physical activity and body mass index) were used to examine predictive relationships between hepatic steatosis (quantified via magnetic resonance spectroscopy) and dietary components. The mean percentage differences between NAFLD and Australian usual intakes were significant for energy, protein, total fat, saturated fat, monounsaturated and polyunsaturated fats (all p < 0.001). The contribution of fat and protein to total energy intake was significantly higher in the NAFLD cohort (p < 0.05). No individual nutrients or food groups were strongly related to hepatic fat in the adjusted models. Higher overall consumption appears to be a major feature of dietary intake in NAFLD when compared to the general population. A whole-diet approach to NAFLD treatment and prevention is likely to be more effective than focusing on single food components.

Nonalcoholic fatty liver disease in adolescents with phenylketonuria

OBJECTIVE

This study aimed to investigate non-alcoholic fatty liver disease (NAFLD) occurrence and factors associated with the disease in phenylketonuria (PKU) patients undergoing exclusive dietary treatment.

METHOD

This cross-sectional study included 101 adolescents 10 to < 20 years of age with PKU, who were undergoing exclusive dietary treatment and monitored since early diagnosis at a single reference service. Anthropometric and biochemical assessments were performed and food intake was documented, and an ultrasound diagnosis of NAFLD was established. Data were evaluated using the Student's t-test for continuous variables, the chi-square for categorical variables, and logistic regression using the Wald chi-squared test; differences with p < 0.05 were considered to be statistically significant.

RESULTS

NAFLD was detected in 26 (25.7%) teenagers. There was no difference in prevalence between the sexes or nutritional status. The final logistic regression model revealed low sensitivity (26.1%) and high specificity (94.7%). The specificity suggested a lower likelihood of NAFLD in older adolescents, in the presence of normal or high levels of alkaline phosphatase, lower carbohydrate intake, and adequate protein and lipid intake.

CONCLUSIONS

The prevalence of NAFLD in adolescents with PKU was higher than that found in healthy Brazilian adolescents and similar to that found in obese Brazilian children, suggesting a higher risk for NAFLD in patients with PKU treated exclusively by dietary modification.

A healthy lifestyle during adolescence was inversely associated with fatty liver indices in early adulthood: findings from the DONALD cohort study

A healthy lifestyle during adolescence is associated with insulin sensitivity or liver enzyme levels and thus might contribute to the prevention of non-alcoholic fatty liver disease (NAFLD). Therefore, we examined the association between adherence to a hypothesis-based lifestyle score including dietary intake, physical activity, sedentary behaviour, sleep duration and BMI in adolescence and fatty liver indices in early adulthood. Overall, 240 participants of the DOrtmund Nutritional and Anthropometric Longitudinally Designed study completed repeated measurements of lifestyle score factors during adolescence (females: 8·5-15·5 years, males: 9·5-16·5 years). Multivariable linear regression models were used to investigate the association between adolescent lifestyle scores and NAFLD risk (hepatic steatosis index (HSI) and fatty liver index (FLI)) in early adulthood (18-30 years). Participants visited the study centre 4·9 times during adolescence and achieved on average 2·8 (min: 0·6, max: 5) out of five lifestyle score points. Inverse associations were observed between the lifestyle score and fatty liver indices (HSI: ß=-5·8 % (95 % CI -8·3, -3·1), P < 0·0001, FLI: ß=-32·4 % (95 % CI -42·9, -20·0), P < 0·0001) in the overall study population. Sex-stratified analysis confirmed these results in men, while inverse but non-significant associations were observed in women (P > 0·05). A higher lifestyle score was associated with lower HSI and FLI values, suggesting that a healthy lifestyle during adolescence might contribute to NAFLD prevention, predominantly in men. Our findings on repeatedly measured lifestyle scores in adolescents and their association with NAFLD risk in early adulthood warrant confirmation in larger study populations.

Race and Ethnicity in Non-Alcoholic Fatty Liver Disease (NAFLD): A Narrative Review

Non-alcoholic fatty liver disease (NAFLD) is a significant public health concern worldwide with a complex etiology attributed to behavioural, environmental, and genetic causes. The worldwide prevalence of NAFLD is estimated to be 32.4% and constantly rising. Global data, however, indicate considerable heterogeneity among studies for both NAFLD prevalence and incidence. Identifying variables that affect the estimated epidemiological measures is essential to all stakeholders, including patients, researchers, healthcare providers, and policymakers. Besides helping with the research on disease etiology, it helps to identify individuals at risk of the disease, which in turn will outline the focus of the preventive measures and help to fittingly tailor individualized treatments, targeted prevention, screening, or treatment programs. Several studies suggest differences in the prevalence and severity of NAFLD by race or ethnicity, which may be linked to differences in lifestyle, diet, metabolic comorbidity profile, and genetic background, among others. Race/ethnicity research is essential as it can provide valuable information regarding biological and genetic differences among people with similar cultural, dietary, and geographical backgrounds. In this review, we examined the existing literature on race/ethnicity differences in susceptibility to NAFLD and discussed the contributing variables to such differences, including diet and physical activity, the comorbidity profile, and genetic susceptibility. We also reviewed the limitations of race/ethnicity studies in NAFLD.

Major Dietary Patterns in Association with the Grades of Nonalcoholic Fatty Liver Disease in Newly Diagnosed Patients Living in North of Iran

BACKGROUND

Evidence suggests that dietary pattern is related to incidence and grades of nonalcoholic fatty liver disease (NAFLD). The aim of this study was to investigate the relationship between major dietary patterns and hepatic histologic features of newly diagnosed patients with NAFLD.

METHODS

This cross-sectional study included 260 newly diagnosed NAFLD patients. Hepatic fibrosis and steatosis were diagnosed using Fibroscan. Dietary information was obtained using a validated 168-item semiquantitative food frequency questionnaire. The association between dietary patterns and odds ratio of the grade of fibrosis and steatosis was examined by multinomial logistic regression.

RESULTS

The mean ± SD age participant was 46.53 ± 11.71 years. Fifty-seven percent of the participants were women. Two major dietary patterns were recognized: "Western dietary pattern" and "Mediterranean dietary pattern." After adjustment for various confounders, adherence to the two extracted dietary patterns was not associated with odds of fibrosis and steatosis (P > 0.05). However, P was not significant. Patients in the second quartile of the Mediterranean dietary pattern had a higher risk for being in the F1 grade compared to those in the reference group in the crude and adjusted model.

CONCLUSIONS

The major dietary patterns of NAFLD patients living in Gilan were not related to the severity of their disease. More precise study design such as cohort or interventional studies is suggested to reveal the strength of this study findings.

Factors early in life associated with hepatic steatosis

BACKGROUND

The rise in prevalence of non-alcoholic fatty liver disease (NAFLD) mirrors the obesity epidemic. NAFLD is insidious but may gradually progress from simple steatosis to steatohepatitis, fibrosis and cirrhosis and/or hepatocellular carcinoma. Intervention strategies to ameliorate developmental programming of NAFLD may be more efficacious during critical windows of developmental plasticity.

AIM

To review the early developmental factors associated with NAFLD.

METHODS

Databases MEDLINE via PubMed, and EMBASE and Reference Citation Analysis were searched and relevant publications up to April 30, 2021 were assessed. Original research studies that included risk factors associated with early development of NAFLD in human subjects were included. These factors include: Maternal factors, intrauterine and prenatal factors, post-natal factors, genetic and ethnic predisposition, childhood and adolescence environmental factors. Studies were excluded if they were review articles or animal studies, case reports or conference abstracts, or if NAFLD was not clearly defined and assessed radiologically.

RESULTS

Of 1530 citations identified by electronic search, 420 duplicates were removed. Of the 1110 citations screened from title and abstract, 80 articles were included in the final analysis. Genetic polymorphisms such as patatin-like phospholipase domain-containing protein 3 (PNPLA3) and membrane-bound O-acyltransferase domain-containing protein 7 (MBOAT7) were associated with increased risk of NAFLD. Familial factors such as maternal obesogenic environment and parental history of hepatic steatosis was associated with offspring NAFLD. Longer duration of exclusive breastfeeding in infancy was associated with a lower risk of developing NAFLD later in life while metabolic dysfunction and/or obesity in adolescence was associated with increased risk of NAFLD. Studies relating to socioeconomic factors and its association with NAFLD reported confounding results.

CONCLUSION

Maternal metabolic dysfunction during pregnancy, being exclusively breastfed for a longer time postnatally, diet and physical activity in childhood and adolescence are potential areas of intervention to decrease risk of NAFLD.

Empirically derived dietary pattern and odds of non-alcoholic fatty liver diseases in overweight and obese adults: a case-control study

Background

The prevalence of non-alcoholic fatty liver disease (NAFLD) is rising at an exponential rate throughout the world. Given the confirmed association between nutritional status and NAFLD, this study aimed to investigate the relationship of dietary patterns with NAFLD in overweight and obese adults.

Methods

In this age- and gender-matched case–control study, 115 newly diagnosed cases and 102 control individuals participated. A validated 178-item semi-quantitative food frequency questionnaire was administered to assess the participants' dietary data. Dietary patterns were extracted from 24 predefined food groups by factor analysis. Multivariate logistic regression was run to evaluate the relationship between dietary patterns and NAFLD.

Results

Factor analysis resulted in: “western”, “traditional”, and “snack and sweets” dietary patterns. The NAFLD odds were greater in participants at the highest quintile of the “western” dietary pattern than the lowest quintile (OR: 3.52; 95% CI: 1.64, 8.61). A significant increasing trend was observed in NAFLD odds across increasing quintiles of the “western” dietary pattern (P-trend = 0.01). After adjusting for the potential confounders, this relationship remained significant (OR: 3.30; 95% CI: 1.06–10.27). After full adjustments, NAFLD had no association with “traditional” or “snack and sweets” dietary patterns.

Conclusion

The “western” dietary pattern containing fast food, refined grains, liquid oil, pickles, high-fat dairy, sweet desserts, red meat, tea, and coffee was associated with increased odds of NAFLD. However, further prospective studies are required to establish these results.

Dietary Patterns and Prevalent NAFLD at Year 25 from the Coronary Artery Risk Development in Young Adults (CARDIA) Study

The prevalence of nonalcoholic fatty liver disease is rapidly rising. We aimed to investigate associations of diet quality and dietary patterns with nonalcoholic fatty liver disease (NAFLD) in Black and White adults. We included 1726 participants who attended the Year 20 Exam of the Coronary Artery Risk Development in Young Adults (CARDIA) study and had their liver attenuation (LA) measured using computed tomography at Year 25 (2010–2011). NAFLD was defined as an LA of ≤51 Hounsfield units after the exclusion of other causes of liver fat. The a priori diet-quality score (APDQS) was used to assess diet quality, and dietary patterns were derived from principal components analysis. Univariate and multivariable logistic regression models were used to evaluate the association between the APDQS, dietary patterns, and NAFLD, and were adjusted for Year 20 covariates. NAFLD prevalence at Year 25 was 23.6%. In a model adjusted for age, race, sex, education, alcohol use, physical activity, smoking, and center at Year 25, the APDQS was inversely associated (p = 0.004) and meat dietary pattern was positively associated (p < 0.0001) with NAFLD, while the fruit-vegetable dietary pattern was not significantly associated (p = 0.40). These associations remained significant when additionally adjusting for comorbidities (type 2 diabetes mellitus, dyslipidemia, hypertension), however, significant associations were diminished after additionally adjusting for body mass index (BMI). Overall, this study finds that the APDQS and meat dietary patterns are associated with prevalent NAFLD in mid-life. The associations appear to be partially mediated through higher BMI.

Healthy dietary patterns and metabolic dysfunction-associated fatty liver disease in less-developed ethnic minority regions: a large cross-sectional study

BACKGROUND

Little is known about the associations between healthy dietary patterns and metabolic dysfunction-associated fatty liver disease (MAFLD) in less-developed ethnic minority regions (LEMRs), where the prevalence of MAFLD is increasing rapidly and dietary habits are quite different from those in developed countries. Moreover, a significant subset of MAFLD individuals in LEMRs are nonobese, but the efficacy of dietary patterns on MAFLD individuals with different obese statuses is also unclear. We aimed to test the associations of two wildly recommended a priori dietary patterns-Alternate Mediterranean diet (AMED) and Dietary Approaches to Stop Hypertension (DASH)-with the risk of MAFLD in the total population, and further in nonobese and obese individuals.

METHODS

We recruited 99,556 participants in the China Multi-Ethnic Cohort Study, an ongoing cohort study in less-developed southwest China. Using validated food frequency questionnaire, each participant was assigned an AMED score and a DASH score. MAFLD was ascertained as hepatic steatosis on ultrasound together with diabetes, overweight/obesity, or two other metabolic risk factors. We performed logistic regression with inverse probability of exposure weighting (IPEW) to examine associations between two dietary patterns and MAFLD, adjusting for potential confounders under the guidance of directed acyclic graphs. Further, analyses were stratified by body mass index.

RESULTS

We included 66,526 participants (age 49.5±11.0; 62.6% women), and the prevalence of MAFLD was 16.1%. Participants in the highest quintile of DASH score showed strong inverse associations with risks of MAFLD (OR = 0.85; 95% CI, 0.80-0.91; Ptrend < 0.001) compared with participants in the lowest quintile. The association between DASH and nonobese MAFLD (OR = 0.69; 95% CI, 0.61-0.78; Ptrend < 0.001) was stronger (I2 = 78.5 % ; Pheterogeneity = 0.001) than that with obese MAFLD (OR = 0.90; 95% CI, 0.83-0.98; Ptrend = 0.002). There was a null association between AMED and MAFLD risk.

CONCLUSIONS

In LEMRs, a DASH diet but not AMED was associated with MAFLD. The relationship appeared to be more pronounced in nonobese MAFLD individuals than in obese MAFLD individuals.

Impact of dietary compositions and patterns on the prevalence of nonalcoholic fatty liver disease in Japanese men: a cross-sectional study

BACKGROUND

This study aimed to examine the impact of dietary compositions and patterns on nonalcoholic fatty liver disease (NAFLD) morbidity in Japanese men.

METHODS

We conducted a cross-sectional study of 281 individuals who underwent comprehensive medical examinations during health screening. Dietary intake was assessed using a semi-quantitative food frequency questionnaire, and factor analysis was performed to detect dietary patterns. NAFLD was diagnosed by the presence of fatty liver on abdominal ultrasonography in nondrinkers (< 30 g/day), and patients were categorized into control (n = 192) and NAFLD groups (n = 89).

RESULTS

Compared with the control group, the NAFLD group consumed fewer mushrooms. Three dietary patterns were identified, namely, a healthy pattern, a western pattern, and a snack pattern. The score of healthy pattern was negatively correlated with the risk of NAFLD. Compared with the lowest tertile of the healthy pattern, the middle tertile was associated with a lower risk of NAFLD after adjusting for age, physical activity, and smoking (odds ratio: 0.47, 95% confidence interval: 0.25-0.91). After further adjustments for body mass index, the middle tertile was associated with a lower risk of NAFLD (odds ratio: 0.46, 95% confidence interval: 0.23-0.92).

CONCLUSIONS

A healthy dietary pattern comprising frequent intake of seaweeds, vegetables, mushrooms, pulses, and potatoes and starches was associated with a lower risk of NAFLD in Japanese men. In our opinion, this healthy pattern closely resembles the Japanese Washoku diet, indicating that adherence to Washoku may help prevent NAFLD.

Association between TFEB gene polymorphism, gene-environment interaction, and fatty liver disease: A case-control study in China

BACKGROUND

Fatty liver disease (FLD) is a serious public health problem that is rapidly increasing. Evidence indicates that the transcription factor EB (TFEB) gene may be involved in the pathophysiology of FLD; however, whether TEFB polymorphism has an association with FLD remains unclear.

OBJECTIVES

To explore the association among TFEB polymorphism, gene-environment interaction, and FLD and provide epidemiological evidence for clarifying the genetic factors of FLD.

METHODS

This study is a case-control study. Sequenom MassARRAY was applied in genotyping. Logical regression was used to analyze the association between TFEB polymorphism and FLD, and the gene-environment interaction in FLD was evaluated by multiplication and additive interaction models.

RESULTS

(1) The alleles and genotypes of each single nucleotide polymorphism and haplotypes of TFEB in the case and control groups were evenly distributed; no statistically substantial difference was observed. (2) Logistic regression analysis indicated that TFEB polymorphism is not remarkably associated with FLD. (3) In the multiplicative interaction model, rs1015149, rs1062966, rs11754668 and rs2273068 had remarkable interaction with the amount of cigarette smoking. Rs1062966 and rs11754668 also had a considerable interaction body mass index and alcohol intake, respectively. However, no remarkable additive interaction was observed.

CONCLUSION

TFEB polymorphism is not directly associated with FLD susceptibility, but the risk can be changed through gene-environment interaction.

A review of non-alcoholic fatty liver disease in non-obese and lean individuals

Non-alcoholic fatty liver disease (NAFLD) is one of the most common causes of hepatic disorders. It represents a wide range of chronic liver diseases in patients with no history of significant alcohol consumption, starting with simple steatosis and progressing towards non-alcoholic steatohepatitis, cirrhosis, and ultimately hepatocellular carcinoma. NAFLD is usually associated with type 2 diabetes mellitus, dyslipidemia, metabolic syndrome, and obesity. This disease has mostly been studied in obese individuals; however, it has been widely reported and studied among the lean/non-obese population in recent years. The pathogenesis of NAFLD in non-obese patients is associated with various genetic predispositions, particularly a patatin-like phospholipase domain-containing protein 3 G allele polymorphism, which results in the accumulation of triglyceride in the liver and resistance to insulin. Additionally, dietary factors such as high fructose consumption seem to play a substantial role in the pathology of non-obese NAFLD. Although there is not enough evidence on the treatment of NAFLD in non-obese patients, the standard approach is to advise altering one's lifestyle in order to diminish visceral adiposity. Dietary modification, weight loss, and increased physical activity are highly recommended. We aimed to review and summarize the existing information on the prevalence, pathogenesis, genetic predispositions, diagnosis, and treatment of NAFLD in non-obese patients according to the latest literature.

Relationship between dietary patterns and non-alcoholic fatty liver disease: A systematic review and meta-analysis

BACKGROUND AND AIM

Non-alcoholic fatty liver disease (NAFLD) is one of the most common causes of chronic liver disease. Previous studies have investigated the association between dietary patterns and NAFLD, but their results are contradictory. Therefore, we carried out this meta-analysis to examine the association between dietary patterns and NAFLD.

METHODS

We searched PubMed, Web of Science, Scopus, and Google Scholar databases until November 14, 2019, to identify the observational studies on the association between dietary patterns and NAFLD. We selected three dietary patterns of Western, Prudent, and Mediterranean. A random-effect model was used to compute the summary risk estimates. Odds ratios (ORs) that were reported for fully adjusted models and their confidence intervals (CIs) were extracted for meta-analysis. Heterogeneity between studies was assessed using Cochran's Q- and I² tests. Eighteen articles (n = 24 867 participants) were entered our systematic review and meta-analysis.

RESULTS

We determined that Western dietary patterns (n = 8787 participants) containing high levels of processed food, red meat, high-fat dairy, and refined grains could significantly increase NAFLD (OR = 1.56, CI = 1.27 to 1.92; P ≤ 0.001). However, the Prudent (n = 13 023 participants) (OR = 0.78, CI = 0.71 to 0.85; P ≤ 0.001) and Mediterranean dietary patterns (n = 3057 participants) (OR = 0.77, CI = 0.60 to 0.98; P = 0.41), defined by high intake of fruits, vegetables, whole grains, fish, and olive oil decreased the risk of this disease.

CONCLUSIONS

We found that Western dietary patterns increased the risk of NAFLD by 56%, although the Prudent and Mediterranean dietary patterns reduced the risk of this disease by 22% and 23%, respectively.

Association of meat consumption with NAFLD risk and liver-related biochemical indexes in older Chinese: a cross-sectional study

Background

Non-alcohol fatty liver disease (NAFLD) is the most common liver disease and an unhealthy lifestyle can lead to an increased risk of NAFLD. The present study aims to evaluate the association of meat consumption with NAFLD risk and liver-related biochemical indexes in middle-aged and elderly Chinese.

Methods

A cross-sectional study was conducted in individuals who were 45 years or older and underwent a physical examination from April 2015 to August 2017 in Southeast China. To evaluate associations between meat intake and NAFLD risk, inverse probability of treatment weighting and subgroup analyses were performed with logistic regressions. Spearman’s rank correlation was carried out to examine the relationship between meat consumptions and liver-related biochemical indexes.

Results

High consumptions of red meat (28.44–49.74 and > 71.00 g/day) (OR_adjusted = 1.948; P < 0.001; OR_adjusted = 1.714; P = 0.002) was positively associated with NAFLD risk on inverse probability of treatment weighting analysis, adjusting for smoking, tea intake, weekly hours of physical activity and presence of hypertension, dyslipidemia and diabetes. Exposure–response relationship analysis presented that red meat intake was positively associated with NAFLD risk. Significant associations of red meat intakes with serum levels of γ-glutamyl transferase, alanine transaminase, aspartate aminotransferase, total triglyceride and high-density lipoprotein cholesterol were found (r_s = 0.176; P < 0.001; r_s = 0.128; P < 0.001; r_s = 0.060; P = 0.016; r_s = 0.085; P = 0.001; r_s = − 0.074; P = 0.003).

Conclusions

These findings suggest that the reduction of meat consumption may decrease NAFLD risk and should warrant further investigations.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12876-021-01688-7.

Plant-Based Foods and Their Bioactive Compounds on Fatty Liver Disease: Effects, Mechanisms, and Clinical Application

Fatty liver disease (FLD), including nonalcoholic fatty liver disease (NAFLD) and alcoholic fatty liver disease (AFLD), is a serious chronic metabolic disease that affects a wide range of people. Lipid accumulation accompanied by oxidative stress and inflammation in the liver is the most important pathogenesis of FLD. The plant-based, high-fiber, and low-fat diet has been recommended to manage FLD for a long time. This review discusses the current state of the art into the effects, mechanisms, and clinical application of plant-based foods in NAFLD and AFLD, with highlighting related molecular mechanisms. Epidemiological evidence revealed that the consumption of several plant-based foods was beneficial to alleviating FLD. Further experimental studies found out that fruits, spices, teas, coffee, and other plants, as well as their bioactive compounds, such as resveratrol, anthocyanin, curcumin, and tea polyphenols, could alleviate FLD by ameliorating hepatic steatosis, oxidative stress, inflammation, gut dysbiosis, and apoptosis, as well as regulating autophagy and ethanol metabolism. More importantly, clinical trials confirmed the beneficial effects of plant-based foods on patients with fatty liver. However, several issues need to be further studied especially the safety and effective doses of plant-based foods and their bioactive compounds. Overall, certain plant-based foods are promising natural sources of bioactive compounds to prevent and alleviate fatty liver disease.

Association between nutrient patterns and fatty liver index: Baseline survey of the Japan Multi-Institutional Collaborative Cohort Study in Tokushima, Japan

BACKGROUNDS

The fatty liver index (FLI) is a good non-invasive approach for fatty liver disease diagnosis. The objective of this study was to examine the associations of nutrient patterns with nonalcoholic fatty liver disease (NAFLD) in a Japanese population.

METHODS

A total of 1,588 subjects (789 men and 799 women) aged 35 to 69 years were recruited in the baseline survey of the Japan Multi-Institutional Collaborative Cohort (J-MICC) Study in Tokushima Prefecture. Factor analysis was applied to energy-adjusted intake of 21 nutrients, and nutrient patterns were extracted. Multiple logistic regression analysis was used to analyze the relationships between nutrient patterns and the high FLI category (≥60).

RESULTS

Four nutrient patterns were extracted: Factor 1, vitamins, dietary fiber, iron and potassium pattern; Factor 2, fats and fat-soluble vitamins pattern; Factor 3, saturated fat, calcium, vitamin B₂ and low carbohydrate pattern; and Factor 4, sodium, protein and vitamin D pattern. After adjustment for sex, age, and other potential confounding variables, higher Factor 1 scores were significantly associated with lower odds ratios of NAFLD (P for trend <0.05). Analysis of each component of FLI showed that there were significant inverse associations between Factor 1 scores and high body mass index and large waist circumference.

CONCLUSION

The present findings suggest that a nutrient pattern rich in vitamins, fiber, iron, and potassium was associated with lower prevalence of NAFLD in a Japanese population. Obesity and abdominal obesity may be intermediate variables for the association between this nutrient pattern and NAFLD.

Gender-specific association between non-alcoholic fatty liver disease and type 2 diabetes mellitus among a middle-aged and elderly Chinese population: An observational study

ABSTRACT

Limited data are available regarding the association of non-alcoholic fatty liver disease (NAFLD) with the risk of type 2 diabetes mellitus (T2DM) in China. Therefore, the purpose of this study is to evaluate the gender-specific association between NAFLD and T2DM risk in a middle-aged and elderly Chinese population.This cross-sectional study was carried out in a group of 1492 Chinese adults (60.30% males) aged between 45 and 69 years old, in Hangzhou city, Zhejiang province who were attending their annual health check-up from June 2015 to December 2016 in the Medical Center for Physical Examination, Zhejiang Hospital. Face-to-face interviews were conducted using a written questionnaire. NAFLD was divided into none, mild, moderate/severe based on ultrasound examination. Logistic regression analyses were employed to determine the relationship between NAFLD and the risk of T2DM, with adjustment of potential confounding variables.Of the 1492 participants, 163 (10.92%) were diagnosed with T2DM. Educational level, smoking, body mass index (BMI), waist circumference (WC), waist-hip ratio (WHR), systolic blood pressure (SBP), diastolic blood pressure (DBP), fasting glucose (FG), triglycerides (TG), alanine aminotransferase (ALT), asparagine aminotransferase (AST)and the prevalence of T2DM were significantly higher in males than in females (P < .05). Besides, females had significantly higher levels of high density lipoprotein-cholesterol (HDL-C) (1.51 ± 0.37 vs 1.29 ± 0.42, P < .001) than males. Pearson bivariate correlation analysis indicated that FG was positively associated with weight, BMI, WC, WHR, SBP, DBP, TG, TC, ALT and AST in both males and females (P < .05). Besides, FG was inversely associated with HDL-C in females (P < .001). After adjusting for confounding variables, NAFLD was positively associated with the risk of T2DM, and the effect of NAFLD on T2DM was stronger in males (OR = 2.442, 95%CI: 1.003-3.757) than in females (OR = 1.814, 95%CI: 1.011-3.257).Our data showed that NAFLD was significantly associated with the risk of T2DM in middle-aged and elderly males than in females. Further prospective cohort studies are needed to determine the causal effect of NAFLD on T2DM.

Complex Dietary Topologies in Non-alcoholic Fatty Liver Disease: A Network Science Analysis

Background and Aims: Previous studies have explored the associations between nutrition (food groups, nutrients, and dietary patterns) and the prevalence of non-alcoholic fatty liver disease. However, it remains unclear whether how foods are consumed together is associated with non-alcoholic fatty liver disease. The present study aims to construct dietary networks from network science and to explore the associations between complex dietary networks and non-alcoholic fatty liver disease. Methods: The present case-control study generated 2,043 multivariate matched controls for 2,043 newly diagnosed non-alcoholic fatty liver disease cases. Mutual information, which represents both linear and non-linear dependencies among food groups, was used to construct the network topologies. Results: The dietary topologies in the studied case and control groups were different despite the fact that only few food groups show differences in absolute intake. The dietary structure of the case group focused on two major components with more cohesion among food groups, while contrarily the control group had one major component with higher diversity of food groups. The dietary topology of the case group showed equality in connections among beneficial and detrimental food groups, whereas the control group focused more on healthier food choices. Conclusions: This study suggests how foods are consumed, besides the absolute intake, could be an important determinant of the occurrence of non-alcoholic fatty liver disease. A diverse diet that focuses on whole grain, tubers, and vegetables could yield beneficial effects regarding non-alcoholic fatty liver disease. Network science could offer a complementary tool in nutritional epidemiology.

Nonalcoholic Fatty Liver Disease in Adults: Current Concepts in Etiology, Outcomes, and Management

Nonalcoholic fatty liver disease (NAFLD) is a spectrum of disease, extending from simple steatosis to inflammation and fibrosis with a significant risk for the development of cirrhosis. It is highly prevalent and is associated with significant adverse outcomes both through liver-specific morbidity and mortality but, perhaps more important, through adverse cardiovascular and metabolic outcomes. It is closely associated with type 2 diabetes and obesity, and both of these conditions drive progressive disease toward the more advanced stages. The mechanisms that govern hepatic lipid accumulation and the predisposition to inflammation and fibrosis are still not fully understood but reflect a complex interplay between metabolic target tissues including adipose and skeletal muscle, and immune and inflammatory cells. The ability to make an accurate assessment of disease stage (that relates to clinical outcome) can also be challenging. While liver biopsy is still regarded as the gold-standard investigative tool, there is an extensive literature on the search for novel noninvasive biomarkers and imaging modalities that aim to accurately reflect the stage of underlying disease. Finally, although no therapies are currently licensed for the treatment of NAFLD, there are interventions that appear to have proven efficacy in randomized controlled trials as well as an extensive emerging therapeutic landscape of new agents that target many of the fundamental pathophysiological processes that drive NAFLD. It is highly likely that over the next few years, new treatments with a specific license for the treatment of NAFLD will become available.

Elevated serum levels of aminotransferases in relation to unhealthy foods intake: Tehran lipid and glucose study

BACKGROUND

Abnormal levels of liver enzymes, particularly aminotransferases, are prognostic features of non-alcoholic fatty liver disease (NAFLD). Considering the important role of dietary intakes in development of NAFLD, we aimed to determine possible association of unhealthy foods (fast foods, soft drinks, sweet and salty snacks) consumption with elevated levels of aminotransferases.

METHODS

This cross-sectional study was conducted within the framework of sixth phase of the Tehran Lipid and Glucose Study (2014-2017), on 187 adult men and 249 adult women (19-70 y). Usual intakes of unhealthy foods (kcal/week) were measured using a validated semi-quantitative 147-items food frequency questionnaire. Serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST) were measured. Multivariable logistic regression models were used to estimate the odds of elevated aminotransferases in each tertile of energy-dense unhealthy foods.

RESULTS

Mean age of participants was 44.44 ± 15.09 years, 43% of participants were men. Higher consumption of fast foods (> 11.39% kcal/week) was associated with elevated ALT to AST ratio (OR: 3.27; 95% CI: 1.90-5.63) and elevated ALT (OR: 2.74; 95% CI: 1.57-4.76). Also, each 1 SD increased energy intakes from fast foods was related to increased chance of having elevated ALT and ALT to AST ratio by 35% (OR: 1.35; 95% CI: 1.08-1.68, OR: 1.35; 95% CI: 1.10-1.66, respectively). There was no significant association between consumption of soft drinks, sweet or salty snacks and elevated aminotransferases.

CONCLUSIONS

Higher intakes of energy from fast foods seems to be associated with an elevated serum levels of ALT and ALT to AST ratio, as indicators of development of NAFLD.

Association between Different Animal Protein Sources and Liver Status in Obese Subjects with Non-Alcoholic Fatty Liver Disease: Fatty Liver in Obesity (FLiO) Study

Non-alcoholic fatty liver disease (NAFLD) is considered the hepatic manifestation of metabolic syndrome. Obesity and unhealthy dietary habits are described as risk factors for NAFLD. The aim of this study was to investigate the association between the consumption of different animal protein sources and hepatic status in NAFLD adults. A total of 112 overweight/obese participants with NAFLD from Fatty Liver in Obesity (FLiO) study were evaluated at baseline. Diet, body composition, and biochemical variables were evaluated. Hepatic status was also assessed by Magnetic Resonance Imaging, ultrasonography, and elastography. Red meat consumption showed a positive relationship with liver iron content (r = 0.224; p = 0.021) and ferritin concentration (r = 0.196; p = 0.037). Processed meat consumption exhibited a positive association with liver iron content (r = 0.308; p = 0.001), which was also found in the quantile regression (β = 0.079; p = 0.028). Fish consumption was related with lower concentration of ferritin (r = -0.200; p = 0.034). This association was further evidenced in the regression model (β = -0.720; p = 0.033). These findings suggest that the consumption of different animal protein sources differentially impact on liver status in obese subjects with NAFLD, showing fish consumption as a healthier alternative for towards NAFLD features.

Intermediary effect of inflammation on the association between dietary patterns and non-alcoholic fatty liver disease

OBJECTIVE

Previous studies have demonstrated that nutritional status is associated with non-alcoholic fatty liver disease (NAFLD). Meanwhile, subclinical inflammation is associated with the prevalence of NAFLD. To our knowledge, however, no study has investigated the intermediary effect of inflammation on the association between dietary pattern and NAFLD. Thus, the aim of this case-control study was to explore the intermediary effect of inflammation on the association between dietary patterns and NAFLD.

METHODS

Using the propensity score matching method, we generated 2043 cases and 2043 controls. Dietary intake was assessed using a valid self-administered food frequency questionnaire. Major dietary patterns in the population were derived by factor analysis. Reduced rank regression with leukocyte count as a response variable was used to derive an inflammatory pattern. NAFLD was diagnosed by liver ultrasonography and drinking history. The association between dietary patterns and NAFLD was tested using multiple conditional logistic regression analysis.

RESULTS

Three major dietary patterns were derived by factor analysis: sweet pattern, animal foods pattern, and traditional pattern. Compared with participants in the lowest quartile of the animal foods pattern, the odds ratio (OR; 95% confidence interval [CI]) of NAFLD in the highest quartile was 1.30 (95% CI, 1.09-1.55). After adjustment of inflammation status, the OR was weaker (OR, 1.23; 95% CI, 1.03-1.48), albeit significant. Compared with the participants in the lowest quartile of inflammatory pattern, the OR of NAFLD in the highest quartile was 1.52 (95% CI, 1.28-1.81).

CONCLUSION

The present data suggested that inflammation may mediate the association between dietary patterns and NAFLD.

Consumption of Sugar-Sweetened Beverages Has a Dose-Dependent Effect on the Risk of Non-Alcoholic Fatty Liver Disease: An Updated Systematic Review and Dose-Response Meta-Analysis

Background: Non-alcoholic fatty liver disease (NAFLD) is a serious health problem, but the dose-response relationship between sugar-sweetened beverages (SSBs) and NAFLD remains uncertain. Methods: A systematic review and dose-response meta-analysis were conducted following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Review Manager 5.3 and Stata 14.0 were used to combine trials and analyze data. The dose-response meta-analysis was performed by non-linear trend regression. Results: Twelve studies recruiting a total of 35,705 participants were included. The results showed that the consumption of SSBs was associated with 1.39-fold increased odds of NAFLD (95% CI: 1.29–1.50, p < 0.00001). The risk of NAFLD rose with an increased consumption of SSBs, while the consumptions of low doses (<1 cup/week), middle doses (1–6 cups/week) and high doses (≥7 cups/week) of SSBs increased the relative risk of NAFLD by 14%, 26% and 53%, respectively (p = 0.01, p < 0.00001, p = 0.03, respectively). Conclusions: This study demonstrates that consumers of SSBs are at significantly increased risk of NAFLD, and the consumption of SSBs has a dose-dependent effect on the risk of NAFLD. The findings of this study strengthen the evidence base for healthy dietary patterns and are meaningful for the primary prevention of NAFLD.

Childhood and Adolescent Nonalcoholic Fatty Liver Disease: Is It Different from Adults?

Paediatric nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease in childhood and adolescence. Although the condition is similar in many ways to NAFLD in adults, there are important differences in predisposition, presentation, differential diagnosis and potentially also in optimal management. Antenatal and early childhood exposures and the particular vulnerabilities to environmental influences in a growing child, present unique opportunities for intervention and modification of risk. The prevalence of significant fibrosis on biopsy in preadolescent children in the context of NAFLD should not be ignored, but the relevance of this fibrosis to long-term outcome is as yet unknown. The approach to children and adolescents with suspected NAFLD needs to include an assessment of risk factors in addition to exclusion of alternative or coexisting liver diseases. Liver biopsy is indicated for younger children and for those without clear predisposing factors leading to metabolic syndrome, also for those in whom significant fibrosis is suspected. The histology in children and adolescents differs from adults in whom type 2 NAFLD may be more prevalent, which is associated in turn with more significant fibrosis. Management in children and adolescents needs to focus on lifestyle intervention, which when weight loss is achieved, demonstrates excellent results in terms of resolution of disease. Appropriate intervention in childhood and adolescence may prove instrumental in avoiding the need for later transplantation while also decreasing all-cause mortality in these at-risk individuals.