Sodium in relation with nonalcoholic fatty liver disease: A systematic review and meta-analysis of observational studies

Association between processed and unprocessed red meat consumption and risk of nonalcoholic fatty liver disease: A systematic review and dose-response meta-analysis

Background

The nature of the relationship between red meat consumption and nonalcoholic fatty liver disease (NAFLD) remains unclear. Through this meta-analysis, we aimed to determine the association and dose-response relationship between red meat consumption (both processed and unprocessed) and the risk of NAFLD.

Methods

We systematically searched CENTRAL, PubMed, Embase, Web of Science and Scopus from inception to February 2022 for observational studies in which the exposure of interest was red meat consumption; the outcome of interest was the risk of NAFLD; and where odds ratios (ORs) or risk ratios were provided or could be calculated. We used random-effects meta-analyses to pool the effect sizes and performed analyses to estimate the linearity of the dose-response relationships between red meat intake and NAFLD risk.

Results

We included 10 studies in this review. The meta-analysis showed a significant association between the intake of red meat (OR = 1.27; 95% confidence interval (CI) = 1.07-1.50, P = 0.000, I2 = 81%), processed red meat (OR = 1.20; 95% CI = 1.04-1.3, P = 0.162, I2 = 34.9%) or unprocessed red meat (OR = 1.28; 95% CI = 1.05-1.55, P = 0.001, I2 = 76.2%) and the risk of NAFLD. We also found a significant linear dose-response association between processed red meat intake and NAFLD, with each 25-g increment of processed red meat intake per day was associated with an 11.1% higher risk of NAFLD (OR = 1.11; 95% CI = 1.01-1.22, P = 0.029), and a nonlinear association between unprocessed meat intake and NAFLD (P = 0.003 for nonlinearity).

Conclusions

Our findings indicate a potential positive association between red meat consumption (both processed and unprocessed) and NAFLD risk, especially in relation to increased intake of processed red meat compared to unprocessed red meat. However, caution is advised in interpreting these results; further research could establish a clearer understanding of the relationship between red meat consumption and NAFLD risk.

Registration

PROSPERO: CRD42022332839.

Dietary patterns and metabolic dysfunction-associated fatty liver disease in China's multi-ethnic regions

BACKGROUND

The prevalence of metabolic dysfunction-associated fatty liver disease (MAFLD) has been rising rapidly in western China. Diet acts as an effective therapy for MAFLD. However, there has been scarce research on the association between a posteriori diet patterns (DPs) and MAFLD in this region.

METHOD

We identified three a posteriori DPs which were "Sichuan Basin pattern" characterized by a high intake of fish/seafood, poultry, fresh fruit and vegetables, indicating a balanced and modern DP; the "Yunnan-Guizhou Plateau dietary pattern" characterized mainly by a high intake of animal oil and salt, indicating an agricultural and poor DP; and the "Qinghai-Tibet Plateau dietary pattern" characterized by a high intake of coarse grains, wheat products, tubers and tea, respectively, indicating a high-altitude DP. Then, we performed marginal structural models that combined logistic regression and inverse probability exposure weighting (IPEW) to examine the associations between MAFLD and these a posteriori DPs.

RESULT

We found the "Yunnan-Guizhou Plateau dietary pattern" revealed stronger positive association (OR = 1.50, 95% CI 1.40-1.60) with MAFLD than that of the "Qinghai-Tibet Plateau dietary pattern" (OR = 1.21, 95% CI 1.14-1.30). In contrast, the "Sichuan Basin dietary pattern" showed no significant association with MAFLD. In the further stratified analysis, we found those above associations were stronger in ethnic minorities and rural residents than their counterparts.

CONCLUSION

Our study implied the unfavourable effects of "Yunnan-Guizhou Plateau dietary pattern" on MAFLD and provided evidence that reducing the intake of oil and sodium may be optimal for MAFLD control in the multi-ethnic region in western China.

Relationship between diet quality and nonalcoholic fatty liver disease predictor indices in Iranian patients with metabolic syndrome: A cross-sectional study

The present study aimed to assess the association between diet quality and nonalcoholic fatty liver disease (NAFLD) predictor indices in patients with metabolic syndrome (MetS). This cross-sectional study was carried out among 344 adult patients with MetS. The diet quality of patients was calculated by Healthy Eating Index-2015 (HEI-2015). NAFLD predictor indices (Hepatic Steatosis Index [HSI], Triglyceride-Glucose Index [TyG], and Fatty Liver Index [FLI]) were calculated and compared according to the HEI-2015 quartiles. The relationship between the HEI-2015 score and HSI, FLI, and TyG Index was estimated using multiple linear regression analysis. The findings of the present study revealed that patients with the highest HEI score had the lowest FLI score (p = .003) and HSI score (p = .05). There was an inverse relationship between the HEI-2015 score and FLI (β = -0.49; p < .001), HSI (β = -0.05; p = .25), and TyG Index (β = -0.002; p = .34). According to our result, after adjusting for possible confounding factors, there was a statistically significant inverse association between HEI-2015 and FLI.

Ultra-Processed Food Intake Is Associated with Non-Alcoholic Fatty Liver Disease in Adults: A Systematic Review and Meta-Analysis

Non-alcoholic fatty liver disease (NAFLD) is associated with overweight/obesity, metabolic syndrome and type 2 diabetes (T2D) due to chronic caloric excess and physical inactivity. Previous meta-analyses have confirmed associations between ultra-processed food (UPF) intake and obesity and T2D. We aim to ascertain the contribution of UPF consumption to the risk of developing NAFLD. We performed a systematic review and meta-analysis (PROSPERO (CRD42022368763)). All records registered on Ovid Medline and Web of Science were searched from inception until December 2022. Studies that assessed UPF consumption in adults, determined according to the NOVA food classification system, and that reported NAFLD determined by surrogate (steatosis) scores, imaging or liver biopsy were included. The association between UPF consumption and NAFLD was assessed using random-effects meta-analysis methods. Study quality was assessed, and evidence credibility evaluated, using the Newcastle Ottawa Scale and NutriGrade systems, respectively. A total of 5454 records were screened, and 112 records underwent full text review. From these, 9 studies (3 cross-sectional, 3 case-control and 3 cohort), analysing 60,961 individuals, were included in the current review. Both moderate (vs. low) (pooled relative risk 1.03 (1.00-1.07) (p = 0.04) (I² = 0%)) and high (vs. low) (1.42 (1.16-1.75) (<0.01) (I² = 89%)) intake of UPF significantly increased the risk of NAFLD. Funnel plots demonstrate low risk of publication bias. Consumption of UPF is associated with NAFLD with a dose-response effect. Public health measures to reduce overconsumption of UPF are imperative to reduce the burden of NAFLD, and the related conditions, obesity and T2D.

Dietary selenium intake in relation to non-alcoholic fatty liver disease assessed by fatty liver index and hepatic steatosis index; a cross-sectional study on the baseline data of prospective PERSIAN Kavar cohort study

BACKGROUND

There is limited and conflicting evidence on the association between selenium and non-alcoholic fatty liver disease (NAFLD). Therefore, the present population-based cross-sectional study aimed to explore the relationship between dietary selenium intake and the risk of NAFLD.

METHODS

A total of 3026 subjects from the PERSIAN (Prospective Epidemiological Research Studies in IrAN) Kavar cohort study were included in the analysis. The daily selenium intake was evaluated using a semi-quantitative food frequency questionnaire, and energy-adjusted quintiles of selenium intake (µg/day) were calculated. NAFLD was defined as the fatty liver index (FLI) ≥ 60 or the hepatic steatosis index (HSI) > 36. The association between dietary selenium intake and NAFLD was evaluated using logistic regression analysis.

RESULTS

The prevalence rates of NAFLD were 56.4% and 51.9%, based on the FLI and HSI markers, respectively. The odds ratios (ORs) for FLI-defined NAFLD were 1.31 (95% confidence interval (CI): 1.01-1.70) and 1.50 (95% CI: 1.13-1.99) for the fourth and fifth quintiles of selenium intake, respectively, after adjustment for sociodemographic variables, smoking status, alcohol drinking, physical activity, and dietary factors (P trend = 0.002). There was also a similar association between selenium intakes and HSI-defined NAFLD (OR = 1.34 (95% CI: 1.03-1.75) for the fourth quintile and OR = 1.50 (95% CI: 1.12-2.01) for the fifth quintile of selenium intake) (P trend = 0.006).

CONCLUSION

In this large sample study, we observed a weak positive association between dietary selenium intake and NAFLD risk.

Dietary Sodium and Nonalcoholic Fatty Liver Disease: A Systematic Review

(1) Introduction: Restriction in sodium intake is an important strategy for reducing cardiovascular morbidity and mortality, considering the direct influence of high-sodium diet consumption on the development of hypertension and cardiovascular diseases. There are only a few studies dealing with the influence of dietary sodium on the development of nonalcoholic fatty liver disease (NAFLD). In this systematic review, evidence in humans and animal models was compiled in a critical view of the influence of dietary sodium intake patterns on NAFLD markers; (2) Methods: Systematic review of PubMed data. Clinical outcomes included the prevalence/incidence of NAFLD for human studies, and NAFLD markers (hepatic lipogenesis, and markers of steatosis, fibrosis, and inflammation) for animal studies. The protocol was registered at the International Prospective Register of Systematic Review (PROSPERO; CRD42023390447); (3) Results and Conclusion: Seven studies in humans and eight in animals were included. All studies in humans were observational and associated high-sodium intake with NAFLD. However, in animals, both the increased and reduced consumption of sodium negatively influenced markers of liver steatosis, inflammation, and fibrosis.

The effect of DASH diet on glycemic response, meta-inflammation and serum LPS in obese patients with NAFLD: a double-blind controlled randomized clinical trial

BACKGROUND

As dietary approaches to stop hypertension (DASH) dietary pattern has been shown to be effective in hypertension and obesity, the present study investigated the effects of following DASH diet on glycemic, meta-inflammation, lipopolysaccharides (LPS) and liver function in obese patients with non-alcoholic fatty liver disease (NAFLD).

METHODS

In this double-blind controlled randomized clinical trial, 40 obese patients with NAFLD were randomly allocated into either "DASH diet" (n = 20) or calorie-restricted diet as "Control" (n = 20) group for 8 weeks. Anthropometric measures, blood pressure, glycemic response, liver enzymes, toll-like reseptor-4 (TLR-4) and monocyte chemoattractant protein (MCP-1) and LPS as well as Dixon's DASH diet index were assessed at baseline and after 8 weeks.

RESULTS

After 8 weeks, although all obesity indices decreased significantly in both groups, the reduction in all anthropometric measures were significantly greater in DASH vs control group, after adjusting for baseline values and weight change. Fasting glucose level decreased in both group, however, no inter-group significant difference was found at the end of study. Nevertheless, serum levels of hemoglobin A1c (HbA1c), TLR-4, MCP-1 and LPS as well as aspartate aminotransferase (AST) decreased significantly in DASH group, after adjusting for baseline values and weight change (p < 0.001, p = 0.004, p = 0.027, p = 0.011, and p = 0.008, respectively). The estimated number needed to treats (NNTs) for one and two grade reductions in NAFLD severity following DASH diet were 2.5 and 6.67, respectively.

CONCLUSION

Adherence to DASH diet could significantly improve weight, glycemia, inflammation and liver function in obese patients with NAFLD.

The obesity and nonalcoholic fatty liver disease mouse model revisited: Liver oxidative stress, hepatocyte apoptosis, and proliferation

The study revisited the diet-induced obesity (DIO) mice and the nonalcoholic fatty liver disease (NAFLD) pathogenesis to serve as a translational model. Hepatic beta-oxidation pathways, lipogenesis, oxidative stress, hepatocyte apoptosis, and proliferation were investigated in obese mice. Three-month-old male mice were divided according to their diet for fifteen weeks, the control diet (C group, containing 10% energy from fat) and the high-fat diet (HF group, containing 50% energy from fat). Body weight (BW), liver mass, and steatosis were higher in the HF group than in the C group. Also, gene expression related to beta-oxidation and lipogenesis showed an adverse profile, and insulin and glucose signaling pathways were impaired in the HF group compared to the C group. As a result, steatosis was prevalent in the HF group but not in the C group. Furthermore, the pathways that generate NAFLD were negatively modulated by oxidative stress in the HF animals than in the C ones. The caspase 3 immunolabeled HF hepatocytes with increased gene and protein expressions related to apoptosis while proliferating cell nuclear antigen labeled C hepatocytes. In conclusion, the findings in the DIO mouse model reproduce the NAFLD profile relative to the human NAFLD's apoptosis, insulin signaling, lipogenesis, beta-oxidation, and oxidative stress. Therefore, the model is adequate for a translational perspective's morphological, biochemical, and molecular research on NAFLD.

Alleviation of Metabolic Disturbance by Substituting Kanjang High in Bacillus for Salt through Modulation of Gut Microbiota in Estrogen-Deficient Rats

A high salt intake may exacerbate menopausal symptoms and substituting for different types of traditionally made kanjang (TMK; soy sauce) may prevent it. This study examined whether substituting salt with lyophilized TMK containing low and high Bacillus and biogenic amines in a high-fat diet might modulate the menopausal symptoms and the energy, glucose, and lipid metabolism in ovariectomized (OVX) rats. They were categorized into salt (Control), TMK with high Bacillus and low biogenic amines (HBLB), TMK with high Bacillus and high biogenic amines (HBHB), TMK with low Bacillus and low biogenic amines (LBLB), and TMK with low Bacillus and high biogenic amines (LBHB). Sham-operated rats consumed the same diet as the Control. HBLB, HBHB, and LBHB prevented increased tail skin temperature compared to the Control. HBHB and HBLB partially inhibited the increased weight gain and abdominal fat mass by reducing the food efficiency without changing the serum 17β-estradiol concentrations. Serum glucose and insulin concentrations and the insulin resistance index by the homeostatic model assessment for insulin resistance showed a positive association for weight gain. HBLB and HBHB decreased the serum malondialdehyde and tumor-necrosis factor-α levels. Hepatic triglyceride storage was lower in all TMK groups than in the Control, while hepatic glycogen accumulation was higher in the HBLB, HBHB, and LBHB groups than in the Control and LBLB groups. Accordingly, the mRNA expression of peroxisome proliferator-activated receptors-γ(PPAR-γ) was higher in the HBLB and HBHB groups compared to the Control, and that of fatty acid synthase was opposite to PPAR-γ expression. However, HBLB and HBHB improved dyslipidemia and insulin resistance compared to the Control, but their improvement did not reach that of the Normal-control. The acetic acid concentrations in the portal vein were lower in the LBLB than in the Control, while the butyric acid contents were higher in the LBHB and HBLB groups than in the Control. HBHB, HBLB, and LBHB elevated Akkermansia and Lactobacillus, and HBLB and LBLB increased Bacteroides and Ruminococcus compared to the Control. Polycyclic aromatic hydrocarbon degradation, bile acid synthesis, and unsaturated fatty acid biosynthesis were significantly higher in the HBLB group than in the Control group. In conclusion, substituting salts to TMK with a high Bacillus content regardless of the bioamine contents partially improved the menopausal symptoms and metabolic disturbance in estrogen-deficient animals.