Daily tea drinking is not associated with newly diagnosed non-alcoholic fatty liver disease in Chinese adults: the Tianjin chronic low-grade systemic inflammation and health cohort study

Relationship of tea consumption with hepatic steatosis and fibrosis: findings from a longitudinal RaNCD cohort

BACKGROUND

Tea, known for its high content of antioxidants and anti-inflammatory compounds such as catechins, is believed to support liver health. This study aimed to explore the relationship between tea consumption and hepatic steatosis and fibrosis.

METHODS

This longitudinal study involved 2,537 participants from the Ravanser Non-Communicable Disease (RaNCD) cohort, conducted from 2015 to 2023. Dietary intake was evaluated using a 118-item food frequency questionnaire (FFQ). The Fibrosis-4 (FIB-4) index and the Hepatic Steatosis Index (HSI) were utilized as predictive indicators for hepatic fibrosis and steatosis, respectively.

RESULTS

After adjusting for potential confounding factors, our findings indicated that tea consumption was not significantly associated with an increased risk of worsening hepatic steatosis or fibrosis (P-value > 0.05). However, participants who consumed more than 2.88 cups of tea per day had a 27% lower likelihood of experiencing improvement in hepatic steatosis compared to those who consumed less than 1.92 cups per day (Relative Risk: 0.73; 95% CI: 0.53-0.99; P-value: 0.046).

CONCLUSION

Our study suggests that higher tea consumption is not significantly linked to an elevated risk of worsening hepatic steatosis or fibrosis. However, it is noteworthy that individuals who consumed more tea were less likely to see improvements in hepatic steatosis. This finding highlights the need for further research to better understand the potential effects of tea on liver health.

Tea intake and non-alcoholic fatty liver disease risk: A two-sample Mendelian randomization study

Background

Non-alcoholic fatty liver disease (NAFLD) is a major global health problem due to its great disease and economic burdens. Tea is a popular beverage consumed by billions of people.globally owing to its health benefits. However, the evidence regarding the association between tea intake and NAFLD risk is inconsistent.

Objective

To examine the genetically predicted causal association between tea intake and NAFLD risk using the two-sample Mendelian randomization (MR) method.

Methods

Single-nucleotide polymorphisms (SNPs) strongly associated with tea intake were obtained from a large dataset (N = 447,485) in the UK biobank, and summary-level genetic data for NAFLD (2,275 cases and 375,002 controls) were collected from the FinnGen consortium. The two-sample MR method was used to investigate the causal association between tea intake and NAFLD risk. The random-effects inverse-variance weighted (IVW) was used as the primary approach for estimating the causal effect, and MR Egger, weighted median, simple mode, and weighted mode were used to verify the robustness of the primary results.

Results

Twenty-four valid SNPs were selected as the instrumental variables for tea intake. The IVW results indicated that tea intake was not causally associated with NAFLD risk (Odds ratio: 1.48; 95 % confidence interval: 0.64, 3.43; p = 0.364); moreover, the results from other methods were consistent with this finding. A leave-one-out analysis further demonstrated the robustness of our results. No evidence of heterogeneity, outliers, or horizontal pleiotropy was found.

Conclusion

Our results do not support tea intake being causally associated with a decreased risk of NAFLD.

Diagnostic indicators and lifestyle interventions of metabolic-associated fatty liver disease

MAFLD has become a major global health problem and is the leading cause of liver disease worldwide. The disease progresses from a simple fatty liver to gradual fibrosis, which progresses to cirrhosis and even hepatocellular liver cancer. However, the methods currently used for diagnosis are invasive and do not facilitate clinical assessment of the condition. As a result, research on markers for the diagnosis of MAFLD is increasing. In addition, there are no clinical medications for the treatment of MAFLD, and lifestyle interventions remain effective in the prevention and treatment of MAFLD. In this review, we attempt to make a summary of the emerging diagnostic indicators and effective lifestyle interventions for MAFLD and to provide new insights into the diagnosis and treatment of MAFLD.

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.

Green tea intake and the risk of hypertension in premenopausal women: the TCLSIH cohort study

Background and aims: Tea polyphenols, such as green tea polyphenols, have been extensively studied as agents that ameliorate cardiovascular disease and blood pressure in vitro and in animal studies. However, epidemiological evidence for the association of green tea consumption with hypertension (HTN) is inconsistent. In addition, such an association has not been prospectively examined in the general adult population, particularly among young women. Therefore, we designed a cohort study to examine whether green tea consumption increases the risk of HTN in premenopausal women. Methods and results: This prospective cohort study investigated 6633 premenopausal female participants without hypertension, cardiovascular disease, and cancer at the baseline. Green tea consumption was measured at the baseline using a validated food frequency questionnaire. Hypertension was confirmed with the SBP ≥140 mm Hg^-1 or with the DBP ≥90 mm Hg^-1. Cox proportional hazards regression models were used to examine the association of green tea consumption with incident hypertension. A total of 488 first incident cases of hypertension occurred during 24 957 person-years of follow-up (median follow-up of 4.0 years). After adjustment for potential confounding variables, the multivariable hazard ratios (95% confidence intervals) for incident hypertension in premenopausal female participants with different green tea consumption frequencies were 1.00 (reference) for almost never, 0.84 (0.67, 1.07) for 1 cup per week, 1.02 (0.77, 1.35) for 2-6 cups per week, and 0.65 (0.44, 0.96) for ≥1 cup per day. Conclusions: The results from our prospective study indicate that the consumption of green tea is associated with a reduced risk of HTN in premenopausal women.

Regulatory Effects and Molecular Mechanisms of Tea and Its Active Compounds on Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD), the most common chronic liver disease, is a multifactorial disease resulting from the interaction between environment, genetic background, and metabolic stress. Most treatments for NAFLD include dietary intervention and exercise show limited efficacy due to the complex mechanisms involved in NAFLD. Meanwhile, drug therapy is accompanied by serious side effects. The development of high-efficiency natural supplements is a sustainable strategy for the prevention and treatment of NAFLD. As the second most consumed beverage, tea has health benefits that have been widely recognized. Nevertheless, the intervention of tea active compounds in NAFLD has received limited attention. Tea contains abundant bioactive compounds with potential effects on NAFLD, such as catechins, flavonoids, theanine, tea pigments, and tea polysaccharides. We reviewed the intrinsic and environmental factors and pathogenic mechanisms that affect the occurrence and development of NAFLD, and summarized the influences of exercise, drugs, diet, and tea drinking on NAFLD. On this basis, we further analyzed the potential effects and molecular regulatory mechanisms of tea active compounds on NAFLD and proposed future development directions. This review hopes to provide novel insights into the development and application of tea active compounds in the prevention and treatment of NAFLD.

Inflammatory potential of diet and risk of nonalcoholic fatty liver disease: a prospective cohort study

BACKGROUND/OBJECTIVES

Diet is an important factor that can exacerbate or ameliorate chronic inflammation, which has been implicated in the pathogenesis of nonalcoholic fatty liver disease (NAFLD). However, no prospective study has yet investigated the relation between the inflammatory potential of diet and NAFLD. The aim of this study was to investigate the association between the inflammatory potential of the diet and the risk of NAFLD.

SUBJECT/METHODS

The study included 12,877 participants aged over 18 years (mean [standard deviation]: 39.4 [11.5] years). Dietary intake was assessed at baseline through food frequency questionnaires. Using white blood cell count as the inflammatory marker, we newly created a dietary inflammatory potential score by reduced rank regression and stepwise linear regression. NAFLD was identified by abdominal ultrasound during yearly health checkups. Cox proportional hazards regression models were used to estimate the association between the dietary inflammatory potential score and the risk of NAFLD.

RESULTS

During a median follow-up period of 4.2 years, 2744 first incident cases of NAFLD occurred. After adjustment for potential confounders, the multivariable hazards ratios (95% confidence intervals) for NAFLD across increasing quartiles of the dietary inflammatory potential score were 1.00 (reference), 1.01 (0.90, 1.13), 1.15 (1.03, 1.29), and 1.26 (1.13, 1.41), with P for trend <0.0001. This positive association appeared greater in men than in women (P for interaction = 0.02).

CONCLUSIONS

Our results indicate that a dietary pattern with high inflammatory potential is associated with a higher risk of NAFLD. Such findings provide the support that inflammation may be a potential mechanism linking diet to the risk of NAFLD.

Functional beverages improve insulin resistance and hepatic steatosis modulating lysophospholipids in diet-induced obese rats

Hypercaloric beverages increase the prevalence of insulin resistance and nonalcoholic fatty liver disease (NAFLD), diets with polyphenolic compounds improved these alterations. The study aimed to evaluate the effect of the consumption of three functional beverages (prepared with: Roselle, green tea, cinnamon, Malabar tamarind, and peppermint in different proportions) on insulin resistance and NAFLD and their relation to liver phospholipid regulation in Wistar rats fed with a high-fat and fructose (HFF) diet. The consumption of beverages showed lower liver triglycerides compared to HFF control group, being the called beverage B the successful triggering up to 30.1%. The consumption of functional beverages improved insulin resistance and decreased the abundance of LysoPC (20:2), LysoPC (16:0), LysoPC (14:0), LysoPE (18:0), LysoPC (15:0), and LysoPC (20:1), with beverage C being the one with the meaningful effect. The results indicate that the functional beverage consumption improves insulin resistance, and decrease the degree of NAFLD, these through modifications of lysophosphatidylcholines, and lipids metabolism.

Mixtures of Tea and Citrus maxima (pomelo) Alleviate Lipid Deposition in HepG2 Cells Through the AMPK/ACC Signaling Pathway

Tea and citrus maxima are natural, medicinal homologous plants, typically used for making beverages, which have anticancer, antiobesity, and antioxidation properties. Green tea, yellow tea, and black tea were combined with citrus maxima to obtain green tea and Citrus maxima (GTCM), yellow tea and Citrus maxima (YTCM), and black tea and Citrus maxima (BTCM). The biochemical components of these mixtures were analyzed, and their possible effects and mechanisms on relieving liver lipid deposition were explored. The tea polyphenols, free amino acids, phenolamine ratio, and caffeine were comparable in YTCM and GTCM, being significantly higher than those in BTCM. In addition, the content of esterified catechins, nonesterified catechins, and total catechins in YTCM was significantly higher than those in GTCM and BTCM. All three mixtures of Citrus maxima tea significantly reduced lipid deposition in HepG2 cells, with GTCM and YTCM being slightly more effective than BTCM. Regarding the possible mechanism, Western blot analysis revealed that the three Citrus maxima tea mixtures could activate the AMPK/ACC signaling pathway, upregulate the expression of p-AMPK, p-ACC, and CPT-1 proteins, and downregulate the expression of SREBP1c and fatty acid synthase proteins to inhibit fat synthesis, thereby relieving lipid deposition in liver cells. In conclusion, as a novel and healthy beverage, Citrus maxima tea has the potential to alleviate liver lipid deposition, and further could be responsible for obesity treatment.