The Association between Nuts Intake and Non-Alcoholic Fatty Liver Disease (NAFLD) Risk: a Case-Control Study

Dietary composition and its association with metabolic dysfunction-associated fatty liver disease among Chinese adults: A cross-sectional study

BACKGROUND AND STUDY AIMS

Metabolic dysfunction-associated fatty liver disease (MAFLD) has become the most common cause of chronic liver disease worldwide. Diet plays a critical role in the prevention and treatment of MAFLD. Our hypothesis was that the intake of some macronutrients, vitamins, or mineral elements is associated with MAFLD.

PATIENTS AND METHODS

Patients with MAFLD can be diagnosed based on the evidence of hepatic steatosis and if they meet any of the three additional criteria of overweight/obesity, diabetes mellitus, or metabolic dysregulation. Diets were recorded using photographs and diaries of meals for seven consecutive days. The consumed dietary composition was compared with the recommended intake according to the China Food Composition Tables (Standard Edition) version 2019 and the Chinese Dietary Reference Intakes version 2013, and its association with MAFLD was assessed by logistical regression analyses.

RESULTS

A total of 229 MAFLD patients and 148 healthy controls were included in this study. MAFLD patients, compared with that by non-MAFLD participants, consumed more polyunsaturated fatty acids (PUFAs) (p < 0.001), vitamin E (p < 0.001), and iron (p = 0.008). The intake of PUFAs (OR = 1.070, 95 % CI: 1.017-1.127, p = 0.009) and vitamin E (OR = 1.100, 95 % CI: 1.018-1.190, p = 0.016) was positively associated with MAFLD. In addition, the percentages of individuals who consumed PUFAs (p = 0.006), vitamin E (p < 0.001), or iron (p = 0.046) above the recommended intake were higher among the individuals with MAFLD. Daily intake of PUFAs > 11 % (OR = 2.328, 95 % CI: 1.290-4.201, p = 0.005) and vitamin E > 14 mg (OR = 2.189, 95 % CI: 1.153-4.158, p = 0.017) was positively correlated with MAFLD.

CONCLUSIONS

Patients with MAFLD consumed more PUFAs, vitamin E, and iron in their daily diet. Excessive consumption of PUFAs and vitamin E might be independent risk factors for the incidence of MAFLD.

Effect of Nut Consumption on Nonalcoholic Fatty Liver Disease: A Systematic Review and Meta-Analysis

Although previous epidemiological studies have been conducted to investigate the relationship between nut consumption and the risk of nonalcoholic fatty liver disease (NAFLD), the evidence remains inconclusive and contentious. The aim of our study was to further conduct a meta-analysis of observational studies to explore the latest evidence of the influence of nut consumption on NAFLD. This meta-analysis included a comprehensive search of all articles published in the PubMed and Web of Science online databases as of April 2023. A total of 11 articles were included, comprising 2 prospective cohort studies, 3 cross-sectional studies, and 7 case-control studies, and a random effects model was used to evaluate the relationship between nuts and NAFLD. Results showed that the odds ratio (OR) of NAFLD was 0.90 (95% CI: 0.81-0.99, p < 0.001) when comparing the highest and lowest total nut intake, indicating a significant negative correlation. Furthermore, subgroup analysis revealed that the protective effect of nuts on NAFLD was more significant in females (OR = 0.88; 95% CI: 0.78-0.98, I² = 76.2%). In summary, our findings provide support for a protective relationship between nut intake and risk of NAFLD. Further exploration of the association between other dietary components and NAFLD is an important avenue for future research.

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.

Intrahepatic Fat Content and COVID-19 Lockdown in Adults with NAFLD and Metabolic Syndrome

Background: COVID-19 lockdowns had a significant impact on people’s health, triggering levels of anxiety, perceived stress, and changes in food and nutritional status. Objectives: To assess the changes in dietary habits, metabolic syndrome (MetS) and liver parameters before and after the COVID-19 lockdown according to changes in intrahepatic fat content in adults with non-alcoholic fatty liver disease (NAFLD) and MetS. Design: Pre- and post-lockdown observation of the COVID-19 lockdown on fifty-nine 40–60-year-old participants with MetS and NAFLD, in a parallel group, randomised experiment intended to treat NAFLD. Methods: Anthropometrics, liver and MetS biochemical parameters, intrahepatic fat content by abdominal magnetic resonance imaging, and dietary assessment using a validated 148-item Food Frequency Questionnaire were collected pre-COVID-19 lockdown and post-lockdown. Results: COVID-19 lockdown led to negative changes in the liver of patients with NAFLD and MetS, with weight gain and increases in glycemia, ALT and intrahepatic fat content post lockdown. Participants with worsened liver status had low consumption of fibre, cheese, nuts and coffee, and high consumption of sweets and pastries. Participants who improved liver status ameliorated ALT values, waist circumference, and intrahepatic fat content, assessed by magnetic resonance imaging post-lockdown. Conclusions: The maintenance of healthy lifestyle habits is vital, especially for populations with NAFLD and MetS, to reduce unhealthy lifestyle patterns displayed during lockdown.

Development of Food Group Tree-Based Analysis and Its Association with Non-Alcoholic Fatty Liver Disease (NAFLD) and Co-Morbidities in a South Indian Population: A Large Case-Control Study

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is a global problem growing in parallel to the epidemics of obesity and diabetes, with South Asians being particularly susceptible. Nutrition and behaviour are important modifiers of the disease; however, studies to date have only described dietary patterns and nutrients associated with susceptibility to NAFLD.

METHODS

This cross-sectional case-control study included 993 NAFLD patients and 973 healthy controls from Trivandrum (India). Dietary data was collected using a locally validated food frequency questionnaire. A tree-based classification categorised 2165 ingredients into three levels (food groups, sub-types, and cooking methods) and intakes were associated with clinical outcomes.

RESULTS

NAFLD patients had significantly higher consumption of refined rice, animal fat, red meat, refined sugar, and fried foods, and had lower consumption of vegetables, pulses, nuts, seeds, and milk compared to controls. The consumption of red meat, animal fat, nuts, and refined rice was positively associated with NAFLD diagnosis and the presence of fibrosis, whereas consumption of leafy vegetables, fruits, and dried pulses was negatively associated. Fried food consumption was positively associated with NAFLD, whilst boiled food consumption had a negative association. Increased consumption of animal fats was associated with diabetes, hypertension, and cardiovascular outcomes among those with NAFLD, whereas consumption of wholegrain rice was negatively associated with these clinical-related outcomes.

CONCLUSIONS

The tree-based approach provides the first comprehensive method of classifying food intakes to enable the identification of specific dietary factors associated with NAFLD and related clinical outcomes. This could inform culturally sensitive dietary guidelines to reduce risk of NAFLD development and/or its progression.

Systematic Review and Meta-analysis: The Role of Diet in the Development of Nonalcoholic Fatty Liver Disease

BACKGROUND & AIMS

The association of nonalcoholic fatty liver disease (NAFLD) with dietary factors is well established but not thoroughly investigated. This systematic review and meta-analysis synthesizes available evidence regarding the effect of nutrition on the presence and severity of NAFLD.

METHODS

A literature search was conducted identifying studies published between January 1985 and May 2021. We included studies with a dietary assessment and anthropometry based on validated tools, performed by a qualified dietitian or a trained health professional. We examined differences between patients with NAFLD and healthy controls as well as patients with NAFLD and nonalcoholic steatohepatitis (NASH). Risk of bias was assessed with the Risk Of Bias In Non-randomised Studies of Interventions (ROBINS-I) tool.

RESULTS

There were 60 eligible studies with 100,621 patients. The risk of bias was moderate for the majority of studies (41/60; 68%). According to meta-analyses, total caloric intake was higher in patients with NAFLD compared with controls (mean difference, 78.08; 95% confidence interval, 41.03-115.13). Macronutrient (protein, fat, and carbohydrate) consumption as proportion of total caloric intake and daily intake of fiber, caffeine and vitamins E, A, and C did not significantly differ between patients with NAFLD and controls. Soft drink consumption had a trend towards association with the presence of NAFLD. However, the odds ratio was 4.4 and the confidence intervals very wide. Finally, there was no significant difference in any comparison between patients with NAFLD and NASH, although the number of patients was relatively small. All meta-analyses had significant heterogeneity.

CONCLUSIONS

Overall, despite high heterogeneity among studies, this meta-analysis demonstrated that higher caloric intake is positively associated with NAFLD, whereas diet composition in macronutrients was not associated with the presence or severity of the disease.

Calcium to magnesium intake ratio and non-alcoholic fatty liver disease development: a case-control study

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease worldwide. Adoption of sedentary life style and westernized diet are shown to be associated with development of NAFLD. Since previous studies suggested that calcium (Ca) to magnesium (Mg) ratio intake is associated with some chronic diseases including dyslipidemia and insulin resistance, we designed this study to find any possible association between this ratio and NAFLD development.

METHODS

The NAFLD was diagnosed using Fibroscan according to a CAP cut-off value of 263 dB/m. Dietary intakes of one hundred and ninety-six patients with incident NAFLD diagnosis, and eight hundred and three controls without NAFLD were assessed using a valid food frequency questionnaire (FFQ). Dietary nutrients were calculated using Nutritionist IV software.

RESULTS

Age of the study population (57 % female) was 43.2 ± 14.1 years. In addition, energy-adjusted daily calcium to magnesium intake ratio was 2.34 ± 0.57 and 2.73 ± 0.69 for control and case groups, respectively. In the multivariable-adjusted model, after adjustment for potential confounding variables; including, age, gender, BMI, alcohol consumption, smoking, diabetes, physical activity, energy, dietary fiber, carbohydrate, fat, and protein intakes, participants in the third (Q3) and fourth (Q4) quartile of Ca/Mg ratio intake had a greater development of incidental NAFLD compared to the lowest quartile (Q1) [(OR = 2.86; 95 % CI: 1.20-6.81), (P-value = 0.017) and (OR = 5.97; 95 % CI: 2.54-14.01), (P-value < 0.001) for Q3 and Q4 compared to the Q1, respectively]. Moreover, energy-adjusted Ca to Mg intake ratio was positively correlated with plasma level of ALT (r = 0.18; P = 0.01); contrarily, it had no correlation with plasma levels of AST.

CONCLUSIONS

The current study revealed that higher dietary Ca to Mg intake ratio is associated with a greater development of NAFLD. Further interventional studies are needed to confirm the causal relationship of the Ca/Mg ratio intake and development of NAFLD.

Nuts and Non-Alcoholic Fatty Liver Disease: Are Nuts Safe for Patients with Fatty Liver Disease?

Diet and lifestyle interventions are the recommended treatment for patients with non-alcoholic fatty liver disease (NAFLD), with the aim of achieving a 7-10% weight loss. Several dietary patterns have been suggested for this purpose, however, to date, the best one is represented by the Mediterranean diet (MD) as it is rich in macro- and micro- nutrients known for their effectiveness in health-promotion and cardio-vascular disease prevention. Moreover, MD is characterized by the inclusion of nuts. These foods have shown potential benefits in health-promotion as they are rich in fibers, which have lipid-lowering effects, rich in mono- and poly-unsaturated fatty acids, which help reduce insulin-resistance and serum cholesterol, and contain anti-oxidants which reduce oxidative stress and inflammation. Additionally, nuts are associated with a better control, or reduction, of Body Mass Index (BMI). All these effects are useful targets to achieve in NAFLD, so that nuts have been proposed as a suitable dietary treatment supplement for weight and metabolic control in these patients. In recent years, health authorities raised an alert on nuts consumption as these may be at high risk of aflatoxin (AF) contamination, for which controls and legislations are different among countries. AF is a well-known cancerogenic agent and a recognized risk factor for hepatocellular carcinoma. Patients with NAFLD have an overall, inherent sevenfold increased risk of developing hepatocellular carcinoma as compared with the general population. In this context, one could argue that recommending the inclusion of nuts in the diet of NAFLD patients has to be balanced with the risk of potential chronic exposure to AF, and every effort should be pursued to assure the safety of these nutrients. In this review, we aim to summarize the benefits of nuts consumption, the evidence for AF contamination of nuts and the consequent potential risks in patients with NAFLD.