In a recent review published in Nutrients Journal, researchers reviewed existing data on dietary patterns, foods, and nutrients to improve nonalcoholic fatty liver disease (NAFLD).
Study: Dietary patterns, foods and nutrients for improving nonalcoholic fatty liver disease: a scoping review. Image Credit: Sweet Marshmallow / Shutterstock.com
Background
Despite being the most common cause of chronic liver disease worldwide, NAFLD lacks pharmaceutical therapy and dietary recommendations to address its serious health consequences.
NASH worsens cirrhosis and hepatocellular carcinoma, leading to increased medical costs, financial loss, and poorer quality of life.
Dietary adjustments, lifestyle changes, and lifestyle modifications are examples of treatment options. Metabolic syndrome, obesity, cardiovascular disease, hypertension, diabetes, and chronic kidney disease have been associated with NAFLD.
About the review
In the present review, researchers described dietary approaches to manage NAFLD. Databases such as MEDLINE, Web of Science, Google Scholar and Scopus were searched between January and July 2023 for relevant records published in English or Spanish.
Diets, dietary guidelines, gut microbiome and NAFLD
The Mediterranean Diet (MedDiet) is a plant-based diet rich in monounsaturated fatty acids (MUFA) and low in red meat. According to research, those who eat a high-fat Western diet are more likely to get NAFLD and worsen it.
The Mediterranean Diet, on the other hand, has been linked to better liver steatosis and a lower risk of NAFLD.
Low carbohydrate consumption, refined carbohydrates and low sugar content, with olive oil providing the greatest amount of added fat, distinguish MedDiet from other diets. MedDiet is linked to a lower rate of NAFLD and a reduction in weight gain, insulin resistance and NAFLD.
The MedDiet, due to its low carbohydrate consumption and plant-rich dietary composition, offers a viable alternative to Western diets.
NAFLD, or nonalcoholic fatty liver disease, is associated with insulin resistance and lack of phospholipid metabolism. Consumption of processed meat, red meat, soft drinks, cookies, and pastries has been linked to insulin resistance and NAFLD.
Saturated fats interfere with phospholipid metabolism, causing mitochondrial malfunction, increased production of reactive oxygen species (ROS), and apoptosis. High animal protein consumption has also been linked to NAFLD in obese people.
Diet directly influences de novo lipogenesis, the process by which hepatocytes convert excess carbohydrates, particularly fructose, into fatty acids. Regular consumption of fructose is linked to increased fibrosis, mainly due to industrial fructose.
High-fructose diets comprising sucrose, fructose, and high-fructose corn syrup have been linked to an increased risk of developing steatosis and NASH, especially in overweight and obese people.
Genetics, Food, and NAFLD Improvement
Diet is important in the development of NAFLD because it affects deoxyribonucleic acid (DNA) homeostasis and telomere biology. DNA production and repair requires folate, calcium, retinol, vitamin E, and nicotinic acid, but trans fats can damage DNA.
Telomere shortening is detected in NAFLD, although it is prevented by fiber, omega-3 fatty acids, and vegetables. High-glycemic carbohydrates, processed meat, and saturated fats promote telomere shortening.
PNPLA3 (patatin-like phospholipase-containing domain 3) is a key regulator of liver fat accumulation and the development of NAFLD. Diets high in carbohydrates and fatty acids can cause the mutant gene to code for proteins. Diet can alter hepatic lipid utilization, insulin resistance, oxidative stress, and mitochondrial function by modulating epigenetic changes.
Deficiencies of betaine, choline, betaine, folate, and vitamin B12 can promote DNA methylation, increasing hepatic triglyceride production. Consumption of nuts, seeds, seafood, and high-fiber diets significantly reduces the risk of developing NAFLD in men.
Walnuts improve lipid profiles, liver disease and inflammation, and potentially effectively treat NAFLD.
Fish can generate omega-3 fatty acids from marine plants, which can help reduce liver fat and prevent NAFLD, non-alcoholic steatohepatitis (NASH), and fibrosis.
Diets high in fiber and whole grains may affect the composition of the gut microbiota, which could influence the hepatic intestinal axis in the development of NAFLD. A diet rich in legumes (peas, lentils, and beans) is strongly associated with a lower risk of NAFLD.
The mechanism underlying the protective benefits of vegetables and fruits on NAFLD risk is not fully understood. However, its lower energy density has been explained after the addition to the diet and the antioxidant activity of polyphenols and carotenoids contained in vegetables and fruits.
Consumption of non-starchy vegetables has been linked to better metabolic outcomes, such as lower visceral and liver fat and increased insulin sensitivity.
Dairy products, particularly yogurt that contain Lactobacillus acidophilus La5 and bifidobacteria lactis Bb12, have been linked to a lower risk of NAFLD due to its high whey protein content, which helps reduce weight and fat mass.
Probiotics, such as bifidobacteria and lactobacillus The strains have been shown to reduce oxidative and inflammatory liver damage while simultaneously decreasing hepatic triglycerides (TG) and hepatic steatosis.
Prebiotics, such as unsweetened filter coffee, may influence the composition of the gut microbiota, which is implicated in the development of NAFLD. Choline is an important B vitamin from food intake and endogenous production. It is digested and stored mainly in the liver.
Micronutrients implicated in NAFLD include zinc, copper, iron, selenium, magnesium, vitamins A, C, D, and E, as well as carotenoids, with antioxidant, antifibrotic, immunomodulatory, and lipoprotective properties reported as mechanisms of action.
Based on the findings, the MedDiet, which focuses on reducing oxidative stress and inflammation, may help control NAFLD.
A high-quality diet, frequent exercise, and limiting sugar consumption are important tactics, and sufficient fiber and coffee consumption can help protect against gut bacteria.
