Nonalcoholic fatty liver disease (NAFLD) is a common chronic liver disease affecting millions of people worldwide. It is characterized by the accumulation of fat in the liver, which can lead to liver damage, inflammation, and fibrosis. While the role of a diet rich in fructose and saccharose in the development of NAFLD is well known, a clinical trial has investigated the effects of a low free sugar diet on NAFLD's main features.
The study randomized participants with proven NAFLD to a 12-week dietary intervention (low free sugar diet or usual diet). The primary outcome was the change in hepatic steatosis measurement between baseline and 12 weeks, while the secondary outcomes included changes in anthropometric measurements, lipid profile, glycemic indices, liver enzymes, and inflammatory factors.
The study found that following a low free sugar diet resulted in significant improvements in various health markers compared to a usual diet. These improvements included decreased levels of ALT (a liver enzyme), TG (triglycerides), TC (total cholesterol), FBS (fasting blood sugar), insulin, HOMA-IR (a measure of insulin resistance), hs-CRP (a marker of inflammation), TNF-α (a marker of inflammation), and NF-kb (a protein involved in inflammation).
Additionally, the low free sugar diet led to reduced fibrosis and steatosis scores (measures of liver damage) and increased QUICKI (a measure of insulin sensitivity). However, there were no significant differences in levels of AST (another liver enzyme), GGT (a liver enzyme involved in bile production), HDL-C (good cholesterol), and LDL-C (bad cholesterol) between the two diets.
These findings suggest that a low free sugar diet in overweight/obese NAFLD patients may reduce hepatic steatosis and fibrosis while improving glycemic indices and decreasing the concentrations of biomarkers of inflammation, TG, and TC levels.
Adopting a low free sugar diet may be a feasible and effective way to improve liver health for individuals with NAFLD. A low free sugar diet involves reducing the consumption of foods and drinks high in added sugars, such as sugary drinks, candy, baked goods, and processed foods. Instead, individuals are encouraged to consume a diet rich in whole, unprocessed foods, including fruits, vegetables, whole grains, and lean proteins.