Association Between Protein Intake From Different Animal and Plant Origins and the Risk of Non-Alcoholic Fatty Liver Disease: A Case-Control Study

Previous studies have frequently reviewed how different macronutrients affect liver health. Still, no study centered around protein intake and the non-alcoholic fatty liver disease (NAFLD) risk relationship. This study aimed to examine the association between the consumption of total and different sources of protein and NAFLD risk. We allocated 243 eligible subjects to the case and control groups, including 121 incidence cases of NAFLD, and 122 healthy controls. Two groups were matched in age, body mass index, and sex. We evaluated the usual food intake of participants using FFQ. Binary logistic regression was conducted to estimate the risk of NAFLD in relation to different sources of protein intake. The age of participants was 42.7 years on average, and 53.1% were male. We found Higher intake of protein in total (odds ratio [OR], 0.24; 95% confidence interval [CI], 0.11–0.52) was significantly associated with a lower risk of NAFLD, despite adjusting for multiple confounders. in detail, higher tendency to the vegetables (OR, 0.28; 95% CI, 0.13–0.59), grains (OR, 0.24; 95% CI, 0.11–0.52), and nuts (OR, 0.25; 95% CI, 0.12–0.52) as the main sources of protein, were remarkably correlated with lower NAFLD risk. In contrary, increased intake of meat protein (OR, 3.15; 95% CI, 1.46–6.81) was positively associated with a higher risk. Totally, more calorie intake from proteins was inversely associated with lower NAFLD risk. This was more likely when the protein sources were selected less from meats and more from plants. Accordingly, increasing the consumption of proteins, particularly from plants, may be a good recommendation to manage and prevent NAFLD.