Higher phenolic acid intake independently associates with lower prevalence of insulin resistance and non-alcoholic fatty liver disease.

Background & Aims: The inverse association between non-alcoholic fatty liver disease (NAFLD) and diets rich in fruit and vegetables has been demonstrated, but the specific compounds that may be responsible for this association need to be elucidated. The aim of this study was to test the association between phenolic acid consumption, NAFLD, and insulin resistance (IR).

Methods: A cross-sectional cohort of individuals included in a metabolic screening program was studied. Liver steatosis was evaluated by ultrasonography and quantified by the hepatorenal index (HRI); fibrosis was assessed by FibroTest; IR by the sample upper quartile of the homeostatic model assessment score. Dietary intake was measured by a food frequency questionnaire. The phenolic acid content of food was calculated according to Phenol-Explorer.

Results: A total of 789 individuals were included (52.6% men, age 58.83 ± 6.58 years). Higher (above the upper median) phenolic acid intake was inversely associated with the presence of NAFLD (odds ratio [OR] 0.69; 95% CI 0.49-0.98; 0.036), higher HRI (OR 0.64; 95% CI 0.45-0.91; 0.013) and higher IR (OR 0.61; 95% CI 0.42-0.87; 0.007), when adjusted for age, gender, body mass index, and lifestyle factors. Considering specific classes of phenolic acids, higher hydroxybenzoic acid intake was independently associated with lower odds of NAFLD, higher HRI and fibrosis. Higher hydroxycinnamic acid intake was independently associated with lower odds of IR.

Conclusion: A higher intake of phenolic acids is associated with a lower prevalence of liver steatosis and IR in a cross-sectional study, suggesting a possible protective effect that requires confirmation in prospective studies.

Lay Summary: High dietary intake of total phenolic acids is associated with a lower prevalence of non-alcoholic fatty liver disease and insulin resistance. A high intake of hydroxybenzoic acids, a class of phenolic acids, is associated with a lower prevalence of steatosis and clinically significant fibrosis, while a high intake of hydroxycinnamic acids, another class of phenolic acids, is associated with a lower prevalence of insulin resistance.