Non-alcoholic fatty liver disease (NAFLD) is an emerging cause of chronic liver diseases and a major health problem worldwide. Dietary patterns may play a critical role in controlling and preventing this disease, but the evidence is limited. The current study aims the association of adherence to the Dietary Approach to Stop Hypertension (DASH) diet and Mediterranean Diet (MeD) with non-alcoholic fatty liver disease (NAFLD) among Iranian adults of Amol Cohort Study (AmolCS).

In a cross-sectional analysis among 3220 adults (55.3% men), age ≥ 18 years (46.96 ±14.67), we measured usual dietary intake with a validated food frequency questionnaire (FFQ) and then calculated dietary pattern scores for DASH and MeD. Sociodemographic and lifestyle factors were collected by a structured questionnaire. The presence and degree of NAFLD were also determined by abdominal sonography. Multiple regression models were used to estimate odds of NAFLD across tertiles of DASH and Mediterranean dietary scores. The associations of DASH and Mediterranean dietary patterns with NAFLD were adjusted for sex, age, BMI, smoking status, physical activity, anti-diabetic medications, heart disease, diabetes, and stroke status. Dietary DASH and Mediterranean components were adjusted for total energy intake, based on the residual methods.

After adjusting for multiple potential confounders, we found an inverse association of DASH and MeD with NAFLD (Ptrend=0.02, and Ptrend=0.002, respectively). Those in the highest tertiles of adherence to the DASH and MeD had the lowest risk for NAFLD (OR=0.80, 95%CI=0.66–0.96, OR=0.64, 95%CI=0.52–0.78, respectively). The results of logistic analysis of MeD stratified by gender and abdominal obesity revealed the favorable association was more pronounced in women (OR=0.42, 95%CI=0.29–0.61, Ptrend=0.004), and in participants with or without abdominal obesity (OR=0.62, 95% CI=0.47–0.81, Ptrend=0.03, OR=0.64, 95%CI=0.475–0.91, Ptrend=0.04, respectively). Similar results were obtained for the adherence to DASH diet score with prevalence NAFLD patients with abdominal obesity (OR = 0.75, 95% CI = 0.57–0.97, Ptrend = 0.04).

The findings suggested that favorable adherence to healthful diets was inversely associated with NAFLD risk in Iranian adults, especially women and subjects with or without abdominal obesity. Further prospective investigations are needed to confirm this suggestion.