Mediterranean diet and nonalcoholic fatty liver disease

Table 2 Cross sectional studies on the association between Mediterranean diet and non-alcoholic fatty liver disease

Authors, year, country[ref.]	Patient population	NAFLD Diagnosis	Adherence to MD	Comment
Kontogianni, 2014, Greece[34]	73 overweight/obese adult patients with NAFLD vs 58 age-, gender-, and BMI-matched controls with normal liver ultrasound/liver chemistry	Patients who met all the following criteria: abnormal ALT and/or GGT; ultrasound evidence of hepatic steatosis and/or compatible liver histology; and no other cause of liver steatosis	Adherence to MD (as estimated by MedDietScore) did not differ significantly between patients and controls	Higher adherence to MD was not associated with lower likelihood of having NAFLD (even after adjustment with abdominal fat level). However, it was associated with lesser degree of insulin resistance and less severe liver disease among patients with NAFLD
Aller, 2015, Spain[35]	82 adult patients with NAFLD (of whom 56 had NASH, and 26 non-NASH; 35 had steatosis grade 1, and 47 steatosis grades 2 and 3)	Liver biopsy in all 82 patients	Higher adherence to MD (as estimated by the 14-item MD assessment tool) was higher in patients with low grade of steatosis than in those with high grade, in patients without NASH than in those with NASH, and in patients without liver fibrosis than in those with liver fibrosis	In the logistic regression analysis,one unit of the 14-item MD assessment tool was associated with a lower likelihood of having NASH (OR = 0.43) and steatosis (OR = 0.42)
Chan, 2015, Hong Kong[36]	797 apparently healthy Chinese adults (332 male, 465 female) of whom 220 (27.6%) had diagnosis of fatty liver	1H MRS was performed to measure IHTG. Fatty liver was defined as IHTG ≥ 5%	Subjects with fatty liver showed lower gender-adjusted MD score than those without fatty liver	Multivariate adjusted regression analyses showed an inverse association between MD score and prevalence of fatty liver, which approached the level of significance
Trovato, 2016, Italy[37]	1199 overweight/ obese adult patients with (n = 532) and without (n = 667) hepatic steatosis	Hepatic steatosis and its severity were assessed by ultrasound	Greater prevalence of overweight/ obesity (as assessed by BMI) and insulin resistance (as assessed by HOMA-IR), sedentary life habits, increased TG and HDL-C, greater use of Western diet food, as well as poor adherence to MD (as assessed by 1-wk recall questionnaire) were found in patients with hepatic steatosis vs those without it	Multiple regression analysis, weighted by years of age, displayed BMI, HOMA-IR and adherence to MD as the most powerful predictors of hepatic steatosis severity
Baratta, 2017, Italy[38]	584 overweight/obese adult patients with ≥ 1 CVD risk factor	Ultrasound evaluation	57 (9.8%) patients had low MD adherence (as estimated by Med-Diet questionnaire), while 436 (74.6%) and 91(15.6%) had, respectively, intermediate and high MD adherence. NAFLD prevalence significantly decreased from subjects with low to high adherence to MD (from 96.5% to 71.4%, P < 0.001)	In a multiple logistic regression analysis, MD adherence (intermediate vs low OR = 0.115; P = 0.041; high vs low OR: 0.093; P = 0.030) were independently associated with NAFLD
Cakir, 2016, Turkey[39]	Overweight/obese children with (n = 106, Group 1) and without (n = 21, Group 2) hepatic steatosis; and children with normal BMI and without known chronic disease (n = 54, Group 3)	Assessment of hepatic steatosis and its severity by ultrasound	Prevalence of a low level of MD adherence (as established by KIDMED index score) was significantly higher in Group 1 children compared to those belonging to Groups 2 or 3	The level of adherence to MD was negatively correlated with BMI, but no significant correlation was found with ALT, total body fat, TG, and HOMA-IR. No significant difference in the level of MD adherence was found between patients with hepatic steatosis grade1 and those with grades 2 and 3
Della Corte, 2017, Italy[40]	4 subgroups of overweight/obese children: with and without fatty liver; with and without NASH.	Among the 243 study children, ultrasound identified and excluded fatty liver in 66 and 77, respectively. The remaining 100 underwent liver biopsy identifying and excluding NASH in 53 and 47, respectively	Prevalence of a low level of adherence to MD (as estimated by KIDMED score) was significantly higher in patients with NASH compared to those without NASH as well as to those with and without fatty liver (100% vs 28.8% vs 37.9% vs 9.1%; P = 0.01)	Poor adherence to MD was associated to severe liver damage, with a negative correlation with NAFLD activity score and fibrotic stage

ALT: Alanine aminotransferase; BMI: Body mass index; CVD: Cardiovascular disease; GGT: Gamma-glutamyl transferase;

¹H MRS: Proton magnetic resonance spectroscopy; HOMA-IR: Homeostasis model assessment of insulin resistance; IHTG: Intrahepatic triglyceride content; MD: Mediterranean diet; NAFLD: Non-Alcoholic Fatty Liver; NASH: Non-Alcoholic Steatohepatitis; OR: Odds ratio; TG: Triglycerides.