Vegan Diet Advice Might Benefit Liver Enzymes in Nonalcoholic Fatty Liver Disease: an Open Observational Pilot Study

Background and Aims: The Western diet is rich in saturated fats, refined sugars and meat consistent with a high-energy load and secondary risk of increased metabolic diseases including nonalcoholic fatty liver disease (NAFLD). However, no data are available on potential benefit of vegan diets in NAFLD and/or nonalcoholic steatohepatitis (NASH). We aimed to study prospectively the effect of a vegan diet, excluding all animal products on liver chemistry in a group of consecutive NAFLD patients. Methods: This was a prospective, pilot study run on 40 consecutive patients affected by NAFLD. Eight subjects refused to join the study for poor diet palatability, leaving 32 patients (19 males, mean age 50 years), with abnormal measures of liver function who agreed to adhere to a vegan diet for six months. The caloric intake was tailored by the dietitian to obtain a weight loss ≥5% of body weight in overweight patients [body-mass index (BMI) ≥25] and ranged from 1500 Kcal to 1800 Kcal. Patients were contacted monthly by phone to reinforce diet and lifestyle advice and were seen at the gastrointestinal clinic when doubtful about diet advice. Results: At six-month follow-up, 6 subjects did not attend the clinic leaving only 26 patients for data analysis. Initial anthropometric values were mean weight 78 kg (range 52-95), mean body mass index (BMI) 26.8 Kg/m2 (range 20.3-31.2). Liver function tests showed mean ALT value 99 U/L (SD±45), mean AST value 54 U/L (SD±44), mean GGT value 160 U/L (SD±122), pre-treatment. After six months mean body weight was 73 Kg (range 52-87), mean BMI was 25.2 Kg/m2 (range 20.3-29.7) (p