A Randomized Controlled Trial of the Effects of an Almond-enriched, Hypocaloric Diet on Liver Function Tests in Overweight/Obese Women

Gradual weight reduction has been shown to be associated with improvements in liver enzymes. However, some evidence demonstrated that liver enzymes may transiently increase immediately after a diet-induced weight loss. This study was designed to assess the effects of a hypocaloric, almond-enriched diet (AED) compared with a hypocaloric nut-free diet (NFD) on liver function tests in the context of a three-month weight reduction program in overweight/obese women. This randomized controlled clinical trial was registered at Iranian Registry of Clinical Trials with ID number of IRCT2013062313751N1. Overweight and obese Iranian women [n = 108; age = 42.7 y, body mass index = 29.6 kg/m2] were randomly assigned to consume an AED or NFD. The carefully planned hypocaloric diets were identical for both groups except for the AED group who consumed 50 grams of almonds daily for three months. Anthropometric measurements and laboratory measurements including alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP) and γ-glutamyltransferase (GGT) were assessed before and immediately after the intervention. Of 108 participants, 50 women in AED group and 50 women in NFD group completed the protocol of the study (response rate: 92.6 %). The AED led to a median weight loss of 3.79 kg (interquartile range: 4.4 kg). Significant decreases within AED and NFD were observed in ALT (-16.6 ± 16.3 and -11.7 ± 16.8, P < 0.001, respectively). Similar significant decreases were observed in AST (-13.6 ± 15.7 and -7.7 ± 16.1; P < 0.001, respectively). The decrease in GGT was also significant in both groups (-11.4 ± 21.6 and -6.2 ± 19.8; P < 0.001 respectively). ALT, AST and GGT decreased significantly in the AED group compared to the NFD group (P < 0.001). AED improved liver enzymes in obese women. However, mild, transient increases in ALT and AST values can be observed immediately after an NFD in women.