Dietary Interventions for the Management of Non-alcoholic Liver Disease

The gold standard treatment for NAFLD is weight loss and lifestyle interventions, which require a diet enriched in fiber and reduced in sugars and saturated fats. Fibres may be advantageous for NAFLD patients since they reduce and slow the absorption of carbohydrates, lipids, and proteins, lowering the energy density of the meal and increasing their sense of satiety. Furthermore, the polyphenol content and other bioactive compounds of vegetables have antioxidant and anti-inflammatory properties preventing disease progression. The aim of this study is to ascertain the effects of a diet enriched by green leafy vegetables and with a moderate restriction of carbohydrate intake in patients with NAFLD over a three month period. Among the forty patients screened, twenty four patients completed the clinical trial consisting of swapping one portion of carbohydrate-rich food for one portion of green leafy vegetables, and liver and metabolic markers of NAFLD were evaluated. All patients underwent routine blood tests, anthropometric measurements, bioelectrical impedance analysis, fibroscan, and fatty liver index (FLI) evaluation before and at the end of the study. The population under study (n = 24) had a median age of 47.5 (41.5–52.5) years and included mainly women (70.8%). We found that FLI, which is used to predict fatty liver (73 (33–89) vs. 85 (54–95), p < 0.0001) and the FAST score, which is a fibroscan-derived parameter identifying patients at risk of progressive NASH (0.03 (0.02–0.09) vs. 0.05 (0.02–0.15), p = 0.007), were both improved after changes in diet. The BMI (33.3 (28.6–37.3) vs. 35.3 (31.2–39.0), p < 0.0001), WC (106.5 (95.0–112.5) vs. 110.0 (103.0–124.0), p < 0.0001), neck circumference (38.0 (35.0–41.5) vs. 39.5 (38.0–42.5), p < 0.0001), fat mass (32.3 (23.4–40.7) vs. 37.9 (27.7–43.5), p < 0.0001), and extracellular water (17.3 (15.2–20.8) vs. 18.3 (15.9–22.7), p = 0.03) were also all significantly lower after three months of diet. Metabolic parameters linked to NAFLD decreased: HbA1c (36.0 (33.5–39.0) vs. 38.0 (34.0–40.5), p = 0.01), triglycerides (72 (62–90) vs. 90 (64–132), p = 0.03), and the liver markers AST (17 (14–19) vs. 18 (15–27), p = 0.01) and γGT (16 (13–20) vs. 16 (14–27), p = 0.02). In conclusion, replacing only one portion of starchy carbohydrates with one portion of vegetables for a three month period is sufficient to regress, at least in part, both mid and advanced stages of NAFLD. This moderate adjustment of lifestyle habits is easily achievable. Full article

Background: Current guidelines aim to limit the dietary glycemic index (GI) and intake of saturated fatty acids (SFA). Several studies have shown favorable effects of low-GI or low-SFA diets on intrahepatic lipid content (IHL), but these studies were performed under overfeeding conditions or extreme differences in GI or SFA to maximize the contrast between diets. By combining changes in GI and SFA, we can mimic how people can improve their diet in a realistic setting. Objectives: We investigated the effect on liver fat content and substrate metabolism of both reducing GI and replacing SFA with polyunsaturated fat in practically realistic amounts under isocaloric conditions. Design and Methods: In a randomized crossover study, thirteen overweight participants consumed two diets, one high in GI and SFA (high GI/SFA) and one low in GI and SFA (low GI/SFA) with identical macronutrient composition, for two weeks each. Diets were equal in caloric content, consisted of habitual food items, and had a macronutrient composition that can be easily achieved in daily life. At the end of each intervention, IHL content/composition and liver glycogen were measured by magnetic resonance spectroscopy. Additionally, fasted and postprandial hepatic de novo lipogenesis and glycemic and metabolic responses were investigated. Results: IHL was significantly lower (−28%) after the two-week low-GI/SFA diet (2.4 ± 0.5% 95% CI [1.4, 3.4]) than after the two-week high-GI/SFA diet (3.3 ± 0.6% 95% CI [1.9, 4.7], p < 0.05). Although hepatic glycogen content, hepatic de novo lipogenesis, hepatic lipid composition, and substrate oxidation during the night were similar between the two diets, the glycemic response to the low-GI/SFA diet was reduced (p < 0.05). Conclusions: Changes in macronutrient quality can already have drastic effects on liver fat content and postprandial glycemia after two weeks and even when energy content and the percentage of total fat and carbohydrate remains unchanged. Full article