In a systematic review and meta-analysis, researchers found some evidence to suggest that diets low in glycemic index and glycemic load may reduce hepatic liver mass and enzyme alanine transaminase (ALT) level in children and adults with nonalcoholic fatty liver disease (NAFLD), according to study results published in Metabolic Syndrome and Related Disorders.
Investigators searched PubMed, Cumulative Index to Nursing and Allied Health Literature, and Web of Science for studies assessing the effect of diets low in glycemic index and glycemic load as therapy for NAFLD, with outcomes including measures of hepatic fat mass, hepatic enzymes, insulin resistance, fasting blood glucose levels, and/or blood lipid panels in children and adults.
A total of 4 studies that included 281 patients with NAFLD were used in the analysis: 2 examined the diet’s effects in children and 2 in adults. When consuming diets with low glycemic index and glycemic load, reductions in ALT levels were seen in both children (as much as -28.5 IU/L within 6 months) and adults (-17 IU/L in 12 months) compared with a control diet.
Improvements in hepatic fat mass were also associated with dietary changes. In 1 study, intrahepatic triglyceride content was significantly lower at 12 months in the intervention group compared with the control group (mean difference, 4.6%; 95% CI, 2.6%-6.6%; P <.001), with remission of NAFLD occurring in 64% of the intervention group compared with 20% of the control group. In another study, patients adhering to a low-glycemic-index Mediterranean diet had significantly reduced NAFLD scores at 6 months (-4.43; 95% CI, -7.15 to -1.71; P <.01). Finally, in a study assessing the efficacy of a low-glycemic-load diet in children with obesity and NAFLD, significant reductions in hepatic lipid content were observed (-8.8%; P =.05).
Although 1 study showed reductions in homeostatic model of insulin resistance (HOMA-IR) with the intervention diet, no significant decreases were seen in fasting blood glucose levels, triglyceride levels, or high- or low-density lipoprotein cholesterol levels of patients consuming a diet low in glycemic index or glycemic load.
“Currently, clinicians are recommended to promote weight loss and regular physical activity in individuals with NAFLD. However, there is potential that carbohydrate quality not quantity may play a role in improving hepatic fat mass and ALT in individuals with NAFLD,” the investigators concluded.
Parker A, Kim Y. The effect of low glycemic index and glycemic load diets on hepatic fat mass, insulin resistance, and blood lipid panels in individuals with nonalcoholic fatty liver disease. Metab Syndr Relat Disord. 2019;17(8):389-396.