Impact of Reduced Added Sugars on Fatty Liver Disease in Children

Overview of Non-Alcoholic Fatty Liver Disease

A recent study published in JAMA investigated the effects of reduced added sugars on non-alcoholic fatty liver disease (NAFLD) in children. NAFLD is the most prevalent liver disorder among children and is linked to a higher risk of type 2 diabetes, end-stage liver disease, liver cancer, and cardiovascular disease. Since added sugars do not provide essential nutrients and contribute to excess calorie intake, understanding their impact on this condition is crucial.

Study Background and Objectives

Conducted in the United States, the study aimed to explore the effects of reduced added sugar consumption on children diagnosed with NAFLD. This condition is characterized by excessive fat accumulation in the liver not related to alcohol consumption, and there has been a rising trend of NAFLD among U.S. children, particularly among boys of Hispanic descent. Recommended treatments include lifestyle modifications and a healthier diet, emphasizing the elimination of added sugars.

Understanding Added Sugars

Added sugars encompass those included in foods and beverages, as well as those naturally occurring in fruit juices. The World Health Organization (WHO) advises that free sugar intake should remain below 10% of total daily calories. Given that added sugars account for 13-17% of additional caloric intake, reducing them could potentially benefit children with fatty liver disease.

Study Methodology

The study, led by researchers Schwimmer and colleagues from Emory University School of Medicine and the University of California San Diego School of Medicine, involved 51 adolescent boys aged 11 to 16 with NAFLD. From the initial group, 40 participants who consumed three or more servings of juice or sugar-sweetened beverages weekly were selected. They were divided into two groups: one maintained their usual diet while the other adopted a diet with significantly reduced added sugars.

A registered dietitian created weekly meal plans for the intervention group, aiming to keep added sugar intake below 3% of total calories. The diet excluded artificial sweeteners and sugar-laden products, while total calorie and macronutrient intake remained unrestricted. Food supplies were provided twice weekly, and adherence to the diet was monitored through bi-weekly phone calls.

Evaluation and Results

Participants underwent evaluations at the beginning, four weeks, and eight weeks into the study. Their liver fat was measured using MRI-PDFF (magnetic resonance imaging proton density fat fraction measurement), and alanine aminotransferase (ALT) levels were assessed to evaluate liver function. Dietary analysis was conducted from weeks three to eight, with participants recalling their food and beverage consumption through questionnaires.

Results indicated a significant decrease in hepatic fat accumulation among those on a low added sugar diet, reducing from 25% to 17%. In contrast, the usual diet group experienced a minor reduction from 21% to 20%. ALT levels in the intervention group fell from 103 U/L to 61 U/L, while the control group saw a decrease from 82 U/L to 75 U/L. Additionally, cholesterol levels dropped in the low added sugar group.

Conclusions and Implications

The findings underscore the potential benefits of reduced added sugar intake for children suffering from non-alcoholic fatty liver disease. The study’s innovative use of precise MRI-PDFF measurements and structured meal plans contributed to its significance. However, it is important to note that the research involved only adolescent boys, mainly of Hispanic descent, which may limit its broader applicability.

Despite the observed improvements in liver fat and ALT levels, the intervention did not restore these metrics to normal. Furthermore, the control group received less attention, which could influence the results.

Future Directions and Expert Opinion

This research highlights a growing concern regarding the prevalence of non-alcoholic fatty liver disease in children. It marks a significant step toward identifying dietary interventions that may mitigate this condition. According to Miriam B. Vos, one of the study’s authors, “Although pediatric guidelines for managing non-alcoholic fatty liver disease recommend a healthy diet, focused reduction of sugary foods and beverages was an unproven treatment. Our results show that if a child with NAFLD consumes a very low amount of sugars in their diet, both fat and inflammation in the liver improves. We are excited by the highly significant results but also realize that a longer study will be needed in order to understand if sugar reduction is sufficient to ‘cure’ NAFLD.”

References

Schwimmer J, Ugalde-Nicalo P, Welsh J, Angeles J, Cordero M, Harlow K et al. Effect of a Low Free Sugar Diet vs Usual Diet on Nonalcoholic Fatty Liver Disease in Adolescent Boys. JAMA. 2019;321(3):256.
Diet low in added sugars significantly improves fatty liver disease in children [Internet]. EurekAlert!. 2019 [cited 31 January 2019]. Available from: https://www.eurekalert.org/pub_releases/2019-01/ehs-dli011819.php