In a recent study published in JAMA, researchers determined whether reducing added sugars will improve fatty liver disease in kids.
Non-alcoholic fatty liver disease (NAFLD) is the most common liver disorder in children. It is associated with an increased risk of type 2 diabetes, end-stage liver disease, liver cancer, and cardio-vascular disease. Added sugar in the diet is not an essential nutrient and contributes to extra calories. A study was conducted in the United States to unfold the effect of reducing added sugar in the diet in non-alcoholic fatty liver disease in children.
Non-alcoholic fatty liver disease is an accumulation of excess fat in the liver due to causes other than alcohol. There is an increased trend of this disease among the children in the US. It is more common in boys, especially of Hispanic origin. Lifestyle modification and a healthy diet are the recommended treatments for this condition. One of the essential components of a healthy diet is the elimination of added sugar.
Added sugars include those added to food and drinks and found naturally in fruit juices
Added sugar includes sugars added to foods and beverages and found naturally in fruit juices. As per the World Health Organization (WHO), daily intake of free sugars should be less than 10% for all people. As added sugar contributes to 13-17% of extra calories, any reduction in this component can have a healthy effect on fatty liver disease. With this concept, a study was conducted by Schwimmer and team at Emory University School of Medicine and the University of California San Diego School of Medicine and was published in JAMA.
For this study, 51 adolescent boys between 11 to 16 years of age, with non-alcoholic fatty liver disease, were screened and 40 were selected. The selected boys consumed three or more servings (eight ounces) of juice or sugar-sweetened beverages per week. These children were randomly divided into two groups; one group was on their usual diet and the other was on a diet with reduced amounts of added sugar.
A registered dietitian generated weekly diet plans for children of the intervention group and their families, based on their regular food habits. Intake of added sugar was kept below 3% of total calories. Artificial sweeteners and,-sugar-containing products were avoided. There was no restriction on total calorie intake and macronutrients. These foods were supplied twice weekly. If the family preferred their home-made food, necessary sugar-free ingredients were provided. Phone calls on a twice-weekly basis by the researchers ensured adherence to instructions.
Evaluation and follow-up were done in the beginning, at four weeks and after eight weeks of study. The participants were evaluated for history and relevant investigations. To calculate the amount of fat in the liver, MRI-PDFF (magnetic resonance imaging proton density fat fraction measurement) was used. Alanine aminotransferase (ALT-a liver enzyme tested to assess liver function) levels were also measured. The childrens’ diets were analyzed between weeks three to eight. During each evaluation, the children were asked to recall their earlier-day food items and amount. A questionnaire was used for beverage consumption.
A diet of low added sugar resulted in a decrease of fat in the liver from 25% to 17%
The boys on low added sugar showed a decrease in hepatic fat accumulation from 25 to 17%, while those on a usual diet had a slight reduction from 21% to 20%. ALT levels reduced from 103 U/L to 61 U/L in the intervention group, while it decreased from 82 U/L to 75U/l in the usual diet group. The children on low added sugar also had a decline in the blood cholesterol levels.
Thus, this study depicts a significant outcome in patients with non-alcoholic fatty liver disease on reduced added sugar. The use of precise measurement of hepatic MRI-PDFF for liver fat, and specific guidelines for meal plans were the highlights of this study.
However, this research is confined to adolescent boys and may not be applicable to the entire population. Most of the children in this study were Hispanic, further limiting its global applicability. There was a reduction in liver fat, blood levels of ALT and cholesterol, however, the intervention did not regain their normal levels. There was less attention paid to the control group on a normal diet.
Reducing sugary foods was unproven advice for NAFLD until this study
In the present trend of health issues, non-alcoholic fatty liver disease is on a rise in children. The findings of this study are the preliminary steps to explore other risks and remedies for fatty liver. The study showed that a healthy diet, such as one that avoids added sugar helps in recovery from non-alcoholic fatty liver disease.
Miriam B. Vos, one of the authors of the study, stated in a press release, “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.”
Written by Dr. Radhika Baitari, MS
- 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