Reducing consumption of sugary drinks and foods with added simple sugars can significantly reduce liver inflammation and hepatic steatosis in children and adolescents with liver disease. A randomized clinical trial, published in JAMA on 1/29/19, adds to previous studies on palm oil and steatosis.
Liver, inflammation and steatosis
Nonalcoholic FattyLiverDisease (NAFLD), so-called ‘fatty liver syndrome,’ is a condition in which fat accumulates in the liver. Non Alcoholic Steatohepatitis(NASH) is a type of NAFLD that is characterized by inflammation and damage to liver cells, along with fat in the liver.
Symptoms and causes. Nonalcoholic hepatic steatosis (NAFLD) and nonalcoholic steatohepatitis (NASH) are often asymptomatic. Certain health conditions-including obesity, metabolic syndrome, and type 2 diabetes cardiovascular disease, conditions that are spreading rapidly in adults and children-make the development of NAFLD and NASH more likely. Certain liver changes, starting with steatosis (so-called ‘fatty liver syndrome’), were associated with dietary intake of palmitic acid from palm oil in a randomized clinical trial at Uppsala University (Sweden). (1)
Diagnosis, prevention, and treatment. Physicians consider history, clinical evaluation, and testing to diagnose nonalcoholic hepatic steatosis (NAFLD) and nonalcoholic steatohepatitis (NASH). Tests may include blood tests, ‘imaging‘ tests and where appropriate liver biopsy.
Prevention of nonalcoholic hepatic steatosis (NAFLD) and nonalcoholic steatosis liver disease (NASH) relies on a balanced diet and maintaining a healthy weight.
The reduction of BMI (Body Mass Index, body mass index) is recommended to treat both diseases, thus being able to reduce liver fat, inflammation and fibrosis. No drugs have been approved for the treatment of NAFLD and NASH. (2)
Liver inflammation and steatosis, the role of sugars
The study from the Universities of San Diego (California, USA) and ‘Emory‘ in Atlanta (Georgia, USA), published in JAMA on 29.1.19, suggests that limiting sugary foods and drinks in the diet may be an effective strategy to alleviate the risk of developing liver inflammation and hepatic steatosis. (3)
The researchers recruited 40 adolescents, average age 13 years, with fatty liver syndrome. Most of them belong to the Hispanic ethnic group, where there is a particularly high prevalence of hepatopathy (21-25% average liver fat content, more than four times the normal limit). (4) Participants were divided into two groups, subjected to different diets for 8 weeks:
– The first group was put on a diet low in simple sugars. With ban on sugary drinks, replaced with unsweetened iced tea, milk
and water
,
–
the second, control group maintained their usual daily diet, without receiving any dietary instructions.
The low-sugar simple-sugar diet applied to Group 1 was not particularly restrictive (outside of this aspect alone), did not reduce carbohydrates or energy intake (kcal/day). Adolescents were able to consume fruits, starches, and pasta without restrictions. Indeed, the aim of the research was to evaluate the effect on liver health of just reducing the intake of added sugars within 3 percent of total energy intake. (5)
Sugar reduction, body weight and liver health
Added sugar intake (to processed and ultra-processed foods), in the first group of adolescents, dropped to 1 percent of daily calories (compared to 9 percent in the control group). The results of this dietary regimen, over 8 weeks, are significant in several respects:
– 3 kg reduction in body weight, average for the sample,
– Substantial improvement in liver health and liver enzymes, with an average 31% reduction in liver fat. (6) No improvement in health condition, conversely, was found in the control group.
Nutritional recommendations
The ‘quality of calories’ turns out to be crucial to an individual’s health. The study under review demolishes the age-old adage ridden by Big Food to justify its junk food, that the balance of a diet should be considered as a whole rather than by assessing the nutritional properties of the individual foods that comprise it. False!
The nutritional guidelines for children and adolescents with hepatic steatosis, in recommending a healthy and balanced diet, emphasize the caution to avoid processed and ultra-processed foods that contain added sugars, other than those naturally present in unprocessed or minimally processed foods, such as fruits and milk. (8)
Numerous studies
confirm that added sugars in processed foods – where taken in excess of a nutritionally safe parameter
undergoing (restrictive) upgrading-increase triglyceride synthesis in the liver. Conversely, foods that naturally contain sugars (e.g. fruits, vegetables, whole grains and dairy products with no added sugars) offer positive micronutrients, such as vitamins and minerals. (8)
Dietary fiber
, in which fruits and vegetables and whole grains are rich, in turn have numerous other health benefits
. In addition to increasing satiety and improving glycemic response.
Dario Dongo and Carlotta Suardi
Notes
(1) See Rosqvist F, et al. ‘Overfeeding polyunsaturated and saturated fat causes distinct effects on liver and visceral fat accumulation in humans‘. Diabetes. 2014. Jul;63(7):2356-68. doi: 10.2337/db13-1622.
Palmitic acid intake is associated with other serious pathological effects in the study by Wu D. et al. ‘Palmitic acid exerts pro-inflammatory effects on vascular smooth muscle cells by inducing the expression of C-reactive protein, inducible nitric oxide synthase and tumor necrosis factor-α‘. Int J Mol Med. 2014 Dec;34(6):1706-12. doi: 10.3892/ijmm.2014.1942
(2) V. ‘
National Institute of Diabetes and Digestive and Kidney Diseases.
‘ (NIDDK, USA),
https://www.niddk.nih.gov/health-information/liver-disease/nafld-nash
Of. On the prevalence of steatosis in the US population and the risks associated with NASH, see the recent contribution by Dr. Wynne Armand, on the Harvard University (Massachusetts, USA) blog, 19.1.19, on https://www.health.harvard.edu/blog/fatty-liver-disease-what-it-is-and-what-to-do-about-it-2019011015746
(3) Research contributed by ‘Nutrition Science Initiative‘, ‘National Institute of Health‘ and ‘Children’s Healthcare‘ of Atlanta. See Jeffrey B. Schwimmer, Patricia Ugalde-Nicalo, Jean A. Welsh et al. ‘Effect of a Low Free Sugar Diet vs Usual Diet on Nonalcoholic Fatty Liver Disease in Adolescent Boys. A Randomized Clinical Trial’(2019). JAMA, 2019;321(3):256-265. doi:10.1001/jama.2018.20579
(4) See Schwimmer JB, McGreal N, Deutsch R, Finegold MJ, Lavine JE. ‘Influence of gender, race, and ethnicity on suspected fatty liver in obese adolescents‘. Pediatrics. 2005;115(5):e561-e565. doi: 10.1542/peds.2004-1832
(5) Efsa is now evaluating, in terms of nutritional safety, thresholds for recommended simple sugars in the daily diet. V. https://www.greatitalianfoodtrade.it/salute/efsa-consultazione-zuccheri
(6) The improvement in liver enzymes, in adolescents subjected to the ‘low added sugars’ diet, was expressed in a significant drop (-40%) in alanine aminotransferase levels
(7) See in this regard the classification of foods proposed in the NOVA study of the University of São Paulo (Brazil), cited at
https://www.greatitalianfoodtrade.it/consum-attori/francia-nuovi-obiettivi-di-sicurezza-nutrizionale
(8) See Vos MB, Lavine JE. ‘Dietary fructose in nonalcoholic fatty liver disease‘. Hepatology. 2013;57(6):2525-2531. doi: 10.1002/hep.26299
Vos MB, Kaar JL, Welsh JA, et al. ‘
Added sugars and cardiovascular disease risk in children: a scientific statement from the American Heart Association
‘. Circulation. 2017;135(19):e1017-e1034. doi: 10.1161/CIR.0000000000000439
Dario Dongo, lawyer and journalist, PhD in international food law, founder of WIISE (FARE - GIFT - Food Times) and Égalité.
Nutritionist biologist, ADA II level master at the University of Milan Bicocca. External lecturer at LUNEX University, Luxembourg.
