New research provides further evidence of the harms of consuming too many sweetened beverages, after linking soda and other fructose-containing products with increased risk of liver disease.
Researchers found that children and adolescents who consumed high amounts of fructose - most commonly from sweetened drinks - were more likely to have nonalcoholic steatohepatitis (NASH), a form of nonalcoholic fatty liver disease (NAFLD).
Senior investigator Dr. Valerio Nobili, of the Bambino Gesù Hospital in Italy, and colleagues recently reported their findings in the Journal of Hematology.
NAFLD is a condition characterized by a buildup of fat in the liver that is not caused by alcohol consumption. In NASH, the fat buildup is accompanied by inflammation and liver cell damage, which can cause scarring, or fibrosis. NASH can lead to severe complications, including cirrhosis and liver cancer.
Excess weight is a leading risk factor for NAFLD and NASH. According to Dr. Nobili and colleagues, estimates suggest that up to 9.6 percent of all children and 38 percent of obese children in Western countries have some form of liver disease, including NASH.
Assessing the impact of fructose intake on NASH
According to the researchers, previous studies have indicated that dietary fructose intake leads to an increase in blood levels of uric acid, and high levels of both fructose and uric acid have been identified in people with NAFLD.
For this latest study, Dr. Nobili and team set out to investigate whether fructose and uric acid might be independently associated with NASH.
"Numerous studies have shown that high uric acid levels are associated with metabolic syndrome and NAFLD, but to date, to the best of our knowledge, no studies have tested the independence of associations among uric acid concentrations, fructose consumption, and NASH confirmed by biopsy," notes Dr. Nobili.
To reach their findings, the researchers studied 271 obese children and adolescents who had NAFLD, all of whom underwent a liver biopsy.
All participants completed a food frequency questionnaire, which disclosed precisely what foods they consumed, how often they consumed them, and the portion size.
Using these data, the team calculated the participants' dietary fructose intake. They found that soda and other sweetened drinks were a major source of fructose; almost 90 percent of subjects reported drinking soda and other sweetened beverages at least once weekly.
Morning and afternoon snacks consisting of pizza, crackers, yogurt, and salty snacks were a regular occurrence for almost 95 percent of the participants, the team reports.
Fructose, uric acid 'independently and positively associated with NASH'
From the liver biopsies, the researchers found that 37.6 percent of the children and adolescents had NASH.
Of these, 47 percent had high concentrations of uric acid, compared with 29.7 percent of participants without NASH.
Importantly, the team found that fructose intake was independently associated with high uric acid concentrations, and fructose intake was more frequent among participants with NASH than those without NASH.
"In this study, we show for the first time that uric acid concentrations and dietary fructose consumption are independently and positively associated with NASH.
The development of NASH may markedly affect life expectancy and quality of life in affected individuals and therefore it is crucial to understand the risk factors for NASH in children and adolescents in order to design effective interventions which can be used safely to treat this young group of patients."
Dr. Valerio Nobili
The researchers add that greater efforts should be made to reduce the consumption of soda and other sweetened drinks among children and adolescents, which may lower fructose intake.