Fructose, a form of sugar that's added to sodas, cookies, and other sweets, is contributing to the increase of non-alcoholic fatty liver disease (NAFLD) in adolescents and children, says a study published in the Journal of Hepatology.

Recent research suggests that dietary fructose intake may increase the amount of uric acid in the blood — which is associated with painful gout — and that both uric acid and fructose consumption may be elevated in individuals with NAFLD.

NAFLD, the accumulation of extra fat in liver cells in people who drink little or no alcohol, is recognized as the fastest growing cause of liver disease in both Western and developing countries. It is estimated to affect up to 30 percent of the general population in Western countries and up to 9.6 percent of all children and 38 percent of obese children.

A team of Italian and British researchers studied obese children and adolescents with NAFLD. All underwent liver biopsy and all completed a food frequency questionnaire, indicating when specific foods were consumed (breakfast, morning snack, lunch, afternoon snack, dinner, etc.), how often (every day of the week, sometimes, or never), and portion size.

Major sources of dietary fructose among children and adolescents are soda and other sweetened beverages. Nearly 90 percent reported drinking sodas and soft drinks one or more times a week. Almost 95 percent of patients regularly consumed morning and afternoon snacks consisting of crackers, pizza and salty food, biscuits, yogurt, or other snacks.

Of the patients studied, 37.6 percent had NASH, a form of liver disease that can progress to severe fibrosis and cirrhosis, and eventually develop into cancer. In addition, 47 percent of patients with NASH also had high levels of uric acid, which can lead to problems such as gout, compared with 29.7 percent of patients who did not have 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," said senior researcher Dr. Valerio Nobili.

High amounts of fructose in modern diets have been associated with a wide range of ailments including diabetes and cardiovascular disease.