Nonalcoholic fatty liver disease is one of the many consequences of obesity, as fat accumulates not only across the body and around the visceral organs, but inside the organ that helps break down fats, filter toxins from the bloodstream and create useable fuel from the food we eat. About 3 in 10 American adults suffer from nonalcoholic fatty liver. But it's a population of patients that's grown so fast, there isn't a lot known about their risks, and what factors aggravate those risks.
Researchers know those with nonalcoholic fatty liver are more likely than those without such fatty deposits to develop cirrhosis, liver cancer and liver failure requiring transplant. Still, a minority of those patients will do so, and doctors wish they could identify what factors may push those with fatty liver toward those outcomes.
The development of tough scar tissue in the liver can be a sign that liver failure may lie ahead. For heavy alcohol consumers, an alcoholic bender can cause scarring, or fibrosis, and lead to trouble. That's why those with signs of alcoholic fatty liver are urged to stop drinking alcohol.
A new study suggests that for those with nonalcoholic fatty liver, drinking a lot of beverages sweetened with fructose may do the same thing as liquor.
The study, published in the journal Hepatology, tracked 427 patients with fatty liver disease to see whether consumption of fructose made a difference in the progression of fatty liver to the organ's failure. The Duke University researchers asked subjects only about how many fructose-sweetened beverages a week they drank, including fruit juices and soft drinks sweetened with high-fructose corn syrup -- yielding a conservative accounting, since the stuff is also used in baking and other processed foods. Though only 19% of the fatty liver patients consumed few or no fructose sweetened beverages, 28% drank at least one a day.
Best represented among the heavy fructose consumers were subjects who were younger, male and Latino, and who had a higher BMI.
Compared to subjects who drank the least fructose beverages, those who drank the most were significantly more likely to have the hepatic scarring that will more often progress to cirrhosis or liver cancer. And older subjects who regularly consumed fructose beverages showed more signs of liver inflammation. After they stripped out the effects of age, gender and body-mass index, the researchers also found that the heavy fructose drinkers also have lower levels of HDL (or "good") cholesterol.
Duke University hepatologist Dr. Manal Abdelmalek said in a news release that high-fructose corn syrup, which was first introduced into the human diet in the 1970s and has accounted for an average of 10% of Americans' caloric intake over the last decade, "may not be as benign as we previously thought." While researchers have demonstrated clearly that the stuff has "fueled the fire of the obesity epidemic," added Abdelmalek, "untill now, no one has ever suggested it contributes to liver disease and/or liver injury."