Chronic fructose consumption puts diabetic, obese people at risk for liver disease

Chronic increased fructose consumption raises the risk of nonalcoholic fatty liver disease (NFALD) in obese and/or diabetic people, according to a study from the Duke University Medical Center.

Increased amounts of fructose, a type of sugar commonly found in soft drinks and fruit juices, also puts obese people at risk for fatty inflammation and scarring, the more severe forms of NFALD.

Researchers discovered that chronic fructose consumption in a diet may deplete a person's store of molecules called ATP. Fructose requires ATP for its metabolism.

ATP provide liver cells the energy for important cellular processes, including metabolism. ATP depletion may increase the risk for inflammation and scarring in the liver.

“The stores of liver ATP are decreased in obese and/or diabetic individuals who chronically consume increased amounts of fructose-containing beverages,” said Manal Abdelmalek, MD, associate professor at Duke University and lead author of the study.

The ability of cells to optimally make ATP is already impaired in obese or diabetic people

“The state of being insulin resistant impairs the ability of a vital enzyme, AMP kinase, to make new ATP molecules,” said Abdelmalek. “Increased fructose consumption, and excess utilization of ATP favors the increase in molecules that lead to increased fatty acid synthesis as well as increased uric acid.”

Too much uric acid is associated with gout, high blood pressure, cardiovascular disease, type 2 diabetes, metabolic syndrome and uric acid stones, a form of kidney stones.

Researchers counseled study participants on lower dietary sugar consumption for the management of diabetes. While the study population had overall lower levels of fructose consumption compared to the general population, the researchers found ATP depletion in people who consumed more fructose.

“The fact we found a difference in liver ATP stores at lower levels of dietary fructose intake does suggest that higher fructose consumption (as would occur with the consumption of processed food and sweetened beverages) could deplete the liver of energy and those risk causing worse metabolic problems and potentially even liver injury,” said Abdelmalek.

Fructose consumption on the rise

Fructose consumption has more than doubled in the past 30 years, according to the study.

Nonalcoholic fatty liver disease describes the accumulation of fat in the liver of people who drink little or no alcohol.

This common condition may cause no symptoms in many people. In others it can cause inflammation and advanced scarring (cirrhosis) in the liver, also known as nonalcoholic steatohepatitis. If severe, NFALD can progress to liver failure.

Sources: Duke University Health System, Mayo Clinic