Widespread use of the sweetener fructose may be directly responsible for some of the ongoing increase in rates of childhood diabetes and obesity, according to a study conducted by researchers from the University of California-Davis and published in the Journal of Clinical Investigation.
Fructose is a sugar that naturally occurs in low amounts in fruits and vegetables, making up as much as 5 to 10 percent of any given fruit by weight. In 1971, however, scientists discovered a way to synthesize a cheap syrup composed of 55 percent fructose and 45 percent glucose. Because normal table sugar is composed of only 50 percent fructose and 50 percent glucose, the sweetener was dubbed “high fructose corn syrup” (HFCS) and quickly became the most popular sweetener in the U.S. food and beverage industry.
HFCS is six times sweeter than sugar and costs only half as much.
Researchers put 16 volunteers on a controlled diet, supplemented with either fructose (derived from corn) or glucose. After 10 weeks, both groups of participants had gained equal amounts of weight. Participants in the fructose group, however, showed an increase of fat cells around major organs including their hearts and livers, and also underwent metabolic changes that are precursors to heart disease and diabetes.
“This is the first evidence we have that fructose increases diabetes and heart disease independently from causing simple weight gain,” lead researcher Kimber Stanhope said. “We didn’t see any of these changes in the people eating glucose.”
The effect seems to occur because fructose is not broken down in the digestive system like other sugars are. Instead, it moves directly into the liver, where it interferes with that organ’s ability to process fat.
The researchers noted that over the long term, participants on the fructose diet would also have gained more weight.
Health professionals agree that everyone could stand to cut back on their sugar intake.
“Historically, we never consumed much sugar,” said Barry Popkin of the University of North Carolina, and a health policy adviser for the U.S. government. “We’re not built to process it.”