Fruit Sugars Might Speed Obesity
They may interfere with insulin to increase weight gain, experts say
THURSDAY, Dec. 15, 2005 (HealthDay News) -- Fructose, the sugar found in fruit, honey and the corn-syrup sweeteners used in many processed foods, may trick the body into thinking it's hungrier than it really is, researchers report.
The findings could explain why sweet foods help boost obesity rates in the United States and elsewhere.
In their studies with rats, researchers at the University of Florida identified fructose as part of a biochemical chain reaction that causes weight gain and other characteristics of metabolic syndrome, the precursor to Type 2 diabetes.
Fructose can also cause an increase of uric acid levels in the blood, the Florida team found. This temporary rise in uric acid blocks the action of insulin, the hormone that regulates how body cells use and store the sugar they need for energy.
If increased uric acid levels occur frequently enough, features of metabolic syndrome may develop over time, the researchers said. These features include obesity, elevated blood cholesterol levels and high blood pressure.
The Florida researchers fed rats a high-fructose diet for 10 weeks. All of the rats experienced an increase in uric acid in the bloodstream and also went on to develop insulin resistance.
"When we blocked or lowered uric acid, we were able to largely prevent or reverse features of the metabolic syndrome," Dr. Richard Johnson, professor of nephrology and chief of nephrology, hypertension and transplantation at the university's College of Medicine, said in a prepared statement. "We were able to significantly reduce weight gain, we were able to significantly reduce the rise in the triglycerides in the blood, the [rats'] insulin resistance was less and the blood pressure fell."
The research appears in the December issue of the journal Nature Clinical Practice Nephrology and in the online edition of the American Journal of Physiology-Renal Physiology.
The American Heart Association has more about metabolic syndrome.