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.
