Fructose affects obesity-linked hormone in rat study
October 24, 2008
by Jeff Gelski
GAINESVILLE, FLA. — Rats fed a diet high in fructose for six months became resistant to leptin, an appetite-control hormone, according to a University of Florida study. Results of the study appeared in the American Journal of Physiology – Regulatory, Integrative and Comparative Physiology.
"Leptin resistance is a condition that leads to obesity in rats when coupled with a high-fat diet," said Dr. Philip J. Scarpace, a professor of pharmacology and therapeutics in the University of Florida’s College of Medicine and senior author of the study. "The surprising finding here was that increasing the amount of fructose in the diet without increasing the amount of calories led to leptin resistance and later exacerbated obesity when paired with a high-fat diet."
While fructose itself may not cause obesity, it most likely blocks leptin’s entry into the brain, thus affecting appetite control and leading to obesity, the researchers said.
The researchers studied two groups of rats. Both groups received the same number of calories each day. One group received chow containing 60% fructose. The other group consumed a fructose-free diet. The rats on the high-fructose diet became resistant to leptin while the other rats did not. Both groups had identical levels of body weight and fat and blood levels of leptin, insulin, glucose and cholesterol.