Corn refiners challenge validity of fructose study
linking fructose in soft drinks with added body fat
"mischaracterizes high fructose corn syrup".
A recent University of Cincinnati study asserted that the body processes high fructose corn syrup (HFCS) differently than other sugars due to the fructose content, leading to greater fat storage.
But Corn Refiners Association managing director Audrae Erickson argues that the scientists are wrong to draw a direct comparison between the experiments on rats and human consumption of soft drinks.
"This study unfortunately confuses pure fructose with HFCS," she told FoodNavigator-USA.com.
"HFCS used in US caloric soft drinks is either 55 percent fructose or 42 percent - not the mixture of pure 100 percent fructose dissolved in water that was used in this study."
Researchers at the University of Cincinnati allowed mice to freely consume either water, fructose sweetened water or soft drinks. They found increased body fat in the mice that drank the fructose-sweetened water and soft drinks - despite that fact that these animals decreased the amount of calories they consumed from solid food.
This, claimed author Matthias Tschöp, MD, associate professor in UC's psychiatry department and a member of the Obesity Research Center at UC's Genome Research Institute, suggests that the total amount of calories consumed when fructose is added to diets may not be the only explanation for weight gain.
Instead, he said, consuming fructose appears to affect metabolic rate in a way that favors fat storage.
But Erickson contends that HFCS also importantly contains glucose, and in about the same proportions as found both in the sucrose-sweetened soft drink used in the study and in table sugar.
By contrast the pure fructose used in the study had no glucose component.
"The absence of glucose makes pure fructose fundamentally different from HFCS," she said. "This is because glucose has been shown to have a tempering effect on specific metabolic effects of fructose."
Once the combination of glucose and fructose found in HFCS and sucrose are absorbed into the blood stream - and regardless of whether they come from beverages sweetened with HFCS or withsucrose - the two types of sweetener appear to be metabolized similarly using well-characterized metabolic pathways.
"This study actually confirmed the tempering effect of glucose on weight gain," said Erickson. "Mice given the soft drink with sucrose - like HFCS, it contains approximately equal amounts of fructose and glucose - did not show significant body weight gain or increased body fat."
As a result, Erickson argues that the conclusions from the study, while important, cannot be extrapolated to HFCS-sweetened soft drinks. The study compares water, a sucrose soft drink and a diet soft drink - all widely used in the human diet - with a fluid fabricated from pure fructose and water that is found nowhere outside the laboratory.
"As a natural, nutritive sweetener, HFCS can be enjoyed as part of a balanced diet," said Erickson.
