Fructose more toxic than table sugar: study

High-fructose corn syrup found in many processed foods is more toxic than sucrose or table sugar, a new study in mice has found.
University of Utah biologists fed mice sugar in doses proportional to what many people eat, the fructose-glucose mixture found in high-fructose corn syrup was more toxic than sucrose or table sugar, reducing both the reproduction and lifespan of female rodents.
"This is the most robust study showing there is a difference between high-fructose corn syrup and table sugar at human-relevant doses," said biology professor Wayne Potts, senior author of the study.
The study found no differences in survival, reproduction or territoriality of male mice on the high-fructose and sucrose diets. The researchers say that may be because both sugars are equally toxic to male mice.

Both high-fructose corn syrup found in many processed foods and table sugar found in baked goods contain roughly equal amounts of fructose and glucose.
But in corn syrup, they are separate molecules, called monosaccharides. In contrast, sucrose or table sugar is a disaccharide compound formed when fructose and glucose bond chemically.

The new study is the latest in a series that used a new, sensitive toxicity test developed by Potts and colleagues. It allows house mice to compete in the semi-natural environment of room-size "mouse barns."
The study compared two groups of mice that were fed a healthy diet with 25 per cent calories from processed sugars. One group ate a mix of fructose-glucose monosaccharides like those in high-fructose corn syrup. The other group ate sucrose.

Female mice on the fructose-glucose diet had death rates 1.87 times higher than females on the sucrose diet. They also produced 26.4 per cent fewer offspring.
The new study found no differences in males on the two diets in terms of survival, reproduction or ability to compete for territory.
But Potts said a 2013 study showed male mice were a quarter less likely to hold territory and reproduce on the fructose-glucose mix compared with starch.
That, combined with the new findings, "suggests sucrose is as bad for males as high-fructose corn syrup," he said.
Ruff said it also is possible that "other factors are more important than the differences between these two diets for the males" - possibly inherited differences in ability to hold territory.

Potts said female mice that ate the fructose-glucose mixture may be more likely to die than male mice because they undergo a bigger metabolic "energy crunch" during such studies: on the day they give birth, they mate and conceive the next litter, so they are nursing their first litter while gestating a second litter.
The study was published in The Journal of Nutrition.