A new study by the Beckman Institute for Advanced Science and Technology at the University of Illinois, determined that fructose contributes to significant weight gain, physical inactivity and body fat deposition.
Fructose, especially high corn fructose syrup, has been associated with significant adverse health effects. High-fructose corn syrup is one of the main ingredients in soft drinks and in processed baked goods, and accounts for 10 percent of caloric intake for U.S. citizens. Male teenagers are the group that has been associated with the highest consumption of corn fructose consuming 15 to 23 percent of their calories from fructose.
The study used a mouse model and studied two groups of mice for two and a half months; one group was exposed to a diet consisting of 18% fructose, mimicking the intake of adolescents in the United States, and the other was fed 18 percent from glucose.
“The link between increases in sugar intake, particularly fructose, and the rising obesity epidemic has been debated for many years with no clear conclusions,” said Catarina Rendeiro, a postdoctoral research affiliate at the Beckman Institute for Advanced Science and Technology and lead author on the study. “The reality is that people are not only consuming more fructose through their diets, but also consuming more calories in general. “One of the key questions is whether an increase in fructose intake contributes to obesity in the absence of excessive calorie intake.”
“The important thing to note is that animals in both experimental groups had the usual intake of calories for a mouse,” said Rendeiro. “They were not eating more than they should, and both groups had exactly the same amount of calories deriving from sugar, the only difference was the type of sugar, either fructose or glucose.”
The research findings determined that fructose caused an excess in body fat, contributing to obesity and lowered physical activity. The exact metabolic pathway still has to be investigated.
“Biochemical factors could also come into play in how the mice respond to the high fructose diet,” explained Jonathan Mun, another author on the study. “We know that contrary to glucose, fructose bypasses certain metabolic steps that result in an increase in fat formation, especially in adipose tissue and liver.”
“We designed this study based on the intake of fructose by adolescents in the United States,” said Rhodes. “Our study suggests that such levels of fructose can indeed play a role in weight gain, favor fat deposition, and also contribute to physical inactivity. Given the dramatic increase in obesity among young people and the severe negative effects that this can have on health throughout one’s life, it is important to consider what foods are providing our calories.”
Catarina Rendeiro, Ashley M. Masnik, Jonathan G. Mun, Kristy Du, Diana Clark, Ryan N. Dilger, Anna C. Dilger, Justin S. Rhodes. Fructose decreases physical activity and increases body fat without affecting hippocampal neurogenesis and learning relative to an isocaloric glucose diet. Scientific Reports, 2015; 5: 9589 DOI: 10.1038/srep09589