Is Fructose the Key to Weight Gain?

According to a newly published study from the University of Colorado, mice models that lack the ability to metabolize fructose don’t gain nearly as much weight as normal ones. Fructose, or fruit sugar, has gained quite a bit of notoriety of late – especially in relation to obesity and its myriad related health concerns. Fructose can be found naturally, in fruit and honey, as well as in table sugar (sucrose) and high fructose corn syrup. The body also creates its own fructose through a process that utilizes enzymes called aldose reductase to modify glucose. The University of Colorado at Denver study began by giving mice models sugared drinking water for 14 straight weeks. As expected, the normal mice gained weight and developed fatty livers and insulin resistance after consuming the 10 percent glucose water. However, it was the mice lacking aldose reductase that surprised the researchers. Not only did they gain less weight, overall, but they also suffered fewer and less severe related conditions. When the experiment was repeated a few weeks later – this time with mice engineered to be lacking in fructokinase, the enzyme that begins the reactions by which fructose is metabolized – the team reached identical results. Even when fed a high fructose diet, the mice lacking fructokinase didn’t gain nearly as much weight as their counterparts. Whether or not a high glucose diet in people contributes to obesity via the same enzyme process remains to be tested, but the findings are an important first step in the study of the link between obesity and fructose.