Fructose may be key to weight gain

Mice that could not make or metabolize the sugar gained less than normal mice

Mice lacking the ability to metabolize fructose don’t gain nearly as much weight as normal mice do, researchers report September 10 in Nature Communications.

Fructose, which some people blame for the obesity epidemic and its related health crises (SN: 6/1/13, p. 22), shows up in high-fructose corn syrup and in table sugar, or sucrose. The body also makes home-grown fructose by modifying glucose in a process involving an enzyme called aldose reductase.

Richard Johnson of the University of Colorado Denver and his colleagues gave mice sugary drinking water that was 10 percent glucose for 14 weeks. Normal mice gained weight and developed fatty liver and insulin resistance, but mice lacking aldose reductase showed less weight gain and less severe related conditions.

The team got similar results when they gave the glucose water to mice engineered to lack fructokinase, an enzyme that trips the chain reaction by which fructose is metabolized. Mice lacking fructokinase had failed to develop these conditions when fed a diet high in fructose, their earlier work had shown.

The authors note that whether a high-glucose diet in people contributes to these medical problems via the same enzyme processes remains to be seen.

More Stories from Science News on Health & Medicine