If worms are any indication, all the sugar in your diet could spell much more than obesity and type 2 diabetes. Researchers reporting in the November issue of Cell Metabolism, a Cell Press publication, say it might also be taking years off your life. By adding just a small amount of glucose to C. elegans usual fare of straight bacteria, they found the worms lose about 20 percent of their usual life span. They trace the effect to insulin signals, which can block other life-extending molecular players. Although the findings are in worms, Cynthia Kenyon of the University of California, San Francisco, says there are known to be many similarities between worms and people in the insulin signaling pathways. (As an aside, Kenyon says she read up on low-carb diets and changed her eating habits immediately – cutting out essentially all starches and desserts -- after making the initial discovery in worms. The discovery was made several years ago, but had not been reported in a peer-reviewed journal until now.) "In the early 90s, we discovered mutations that could double the normal life span of worms," Kenyon said. Those mutations effected insulin signals. Specifically, a mutation in a gene known as daf-2 slowed aging and doubled life span. That longer life depended on another "FOXO transcription factor" called DAF-16 and the heat shock factor HSF-1. Now, the researchers show that those same players are also involved in numbering the days of worms who are fed on glucose. In fact, glucose makes no difference to the life span of worms that lack DAF-16 or HSF-1, they show. Glucose also completely prevents the life-extending benefits that would otherwise come with mutations in the daf-2 gene.
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