Sugar may have a harmful effect on life expectancy

A spoonful of sugar might help your life expectancy go down, new research suggests.

US scientists found that adding just a small amount of glucose sugar to the bacteria diet of laboratory worms cut the creatures' lifespans by a fifth.

The effect was traced to insulin signalling pathways - which exist in humans as well as simple worms.

This raised the possibility that "glucose may have a lifespan-shortening effect in humans" the researchers wrote in the journal Cell Metabolism.

On the other side of the coin, glucose is a vital source of energy without which cells cannot function.

The tiny worm Caenorhabditis elegans is a standard laboratory tool often used in studies of metabolism.

Scientists led by Dr Cynthia Kenyon from the University of California at San Francisco, carried out experiments in which worms were fed small amounts of glucose.

They found that giving sugar to the worms reduced their normal lifespan by about 20 per cent. Glucose affected insulin signals and genes and proteins previously shown to extend lifespan in C. elegans.

In particular, a sugary diet blocked the transport of glycerol, part of the process by which the body produces its own glucose.

Dr Kenyon said the findings may have implications for new diabetes drugs now in development that inhibit glycerol channels.