Scientists have stopped the ageing process in an entire organ for the first time, a study released today says. Researchers at the Albert Einstein College of Medicine ... also say the older organs function as well as they did when the host animal was younger. The researchers, led by Associate Professor Ana Maria Cuervo, blocked the ageing process in mice livers by stopping the build-up of harmful proteins inside the organ's cells. As people age their cells become less efficient at getting rid of damaged protein resulting in a build-up of toxic material that is especially pronounced in Alzheimer's, Parkinson's and other neurodegenerative disorders. The researchers say the findings suggest that therapies for boosting protein clearance might help stave off some of the declines in function that accompanies old age. In experiments, livers in genetically modified mice 22 to 26 months old ... cleaned blood as efficiently as those in animals a quarter their age. The benefits of restoring the cleaning mechanisms found inside all cells could extend far beyond a single organ, says Cuervo. Our findings are particularly relevant for neurodegenerative disorders such as Parkinson's and Alzheimer's," she says. "Many of these diseases are due to 'misbehaving' or damaged proteins that accumulate in neurons. By preventing this decline in protein clearance, we may be able to keep these people free of symptoms for a longer time." If the body's ability to dispose of cell debris within the cell were enhanced across a wider range of tissues, she says, it could extend life as well.