MODERATE eating may help promote a longer life, according to a study of so-called Methuselah mice, who lived to the equivalent in human age of more than 150 years thanks to a reduced diet. Scientists took a batch of rodents called Ames dwarf mice, a small ”mutant” mouse which enjoys longevity thanks to a well-explored variation, or allele, in a growth gene called Prop1. The batch was split up into two groups, one of which was given a sustained, normal diet, while the other had its food intake progressively reduced until it was 70% of normal levels. The slimline mice lived about 50% longer than their brethren who were on a normal diet, according to the team, led by Andrzej Bartke, of Southern Illinois University. The findings suggest that hormones play a key role in regulating lifespan, adjusting the mouse’s metabolism in response to food availability. ”Calorie restriction… seems to decelerate ageing, whereas the Prop1 allele seems to delay it,” the researchers report in Thursday’s issue of the British science weekly Nature. The Prop1 mutation has been found to give Ames dwarf mice a lifespan that is about 50-60% longer than ordinary mice. It brakes the onset of ageing, but does not prevent it. Similar genetic links have been spotted in the fruitfly, the roundworm and yeast, the other big laboratory favourites for research. – Sapa