The cocktail of amino acids – building blocks of proteins – was found to increase the lifespan of mice by 12 per cent.
Researchers believe it may also benefit humans, especially the elderly or sick.
In laboratory experiments, middle-aged male healthy mice were given drinking water laced with three specific amino acids.
The animals lived significantly longer than other mice fed a normal diet.
Their lifespan range had a midpoint of 869 days compared with 774 days for untreated mice, a difference of 12 per cent.
Longer survival was accompanied by biological changes which boosted the energy supply to cells and reduced oxidative damage caused by destructive molecules called free radicals.
The treated mice had more stamina and improved muscle co-ordination.
“This is the first demonstration that an amino acid mixture can increase survival in mice,” said study leader Dr Enzo Nisoli, from the University of Milan in Italy.
Last year scientists showed that the same amino acids, leucine, isoleucine and valine, could extend the lifespan of single-celled yeast.
The new findings, reported in the journal Cell Metabolism, raise the possibility of amino acid supplements benefiting humans.