The new study focused on extending the lifespan of a microscopic worm called Caenorhabditis elegans (C. elegans). This worm is often used in aging studies due to its biological simplicity that allows researchers to clearly and rapidly examine the effects of any genetic or drug intervention.

The research first set out to establish a variety of previously identified anti-aging biological pathways alongside drugs already proven to extend an animal’s lifespan in other experiments. The goal was to experiment with different drug combinations to identify the most promising cocktail for life-extension. With a view on ultimately transferring any results into human tests, the drugs examined were compounds either already approved for human use or already recognized as safe for mammals.

Five drugs were ultimately included in the experiments, including an antibiotic called rifampicin, an immunosuppressive agent called rapamycin, and metformin, a drug commonly used to treat type 2 diabetes. After extensive tests, the researchers discovered a novel triple-cocktail of rapamycin, rifampicin, and allantoin resulted in the best lifespan-extending effects.

The unique drug cocktail almost doubled the mean lifespan in C. elegans, a result that is notably the largest lifespan extension ever reported using a drug intervention in animals. It was also reported that no adverse health effects were seen, and the drug seemed to extend the worm’s healthspan as well.

The researchers confirmed the efficacy of this triple-combination drug in experiments with fruit flies, again finding significant lifespan extension from the treatment. It is hypothesized that since similar effects were seen in such distinct organisms, it is reasonable to conclude some universality in the aging pathways that this drug cocktail acts upon. The hope is that this means it is much more likely that similar results could be seen in humans.

“If we can find a way to extend healthy lifespan and delay aging in people, we can counteract the detrimental effects of an aging population, providing countries not only medical and economic benefits but also a better quality of life for their people,” says principle investigator on the study, Jan Gruber.

Gruber notes that this research is still in a proof-of-principle stage, meaning it is less about establishing specific anti-aging drug targets, and more about demonstrating how targeting multiple aging pathways simultaneously with a variety of drugs could effectively extend an animal’s lifespan.

Now that the researchers have shown this can be done, the next stages of the study will be to better understand how the different combinations of drugs interact with each other to delay aging. Computer models are planned to help rapidly test thousands of different molecular combinations in order to develop the most effective drug intervention to ultimately test in humans.