The researchers said their aim is not to find the secret of eternal life, but to figure out the mechanism of the aging process to find ways to help people stay healthy for longer.
“We are not trying to cheat death, but help people be healthy and disease-free in their final years,” said Linda Partridge, a professor at University College London’s Institute of Healthy Aging and the Max Planck Institute for Biology of Aging who co-led the work.
The three drugs - the mood stabilizer lithium, a cancer treatment called trametinib and an immune regulator called rapamycin - target different cellular processes and had a “quite remarkable” impact on the flies’ lifespans, the scientists said.
And since the three drugs are all already in use as medical treatments, they are known to be safe to use in people, we have found that a combination drug treatment ... may be an effective way to slow down the aging process,” said Jorge Castillo-Quan, who co-led the research.
Partridge said the findings add to growing evidence that so-called polypills – pills that combine low doses of multiple drugs – could one day help prevent age-related diseases.
“This may be possible by combining the drugs we’re investigating with other promising drugs, but there is a long way to go,” she said.
This research adds to previous studies finding that individually, lithium, trametinib and rapamycin can each extend lifespan in fruit flies. That evidence has also been supported by further studies in mice and worms, the scientists said.
In this study, published in Proceedings of the National Academy of Sciences journal, Castillo-Quan’s team gave fruit flies doses of the three drugs separately and in combination.
Each drug individually extended lifespan by an average of 11%, they found, and pairing two drugs extended lifespan by around 30%. But when all three were combined, the fruit flies lived 48% longer than flies that did not get the treatment.
“We found it was quite remarkable that this drug combination enabled them to live 48% longer,” said Castillo-Quan, who now works at Harvard Medical School in the United States.
The researchers said they plan to conduct more studies to try to decipher exactly how the drugs work in combination with each other. They hope to move on to experiments in more complex animals, such as mice, to gauge the effects on the entire body before eventually progressing to human trials.