Calorie restriction diets have previously been shown to slow down the ageing process, and strangely enough, a common ingredient in face creams appears to mimic these life-extending effects – and all without the pain of going hungry.

Researchers in the UK have found that allantoin, a chemical compound found in botanical extracts of the comfrey plant and an ingredient in many anti-ageing skin creams, can increase the lifespan of certain worms by more than 20 percent – comparable to the manner in which calorie restriction achieves the same effect.

If drugs developed for humans could reproduce this, it's possible that we could help slow down the clock when it comes to genetic ageing – and 20 percent extra lifespan is a pretty amazing boost to try to replicate.

"Calorie restriction has been shown to have health benefits in humans and, while more work is necessary, our findings could potentially result in human therapies for age-related diseases," said João Pedro de Magalhães, a researcher in ageing genomics at the University of Liverpool.

To identify what kinds of compounds might mimic the effects of calorie restriction in humans, the team sourced data from the Connectivity Map, a comprehensive database of molecular signatures from human cells treated with a variety of small-molecule drug candidates.

Using pattern-matching algorithms to find links between drug compounds and the effects of calorie restriction, the researchers found 11 potential matches, and tested five of the compounds on nematode worms.

What they found was that allantoin, and three of the other compounds – rapamycin, trichostatin A, and LY–294002 – made the treated worms live healthy lives for longer. Three of the compounds, including allantoin, also extended the lifespan in a strain of mutant worms via anti-ageing mechanisms similar to the way in which calorie restriction works.

"We have shown so far that our compounds work in worms, but studies in mammalian models are now necessary," said one of the team, Shaun Calvert. "The next step for us is to understand the mechanisms by which allantoin extends lifespan, as this could reveal new longevity pathways."

If those same pathways can be effected in humans – although there's no guarantee they will be, as many results from experiments on animals are not replicated in people – it may well mean we can find ways to live longer, and do so without the pain, inconvenience, and risks of committing to so-called starvation diets.

"We have known for many years that caloric restriction diets increase lifespan in all manner of organisms," said Stephen Simpson from the University of Sydney in Australia), in reference to separate research he published earlier in the year. "However, except for the fanatical few, no one can maintain a 40 percent caloric reduction in the long term, and doing so can risk loss of bone mass, libido and fertility."

The findings have been reported in Aging Cell.