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Many people would like to live for a long time, though often only on the condition that they remain as healthy and active as possible. We would all be happy if we could be spared illness and physical limitations. Although products and tablets which claim to slow the ageing process are big business, no genuinely effective formula to combat ageing has yet been found.

A fresh-water organism that does not age

Dr Ralf Schaible

A tiny organism is one important step ahead of the health and beauty industry. As the biologist Dr Ralf Schaible and his colleagues from the Max Planck Institute for Demographic Research in Rostock have discovered during the course of a research project, the Hydra – a fresh-water polyp that is as thin as a pin and no more than a centimetre long – does not age. They have studied more than 1,800 Hydra in the lab since 2006. Each lives in its own dish of mineralized water at a constant 18 degrees Celsius.

What do researchers mean by ageing?

Bakterium

So what exactly do Dr Schaible and his colleagues mean when they talk about ageing? “For demographers, ageing refers to the risk of dying at a certain age. In humans this risk increases, but it does not in Hydra”, explains Schaible. Related to the jellyfish, this organism is not immortal nonetheless. Hydra normally live in waterways such as ponds and lakes, where they have natural predators which can eat them. Such predators are not present in the lab. “Our Hydra can live for several centuries, and their risk of dying always remains the same”, says the researcher. “They tend to die as the result of an accident, for example because they get stuck to the lid of the dish or fall onto the floor.” In other words, the reason they die has nothing to do with their age.

Why do Hydra not age?

As anyone who has ever had a minor cut on their finger knows, it disappears almost completely within just a few days. The skin cells renew themselves – a capability that the Hydra also has, though to a different extent. In this fresh-water organism it is the stem cells which renew themselves: if you cut one in half, each of the two halves grows into a complete new individual within a matter of days. Rather than decaying, the Hydra’s body renews itself time and time again. This is the secret to its longevity.

An end to human ageing?

Does this finding mean an end to human ageing? Ralf Schaible waves this suggestion aside, saying that although it is conceivable that humans have a similar genome that is perhaps not activated, this is merely speculation and does not fall within his current remit. The results are of interest all the same, for example in cancer research. “Cancer cells regularly divide and, much like Hydra, are virtually immortal”. Once it has been clarified how exactly Hydra renew their damaged cells, this could prove extremely beneficial for stem cell research.

The Hydra will remain the focus of the biologist’s work until the end of 2017 – when his Max Planck Society- funded project comes to an end. “There is no comparable database about the Hydra ageing process anywhere in the world – this could form the basis for many other projects.”