The human organ is less than three years old when attached to someone younger than it, according to new research.

Using mathematical modeling and a technique called retrospective birth dating, scientists have found that the renewal of the liver is unaffected as we grow.

The primary function of the liver is to clear toxic substances out of the body. The waste removal takes a toll on the organ, but it can be regenerated after being damaged.

"No matter if you are 20 or 84, your liver stays on average just under three years old," says Bergmann from the Dresden University of Technology in Germany.

The team analyzed tissue samples from more than 50 people. Our biology keeps a tight control over the mass of the liver throughout our lives.

The cells are under analysis. Paula Heinke is a person.

Our bodies are less able to carry out repairs as they get older. The new study shows that this doesn't apply to the hepatocytes. There is more clarity in the results of animal studies.

A small fraction of the cells can live to be 10 years old. It seems to be related to how many sets of chromosomes they have.

Our entire genome is carried by most cells in our body. The proportion of cells that generate more copies of our whole DNA library is odd.

Bergmann says that the cells richer in DNA can reside in the liver for up to a decade.

As this fraction gradually increases with age, it could be a protective mechanism that protects us from harmful mutations. We need to find out if there are similar mechanisms in chronic liver disease, which can lead to cancer.

The more we know about how the body works, the better we can figure out how to keep it healthy and cure it from disease.

The researchers are looking at the heart to see how quickly cells are regenerated. The same technique can be used to date cells and work out renewal rates.

It is one of the best methods for figuring out the age of human tissue, using the decay rates of radiocarbon in the atmosphere to correspond to traces in the body. Your organs may not be as old as you think.

Bergmann says that their research shows that studying cell renewal directly in humans is technically very challenging but it can provide unparalleled insights into the underlying cellular and molecular mechanisms of human organ regeneration.

The research has been published.