New discovery: The age of most people's liver is only... 3 years old

A study published last week showed that the human liver remains young even as we age. Using a radioactive aging technique, the researchers estimated that the average age of human liver cells is about 3 years old. However, some cells seem to live longer than others, and the discovery may help scientists better understand why, as well as the conditions that predispose many diseases such as cancer, to cancer. liver occurs again.

The above study was carried out by a group of scientists from the University of Technology Dresden (Germany). They sought to estimate the lifespan of liver cells collected from more than 30 people who have died of various diseases, ranging in age from 20 to 84. To do that, they relied on a technique called "radiocarbon dating back", which was developed in the early 2000s.

The level of radiocarbon activity in the environment has fluctuated in recent decades due to the start and end of ground-based nuclear weapons tests. And because traces of radioactive carbon in the environment can be found in the DNA of plants and animal cells, scientists can use radiocarbon as a "barometer" to find out the age of a cell. cell. The older the cell, the more radioactive carbon is likely to exist in its DNA.

The average age of human liver cells is about 3 years old.

When the team traced the birth dates of liver cells from the sample group, they discovered a common feature regardless of the age of the liver owners: most of the liver cells were young and roughly the same age. each other's age. They then estimated that most liver cells replace themselves about once a year, and on average, our livers are less than 3 years old!

The liver is known for its endurance and rapid recovery - an important trait for an organ that must constantly filter harmful substances from our bodies. But the researchers say they still don't know much about how the liver renews itself, and whether this resilience wanes over time. Research shows that the liver can stay young even in an aging body.

On the other hand, as we age, it seems that the liver will also have corresponding changes. Some cells in the liver can carry more than two sets of chromosomes and still function properly, unlike most other cells in the body. The team found that these DNA-containing cells are able to live much longer than other liver cells - up to a decade - and that the human liver seems to accumulate more and more cells. such cells. Therefore, researchers believe that this change is the cause of our liver's long-term health. And if that's true, people's risk of liver-related health problems can also be increased when the above process doesn't go as planned.

"Since the number of such cells increases with age, it could be a mechanism to protect us from accumulating harmful mutations," said study author Olaf Bergmann, a long-term researcher. years at the Dresden Regenerative Therapy Center. "We need to find out if there are similar mechanisms in chronic liver disease, which in some cases can turn cancerous."

The team's findings will be evaluated by other research groups before being incorporated into the medical academic literature. But their same study earlier this year showed evidence that certain brain cells can renew themselves even as we age - which is quite coincidental with this study. The team's next plan is to find out if the heart cells of people with chronic heart disease still retain the ability to regenerate!