Researchers in Germany have turned blood cells from an 80-year-old into stem cells with a molecular age of less than 20 years. The team, from the University Hospital of Bonn and the University of Bonn, did this in a test tube, and the slow pace of this cell rejuvenation is exactly what makes it useful to scientists. The study was published in the journal Aging Cell.
Before anyone gets excited about reversing their own age, an important point: this happened to cells in a lab dish. It is not a treatment, and no person was made younger.
How cell reprogramming works
Every cell in your body carries the same DNA, but each one is committed to a job. A skin cell doesn’t naturally become a liver cell, and a blood cell doesn’t become a nerve cell. In the lab, though, scientists can reverse this using a cocktail of proteins called transcription factors, which make a cell read different genetic instructions and take a new path.
“Using this method, we have directly converted red blood cell precursors into neural stem cells,” said Prof. Dr. Oliver Brüstle, Director of the Institute of Reconstructive Neurobiology at the University Hospital of Bonn. Neural stem cells are the cells that can go on to form neurons.
Resetting the molecular clock
To measure age at the cell level, the team used “epigenetic clocks”. These track chemical changes on DNA that build up as we age. The changes don’t alter the genetic code itself, but they affect how often that code is read.
During reprogramming, these clocks were reset sharply. Cells from an 80-year-old ended up with a molecular age below 20. “We also know that this epigenetic rejuvenation ensures that the cells actually behave like young cells,” Brüstle said.
Why slow is actually useful
Rejuvenation during reprogramming was already known, but mostly in a two-step method: blood cells are first turned into pluripotent stem cells, which can become almost any cell, and then into neural stem cells. In that route, the rejuvenation happens very quickly.
The Bonn team skipped the pluripotent stage and went straight from blood cells to neural stem cells. Here, rejuvenation happened gradually and could be tracked for over 100 days. That slow reset gives researchers a long window to test which factors or substances speed up or slow down the process.
Brüstle points to brain health as a key reason to care: “After all, age is the most important risk factor for neurodegenerative diseases such as Alzheimer’s!” In earlier work, the same group showed that nerve cells made this way formed connections with existing neurons after being transplanted into the brains of mice.
What it doesn’t tell us yet
This is early-stage lab research. The headline result describes cells, not people, and the announcement doesn’t claim any treatment is close. Anti-ageing is also an area full of bold marketing claims, so it’s worth reading headlines like “rejuvenated cells” carefully. Questions about safety, and whether any of this could ever be used in patients, would need far more research to answer.
Why this matters
As a writer, I feel this is a good example of science that is genuinely exciting but easy to misread. “60 years younger” makes a great headline, and I’ll admit it caught my eye too. But what I find more interesting is the slow-motion part: a model that lets scientists actually watch ageing being undone in cells, step by step. If that helps us understand diseases like Alzheimer’s better, that’s valuable on its own. Whether it ever leads to treatments is a question I’d leave open for now, and I’d encourage you to be sceptical of anyone selling “cell rejuvenation” as a product today.
Related reads on TechStory Corner: why brain health could unlock $6.2 trillion in global GDP and Cambridge scientists find a hidden layer of DNA information.