Medical practice

Another cell study spun as 'age-reversing miracle'

Those of us concerned that we may not be looking as young as we used to have received an early Christmas present according to various news outlets.

The Mail Online tells us that, "the secret of looking up to 40 years younger" has been identified by scientists in the US.

Sadly, this Christmas present fails to deliver. The research in question was only carried out in mice and didn't focus on reducing their wrinkles.

What the scientists actually did was identify why the "power houses" of cells – mitochondria – perform less well as cells age.

The scientists used a chemical to reverse this process, making the muscle cells of 22-month-old mice more like those of six-month-old mice.

As yet we don't know what the long-term effects of this treatment are in mice, or whether it has any effect on the more visible and life-changing effects of ageing, rather than just on cells.

A press release for this study leaves readers with the impression that the findings apply to humans. It says that the effect "would be like a 60-year-old converting to a 20-year-old in these specific areas".

But we don't know what effect the treatment will have on humans yet. While we might like to think that scientists have found the elixir of youth, there's still a considerable way to go.

Where did the story come from?

The study was carried out by researchers from Harvard Medical School and other research institutions in the US, Portugal and Australia. The researchers and their labs were supported by grants from various national institutes, research councils and charitable foundations. It was published in the peer-reviewed scientific journal, Cell.

A press release from Harvard University has prompted many news sources to prematurely extend these findings to humans, saying that the effect they saw in mice "would be like a 60-year-old converting to a 20-year-old in these specific areas".

The Mail's headline is misleading, as the study did not look at reversing the effects of ageing on a person (or even a mouse's) appearance. To its credit, the Mail Online story does include a picture of a mouse, so it is clear that this is not human research.

The BBC News website takes the opposite tack – their headline makes it clear that this is animal research, but illustrates the story with a picture of an elderly person. But the BBC does make it clear in its reporting that these tests were on mouse muscle rather than skin. It also balanced its story by making it clear that ageing is a complex process and would not be entirely reversed by this approach alone.

What kind of research was this?

This was animal research looking at what happens to the mitochondria – the "power generators" of the cells – during ageing. As cells get older, the mitochondria in them gradually work less well. This influences the ageing of the cell and the animal as a whole.

The researchers wanted to know why this happens. They thought this might help them understand how this process could be reversed.

This type of research into how cells work and change is often more feasible to carry out in animals, such as mice, rather than humans.

What did the research involve?

The researchers carried out a series of experiments. They started by looking at what happens to energy production in the mitochondria found in mouse muscle as the mice age.

Mitochondria contain DNA that carries instructions (genes) for making some of the important proteins they need to produce energy for the cell. The instructions for making other proteins involved in this process are in the DNA of the chromosomes, and these are found in another part of the cell called the nucleus.

The researchers tried to pinpoint which proteins involved in the process were not working as well, and whether the genes that produce them were found in the mitochondria or in the nucleus.

They then looked at whether these genes might be producing less of these proteins as the cells age and what might cause this. Finally, they took what they learnt and tried to see if they could reverse the process and make older mitochondria perform as well as younger mitochondria.

What were the basic results?

The researchers found that the energy production in the mitochondria performed less well as mouse muscles aged. They found that the proteins that work less well as the cell aged were the ones that were produced from genes in the mitochondria themselves. They also found that these genes became less active as the cells aged and therefore less of the proteins were produced.

A series of complex experiments then allowed the researchers to work out parts of the complex chain of events that leads to these changes. A decrease in a chemical called NAD+ in the nucleus of the cell was found to be the key trigger for these events.

Giving 22-month-old mice a chemical that increased the levels of NAD+ in the cells over a week led to increased levels of activity of mitochondrial genes, and reduced some of the other signs of ageing in the cells to the levels of a six-month-old mouse.

If the ageing was truly reversed by this treatment, these older mice might be expected to have increased strength in their muscles, which weaken as they age. However, the mice's muscle strength did not improve after the treatment. The researchers suggested that this might be because longer treatment might be needed to have this effect.

How did the researchers interpret the results?

The researchers concluded that they have identified a new pathway that causes some of the changes seen in ageing cells.

They say that this pathway is "readily reversible" and that this has "implications for treating ageing and age-related diseases".


This research has shown that some of the changes in cells that occur with ageing can be reversed in mice in the short term. The longer term effects of the treatment used in this study on mice are not yet known.

The treatment did not reverse the age-related weakening of the mice's muscles, so the researchers will need to show if it can have an effect on this or other wider consequences of ageing. Whether the findings apply to humans also remains to be seen.

Ageing is a complex process. As BBC News rightly points out, this treatment is unlikely to be a "cure-all for ageing", as it only targets one aspect. While it's tempting to think that scientists have found the elixir of youth, there's a considerable way to go yet.

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