• Question: Do you know how long the human life span can be extended?

    Asked by Daisy to Ahmed, Francesca, George, James, Nitheen on 7 Nov 2014.
    • Photo: James Sullivan

      James Sullivan answered on 7 Nov 2014:

      Hi Daisy,
      Thanks for this – an important question.
      There is no clear answer to this. Medicines and medical techniques, and improvements to our diets and lifestyles will result in increased life expectancy for humans.
      As to whether there is a limit to how old someone can get – I don’t know the answer to that question. And this is not my area.
      There is a theory that there are a limited number of times a cell can divide and replicate – below is my stab at what I understand about this.
      When our cells divide to generate daughter cells which replace damaged tissue, the replication of DNA is an important step in the process.
      There are lengths of bases at either end of a DNA strand called telomeres. Their role is to protect the strand of DNA. Every time a DNA strand replicates this telomere gets shorter, and eventually it becomes too short and the DNA can no longer replicate (so damaged tissue cannot be replaced). This suggests that at some stage our cells will no longer be able to replace themselves.
      I hope this helps. You might also ask in the evolution zone (where the biologists are).
      James

    • Photo: George Dowson

      George Dowson answered on 8 Nov 2014:

      There’s not a lot I can add to James’ answer except to highlight the fascinating work being done by the Methusalah Mouse project.
      This project has two aims, to see if we can breed a mouse that lives significantly longer than a normal mouse and to take a normal mouse and extend its lifespan.
      Both areas have yielded interesting results looking at both diet and things like blood transfusions between young mice and old ones that looks very promising. I would recommend this as a good place to start looking if you’re interested in extending human longevity (lifespan).

      Methusalah was a Biblical man who lived to a very old age, hence the name of the project!

    • Photo: Ahmed Osman

      Ahmed Osman answered on 10 Nov 2014:

      To be Honest I watched last week a documentary movie about the End Of The World and I think we are very near from that.

    • Photo: Francesca Paradisi

      Francesca Paradisi answered on 10 Nov 2014:

      Very good answers from James and George, I can only make some further comments on how we have managed to “immortalise” cells for replication in the lab. Very similarly to what happens to cancer cells that do not stop dividing, we can block the natural death of a cell after a few cycles of divisions like James explained. We are nowhere near being able to apply this process in a control manner to a whole organism, and even if we could, I am not sure it would be a good idea!

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