• Question: Why do people age?

    Asked by olirose to Amy, Alex, Andy, Georgia, Ollie on 22 Jun 2011. This question was also asked by luvponies1404.
    • Photo: Amy Reeve

      Amy Reeve answered on 13 Jun 2011:


      This is a very good question :). People have different ideas about why people age. Some people believe that our bodies and organs only have a limited lifespan, they can only survive for a certain length of time. For example our hearts can only beat a certain number of times before they wear out.

      Other people think that we age because our cells get damaged, and as we get older this damage builds up and our cells stop working properly.

      A lot of research is going on to slow down this ageing process so that we can potentially live longer. In my lab we are trying to understand what makes old people more likely to develop diseases like Parkinson’s disease and Strokes. We want to understand this so they are healthier for longer, rather than making them live for longer.

      Thanks for your question.

    • Photo: Ollie Russell

      Ollie Russell answered on 21 Jun 2011:

      Hi oli and iluvponies,

      This is a really good question! There are a couple of answers for it. Amy has covered the cell biology side of it, but there are also evolutionary theories as to why we age.

      Animals in the wild hardly ever reach and age where they can suffer from old age, so why do humans reach a point where there bodies stop working? Some people believe that animals dont get old because they dont use there energy to protect there cells from damage. Instead they use this energy to make it more likely that they will reproduce. This means that they can pass on their genes to the next generation.

      Humans are obviously different as we from lasting realtionships and we essentially have a choice as to whether we reproduce or not. Therefore our cells can use this energy to maintain themselves better, so we get older. Unfortunately this cant last forever so things eventually go wrong with the cells and you get symptoms of ageing.

    • Photo: Georgia Campbell

      Georgia Campbell answered on 21 Jun 2011:

      Hi olirose and luvponies1404, thanks for your question 🙂

      Aging happens when things start to go wrong with the cells that make up all of the different parts of your body. Cells can accumulate damage from all sorts of sources – environmental damage, UV damage, toxins from bad foods smoking or alcohol, and nasty waste products from the jobs your cells need to do are just some of the causes of this damage! Over time this damage all adds up, and some cells will start to get sick and die, and this causes your body to stop working as efficiently and you start to age.

      The reason we are healthy for so long, and then seem to age so rapidly, is probably due to all the changes we’ve made to our own envirnoment! Over the last few hundred years we’ve made so many advances in science, technology and medicine that we can overcome a lot of illnesses and disabilities and so the average human life is a lot longer now than it used to be. However, in evolutionary terms, a few hundred years really isn’t very long! And this means we haven’t adapted to our longer life-spans yet, and that’s probably why we struggle to age healthily after a certain point.

      Hope that answers your question! 🙂

    • Photo: Andy MacLeod

      Andy MacLeod answered on 22 Jun 2011:

      Hi guys. Thanks for your question.

      Our bodies are constantly changing over time. As old cells die, new ones come to replace them. But eventually, that process wears out. Our cells accumulate damage, our DNA builds up mutations, and eventually the body just can’t maintain itself like it used to and starts to decline.

      The physical features of ageing can be pretty obvious. People’s hair starts going grey or starts to fall out. They become a lot slower in their movements, and more prone to injuries. Inside the body, a lot of organs start to deteriorate. The brain actually starts to shrink, and can’t transmit signals as quickly. Some mental abilities – like general knowledge and reasoning can be retained into old age (although the amount of retention varies between people), but things like reaction time will inevitably decline as the brain gets older.

      There is research being done to try and lessen some of the worst symptoms of ageing, but we still don’t know exactly what causes a lot of them. I’m looking at the effect that genes have on the loss of thinking ability in old age, and while we’ve identified a couple of genes that might have an effect, we still don’t know exactly what they do, and how they affect thinking. But at least it gives us some clues, suggests new avenues to explore.