Question: how long can human life be extended by?

  1. Hmm. Some. Difficult question.

    Human life is as long as it is mainly due to quite simple things like access to fresh water, clean hospitals, clean air, good diet. There have been amazing improvements in these things in the last 100 years. I don’t think that we can improve massively on things as they are (in rich nations – naturally things are still bad in the poor nations) which is why the life expectancy we have is not going up so fast any more.

    And if we look around us it’s not as though old people are dying from terrible diseases when they are otherwise in their prime. Old age is a complex mix of things – the body gradually going into decline. If it was one disease or another we might say “Well, if we can just cure that, that’ll make a huge difference and we can all keep on living”.

    So it’s a tough one. Some people recently said that one discovery promised to make a huge difference to life expectancy: telomeres. It turns out there are bits on the end of your DNA that get chewed off every time a cell divides. So the more times it divides, the shorter these bits, and that means the body kind of “knows” how old a cell is. If it gets too old, it’ll be terminated.

    There are probably good reasons for the body to do this, but people were saying “Hey, maybe we can switch that off and a cell will live forever”. I’m skeptical. Like I said, age is not determined by one thing. It’s a range of stuff. I’d expect life expectancy to keep going up, but not quickly. Extending it too much through one discovery will probably mean you’ll die from something else… 🙁

    There are also those people who are freezing themselves in the hope they can be woken up in the future and that there will be a “cure” for whatever they had. Maybe. If the freezing process works. Personally, I’d be skeptical of my brain surviving that, but I’m no expert.

    But look on the bright side. Life’s looooong.

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  2. The reason that we age, and eventually die, is that our cells get old and can’t divide anymore. Every second, cells in our body are dying and being replaced by new cells (one cell divides and produces two new cells). The cells can’t keep dividing forever though, so eventually they will start to die and not be replaced. When this happens our body can no longer work properly and eventually we will die of ‘old age’ or more specifically, organ failure.

    It is possible to do things to cells which stop them from dying or make them live longer. Most of these aren’t practical within our bodies, but new research is showing that a particular enzyme, called telomerase, can turn a normal cell into a cell which could live forever, or at least much longer. This enzyme acts on the end of the chromosomes, the curled up strands of our DNA. It makes a protective cap which prevents the ends of the DNA from being damaged. In normal cells these caps eventually disappear and the ends of the DNA start to get chewed up so the cell will die.

    The problem with trying to make our cells live longer is that it often goes too far and causes cancer to develop. Cancer is the opposite of cell death; it is a cell which lives when it should not and keeps dividing to produce more copies of itself.

    I think that scientists will learn how to make people live for longer than they do now, but I don’t know if that’s a great thing! I think it’s more important to work on making people healthier in their old age, so they can enjoy the years they have.

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