Andy, of Kirkwood Intermediate School, asks :-

Why cannot people live forever?

Tim Wilkinson, a consultant physician at the Christchurch School of Medicine, responded.

This question is best answered by looking at what makes people die, that is, not live forever.

As people get older the arteries carrying blood around the body get narrower. The end result of this is that some parts of the body don't get enough blood and become damaged, usually permanently, such as the heart in a heart attack or the brain in a stroke. This artery narrowing is called atherosclerosis.

Many cells in our body divide to replace themselves or other cells that are lost. This happens throughout our lives. As people get older some cells may divide too much (causing cancer) while others get worn out and cannot repair themselves or divide enough.

Together, artherosclerosis and cancer cause nearly two thirds of all deaths in New Zealand. Most of the remaining deaths are caused by infections, accidents and smoking related lung diseases.

To help people live longer we need to find out why we get these diseases. Although we are living longer now than ever before in time, it is probably just as well that we don't all live forever. The world might get a bit crowded.