Health Check: Science of ageing around the globe
Living longer, healthier lives is now possible - thanks to advances in modern medicine and sanitation. Life expectancy has doubled in the past 200 years. The World Health Organisation predicts that by 2050 the number of people over 60 will triple - to 2 billion - and most of the increase will be seen in developing countries.
Distinguished biologist and octogenarian Professor Lewis Wolpert has written a book "You're Looking Very Well - the surprising nature of getting old" which explores some of the science and myths around ageing.
He reveals how ageing is not "programmed" into our cells but is a consequence of "wear and tear". Scientists try to genetically modify creatures such as nematode worms and fruit flies to lengthen their lives - but Lewis believes that it would be too complex to attempt in humans.