London: Older mothers may live longer because of the hormone oestrogen and because they don’t have lots of children, according to doctors in a TV programme on the National Geographic Channel programme called Animal Ageing Secrets (12 March 2pm UK).

Larger amounts of the hormone oestrogen are released when a women becomes pregnant helping extending lifespan by protecting the body from various diseases of ageing such as osteoporosis. Normally the hormone declines from around the age of 30.

Oestrogen is given to women as part of hormone replacement therapy to relieve some of the effects of the menopause which can lead to loss of skin elasticity, hair loss and othe symptom such as hot flushes and obesity.

The bodies of older mothers are also likely to suffer less wear and tear than younger mothers because they tend to have fewer children, say scientists from the University of Manchester. Dr Dawn Skelton said: ‘After 30, there is a dramatic reduction of oestrogen in women.

‘By leaving it longer before having our first child, we’re giving ourselves a big burst of oestrogen, which helps in all sorts of ways – muscle, bone, nervous function.

‘It also helps that the later we reproduce, the less we reproduce.

‘It means that we’re not going to have lots of babies – the more children we have, the bigger toll it takes on our bodies.’

A good love life may also increase life expectancy.

‘A healthy sex life can have enormous benefits,’ added Dr Skelton, who is to feature on a
‘Testosterone levels drop in men and women as they grow older. But sex produces more testosterone, which may help keep our hearts in good shape. Those people who maintain a healthy sex life have a better outlook on life.

‘And trials of the oldest among us – 90-year- olds and above – show that 20 per cent are still actively engaged in sex.

‘That activity increases heart rate and the metabolism and decreases stress.’

In the UK in 2004, 22,700 women over 40 became pregnant, up by 1,800 on 2003 – the highest number since the post-war baby boom of the early 1960s. The figures follow growing concern of a ‘baby gap’ caused by women putting their career and financial security ahead of starting a family. And sn estimated 92,000 planned babies a year are never born because women who choose to delay motherhood have fertility problems.