Thousands of women might be spared the agony of breast cancer if they extended the period for which they suckle their babies.

Research published on Friday suggests that for every year of her life spent breastfeeding, a woman's risk of the disease drops by 4.3%

This is on top of the 7% reduction she enjoys for every baby to which she gives birth.

If women in the UK breastfed on average for an extra six months each, 1,000 cases of breast cancer - and hundreds of deaths - would be prevented each year.

We need to see a real shift away from the current bottle-feeding culture

Belinda Phipps, National Childbirth Trust

However, experts say that too few women in this country are breastfeeding their babies - partly because too little support is available to help them start.

Belinda Phipps, the chief executive of the National Childbirth Trust, said: "Currently, only one in five UK mothers are still breastfeeding after six months - we know that many give up before they want to.

"It is clear that UK women are still not getting the information and support they need to breastfeed their babies.

"We need to see a real shift away from the current bottle-feeding culture in the UK to one where breastfeeding is completely accepted."

Developing world

The latest study was carried out by analysts at Cancer Research UK, who pooled data from dozens of different studies into the benefits of breastfeeding.

Differences in childbearing and breastfeeding habits could partly explain why rates of breast cancer are so low in the developing world.

On average women in the developing world breastfeed for approximately two years, and have six or seven children, as opposed to two months per child and two or three children in the UK.

Professor Valerie Beral said: "It's long been known that breast cancer is common in situations where women have few children and breastfeed for short periods.

"We've shown that these factors alone account for much of the high rates of breast cancer in these settings."

Common cancer

Fellow researcher Dr Gillian Reeves said: "Even if women in the West were to breastfeed each of their children for an extra six months, this could prevent 5% of breast cancers each year."

Breast cancer is now the most common cancer in women - there are well over 30,000 cases each year, and mortality is approximately a third.

A spokesman for Breakthrough Breast Cancer said: "This study has indicated a relationship between breastfeeding and a lower risk of cancer -but more research is necessary to clearly establish a causal link."