An increase in oesophageal cancer in women has been blamed on more obesity - and poorer diet.

The oesophagus is the tube which links the throat to the stomach, ringed by muscles which help transport lumps of food downwards.

Researchers from five UK universities looked at a number of cases of a particular type of oesophageal cancer in women under 75 years old.

They found significant differences between these women and similar women who had not suffered from cancer.

The women, whose average age was 65, were more likely to be obese, and to have suffered from indigestion in the past for more than two weeks at a time.

In addition, they consumed less fruit, and were less likely to have breast fed their children.

Smoking and alcohol drinking, both considered to be risk factors for the illness, were not linked to cancer in this study, although levels of both were fairly low in the sample.

Those who drink and smoke more heavily - particularly those who do both - may still be at greater risk.

Professor Kar Keung Cheng, from the department of public health and epidemiology at Birmingham University, said : "Breast feeding may confer a protective effect but this needs confirmation.

"This cancer is a largely preventable disease."

There are more than 7,000 cases of oesophageal cancer in the UK every year, and long term survival rates are low.

Surgery and radiotherapy are used to treat the cancer, but neither is particularly effective.

High death rates

On average, only 5% of men and 8% of women diagnosed with the cancer are alive five years later.

A diet rich in fruit and vegetables is generally recommended to reduce the risk of developing certain types of cancer.

The obesity which increased the risk of oesophageal cancer had generally started around the age of 20.

Obesity is also a risk factor in the development of type II diabetes and coronary heart disease.