A new study shows obese people are six times more likely to develop esophageal cancer than people with healthy weight, media reported Friday.

Researchers from the Queensland Institute of Medical Research in Brisbane, Australia, found people with a body mass index (BMI) of 40 or more are six times as likely to have esophageal cancer as those with a BMI between 18.5 and 25 (a BMI of 30 is considered the threshold for obesity).

A passenger waits for a delayed flight at Heathrow airport's terminal four in London's Heathrow airport. (Xinhua/Reuters Photo)

Obesity is an independent risk factor for esophageal cancer, said the researchers, who explained that higher levels of fat tissue in the body increase insulin production. This, in turn, boosts levels of circulating insulin-like growth factor.

Both these hormones stimulate cell growth and inhibit cell death -- conditions that can lead to cancer development, the team said.

The researchers also noted that fat cells produce hormones called adipocytokines that speed up cell growth and play a role in inflammatory processes.

Repeated symptoms of severe heartburn or gastrointestinal reflux disease are also associated with a much higher risk of esophageal cancer, the researchers said. The more frequent the symptoms, the greater the risk.

(Agencies via Xinhua News Agency)