Grapefruit extract can help to heal stomach ulcers, research suggests.

Polish researchers used an extract of the fruit's seed to reduce the size of stomach ulcers in rats.

They found the extract had strong antibacterial and antioxidant properties, which calm the gastric tract and aid the healing process.

Details of research, by Jagiellonian University, were presented at Digestive Disease Week - a conference of leading digestive experts in Chicago.

The researchers induced gastric ulcers in rats, and applied graded doses of the fruit extract to measure its effect.

In particular, they looked at levels of gastric secretion - one of the major causes of gastric ulcers.

Rats treated with GSE at 10 mg/kg experienced a 50% reduction in gastric acid secretion, and a progressive decrease in the area of their ulcer.

The treatment also prompted a significant rise in blood flow at the ulcer sites - another phenomenon that can aid healing.

The beneficial effects, however, were diminished in the presence of drugs which inhibit two enzymes, COX-1 and COX-2, which play a key role in maintaining the health of the stomach lining.

The researchers believe that the grapefruit extract somehow joins forces with these enzymes to promote healing.

Lead researcher Dr Thomas Brzozowski said: "Because grapefruit is acidic in nature, people with ulcers might assume that they should not include the fruit in their diet.

"However, this research suggests the exact opposite."

Dr Lee Kaplan, of Massachusetts General Hospital, said: "Incorporating healthy eating habits and lifestyle choices can directly benefit digestive and overall health over the long term."

However, Dr John Bennett, chairman of Core, the UK charity fighting gut and liver disease, said the findings were of limited practical value, as powerful drugs were available both to treat, and minimise the risk of a stomach ulcer.

"I suppose this might potentially provide an alternative to patients who do not want to take anti-secretory drugs," he said.

Grapefruit juice can interact with some drugs, including cholesterol-reducing statins, and calcium channel blockers, given to heart patients.