Hypnosis can relieve suffering and improve the quality of life of cancer patients, researchers said on Thursday.

Although it has been used to help people to give up smoking, lose weight and overcome phobias, its real therapeutic potential is still untapped, they believe.

Dr Christina Liossi, of the University of Wales in Swansea, said there is medical evidence that hypnosis helps to relieve the depression, nausea, vomiting and pain suffered by cancer patients.

There have also been suggestions that hypnosis could increase survival in patients with the disease, but she added there is not enough evidence to support them.

“We know that hypnosis can modify the immune system,” she told a news conference at the annual British Association for the Advancement of Science meeting.

In studies with children suffering from cancer, Liossi found that youngsters who were hypnotized and given a local anaesthetic felt less pain during medical procedures than those who were not hypnotized.

Professor John Gruzelier, of Imperial College London, said he has used brain-imaging technique to observe changes in the frontal lobe of the brain, which is involved in critical evaluation and behavior, in people under hypnosis.

He believes the changes could help to explain some of the mechanisms by which hypnosis works and why people hypnotized during stage acts obey when told they are told to do something embarrassing.

“We have a magnificent therapeutic tool which has been ignored because there has been no evidence of the mechanism (of how it works),” Gruzelier said.