Acupuncture involves the insertion of tiny needles at various set points around the body. Although there is evidence that it works for a variety of conditions, no-one is fully sure how.

Electroacupuncture also involves inserting needles, but then passing different strengths of electrical current through them.

The latest study to back the technique was carried out at the National Institutes of Health in Maryland, US, and reported in the Journal of the American Medical Association.

Thirty-seven patients were given electroacupuncture through two "classic" points.

They were also given three conventional anti-emetics, while 33 other patients had a less intense form of acupuncture, and 34 only drugs.

Among the acupuncture group, the average number of sickness bouts during the five following days was five, 10 for those receiving the less intense acupuncture, and 15 for those simply taking anti-emetics.

Recommended treatment

The authors are now recommending that hospitals offer the treatment to patients in whom conventional drugs have failed to prevent vomiting.

Mark Bovey, a research co-ordinator, at the Acupuncture Research Resource Centre at Exeter University, said that doctors were beginning to become far more accepting of acupuncture as a viable therapy.

He said: "Acupuncture is well-known as a control of various sorts of nausea and vomiting, such as post-operative pain, morning sickness and travel sickness.

"There a single particular point on the wrist which is always used."

He said: "Any therapy which involves the insertion of needles is always going to have somewhat of an image problem, but a recent BMA survey found 80% of GPs were interested in acupuncture for their patients."