A study yesterday suggested that acupuncture works - but not because of any skilful manipulation of needles learned through centuries of eastern tradition.

"Real" acupuncture was no better at preventing migraine headaches than a fake treatment, researchers found.

The explanation could either be an unknown effect of pricking the skin with needles that had nothing to do with acupuncture, or a "placebo" reaction due to mental expectation, or a combination of both, they said.

Last week, another team of scientists claimed to have shown that the beneficial effects of acupuncture were "all in the mind".

The latest study involved a group of 302 mostly female migraine patients in Germany.

Some were treated with real acupuncture over a period of eight weeks while others received a "sham" treatment consisting of needles placed into non-acupuncture points on the skin.

In both cases, about half the patients reported a reduction of at least 50 per cent in the number of days they suffered headaches.

This compared with a response rate of just 15 per cent from a third group on a waiting list who received no treatment at all.