LONDON (Reuters) - Science experts in Britain's House of Lords called Tuesday for tougher regulation of alternative medicines, saying many practices offered no evidence of helping the ill.

Peers in parliament's upper chamber said there was also a risk that patients would pursue alternative therapies at the expense of traditional treatment, endangering their health.

"One of the main dangers of complementary and alternative medicine (CAM) is that patients could miss out on conventional medical diagnosis and treatment because they choose only to consult a CAM practitioner," the Lords' science and technology committee said in a report.

The Lords, who conducted a year-long inquiry, said there are about 50,000 CAM practitioners in Britain but only a fifth of them were registered health professionals. Up to five million Britons have consulted one in the past year.

"We recommend that only those CAM therapies which are statutorily regulated or have a powerful mechanism of voluntary self-regulation should be made available by reference from doctors and other healthcare professionals," it said.

The committee divided treatments up into various groups.

Group One included established procedures such as osteopathy, acupuncture, herbal medicine and homeopathy.

Group Two housed therapies generally used to complement conventional medicine -- massage, counseling, stress therapy and the like.

Group Three included disciplines "indifferent to the scientific principles of conventional medicine" -- such as crystal therapy, iridology (looking at the eyes to highlight health problems) and dowsing.

"These aim to operate as an alternative to conventional medicine and have sparse or non-existent evidence bases," the Lords said.

Practitioners in Groups One and Two should build up evidence to demonstrate the offered therapeutic benefits, the committee said. It also called for a single professional body for each therapy.

It said acupuncture and herbal medicine appeared to work in at least some circumstances and so were already at a stage where they could seek statutory regulation under health laws.

"Other professions must strive to come together under one voluntary self-regulating body," it said.

(From Reuters)