Researchers at St Thomas's Hospital, London, said their work could provide women with better advice on drinking.

It is already known that excessive drinking is a major cause of the disorder in men.

However, it is now thought that moderate drinking may confer benefits, as is the case for some people at risk of heart disease.

The St Thomas's study aims to test this idea in a project involving 1,500 identical women twins.

Fractures

Osteoporosis leads to bone fractures. Known causes include lack of calcium, regular exercise and vitamin D.

Specialists predict the number of hip fractures in Europe will more than double in the next 50 years as people live longer.

One in eight Europeans over the age of 50 is expected to suffer from osteoporosis.

From the 1,500 twins, the researchers hope to select around 150 pairs to aid their work.

Twins with different drinking habits are ideal

Project director Dr Timothy Spector said that generally identical twins have similar drinking habits due to identical genetic make-ups, and similar social and environmental factors.

He added: "We need more volunteers as ideally we are looking for twins where one is a non-drinker and the other is a moderate drinker, which is unusual.

"Using twins is a novel way of exploring the effects of drinking that avoids confusion from other social and lifestyle effects."

The study also aims to give better information on the effects of alcohol on bone density before and after the menopause.

It is supported by a £65,715 grant from the medical research charity, the Arthritis Research Campaign.