Animal-science lecturer and biology-doctorate candidate Nontakorn Urasopon told a research presentation that pueraria mirifica - also known as butea superba and, in Thai, kwao krua - prevents the painful, debilitating disease.

The Thai Research Fund presentation at Pattaya City yesterday heard that the disease, most common in the elderly and women, greatly reduces bone-mineral density. This makes bones more likely to fracture. Breaks are most common to wrists, hips and the spine.

In post-menopausal women the disease results from declining oestrogen levels. It affects three in 10 women aged 60 or older. It affects just one in 10 men.

According to the National Statistical Office, Thailand has 5.7 million people aged over 60 - or 9.4 per cent of the population. This group will double in the next 20 years.

Nontakorn said patients usually discovered the disease only after it became severe. He added that current prevention and treatment was to take oestrogen supplements to halt bone-mineral-density reduction.

However, oestrogen can increase the risk of breast and cervical cancers and increase tumour sizes in cancer patients, he said.

Nontakorn said kwao krua contains phytoestrogens that function like oestrogen but with fewer side effects. The research team tested kwao krua on seven-month-old mice - the age at which rodent bones are fully developed. There were six test groups - one a control and the others with their reproductive organs removed to induce the reduction of bone-mineral density.

The second group was treated with oestrogen, the third with distilled water, while groups four, five and six were treated with kwao krua in doses of 10 milligrams, 100 milligrams and 1,000 milligrams per kilogram of weight. The treatment lasted three months. The groups underwent bone-mineral-density testing in Japan, where "peripheral quantitative computed tomography" was employed.

In the 100-milligram and 1,000-milligram kwao krua trials, success rates were 85 per cent and 100 per cent respectively.

Osteoporosis occurred in the oestrogen group at a rate of just 20 per cent. The 10-milligram kwao krua group developed it in 80 per cent of subjects.

The herb curbed bone-mineral-density decline as well as and better than oestrogen, he said.  Phytoestrogens in kwao krua help reduce cholesterol and the symptoms of menopause, too, he said.

He believed a drug produced from kwao krua would eliminate the need for expensive imported drugs and provide another cash crop for local growers.