A soy-rich oriental diet can protect women from bone weakening and osteoporosis after the menopause, a study has found.

Women become more susceptible to the brittle bone disease after “the change” as levels of protective oestrogen fall.

Since soybean foods contain plant chemicals called isoflavones that mimic the hormone, it has been suggested they might combat some effects of the menopause.

To test the theory, 200 women in early menopause were either given a daily supplement containing soy protein with 66 milligrams of isoflavones, or one containing only soy protein for six months.

Women on the soy-plus-isoflavones supplement had significantly lower levels of a blood protein marker of bone loss, suggesting a reduced risk of osteoporosis. They also had less risk of heart disease than those taking soy protein alone.

Thozhukat Sathyapalan said: “We found that soy protein and isoflavones are a safe and effective option for improving bone health in women during early menopause.

“The actions of soy appear to mimic those of conventional osteoporosis drugs.

“The 66mg of isoflavone that we use in this study is equivalent to eating an oriental diet which is rich in soy foods.”

Next, the scientists plan to investigate the long-term effects of taking soy protein and isoflavone supplements beyond bone health.

The findings were presented at the Society for Endocrinology’s annual meeting.