Henry Burger, a director of the Jean Hailes Foundation for Women's Health, said doctors and patients had been deterred by a "grossly misleading" July 2002 report that linked hormone therapy to an increased risk of heart attack and breast cancer.

Professor Burger said the researchers' interpretation was later discredited, but they had done lasting "damage" and committed a "crime against women".

He said that after the announcement, hormone therapy numbers dropped by half, with women scared off by the publicity about health risks and doctors afraid of being sued.

"Some women went back on because their [menopausal] symptoms were so awful, but others stayed off and they paid the price for staying off in the years to come."

He said the "price" included heart disease, heart attacks, or fractures from osteoporosis that could otherwise have been avoided.

Professor Burger said that when the report's data was scrutinised, women of menopausal age (50-59) on hormone therapy were shown to have had a reduced risk of heart attack.

The results were skewed by an increased risk for women aged 70-79.

Similarly, he said there was no increased risk of breast cancer for menopausal-aged women.

"If you look at the benefits and the risk, there's a small increased risk of getting a blood clot in your leg vein, much like the risk for a young woman on the contraceptive pill. That's the only significant risk."

He said about 40-50 per cent of women developed severe to moderate menopausal symptoms, such as regular hot flushes, vaginal dryness, mood swings and frequent urination, and could benefit from hormone therapy.

He said studies showed that many alternative therapies, with the exception of the antidepressant Effexor, were no more effective than a placebo.