The supplement, called Diindolylmethane (DIM for short), is available in the US as a herbal remedy where it is said to help with pre-menstrual syndrome.
A research team headed by Professor Alison Fiander, head of the department of Obstetrics and Gynaecology at the Wales College Of Medicine in Cardiff, believe that it could also help in the fight against cervical cancer.
In May, researchers at the University of California, Berkeley, reported finding that the chemical, produced when digesting cruciferous vegetables like broccoli and kale, could stifle the growth of human prostate cancer cells. They said it was the first plant-derived chemical found to act as an anti-androgen.
The new trial, sponsored by Cancer Research UK, is recruiting women with either a second borderline or mildly abnormal cervical smear who will take DIM daily for six months.
If a positive result is seen the research may be extended to include different groups of women, for example those with more severe abnormalities on their cervical smear.
Every year, about 10,520 women in the United States get cervical cancer and about 3,900 women die from it. In other countries, cervical cancer affects approximately 500,000 women each year. In some parts of the world, it is still the most common cancer in women.