Researchers in Britain published a report that suggests use of the contraceptive pill protects against cancer, when taken for less than eight years.

British researchers analyzed data from a 36-year study, one of the longest studies of contraceptive pills, and found that most women who took the pill for up to eight years had a reduced risk of developing cancer.

The study was run by the Royal College of General Practitioners and started in 1968. The participants’ doctors offered updates on their health every six months. Some 46,000 women were included in the study.

Over the past four decades, more than 300 million women are thought to have used oral contraception around the world.

Professor Philip Hannaford of Aberdeen University and his colleagues found that any increased risk of breast and cervix cancer linked to pill use appeared to be cancelled out by long-term protection from other cancers.

The researchers found that the risk of cancer was up to 12% lower among those women who had taken the pill.

However, women who had taken the pill for longer than eight years, a quarter of those in the study, had a slightly increased risk of developing cancer.

Hannaford said the small increase in cervical cancer in those who took the pill for longer periods, was outweighed by reductions in bowel, ovarian and womb cancers registered in women who took the pill for fewer years.

Hannaford, quoted by the AP, said: “These results show that in this UK cohort the contraceptive pill was not associated with an overall increased risk of any cancer, indeed it may produce an important net public health gain.

“These findings will probably reassure most Pill users living in the UK and their doctors.”

The report is published in the British Medical Journal.