Women who have taken the oral contraceptives seem have a reduced risk of developing some types of cancer for as long as thirty years, suggests new research from The University of Aberdeen, published in the American Journal of Obstetrics and Gynaecology.

Data from the longest-running study in the world to look at the effects of taking the contraceptive pill showed that women who had used this form of birth control are less likely to have colorectal cancer, endometrial cancer or ovarian cancer than those who hadn’t.

The Oral Contraception Study, established by the Royal College of General Practitioners’ in 1968 creating more than 1.2 million women-years of observation, also shows that using the pill during reproductive years does not produce new cancer risks later in life.

Dr Lisa Iversen, research fellow in the Institute of Applied Health Sciences at the University, said the results are “reassuring”.

“Because the study has been going for such a long time we are able to look at the very long term effects, if there are any, associated with the pill. What we found from looking at up to 44 years’ worth of data, was that having ever used the pill, women are less likely to get colorectal, endometrial and ovarian cancer.

“So the protective benefits from using the pill during their reproductive years are lasting for at least 30 years after women have stopped using the pill.”

“Millions of women worldwide who use the combined oral contraceptive pill should be reassured by this comprehensive research that they are not at increased risk of cancer as a result – and that taking the pill might actually decrease their risk of certain cancers,” commented professor Helen Stokes-Lampard, chair of the Royal College of GPs.

“This is not to advocate that women should be given the pill as a preventative measure against cancer as we know that a minority of women do have adverse health effects as a result of taking the pill. Ultimately decisions to prescribe the pill need to be made on a patient by patient basis, but this research will be useful to inform the conversations we have with our patients when discussing various contraceptive options that are available.”