A new large-scale study has found that taking the oral contraceptive pill can protect women from some cancers for as long as 30 years.

Carried out by the University of Aberdeen, Scotland, the team looked at 46,022 women taking part in the Oral Contraception Study, established by the Royal College of General Practitioners in 1968 to investigate the long-term health effects of oral contraceptives.

The study looked at the risk of all types of cancer in women who have taken the pill, following participants for up to 44 years.

It the longest-running study in the world to look into the effects of the oral contraceptive.

The team found that women who took the pill during their reproductive years showed no evidence of new cancer risks appearing later in life -- the time when more cancers occur.

In addition, the results showed that women who had taken the oral contraceptive pill had a lower risk of colorectal cancer, endometrial cancer or ovarian cancer than women who had never used the pill, with women protected from these cancers for at least 30 years after they had stopped using the pill.

Although oral contraceptives have been used by hundreds of millions of women around the world, important questions remain regarding the long-term cancer risks associated with the pill.

Dr. Lisa Iversen, who led the study, described the new findings as "reassuring."

The results back up a 2016 study which found that deaths from ovarian cancer fell significantly in Western countries between 2002 to 2012 thanks to widespread use of the contraceptive pill. The team behind the study also predicted that deaths from ovarian cancer, dubbed a "silent killer" as it is often diagnosed too late, would continue to fall due to widespread pill-use.

A 2015 study from the University of Oxford which looked at 27,276 women also found that taking the pill long-term could protect against endometrial cancer, which affects the womb.

However some previous studies have linked use of the pill to a slight increase in breast cancer risk.

The results of the new research can be found online published in the American Journal of Obstetrics and Gynaecology.