The contraceptive pill can protect women from some types of cancer for as long as 30 years, according to new research.
The study also confirmed that the pill does not lead to more cancer risks later in life, researchers say.
The findings are the latest published from the Oral Contraception Study – established by the Royal College of General Practitioners in 1968 to explore the effects of taking the contraceptive pill.
The latest study relates to 46,000 women followed for up to 44 years.
Dr Lisa Iversen, who led the study, said: “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.
“We were also interested in what the overall balance of all types of cancer is amongst women who have used the pill as they enter the later stages of their life.
“We did not find any evidence of new cancer risks appearing later in life as women get older.”
She added: “These results from the longest-running study in the world into oral contraceptive use are reassuring.
“Specifically, pill users don’t have an overall increased risk of cancer over their lifetime and that the protective effects of some specific cancers last for at least 30 years.”
The contraceptive pill prevents ovulation and contains artificial versions of female hormones oestrogen and progesterone.
It is prescribed to approximately 3.5 million women in Britain.