Taking oral contraceptives do not increase a woman's risk of cancer and could even reduce the risk of developing this serious disease, a major British medical study showed on Wednesday.

Researchers at Aberdeen University who studied the records of 46,000 women over a 36-year period found that taking an oral contraceptive for up to eight years did not lead to an increased risk of cancer over a woman's lifetime.

However, doctors said the risks of cancer were greater in women who took the pill for longer than eight years.

Researchers, led by Prof. Philip Hannaford, found that "there was no overall increased risk of cancer among pill users" and that taking the pill could cut the risk by up to 12 percent in some cases.

A 12 percent reduction equated to one fewer case of cancer for every 2,200 women who used the pill for a year, the study published by the British Medical Journal showed.

"It is pretty small, but if you take that across 3 million women in Britain and 100 million women throughout the world actually a small risk translates into major benefits," Hannaford told BBC radio.

The study, analyzing data from the Royal College of General Practitioners, compared half the sample of women who began taking the pill in 1968 and half who had never taken it.

In one of two main datasets analyzed women on the pill "had significantly lower rates of large bowel/rectal, uterine body and ovarian cancer," the study concluded.

"Many women, especially those who used the first generation of oral contraceptives many years ago, are likely to be reassured by our results," the authors of the report said.

Evidence also suggested that women were protected from the risk of developing cancers for at least 15 years after stopping.

Since its introduction in the early 1960s, more than 300 million women are thought to have used oral contraception, often for prolonged periods.

There have been hundreds of studies into the pill's safety since its launch in 1961, some showing benefits and others claiming it increases the risk of cancer.