Women using the oral contraceptive pill could be up to 30% less likely to develop bowel cancer, research suggests.
Researchers believe that over the last 20 years, mortality rates for bowel cancer have dropped more in women than in men because of hormones found in the Pill.
Researchers believe the protective benefits of the Pill are due to the way oestrogen - a female sex hormone - works in the body. When oestrogen in the Pill is released into the body, it blocks the growth of cancer cells by reducing the amount of bile acids, which have been linked to colon cancer. The oestrogen may also help to reduce levels of a hormone called IGF-I that has also been linked to an increased risk of bowel cancer.
They focused on the results from 19 international studies that compared bowel cancer rates for women who had taken an oral contraceptive between the mid-1970s and 1980s.Lead researcher Dr Carline , from the Institute of Pharmacological Research in Milan, Italy, said: "For a while now we have suspected oestrogen in the Pill could protect against bowel cancer and our research has gone some way to confirm this. "Mortality rates for female bowel cancer have steadily dropped over the last 20 years - we believe this is partly due to the Pill. "In the future, it may be possible to develop new treatments that take advantage of the anti-cancer qualities of the Pill."
The results also indicated that protection was stronger for women who had stopped using oral contraceptives within the last 10 years of the research period, compared to those who had stopped taking the Pill for longer. The Cancer Research Campaign's Director General, Prof Gordon Vickie, said: "The results show that women might have a secret weapon against the disease that kills 46 people in the US each day.