London, 8 January 1999 (RFE/RL) -- The largest study ever undertaken has found that oral contraceptives have no long-term effect on the health of the women who take them.
Authors of the study, published today by the British Royal College of General Practitioners, say the results should reassure women who have taken the pill in the past or are taking it now.
The oral contraception study, set up in 1968, monitored the health of 46,000 women over 25 years. It found that the death rates of those who took the pill were hardly different from those who never took it.
Valerie Beral, leader of the study -- published in the British Medical Journal -- says the findings are good news for women, particularly because the study was so comprehensive.
Beral said "the new findings are a follow-up of women in their 40s and 50s who took the pill when they were in their 20s."
More than 300 million women worldwide have used oral contraceptives since their launch in 1959. An estimated 100 million are currently on the pill. The pill heralded a new era of choice for women and a sexual revolution in society. But, from the outset, there were fears about possible bad side effects.
It had been feared that the pill's known tendency to increase slightly the risk of strokes and certain cancers -- including those of the breast and cervix -- might persist long after women had stopped using it. But Beral says her study's results should ease those concerns: "We found that 10 or more years after they've stopped taking the pill, their death rates from all sorts of conditions are exactly the same as if they'd never taken the pill at all. So basically there is no persistent effect at all."
The oral contraception study was a collaboration involving 1,400 doctors' practices throughout Britain. The 46,000 women in the study were in their 20s when they were enrolled and on average used the pill for five years until an average age of 33.
The study focused on the 1,600 deaths that occurred in the group by the end of 1993. Of these, a total of 829 women died of cancer, including 259 from breast cancer, and 380 from heart disease or strokes. The study shows that the risks of developing heart disease, strokes, and breast and cervical cancer were only marginally higher when women were taking the pill and in the early years after they stopped. This bears out the findings of many other surveys. But the slight health risk fell off after they stopped.
Most of the women in the study were on so-called "combined" pills that contain 50 micrograms of estrogen. That is well above the hormone dose contained in today's low-dose contraceptives which, according to Beral, are regarded as safer.