Clearer skin, more regular periods, avoiding unwanted pregnancy…there are a lot of perks to taking the Pill. But recent research has found there’s another “pro” to add to the list: a lower risk of developing endometrial cancer—even after you go off of birth control.
For the study, published in the journal The Lancet, the authors examined data about more than 27,000 women with endometrial cancer and more than 115,000 women without endometrial cancer, all gathered from 36 different studies. They looked at a variety of factors, including the women's height, weight, reproductive history, use of hormone therapy for menopause, alcohol and tobacco use, and family history of endometrial and breast cancers. They also looked at whether or not women had taken oral contraceptives and, if so, how long they took them. With this info, the researchers then calculated the relative risk of endometrial cancer based on contraception use, comparing the women who had endometrial cancer to those who hadn't had the disease.
Turns out, the longer women used birth control pills, the lower their risk of developing endometrial cancer. The risk went down by about 25 percent for every five years a woman was on the Pill, and—here’s the amazing part—the reduced risk lasted for more than 30 years after women stopped taking the Pill.
Researchers also discovered that, in high-income countries like the U.S., taking the Pill for 10 years reduced the risk of developing endometrial cancer before the age of 75 from 2.3 to 1.3 cases per 100 users.
The reduced risk varied by tumor type—women were less likely to develop a carcinoma (which develops in skin tissue or the lining of the womb) vs. sarcoma (which develops in the body’s connective tissue). Granted, these are all associations—we don't know if the Pill actively helped prevent cancer. But researchers think that may be the case.
Researchers estimate that the Pill may have helped stop 400,000 cases of endometrial cancer, including about 200,000 cases in the last decade.
According to the American Cancer Society, endometrial cancer is the most common cancer of the female reproductive organs. Nearly 55,000 new cases of endometrial cancer will be diagnosed each year and more than 10,000 women die from it each year.
The cancer is rare in women under 45, the American Cancer Society reports, and most cases are found in women over the age of 55.
This isn’t the first time the Pill has been linked with a reduced risk of developing cancer. A study published in the journal Obstetrics and Gynecology in 2013 found that oral contraceptive pills may also help prevent ovarian cancer.
This new study also focused on oral contraceptives, so more research is needed to find out whether hormonal IUDs or other forms of hormonal birth control have the same effect.
In the meantime, it’s good to know that little pill is working hard to protect your uterus—in more ways than one.
Korin Miller is a writer, SEO nerd, wife, and mom to a little 2-year-old dude named Miles. Korin has worked for The Washington Post, New York Daily News, and Cosmopolitan, where she learned more than anyone ever should about sex. She has an unhealthy addiction to gifs.