The Massive Benefit of Birth Control That No One Talks About

August 5th 2015

Laura Donovan

A new study in The Lancet journal reveals that the birth control pill has prevented 400,000 cases of endometrial cancer over the past 50 years. Around half of these cases have been prevented in the last decade, according to the report.

Endometrial cancer, which develops in the lining of the uterus, is the most common form of cancer for female reproductive organs and nearly 55,000 new cases are diagnosed every year, according to the American Cancer Society. Of those cases, more than 10,000 women die annually.

The study, which was conducted by Oxford University researchers, found that women who take the pill for a longer period of time reduce their risk of getting endometrial cancer. Women on the pill for 10-15 years cut their endometrial cancer risks in half, and those who take it for five years had nearly a 25 percent lower risk of getting endometrial cancer. In other words, you lower your risk of endometrial cancer by a quarter for every five years you spend taking the pill. The researchers came to these findings after looking at data from 36 studies involving nearly 30,000 women with uterine cancer worldwide.

"The strong protective effect of oral contraceptives against endometrial cancer — which persists for decades after stopping the pill — means that women who use it when they are in their 20s or even younger continue to benefit into their 50s and older, when cancer becomes more common,” study lead Valerie Beral said in a news release.

Beral also acknowledged that previous research has shown that the pill reduces the risk of getting ovarian cancer. In addition, researchers have found that the pill can lower one's risk of bowel cancer. While some worry that the pill can cause cancer, Beral says studies show the opposite is true.

“Previous research has shown that the pill also protects against ovarian cancer,” Beral said. “People used to worry that the pill might cause cancer, but in the long term, the pill reduces the risk of getting cancer.”

The pill also contains lower levels of estrogen now than it did in the 1960s. The authors noted that pills from the 1980s typically had less than half the amount of estrogen as pills from the 1960s. Barel's team says their findings suggest estrogen levels in low dosage pills are enough to help prevent uterine cancer.

Dr. Jennifer Wu, an OB-GYN in New York City, told Health that this research is particularly interesting because the pill appears to prevent endometrial cancer decades after a woman is done taking it. This is especially good news because the majority of endometrial cancer cases are found in women who are 55 and older after their reproductive years have concluded, and there's little-to-no need to continue taking the pill.

“One of the most impressive aspects of the studies showed that the reduction in risk persists long after the patient ceases use of the pill, even up to 30 years later,” Dr. Wu said.