This Week in Sex is a weekly summary of news and research related to sexual behavior, sexuality education, contraception, STIs, and more.

Lower-Dose Can Still Mean Lower Chances of Ovarian Disease

A new study of almost 2 million women suggests that even with lower doses of hormones, the current generation of birth control pills provide protection against ovarian cancer.

This finding is important because there is no reliable screening test for finding ovarian cancer in its early stages, which means it is often found after it has spread to other parts of the body and is harder to treat.

Researchers have known for many years that using combined oral contraceptives (those birth control pills that contain both estrogen and progesterone) may reduce a woman’s risk for some cancers. As Rewire.News reported last year, a long-term study in the United Kingdom found that using the pill reduced a woman’s chances of getting ovarian cancer by 33 percent. That study also concluded that the positive benefits of using the pill could last as long as 35 years after a woman stopped taking it.

That study, however, began in 1968, and many of the women in it were using birth control pills that contained high levels of both estrogen and progesterone. Over the years, pill manufacturers have continued to change the formula and reduce hormone levels in the hopes of reducing potential side effects such as blood clotting, weight gain, or breast tenderness. Though today’s pills are as effective at preventing pregnancy, researchers wondered whether the correlation between pill use and reduced risk of cancer would remain strong.

For this study, which was published in the BMJ (formerly the British Medical Journal), researchers examined the medical records of 1.9 million Danish women ages of 15 to 49 between 1995 and 2014. Women were categorized as never users, current users, or former users of the pill. The analysis took into account other factors, including whether the women had ever given birth, and found that the pill did have a positive impact.

The number of cases of ovarian cancer in women who had never used the birth control pill was higher (7.5 per 100,000 person years) than in those who had ever used it (3.2 per 100,000 person years). Researchers arch estimated that pill use prevented 21 percent of possible cases of ovarian cancer in this population. These findings did not hold for those who had used the progestin-only pill, which is sometimes called the mini-pill.

The researchers warn that their results do not show cause and effect, but confirm a strong correlation that has been found in previous research.

In Australia, Cervical Cancer Could Be a Disease of the Past

A new Lancet report says that Australia is within decades of eliminating cervical cancer thanks to its government’s proactive measures to vaccinate against and screen for the potentially deadly disease. By 2028, the report estimates, that fewer than four in 100,000 women in the country would be diagnosed with the disease. That number would be drop to less than one per 100,000 Aussie women by 2066.

Cervical cancer is a slow-growing cancer that can be detected and treated in its earliest stages. Rates of cervical cancer around the world have gone down dramatically since the 1950s when the Pap smear—a test that collects cervical cells and examines them under a microscope—was introduced. In addition, we now know that most cervical cancer (99 percent) is caused by nine high-risk types of the sexually transmitted human papillomavirus (HPV).

Despite some controversy over vaccinating young people against an sexually transmitted infection, the Australian government began its campaign against cervical cancer in 2007, shortly after the first HPV vaccine was released, with a free, school-based vaccine program for girls. In 2013, the vaccine program expanded to boys as well. More than 9 million vaccines have been given to young men and women in that country since the program began and the results are impressive. The country has experienced a 77 percent reduction in the types of HPV covered by the vaccine; an almost 50 percent reduction in the incidence of high-grade cervical abnormalities (an early warning sign for cervical cancer) in girls under 18 years of age living in Victoria state; and a 90 percent reduction in genital warts in heterosexual men and women under 21 years of age.

Vaccines alone, however, would have missed many women who contracted HPV before 2007, which is why the government coupled the program with increased screening. Last year, the screening program began using a newer screening test that is more sensitive than the traditional Pap smear. Experts estimate this will lower the cancer rate in the country by an additional 20 percent.

Despite the existence of a vaccine and screening methods, cervical cancer remains the fourth most common type of cancer in women with 570,000 cases expected to be diagnosed worldwide this year. Most cervical cancer cases occur among women in low- and middle- income countries that do not have the resources for widespread vaccinations and screening programs.

But even countries like the United States could learn things from our friends Down Under. Here, the HPV vaccine remains controversial. The anti-vaccine movement—which still falsely claims that vaccines cause autism—is partly to blame for the mistrust of the HPV vaccine. And equally false arguments that vaccinating young people against a sexually transmitted infection will encourage sexual activity don’t help, either. Only three places in the United States (Rhode Island, Virginia, and Washington, D.C.) mandate HPV vaccines for school attendance.

In 2016, only 65 percent of girls and 56 percent of boys in the United States had received one dose of the vaccine, which is given a series of three shots. In comparison, 79 percent of girls and 67 percent of boys in Australia had received the vaccine.

Increasing our vaccination rates and improving our screening programs would go a long way in meeting the new standard being set by the Aussies—complete elimination of cervical cancer. It’s doable, but only if our government, health-care providers, and parents are on board.

The Little Blue Pill May Have You Seeing Red—Literally

Anyone who has watched television in the last two decades probably knows that one of the potential side effects of the erectile dysfunction (ED) medication Viagra is an erection that last four or more hours.

But a medical case suggests another potential reaction that may last even longer. A 31-year-old man in New York City suffered permanent vision damage that causes him to literally see red.

The man purchased the liquid form of sildenafil citrate, the active ingredient in Viagra and other ED treatments, online and took more than the recommended dose of 50 milligrams. Two days later, he went to urgent care, complaining that everything in his field of vision was tinted red. Eye experts found damage to his eyes’ cone cells, which are responsible for seeing color.

This is not the first case of this type of medication leading to vision changes. Cyanopsia, a condition that causes blue-tinted vision, is known to be an uncommon side effect of these drugs but tends to resolve quickly.

That hasn’t been the case for the unnamed New York man. Doctors have tried to repair the New York man’s red-tinted vision for more than a year.

Just another reason to use this—and all medication—only as directed.