THE Catholic church condemns all forms of contraception, a policy that Paul VI laid out in detail in Humanae Vitae in 1968. Over the subsequent decades it has had various brawls with secular authorities over the use of birth control pills. Most recently, Americas bishops have fought to keep Barack Obamas health law from providing contraception free. The church has already won an exemption for women who work for a church, but it also wants to keep coverage from women who work for any Catholic institution, even if the women in question are not Catholics and the institution has a secular purpose, such as a school, say, or hospital. Given all this, it would seem unlikely that the church would want to give the Pill to its nuns. Yet that is precisely what a recent paper in the Lancet suggests. Its authors, Kara Britt and Roger Short, of Monash University and the University of Melbourne, urge the Church to provide oral contraception to the sisters. Nuns need the Pill not to prevent pregnancy, but to prevent cancer. In 1713, the authors write, an Italian doctor observed that nuns had a very high rate of that accursed pest, breast cancer. Modern studies have confirmed that Catholic have a higher risk than most women of dying from breast, ovarian and uterine cancers. Women who bear children have fewer menstrual cycles, thanks to both pregnancy and lactation . Other studies have established a relationship between menstrual cycles and the prevalence of cancer, with fewer cycles meaning a smaller risk. Nuns - who are required to be celibate - experience more cycles than the typical woman, and therefore run a higher risk of developing cancer. The Pill can help to counteract this. The overall mortality in women who use, or have used, oral contraception, is 12% lower than among those who do not. The effect on ovarian and endometrial cancer is greater: the risk of such cancers plummets by about 50%. Drs Britt and Short make a compelling medical case. But it is unlikely to sway the Church.