The point is that some Australian researchers report a link between the celibate life of a nun and a higher risk of contracting breast, ovarian and uterine cancer. Further, they note that the contraceptive pill is reported to reduce such risks (though in the case of breast cancer, at least, there has been much contradictory reporting of evidence over the years, so the case is perhaps not quite so clear cut.)
Therefore, Catholic Nuns should be put on the Pill.
I have a few observations to offer:
One is that I can't help thinking that some of the motivation behind this reporting is anti-Catholic and slightly puerile: ho ho ho nuns on the Pill - that'll show the Vatican!...
A second is that if the Pill is taken as a bona fide medicine, by a celibate woman, and therefore with no chance of it acting as either a contraceptive or an abortifacient, it's probably a non-issue; just as if I use a condom as an insulating material in an electrical circuit (as happened in The Day of the Jackal, if I remember correctly), that is not a moral problem.
A third (and Scout will love this one) is that the whole argument is premised on the assumption that nuns will want to avoid disease and live longer and healthier lives. That is not an unreasonable assumption; but there are other possibilities. The celibate life is overtly and deliberately self-sacrificial (that is one of the principal reasons it is so derided). St Bernadette, for example, saw her vocation as to suffer, and was by no means unique in this. So it seems to me quite possible that some (a few? many? all?) nuns may be quite happy to accept the cup that their Lord is offering them when they swear to celibacy, even including an earlier death.
But for the average Guardian reader, I fear that will be entirely incomprehensible.