education causes cancer, but only in women

tonight i attended greg mortenson's lecture at the the toronto reference library. for an hour or so, he talked about how he started his pennies for peace initiative, which builds schools in afghanistan and pakistan. (here's an article about his ongoing work!) he emphasized the impact educating children can have on a community, and came back again and again to the importance of giving girls in particular access to schooling.

this wasn't brand new to me. campaigns like because i am a girl also make the argument that "when you educate a boy, you educate an individual; when you educate a girl, you educate a community" (african proverb cited by mortenson tonight).

in the part of the world in which mortenson is investing, this plays out in at least one amazing way: educated women are less likely to grant their sons permission to join tribal gangs or terrorist cells. because their culture is built around the importance of a mother's blessing, educating girls will have a marked impact on the recruitment of young men into such enterprises. yay!

but here's what really grabbed me by the (proverbial) collar and shook me: mortenson said that the education of girls in bangladesh coincided with a drop from 8 births per woman to 2.8 births per woman, over her lifetime. actually, he claimed that it caused the drop.

again, this wasn't earth-shattering by itself. there are a couple of options here: either this education includes some information about birth control, or educated women get married later (if at all) and pursue careers alongside child-rearing, or a (liberalized) community that values the education of girls doesn't tend to treat women like baby-makers... or (my guess) some combination thereof. education and industrialization/ urbanization go hand in hand and i suspect that the latter always lead to smaller families.

the thing is... cancer. i've been reading malcolm gladwell's what the dog saw, which is a collection of his best essays (according to him) from the new yorker. between insights into the clairol/l'oreal hair-dye market and an investigation into dog whispering (the title of the book came from the latter) is john rock's error,which describes the limitations of the birth control pill, the impact of modern medicine and lifestyles on female physiology, and the danger of too many periods.

yes, dangers. see, because today's woman starts menstruating earlier than ever before and spends fewer years of their lives pregnant or breastfeeding than ever before, she ends up ovulating many, many more times than her ancestors did. like 400 times, compared to 100. one result seems to be an increased risk of ovarian cancer, endometriosis, endometrial cancer, and other "below the belt" diseases.

simply put, both ovulation and the preparation of the uterus for pregnancy are processes which involve cell division. the more division, the higher the statistical probability of something going wrong... and cell division gone wrong is a loose definition of cancer. studies suggest that each full-term pregnancy reduces a woman's chance of ovarian cancer by 10%. when taken over a long period of time, birth control pills also go a long way to protecting against some of the perils of modern life.*

there's a lot behind this argument, and i encourage you to read gladwell's piece on this, if you have a chance. (the whole thing is available at the link above!) but the bottom line is this: a society in which women are educated is one in which they tend to menstruate much more often... and in which they will therefore be at far greater risk of developing cancer.

all things being the same, that average bangladeshi woman was about 41% less likely to develop ovarian cancer when she was having eight kids.

so this is the inconvenient truth: our biology is not only confused, but also endangered, by our self-made destiny.


* because the birth control pill suppresses ovulation but still leads to a period, the risk of endometrial cancer is not much diminished. read gladwell's fascinating piece to find out why the stupid 28-day cycle was maintained by the co-inventor of the pill, john rock.