genetics | Based on a Sprue Story

I know why I got celiac disease. Do you?

We all have our special origin stories when it comes to why we are the way we are. Humans love to reach back through the strands of our past and attempt to reweave them retrospectively into a narrative we can understand. “X happened, and Y happened, and Z happened” isn’t an appealing way to view our life story: it’s disorganized and random. “X happened, and therefore Y happened, and it all came to a head with Z” is neater and much more satisfying.

So, I know why I have celiac—or, at least, I like to believe I do. I’ve taken all my precious, faulty memories and molded them into a story that makes sense.

My Theory

It’s simple enough: I was born with the celiac gene and lived happily in my glutenous environment, eating whatever I darn well pleased, without so much as a twinge from my cast-iron stomach. Then, I lost sixty pounds in a year, messing with my gut bacteria in ways not even scientists understand. Immediately after I stopped losing and started maintaining, I got sick. Eventually, I learned it was celiac.

To me, the timing is too coincidental to be coincidence. Thus, with no hard evidence whatsoever, I’m convinced: I wreaked havoc on my body’s bacteria, then I gave them some gluten and ruined everything—all in pursuit of thinness. (How many pounds my body has reacquired in revenge is not an important part of the story.)

“But Molly,” you may protest, “I’m a naturally svelte god/goddess who has never actively tried to lose a pound in my life, yet I too have celiac disease. How can this be?”

If that’s so, then after mumbling something less polite, I would thank you for the insightful question, because it leads nicely into the second half of my post.

The Pie Theory

One of the best parts of the recent Columbia conference was Dr. Benjamin Lebwohl’s discussion of causal pies. This is a yummier name for a fundamental principle of epidemiology known as “the sufficient-cause model.” According to it, multiple risk factors for a disease come together in one person, like pieces of a pie. Once the sufficient factors (or ingredients) are there, the person gets the disease.

However, more than one set of ingredients can be combined to make a pie (as any gluten-free baker who has ever had to choose between all-purpose blends knows all too well). Similarly, most diseases have more than one sufficient cause; there’s more than one way to develop them.

For celiac disease to develop, two pieces of the pie must be there: genes (HLA DQ2 or DQ8), and gluten. But by themselves, they’re insufficient cause; almost a third of the US population has the gene and eats gluten, but most of them don’t have celiac. (There could be other universally necessary causes, but no one’s found them yet.) The rest of the pie needs to be filled in, perhaps completely differently for you and for me, with other causes.

causal-pies The other pieces might include:

early OR late gluten introduction by parents (which I have complained about before)
spring or summer birthday (because you probably started eating gluten in the winter, when infections were going around)
microbiotic dysbiosis (messed-up gut bacteria)
antibiotic usage (possibly insofar as it contributes to the above)
GMOs (but I doubt it. As Dr. Alessio Fasano pointed out, “There are no GMOs in Europe, but we still have celiac disease!”)
leaky gut (which Dr. Fasano talks up in his new book, Gluten Freedom)
headache medication (possibly because it makes your gut leak; the aspirin-based ones I regularly overused in high school before discovering caffeine are not included here)
other autoimmune diseases (though they may in fact be consequences of the same factors as celiac—pies rather than pieces)
excessive hygiene (which I’ve joked about before)
and so on.

Why all the theories?

It’s important to determine causes of celiac disease not only because humans hunger for coherent life stories, but also because discovering causes could help us prevent, treat, or even cure future cases. This is particularly crucial because celiac disease is increasing in prevalence.

Plus, differently constructed pies may require different treatments. The baking metaphor breaks down a bit here, but we know that some people take longer to heal than others, and that some people must adopt additional measures beyond the gluten-free diet to get well, while others get cross-contaminated regularly with no consequences. Maybe that’s because their identical disease has different causes.

Why do we get celiac disease? (It's all because of pie.)

Original photo of a probably glutenous lemon pie © speedbug | Flickr

Dr. Lebwohl did not make any jokes about a) the gluten content of causal pies, or b) celiac disease being “easy as pie” to develop, so please consider those bad jokes my contribution to the scientific conversation.

**Now, it’s your turn to contribute: Why do you think you got celiac disease, or another GRD? Do you have a pet theory about why they are increasing in prevalence?**

This is the latest installment in my Sprue/False series of simple but difficult-to-answer questions about celiac disease. (See also Is a Gluten-Free Diet Good Enough? and More on Drugs.) By the way, although “Why do we get other gluten-related disorders?” is a great question too, I focused on celiac because, unfortunately, we’re even farther from answers when it comes to other GRDs.

Pride and Prejudice and Gluten

It is a truth universally acknowledged, that a celiac man in possession of a good fortune, must be in want of a wife.

However little known the appetite or baking ability of such a man may be on his first entering a neighbourhood, this truth is so well fixed in the minds of the surrounding families, that he is considered the rightful property of some one or other of their daughters.

Someone, after all, must take on the hard but fulfilling task of baking her way through that fortune, one bag of superfine rice flour at a time.

So begins PRIDE AND PREJUDICE AND GLUTEN, the classic novel reimagined to include something scarier than ballroom dancing and zombies alike.

When Mr. Bingley moves into the neighborhood, he doesn’t know quite what he’s getting himself into. He quickly learns he has entered a zone of intensely elevated celiac prevalence, brought on no doubt by many years of marrying one’s cousin and so forth.

Just as quickly, the news spreads that a likely young bachelor has let Netherfield Park. The gritty gifted cupcakes begin pouring in, as do the invitations with postscripts appended in the beautiful script that comes naturally to those women who have spent years practicing, all to the effect of, The buffet will have hummus.

Bingley good-naturedly agrees to attend, and brings along his friend, Darcy, with whom he pleads, hovering by the refreshments table in the grand tradition of non-dancers at balls, “Come, Darcy, I must have you try a bite of this.”

“I certainly shall not. You know how I detest anything gluten-free, unless I am particularly acquainted with the brand. With such a spread as this it would be insupportable. If there were any traditional baked goods, I might consider it, but alas, there is not a cracker or pudding in the room it would not be a punishment to eat.”

Having overheard all, Elizabeth Bennet—snarky before her time and with a measured but abiding pride in her own talent for recipe development, which though passable is widely understood, even by Elizabeth herself, to be inferior to her sister Jane’s—writes Darcy off as the worst kind of gluten-eating boor: too proud of his own lack of immune response to gluten, too prejudiced to try the teacakes at which Elizabeth has slaved away, combining four different recipes and throwing out three batches before she got them just right.

“I could easily forgive his pride,” Elizabeth sniffs, “if he had not mortified mine.”

You may think this story over before it has even begun, but there are twists and turns to come as Jane Bennet and Bingley fall in love over millet scones and buckwheat biscuits, then are driven apart by Darcy’s cynical remarks about their future children’s double genetic risk and the Bennet family’s inappropriate dinnertime discussion of matters gastrointestinal. After a suitable amount of mutual anguish, the two come together again as the beautiful and gluten-free always do.

In between, there’s a spot of trouble for Lydia, the youngest Bennet daughter, involving one Mr. Wickham, a roguish character who never truly intended to keep his kitchen cross-contamination-free. Darcy, it seems, has known all along that Wickham’s promises were as thin as the paper towels he wouldn’t actually use to wipe up his own crumbs. It is Darcy who alerts the family, though sadly not before a glutening catastrophe to which he refers in only the most euphemistic of terms; this is, after all, a novel of manners.

Darcy’s aid in this matter, and then in reuniting Jane with Bingley, endears him somewhat to Elizabeth, but what seals the deal is a letter he sends her with, enclosed, his recent positive biopsy results. It is revealed that his excessive pride was born of his fear that he himself may all too soon be forced to sup on sandwiches insupportable by their fragile bread, and piecrusts made of grains his family would scorn as peasants’ fare. Furthermore, it was persistent gluten exposure that caused his irritability and dour physiognomy.

The twin barriers of Darcy’s gluten eating and terrible personality now removed, there is nothing to stop Elizabeth from wedding him immediately, which she so does. As in the original, they all live happily ever after, except for Lydia.

So what do you think? Will Keira Knightley agree to take the lead?

Text adapted from Jane Austen’s Pride and Prejudice, now in the public domain. Wheat image from jayneandd at the Flickr Creative Commons. Book cover image stolen shamelessly from Penguin—they can afford it.

Based on a Sprue Story

Tag Archives: genetics

Why do we get celiac disease?