TL;DR: If you have celiac disease, and you continue to eat gluten, you have a significantly increased chance of dying at a younger age than someone from the general population.
Recently, particularly in r/glutenfree, I’ve run into a lot of people who either don’t understand why they should be gluten free if they have celiac disease, or who second guess why I wish I had an official diagnosis for celiac disease. To the first group, I always make the same comment: if you have celiac disease and you continue to consume gluten, you increase your odds of dieing sooner. To the second group, it really is the same answer as the first. If I had an official celiac disease diagnosis, then I’d know that I need to be gluten free for the rest of my life. The flip side is that if I’m not celiac, then my body -might- be okay with small quantities of gluten (ie, if I had a gluten/wheat allergy or intolerance); the research is still out on this, and I haven’t seen anything good recently on this topic.
So the other night, who knows what I was doing, but I stumbled across this paper:
Biagi F., and G. R. Corazza. 2010. Mortality in celiac disease. Nature reviews Gastroenterology & hepatology. 7:158-62.
I always like reading primary literature, but as a graduate student in the sciences, I also know that I need to be mindful of what I spend my time reading. Needless to say, I find the Nature Reviews series helpful, especially when I’m reading for my own interests, versus what I read for my lab work. Generally, these style papers are easy for me to read, and the shorter ones often get the point across without being overly detailed. So while I know that reading the primary literature is important because review authors don’t always get the details right, for something like this, I’m grateful for reviews that give me the overall pictures in a concise easy to read manner.
This is my attempt to summarize what is contained in that review for a more general audience.
It has been postulated for years that celiac patients die at a higher rate than the general population. But the research done has been somewhat diffuse, with many inconsistencies, and no clear overarching story. It’s been known for well over 20 years that a celiac patient who adheres to a strict gluten free diet will increase their average life span. And all of this is about average life spans, or how often we die and at what age compared to the general population.
Lets start off with what celiac patients die of. The biggest killers are gastrointestinal malignancies such as non-Hodgkin’s lymphoma and small bowel cancer. Also high on the list are other autoimmune diseases such as rheumatoid arthritis, ischemic heart disease, and oddly enough, violence. Location also seems to play a part. Celiac patients in Sicily die at a higher rate than those in Finland, for example.
So lets look at some of the nuances when asking how and when celiac patients die. For this, we need to consider that not all celiacs are equal, they can include: actual celiac diagnosis, suspected celiac disease, dermatitis herpetiformis, and refractory celiac disease. To further complicate the picture, we also need to consider if the patient is eating gluten and how well they adhere to being gluten free.
General studies have found that for diagnosed celiac patients, if they adhere strictly to a gluten free diet, they die at the same rate as the general population. This is great news. If you have celiac disease, and you are as gluten free as you can be, your risk of dying earlier is the same as any non-celiac person. BUT, if you are celiac, and you aren’t careful, your likelihood of dying earlier is nearly double. Know you have celiac disease and disregard it to eat gluten any way? Your risk of early death jumps up to six times the general population. While these numbers seem to hold up well, some studies have found that for some patients, even if they adhere strictly to a gluten free diet, they still seem to die at a higher rate than the general population. For those of you with celiac kids, or those of you who were diagnosed as a child, your odds are even better. All those years of NOT doing damage to your body puts your risk pretty damn close to the general population.
Eight of the papers in the review that looked at celiac patients over time found that patient mortality significantly decreases over even the first year. But three other papers found no effect. What gives? Well, if you include refractory celiac patients, they tend to skew the data towards early mortality. Oddly enough, one paper found that even over a 25 year span, celiac patients tended to die more often of things that aren’t as easy to tie to celiac disease: accidents, suicides and violence.
How about healthy individuals who test positive for celiac antibodies?
Two studies showed that mortality was not increased, a caveat though is that these two studies were done in countries (Finland and the UK) who have the lowest general deaths of diagnosed celiac patients. In two different studies in the US and Germany, they found significantly increased mortality of this population.
How about patients with dermatitis herpetiformis?
Four papers looked at death in this group, two from the UK and two from Finland. Mortality does not appear to be increased in this group.
How about patients with diagnosed celiac disease that does not respond to being on a gluten free diet (refractory celiac disease)?
There are two types, type I and type II, though I don’t really understand the difference between the two. The authors were clear though that Type II is more severe. For type I, the 5 year survival rate is 80-96%, but for type II it is 44-58%. And “The survival rate dropped to 8% in patients with refractory celiac disease type II who developed enteropathy-associated T-cell lymphoma.”
So why don’t we have a clear picture of mortality for compliant celiac patients, undiagnosed celiac patients, and refractory celiac patients?
Part of the problem is the different methods and assumptions of the different groups who did this work. The other problem seems to be the base these patients start at. The authors of this review hypothesize that the amount of gluten consumed prior to diagnosis is indicative of how much problems a celiac patient will have, even after going gluten free. “Indeed, there seems to be a relationship between standard mortality rate and pasta and bread consumption in the six countries where symptomatic celiac disease has been studied.” We know “The quantity of gluten that is sufficient to trigger celiac disease is known to be very small.” But it appears that there might be some sort of lifetime threshold for celiac patients where if they go gluten free before that amount, they will be relatively ‘fine’. But if they either get diagnosed too late, or continue to consume gluten, they are significantly more likely to die earlier of untreated celiac associated disease. The authors have coined it the ‘lymphoma triggering amount of gluten’ and define it as “the sum of gluten ingested before and after the diagnosis of celiac disease.”
For me, this confirms what I’ve thought, and how I’ve started to live my life the past two years or so. When I first went gluten free, I wasn’t incredibly strict, going so far as to eat gluten at weddings (that was my ‘cheat’). But about two years ago I put the pieces together: I am better on a gluten free diet and my dad is a diagnosed celiac. This likely means that I too have celiac disease. Maybe next summer I’ll be in a place where I can get an official diagnosis. It is something I would like to know at some point, it’s simply been a manner of having health insurance at the same time as being in a place to possibly be incapacitated and still be functional.
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