Freakonomics Radio - 305. The Demonization of Gluten

Episode Date: October 19, 2017

Celiac disease is thought to affect roughly one percent of the population. The good news: it can be treated by quitting gluten. The bad news: many celiac patients haven't been diagnosed. The weird news: millions of people without celiac disease have quit gluten – which may be a big mistake.

In the 1930s, a Dutch pediatrician named Willem Dicke began to study a mysterious, often fatal disease that was afflicting his patients. Children were losing weight and becoming malnourished despite consuming plenty of calories. The symptoms were intense and widespread. The damage is in the intestine. Really, this is a systemic disease that does not spare any tissue organ in your body. That's Alessio Fasano. I'm a professor of pediatrics at Mass General Hospital for Children. Willem Dicke suspected the illness was somehow related to the children's diet, but it wasn't until years later that he found the proof he was looking for. It came in the form of a grotesque natural

experiment produced by the Second World War. In 1940, Germany had invaded and occupied the Netherlands. In 1944, Dutch railway workers held a strike in support of the Allies. This prompted the Nazis to cut off food shipments to Dutch civilians. This was called the Hunger Winter. That's Alan Levinowitz, a religion scholar at James Madison University. It was horrific. Children everywhere were starving. Some people resorted to eating grass or tulip bulbs. Thousands died of starvation.

But Willem Dicke noticed something strange. His pediatric patients, who'd been sick before the war, were actually improving. And then, in 1945, the hunger winter ended, bread was dropped over Holland, and everyone's lives improved, except for those of the children who immediately relapsed into the condition that they had been suffering before. And this pediatrician, Dr. Dicke, the reason what we did not have during the war, that now is coming back, that can be the culprit. And he made the hypothesis that were grains the culprit. That's right, grains, which the kids hadn't been eating during the hunger winter,

but now after bread came back, they were. So Dickey ran a little experiment. So, he took six of these kids, put them on a gluten-free diet, showing that the symptoms were completely gone, put them back on a regular diet, showing that the symptoms came back, and that was the cornerstone, it still is, of our understanding how you trigger celiac disease. And that is how our modern understanding of celiac disease came to be.

Even today, it's still somewhat mysterious. But one thing that isn't mysterious at all is the trigger. And it's gluten. Gluten. Gluten. Today on Freakonomics Radio, we'll look at the recent spike in celiac disease and why, historically, it's been underdiagnosed. The symptoms, unfortunately, are not straightforward like many other immune diseases.

We'll look at the intersection between health trend and media sensation. Jenny McCarthy was hugely influential. We look at the economic implications of the gluten-free movement, both micro... I probably spend upwards of $1,200 a month on groceries. And macro. The northern plains of the U.S. have seen declining plantings of wheat. Gluten, gluten everywhere. That's right after this. From WNYC Studios, this is Freakonomics Radio, the podcast that explores the hidden side of everything. Here's your host, Stephen Dubner. Alessio Fasano is one of the world's leading authorities on celiac disease and gluten.

I can't make that statement myself. But we can. And he is. By the time Fasano started his medical studies in the 1980s, celiac disease was understood much better than in Willem Dicke's era. So let's start with what we know. Celiac disease was understood much better than in Willem Dicke's era. So let's start with what we know. First of all, the name celiac, it's from the Greek meaning a sickness of the belly. And how is the disease defined?

This is truly an autoimmune disease. It's like having diabetes, multiple sclerosis, rheumatoid arthritis. So celiac is an autoimmune disease with, as Fasano puts it, a recipe containing at least two ingredients. One, genetic predisposition. Many genes need to come together to make you a risk. And two, an environmental trigger that is mismanaged by your immune system. And what sometimes happens when the environmental trigger meets the genetic predisposition...

The immune system starts to attack its own body rather than get rid of the enemy. An immune system attacking its own tissues. That's the definition of an autoimmune disease. But there's one major way in which celiac is unlike other autoimmune diseases like rheumatoid arthritis or diabetes or multiple sclerosis. Celiac is unique among autoimmune diseases. Because the culprit, the enemy that turn on immune system to attack your own body is known, and it's gluten. This known enemy, gluten, is a protein that's found in rye, barley, and most prominently, in wheat.

Gluten is what gives structure to foods like bread, pasta, and cake. So gluten is the trigger for celiac disease. And the treatment then is what? The treatment is the elimination of gluten from the diet. And how quickly and how completely does that treatment address the issue? Some people, they will have resolution to symptoms rather than quickly. Others will take much longer. And the vast majority will be a complete resolution. How does it feel to know that you're responsible

for people crossing those beloved food items off their lists forever? Being Italian, I feel awful. It is definitely a tremendous change in lifestyle. No question about that. We face this all the time. You know, a newly diagnosed celiac will go through a serious change in feelings from denial to be upset to frustrated to depressed. Because, you know, one of the most natural activities of humankind, eating, will become a very challenging mental exercise rather than a

very spontaneous activity. Fasano got his medical training in Italy. There was a university in Naples where celiac disease was a big deal. Indeed. The University of Naples had a celiac research center. Italian schoolchildren were enrolled in large-scale screening programs. Epidemiological studies showed that roughly one in 300 Italians had celiac disease. That's pretty common.

And because it was fairly common, Fasano wasn't that interested in studying it further. And one of the reasons why I decided to move to the United States is because I was sick and tired to talk about celiac disease and work on it. In 1988, he arrived at the University of Maryland. In the U.S., celiac disease was thought to be much rarer than in Europe, one in 10,000 people versus one in 300. Days passed by and weeks passed by and months passed by and I didn't see a single case of celiac disease. So I went from the 20 cases a day that I was forced to see in Italy to zero. Fasano's plan to get away from celiac disease had worked. But he began to wonder why there was such a huge difference. I was wondering, you know, if the genetic background is the same in Europe

and we eat the same gluten-containing grains that they consume in Europe, why celiac disease is so frequent there and does not exist here? You know, I reason of the two, either truly the disease does not exist in the United States, so it will be a very interesting proposition to understand why. And the alternative was that it was overlooked and so it's underestimated. In other words, was celiac disease really so rare in the U.S., or were American doctors just missing it? Fasano decided to find out.

He headed over to his local Red Cross to get some blood samples. And I was shocked to know that I had to pay for it. So they asked me for $6 apiece, and I said, you must be out of your mind. I would never pay such amount of money. And we engaged in this back-and-forth negotiation that is actually the heart and soul of the Neapolitan attitude. You never pay whatever they ask for. Eventually, they settled on $3 apiece.

Fasano bought 2,000 samples and began testing them. If someone who has celiac disease eats gluten, their body produces abnormally high rates of certain kinds of antibodies. Gluten has been recognized as an intruder and their body is trying to fight it off, but instead, the antibodies end up attacking healthy cells. This activity can be detected in a blood test. So when Fasano screened the Red Cross blood samples, what did he find? The prevalence was 1 in 250. A prevalence of 1 in 250. The previous estimate in the U.S., remember, was 1 in 10,000.

This new finding would make celiac disease 40 times more common in the U.S. than previously thought. Under the old estimate, only 27,000 Americans likely had celiac disease. The new estimate suggested it was more like a million. That gave us the impetus to move to this large epidemiological study on a national scale, in which we recruited more than 40,000 people. This new national study, published in 2003, yielded an even higher estimate. It found that one of every 133 Americans had celiac disease. This was pretty much in line with the most recent European numbers. So, America wasn't so different from Italy after all.

According to Fasano's research, more than 2 million Americans had celiac disease. Now, how was it possible that a disease so well identified in some places had been practically invisible in the U.S.? The symptoms of celiac disease, unfortunately, are not straightforward like many other immune diseases. Intuitively, the vast majority of the symptoms are gastrointestinal, like, you know, chronic diarrhea, weight loss, failure to thrive. The knock-on effects are various and serious. So you can have anemia because you can't absorb iron, and with that, chronic fatigue.

You can have joint pain. You can have a skin rash. You can have changing your behavior because inflammation spills into the brain. You can have infertility. Over the last couple decades, the diagnosis and treatment of celiac disease in the U.S. have greatly accelerated. That's good news, especially since an effective treatment, the gluten-free diet, is well known. But rather than waiting to be diagnosed and then going on a gluten-free diet, wouldn't it be better if we could prevent celiac disease in the first place? If we could understand where it exists and why and exactly how it's triggered?

Well, if you ask someone what causes celiac disease, the pat answer is gluten causes celiac disease. But I don't think that's a fair response. That's like saying that peanuts are the cause of peanut allergy, right? That's Benjamin Lebwal. He, like Fasano, is a gastroenterologist. I'm the director of clinical research at the Celiac Disease Center at Columbia University. Lebwal and other researchers have looked all over the world for clues that could explain why celiac disease is triggered in one person and not another.

It used to be thought that people who were susceptible to celiac disease were Irish or Northern European and perhaps more broadly Caucasians. But celiac disease is present in Asia. It's actually quite prevalent in Northern India. And really in virtually every country in the world, celiac disease has been identified. Okay, but are people who eat a lot more gluten more likely to get celiac disease? We know that there's this necessary genetic makeup. We also know that there are regions in the world where the genetic makeup isn't so different, but the environment is quite different, and there's a lot more celiac disease in one spot than another.

For example, in India, we know that the necessary gene is similarly present in the north and the south of the country. But there's a lot more celiac disease in the north than the south. And it's not just a matter of increased detection. The going explanation, and I think this is a plausible explanation, is that there's a lot more gluten consumption in the North, whereas in the South, it's a much more rice-based cuisine. Now, that has not been conclusively proven, but it's awfully compelling when you have a population with a similar genetic makeup, but very different gluten levels in their diet, and suddenly you're seeing these widely disparate rates of celiac disease.

The highest frequency, believe it or not, is the Berber nomadic population in North Africa, 6%. This is a very ancient population that was displaced for their normal position because of the civil war in Africa. And that led to very high mortality because of malnutrition, famine, no food available. So UNICEF and the WHO stepped in and they have to decide what to send there to save these people. And the question was, what we can send in the desert that is not perishable and can be used for many purposes? And the answer was wheat. So a population that for 4,000 years, whose diet was based mainly on camel milk, common meat, fruits and vegetables, for the first time in their history were introduced to

gluten. So was it the sudden influx of that diet that triggered it? Or was it a case of selection among the population, just the way that natural selection works over time? Was it related to that? The latter. So that's why probably this know, the natural history of celiac disease. I see, yeah. There were people that are much more susceptible. Remember, once upon a time, there was high mortality of celiac disease. So the ones that had the most violent reaction to gluten, destroying the vast majority of the intestine, making the intestine not capable to absorb or digest foodstuff are the ones that didn't make it.

So it's likely that celiac disease used to be much, much more prominent among earlier generations and that natural selection has worked its magic. But since it's still relatively prominent, researchers are trying to learn everything they can about how it strikes, often by studying populations where it strikes the hardest. Benjamin Lebwal again. Not everyone knows about the great celiac disease epidemic in Sweden from the mid-1980s to the mid-1990s. But there was one. And this was an epidemic that primarily affected the youngest children, so infants and children under two years of age,

and it typically caused what we call the classical form of celiac disease, babies with diarrhea, failing to grow, etc. And then in the mid-90s, just as rapid was the rise, was a rapid fall. And the working hypothesis was that it had to do with how those infants were being fed. Rates of breastfeeding were not very high and in general were not overlapping with the first introduction of gluten into the diet. Moreover, infant formula had very high quantities of gluten, which is very different from today. When more overlap with breastfeeding was encouraged and when gluten was minimized from the infant formula, that coincided with the end of the epidemic. But that's correlation, and we have been hesitant to say that's causation.

There's another clue from a study in Finland and Russia. There was a study that compared rates of celiac disease in two regions very close to each other geographically, but very different socioeconomically. These two regions were in Finland and right across the border with Russia in a region called the Russian Karelia. The genetic makeup of those two populations was similar. They both had rates of the celiac disease genes that were comparable. But when screened, celiac disease was present in about 1 in 100 in Finland and about 1 in 500 in the Russian Karelia right across the border. The researchers suspected that income had something to do with it.

One theory? Lower-income people had more exposure to certain bacteria that somehow protect them from celiac disease. For instance, the bacteria H. pylori, known to cause ulcers, seems to cut the risk of celiac disease in half. We found that actually there's more celiac disease in people who live in zip codes of a higher income than those who live in zip codes of a lower income. The effect is not large, it's not very strong, but it's there and appears to be independent of other factors we

controlled for. There's something about either growing up wealthy or being in a wealthy environment and subsequently losing the ability to tolerate gluten. Okay, so people are still getting sick from celiac disease. They're still dying from it. And the epidemiology is not locked down. So given that the disease's trigger is known, how much sense would it make as a preventive measure for everyone to go gluten-free? Adopting a strategy of going gluten-free can really backfire.

That's coming up right after this. So can we hear the story of your being diagnosed with celiac disease? So it was about eight years ago in 2009, and I started having heartburn for about six weeks. Emma Morgenstern is a producer on our show, and she's the reason we're doing this episode about celiac disease. I didn't really get a full diagnosis until I went to see a specialist, a GI specialist. And then he did an endoscopy where they stick a camera down your throat and take a biopsy of your small intestine. And he did confirm with that endoscopy that I had celiac disease. How hard was it for you to go gluten free?

It was just awful. I came to terms with it fairly quickly because I had to. But you start having to think so much about what you're eating. imagine that that is a relatively challenging and tempting place to not be eating gluten, yes? Oh, you mean with the croissants and the baguettes and the pain au chocolat? I wasn't going to name them by name. I didn't want to torture you. Yeah, that was kind of a bummer. As much of a bummer as celiac disease has been for Morgenstern, it's been helpful for us to have a producer on this episode who actually has the disease because she knows a lot about it and has been thinking about it for years. But alas, Emma Morgenstern is a radio producer with celiac disease. For our show, sure would be nice to speak to an economist with Celiac.

Hey, it's Stephen Dubner. Is that Catherine Russ? Hi, Stephen. Yes. You can call me Katie. Katie Russ teaches economics at the University of California, Davis. I specialize in international trade and finance. Russ had to overcome a lot to get to where she is today. I've had stomach aches and stomach problems since I was very small. I had a preterm birth due to HELLP, which is another autoimmune disease. I had vitamin D deficiency for years, anemia for years, these persistent headaches for

years. After all of those medical problems, Russ was diagnosed with celiac disease in 2011. You know, you read in the news that everyone thinks they have celiac disease or gluten sensitive. And so I was really afraid to say anything to the doctor until I thought I had some evidence of it. So I went gluten free for about four months first, maybe closer to six, just to be sure. And then she told me that I had to eat gluten for six weeks before I could be tested. And were you willing to do that? Well yeah I wasn't sure at first whether or not it was necessary to be tested. It's really it makes a night and day difference. Why? Well first the way that you're treated in the medical community that they take the gluten issue very

seriously and you know, if you're admitted to the hospital or something, people need to be watching out for any kind of gluten exposure for you. Second, it's hereditary. So if you test positive for celiac disease, then everyone in your immediate family at least needs to be tested. I mean, celiac disease, if left untreated, shortens your life. So it's very important that people know. And then also just how seriously you as a person take it. If you know that you have an autoimmune disease, then you're much more likely to take it seriously than if you think, oh, you know, I get a stomach ache or something after I eat something. So I only

take a bite every once in a while. Whoa, no. Celiac disease is a totally different world than that. The landmark 2003 study, you will recall, put the incidence of celiac disease in the U.S. at one out of every 133 people. But then there are people who say they have a gluten sensitivity or perhaps an intolerance.

Having symptoms that might resemble celiac disease that are not celiac disease, but you still get better on a gluten-free diet. And the term for that is non-celiac gluten sensitivity or non-celiac wheat sensitivity. That, again, is Benjamin Lebwal. A diagnosis of non-celiac gluten sensitivity, he says, is trickier to pin down because there's no test for it. We asked Lebwal, therefore, if non-celiac gluten sensitivity is a real thing. I think it's really counterproductive to question whether non-celiac gluten sensitivity is real. Clearly, the symptoms are real. The suffering is real. I don't have to tell you how many

patients I've seen. I promise they're real. What we don't know is what exactly is driving their symptoms and what's the biological basis. Many of them are coming to celiac disease specialists because they really don't have elsewhere to go in the area of so-called conventional medicine because there isn't a well-defined pathway for these patients. So we need to better understand them, listen to them, try to understand what's driving your symptoms. And I've certainly seen such patients where it really appears to be gluten that's driving symptoms, even though we can't, for the life of us, find a marker in the blood or the intestine. So we need to study these patients. We need to take care of them. I certainly wouldn't doubt that it's real, though. I think we just need better science.

There are also plenty of people who go gluten-free, apparently because they've heard that going gluten-free is a good idea. Here's a Jimmy Kimmel segment from a few years ago. Now, some people can't eat gluten for medical reasons, which that I get. It annoys me, but I get it. But a lot of people here don't eat gluten because, someone in their yoga class told them not to. So I started to wonder how many of these people even know what gluten is. So we decided to find out. Do you maintain a gluten-free diet? I do indeed. And what is gluten? As far as for me,

how it affects my body. But what is gluten? This is pretty sad because I don't know. There are people who go on a gluten-free diet under the assumption, and this is largely a mistaken assumption, that it will promote weight loss. And there are probably people who are buying gluten-free food and avoiding gluten simply because of a vague notion that it's healthier, even though that might not be the case. Among people who are on a strictly gluten-free diet, the great majority do not have celiac disease. And the best data we have to date gives an estimate of about one and a half percent of people in this country being strictly gluten-free, even though they don't have celiac disease. Recent studies suggest that as many as 30 percent of Americans are trying to reduce

their gluten consumption or avoid it altogether. We went from the complete obsolete, non-known field of what celiac disease is and what gluten really can do to your body, to the opposite extreme. Alessio Fasano again. So we did such a good job that now the awareness of gluten and gluten-free lifestyle, it becomes one of the most popular, if not the most popular diet ever embraced in the United States. And this created a tremendous amount of confusion. Part of that confusion is that gluten-free doesn't really mean healthy. Adopting a strategy of going gluten-free can really backfire. First of all, because gluten is everywhere, it's so difficult to avoid. It can make eating out and grocery shopping and socializing or dating

really fraught. There are also potential health concerns with going gluten-free. Gluten-free substitute foods often have more calories than a gluten-containing item. They often have higher fat contents. A gluten-free diet is often a diet low in whole grains, low in fiber. We actually compared people who ate high-gluten diets to those who ate the lowest-gluten diets. And we found, actually, that overall, when looking at the outcome of rates of heart attack, for example, there was no significant difference with regard to heart attack risk according to how much gluten you eat in your diet. But if you then take into account whole grains, those who ate more gluten in their diet

due to having a higher whole grain content in their diet, actually had a lower heart attack risk. In other words, a gluten-free or low-gluten diet, if deficient in whole grains, could actually increase the heart attack risk. Well, let me clarify something. Not only gluten is not a villain, but without gluten, you and I, we still jump from one tree to another. And we will not have built the Colosseum or the Eiffel Tower.

Because before the agriculture and therefore predictability when food was available, humankind spent 90, 90%, 95% activity for food procurement and 5% for reproduction. No time to unleash ingenuity or doing anything about it. So without agriculture, and therefore without gluten, we would definitely be at the same level of any other species and probably not the dominant species. I would personally never, ever, ever recommend a gluten-free diet to somebody that does not have the medical necessity. Myself, I eat gluten. I do this with moderation as we should do for anything.

A gluten-free diet is also potentially more expensive, particularly if looking at gluten-free substitutes. Oh yes, it's much more expensive. The economist Katie Russ again. I'm a little bit, I'm afraid to tell you how much I spend on groceries a month. I mean, I spend a lot of money. I'd like to know. I probably spend upwards of $1,200 a month on groceries. There are three of us in the household.

So yeah, it's very expensive. Yeah, so you can do just gluten-free and that would probably be a bit cheaper, quite a bit. I'm one of those people that does the gluten-free and tries to go organic and pastured, grass-fed, etc. All right. Tell me what you can about how much more expensive gluten-free foods are. Yeah. The few studies that I've seen have put gluten-free foods at somewhere between two and four times the price of non-gluten-free equivalents. Yeah, I think one of the more widely cited studies says 242% higher. Wow. Okay. So fortunately, you're an economist, you can answer this question from a price theory standpoint, but how much of that has to do with supply and how much to do with demand? Okay. So I did some sleuthing to try to look into that question.

So I looked at brownie mix and if we look at a standard national brand, it may cost say 12 cents per ounce. Now the's... Not bad. Yeah, about a third more. But I don't know if it was a lost leader or not. So the next lowest I found was about $0.23 per ounce. That was also on sale. Now getting into the two times range. Yeah, exactly.

So if we take the lowest cost one and then separate out the others at, say, 30 cents per ounce or more into a premium category, then among those premium categories, we see markups of between 3 and 40 percent. So if the gluten-free diet is less nutritious and more expensive, why would someone who doesn't have celiac disease or gluten sensitivity want to go gluten-free? Gluten-free came on the heels of the low-carb craze. So in the aftermath of Atkins, the idea that carbohydrates are bad for you is still very prevalent. So for a population that has been told time and time again that what is making their waistlines expand is carbohydrates,

it makes complete sense to think that, in fact, there's a hidden villain in these carbohydrate, high carbohydrate foods, gluten, that's the real culprit. That's Alan Levinowitz. I'm an assistant professor of religious studies at James Madison University. He's also the author of a book called The Gluten Lie and Other Myths About What You Eat. Right, exactly. You may be wondering why a religion professor has written a book about diet. You know, I think if people reflect on it, they'll find that diet is actually at the heart of whatever knowledge they have of religion. So one of the first things people think of when they think of Judaism is keeping kosher.

And there are certain foods that are prohibited by God and certain foods that you're allowed to eat. But Levinowitz doesn't study Judaism either. I specialize in classical Chinese thought, as well as the intersection of religion, science, and medicine. And what he realized, I realized that there were some really interesting parallels between Taoist monks' prohibitions on the five grains, the so-called wu gu, and modern avoidance of grains. The promises that these monks made were promises of miracles. They said you could fly if you didn't eat the grains, you could teleport, you could avoid disease, live forever, clear up your skin. And I started to think to myself, well, what if what seem like scientific prohibitions on foods today actually have more in common with these religious prohibitions

than most people think? Instead of Taoist monks, now we have celebrities. Jenny McCarthy was hugely influential when she told everyone that she had put her autistic three-year-old on a gluten-free, casein-free diet. Once you had celebrities coming out against eating gluten-containing foods, you immediately got unscrupulous physicians jumping on the bandwagon. Jumping on the bandwagon and pointing at gluten as the cause of any variety of ailments. They would say things like, if you go gluten-free, it will cure your arthritis. If you go gluten-free, it over the grocery store these days as if it's a symbol of excellence and purity. The same goes for a lot of restaurants and you can see this shift reflected on a macro scale. So my position allows me to really dig deep into what's going on in domestic markets for

all classes of wheat as well as crops that are called pulses, like dry peas, lentils, chickpeas, which are real popular right now, and dry beans. That's Jennifer Bond. She's an economist with the USDA's Economic Research Service. She points out that when it comes to the consumption of certain foods, it's a lot easier to establish correlation than causality. Furthermore, wheat consumption has had plenty of historical ebbs and flows. In the 1800s, Americans were eating 225 pounds of flour per person. A hundred years later, that dropped by almost 100 pounds per person. And then it rose again slightly as incomes increased and we had access to more diverse food.

And then in the 70s, there was actually a trend towards increased consumption of wheat again, in part driven by the desire to consume less animal protein. And so for about three decades, we saw increasing per capita consumption until the recent high point in the 2000s. And then Adkins hit and put some downward pressure on per capita consumption for the recent high point in the 2000s. And then Adkins hit and put some downward pressure on per capita consumption for the next seven years until per capita consumption began to rebound a little bit until perhaps the emergence of the gluten-free trend, which we are seeing a correlation between per capita consumption of wheat flour and increasing sales of gluten-free products.

Okay, so wheat demand has been all over the place. What's the current trend on the supply side? On one hand, we have record low plantings of wheat. And on the other hand, pulse crops plantings reached a new record high this last year. Again, it's hard to say specifically that consumer taste and preference trends are driving the expanded availability of pulse crops. But what the data is showing us is that there has been some pretty steady growth in chickpea and lentil per capita availability in particular. And pulse crops tend to be grown in the same area as wheat is grown too. So the northern plains of the U.S. have seen expanded production of chickpeas, dry peas, lentils, and declining plantings of wheat. So for people with celiac disease or otherwise concerned about gluten, this would seem to be a big win.

Gluten-free products are becoming more easily available, and awareness is growing. And on the medical front, it no longer takes a large-scale famine like the one in Holland during World War II to identify celiac patients. These developments are exactly what doctors like Alessio Fasano and Benjamin Lebwal have been working towards, right? Well, despite all of our interest in celiac disease and efforts to raise awareness, Lebwal again, it looks like the majority of patients with celiac disease are still going undiagnosed and therefore eating gluten, possibly to long-term medical harm. Despite that, we have all these other people who don't have celiac disease

and have adopted the gluten-free diet. So it could very well be that our efforts for outreach and awareness of celiac disease have been basically met on the wrong audience or a different audience. And so our efforts to say celiac disease can affect all races and ethnicities, young and old, the many faces of celiac disease, has not fallen on deaf ears, but fallen on other ears, a different set of ears, right? Those with celiac disease has not fallen on deaf ears, but fallen on other ears, a different set of ears, right? Those with celiac disease, by and large, haven't gotten the message. I went back to Emma Morgenstern, our producer who has celiac disease, to ask about Lebwal's concern with all the undiagnosed cases still out there.

Oh, I think we should be concerned about it. Celiac can be really harmful to people who don't know they have it. So I guess one prescription would be for much more widespread screening. But as we've seen with a lot of maladies, an increase in screening can also turn up a lot of false positives, which can lead to its own set of problems. So how much of a concern is that in the case of celiac disease? Well, I definitely think that's a concern.

And I have recently kind of found myself in the position of maybe having been overdiagnosed. Oh, no. For celiac disease? Yeah. Tell me more. Funnily enough, yeah, with doing research for this episode, I was reading about the recommendations for celiac patients and follow-up. And I realized that I hadn't actually done any follow-up for almost eight years since I was diagnosed. And I decided that I would go to see a celiac specialist. So how did that work? He or she then looked at your file or ordered up new tests and data?

What happened? I had brought my medical records, including the records from my original diagnosis, and I gave that to her. She started flipping through it. And then she looked up at me and said, you know what? I would not have diagnosed you with celiac disease based on these results. Oh my goodness. Uh-huh. And so I was just totally shocked to hear her say that and didn't quite understand how it was possible that she and my original doctor could come to different conclusions. And I have to say that I feel like the story that we've been telling in this episode and the image that we've been drawing for listeners is that it's a thing that you have or don't have.

But is there that much gradation in just the yes or no, whether you have it or not? Or were you in maybe some kind of pre-celiac condition that your original doctor was concerned would tip into full celiac? Yeah, so that is exactly right. Or at least that's my understanding of it. So when they do the biopsy with the endoscopy, they categorize the damage to your intestine on this thing called the Marsh scale. So they categorize the symptoms as Marsh 1, 2, or 3. Marsh 3 is the most severe damage. Marsh 1 is the least severe. So I had Marsh 1 symptoms when I was diagnosed, which I didn't even really think about. Like, I didn't assimilate that information when I was diagnosed. According to my new doctor,

that Marsh 1 symptom level is not enough for her to put somebody on a gluten-free diet. She doesn't think the original diagnosis was wrong exactly, but she would call it aggressive. I assume the way to test whether you truly don't have celiac disease is to ingest a lot of gluten. So question number one, does that mean that you have been commanded to go eat a whole bunch of bagels and pizza for a while? And number two, if so, don't you feel like the world's biggest sucker for not eating them for eight years? I guess it's how you look at it.

So I have been commanded to eat gluten for six to seven weeks and then have an endoscopy. What was the first piece of food you ate with gluten and what did it taste like? I had pizza and it was not that amazing. But then I had croissants and those are amazing. That is just something you cannot replicate gluten free. Are you having any adverse effects? I feel pretty much fine. I mean, I'm a little bit worried to say that or superstitious about saying that, but so far I haven't had any problems. Do you think there's still a good chance that you actually do have celiac disease? Yeah, well, I've been trying to manage my expectations about not having it because it's very possible that I'm going to go have the endoscopy and they'll say,

you need to stay gluten-free forever and I will be okay with that. And as far as being a sucker, yeah, I feel a little... Let me rephrase. I don't mean to call you a sucker, Emma, because I'm so fond of you, but let me rephrase it. Have you thought about a lawsuit, perhaps? Yeah, it's crossed my mind. When I told my sister about this whole situation, she said to me, you should sue that original doctor for a million croissants. Coming up next time on Freakonomics Radio, we check in on a wildly ambitious project we first told you about several months ago. It set out to solve a problem. A problem that if we fixed it could truly solve every social problem we could think of.

The project is called Behavior Change for Good. It'll involve millions of real world research subjects, a long list of corporate partners, and one of the most impressive collections of academic researchers we have ever seen. We think because this is like the Hall of Justice with all the superpowers in one place that we might have a shot at doing something that hasn't been done before. These academic superheroes spent a couple of days together

drawing up their plans for world behavioral domination, and we were there. We'll share with you the bold ideas. I mean, we're spending hundreds of billions of dollars in colleges, and I think we're not getting much value for our money. The candid pushback. I disagree, actually. I disagree. I disagree.

And the risks of such a high-stakes enterprise. If they fail, that's going to be quite costly for a long time. That's next time on Freakonomics Radio is produced by WNYC Studios and Dubner Productions. This episode was produced by Emma Morgenstern. Our staff also includes Allison Hockenberry, Greg Rosalski, Merritt Jacobs, Stephanie Tam, Eliza Lambert, Harry Huggins, and Brian Gutierrez. The music you hear throughout the episode was composed by Luis Guerra. You can subscribe to Freakonomics Radio on Apple Podcasts or Stitcher or wherever you capture your podcasts.

You should also come check out our archive at Freakonomics.com. You can stream or download every episode we have ever made. You can also find the transcripts and links to the underlying academic research. We can also be found on Twitter, Facebook, or via email at radio at Freakonomics.com.