Should you worry about gluten?

The last decade saw a rise in gluten-free diets. But the number of us with diagnosed gluten intolerance hasn’t changed.

Eliminating gluten is the only treatment for those with celiac disease, but the rest of us could be doing more harm than good by embracing ultra-processed gluten-free foods.

In today’s short episode of ZOE Science & Nutrition, Jonathan and Will ask: Should you be worried about gluten?

Studies referenced in this episode:

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This podcast was produced by Fascinate Productions.


[00:00:00] Jonathan Wolf: Hello, and welcome to ZOE Shorts, the bite-sized podcast where we discuss one topic around science and nutrition. I'm Jonathan Wolf, and I'm joined by my friend Dr. Bulsiewicz and today we're talking about gluten. 

[00:00:31] Will Bulsiewicz: There's a lot of fear-mongering out there about gluten. Gluten is bad, is the message we're getting everywhere from the supermarket to social media and all this anxiety can make it hard to get to the truth,  

[00:00:42] Jonathan Wolf: So Will. Is gluten really as bad as everyone seems to think?  

[00:00:47] Will Bulsiewicz: Well, Jonathan, there's now a good amount of science on gluten, and also there's a lot of myths, so I think there's a clear answer, Jonathan, and we're gonna get into it. 

[00:00:55] Jonathan Wolf: All right? I want to hear it. 

[00:01:37] Will Bulsiewicz: We need to start Jonathan with what gluten is because there's so much misinformation. Picture a chef stretching out a ball of dough at your favorite pizza joint, and they're tossing it up into the air to make that perfect pizza base without gluten. The dough would tear.  

[00:01:53] Jonathan Wolf: So it turns out that gluten is a protein that's naturally found in certain plants, such as wheat, rye, and barley. Cooks have loved it for millennia because it helps food keep its shape.

Gluten actually comes from the Latin word meaning glue, and humans have been using its properties for long before even the Romans, it turns out Will. So apparently the remains of a flatbread baked by hunter-gatherers fourteen thousand years ago have been found by archeologists in Jordan. The gluten helped combine all the grains into bread, which is presumably a lot easier to carry around on a hunting trip than a bunch of seeds. 

[00:02:31] Will Bulsiewicz: Yeah, especially since you didn't have any sort of bag to carry those seeds that easily back then. But anyway, it's quite difficult to separate gluten from wheat, barley, and rye. So anything that contains these ingredients could potentially be problematic  

[00:02:43] Jonathan Wolf: And problematic because gluten is bad for you, right Will? It causes gas and bloating and a whole host of other digestive issues.  

[00:02:52] Will Bulsiewicz: Well, no, that's not strictly true. What you're probably thinking of is Celiac disease.  

[00:02:57] Jonathan Wolf: As I understand it, Will, celiac disease is a very serious inflammatory condition that affects a small intestine and its ability to absorb nutrients. People with the condition can't consume gluten because it's going to trigger their immune system.  

[00:03:11] Will Bulsiewicz: Correct. It was identified by a pediatrician during the Dutch famine of 1944 who noticed that his celiac patients improved with the strict flower rations. Untreated celiac disease can lead to severe diarrhea, abdominal pain, bloating, malabsorption, infertility, weight loss, and even iron deficiency anemia. It causes chronic inflammation inside the intestines. So over time, it could potentially lead to cancer, even though that's very rare.  

[00:03:39] Jonathan Wolf: So it's an incredibly serious disease. I remember my wife talked about it with patients that she's seen in the past and just sort of how serious it is now. This is something that you can go to the doctor and get a blood test. Is that right?  

[00:03:52] Will Bulsiewicz: It's important for people to know, Jonathan, that the testing doesn't have to be invasive, particularly up front. Many times the right place to start is with a blood test, and the blood test can provide insights there is some additional confirmatory testing that may be required, but usually, that's where we would begin. 

[00:04:07] Jonathan Wolf: And what's the treatment if you are diagnosed with celiac?  

[00:04:11] Will Bulsiewicz: Well, there's only one treatment. It's very clear, and that is the strict elimination of gluten from your diet. You have to be gluten-free. It's estimated that celiac disease affects at least one in a hundred people in both the UK and us. But interestingly, only about 30% of these people are currently clinically diagnosed.  

[00:04:31] Jonathan Wolf: I find that shocking Will that you're saying maybe 70% of people are not diagnosed, given that it is such a serious disease and that you can change your diet to have such a profound impact on your symptoms. However, if it is only one person in a hundred has it. Why do so many people think that gluten is bad for them?  

[00:04:51] Will Bulsiewicz: Well, partly it's the general awareness and some of the fear that comes from the serious effects of celiac disease. There's no doubt about that. But at the same time, there were some studies done that raised concerns about gluten going back about 15 years ago, Jonathan, that concluded that gluten is inflammatory and it causes bowel damage, which of course, fanned the flames of the gluten is bad narrative. 

But the thing that people need to understand is that those studies were done in labs with rats or in test tubes. There's very little robust or high-quality evidence showing that gluten is bad when real humans eat real food.  

[00:05:29] Jonathan Wolf: It's interesting because we talk often on this podcast about how you have to be very careful before you assume that a study done on animals also applies to humans. It sounds like we need to be very careful here when we're accepting those studies about gluten as the truth for human beings.  

[00:05:47] Will Bulsiewicz: Absolutely. And here's the complicating factor. Some people do have an adverse reaction to gluten-containing foods that are not due to celiac, and they might experience fatigue or bloating, abnormal bowel movements, or even a rash or neurologic symptoms.  

[00:06:03] Jonathan Wolf: So if it's not celiac disease, why the adverse reaction?  

[00:06:07] Will Bulsiewicz: Well, there are three possibilities for a person who's having this type of adverse reaction. Jonathan. So I wanna run through them if we could. , number one, you have side effects when you eat wheat, but importantly not when you eat rye or barley. 

So the first thing that you need to do in this case is to make sure that you don't have celiac disease. Any person who reacts to these foods should be tested for celiac. But if there are symptoms only when eating wheat, that's more likely to be a wheat allergy.  

[00:06:34] Jonathan Wolf: Got it. And I guess you do have symptoms when you consume gluten that is similar to Celiac disease, so you are feeling bloated and you're getting abdominal pain, but you're not seeing the positive blood test or some other evidence from the doctor. So does this exist?  

[00:06:50] Will Bulsiewicz: Yeah, this exists. These are patients that I've taken care of. Thousands of times throughout my career. This is the most common scenario among people who have some sort of symptoms when they consume gluten-containing foods. And Jonathan, what we call this is non-celiac gluten sensitivity, or you could also call it gluten intolerance. 

And there's something really interesting about this. It turns out that this condition which we're calling gluten intolerance, may not be gluten at all. You see wheat, barley, and rye. These foods aren't just a big ball of gluten. They contain other nutrients. An example of this is fructans. Fructans are a type of fiber that is called a FODMAP found in gluten-containing foods. 

People may have heard of the low FODMAP diet. They did a recent study comparing the effects of gluten and fructans to placebo and what they found was that when people consumed gluten, it did not affect their symptoms at all. But on the flip side, when they consumed the fructans, it actually triggered their symptoms. 

We usually attribute these symptoms to gluten, but we probably should be attributing them to fructans instead.  

[00:08:07] Jonathan Wolf: That's interesting cuz what that means is there might be lots of people listening to this right now who think that they have this intolerance to gluten, but they're intolerant to something else and in which case, switching to gluten-free food is a horrible mistake. Cause they're just gonna eat lots more ultra-processed food; for no benefit.  

[00:08:27] Will Bulsiewicz: Exactly. And if you have symptoms eating bread, I have an interesting way that you could approach this to test at home. And the way that you do this is by eating sourdough bread because it turns out that sourdough bread is low in fructans. So like the fermentation process will reduce the fructan content, the sourdough bread still contains gluten.  

So if you consume sourdough bread and you have no side effects, Then you may have an inversion to fructans rather than gluten, which means that the good news, here's the bright side, you get to enjoy lots of yummy sourdough bread. 

[00:09:02] Jonathan Wolf: Brilliant. So that was the first and second categories. What's the third category Will?  

[00:09:07] Will Bulsiewicz: The third category manifests outside of the digestive system, and it could be things like neurologic symptoms, like poor muscle control or difficulty with balance. We have a term for this. It's called gluten ataxia. 

Or it could be a rash with itchy fluid-filled spots that are occurring on your forearms, on your knees, potentially your scalp, or your bottom. We call this dermatitis or performs. Now, these things just to be upfront, sound scary. People need to know they are extremely rare.  

These are far less common than celiac disease, and in fact, actually in the vast majority of these people, If you test them, you will find that they do have celiac disease. It's not just happening without celiac. So either way, the solution is a gluten-free diet. They both resolve on a gluten-free diet. 

[00:10:18] Jonathan Wolf: All right then Will, so what have we learned from all of this? Is gluten really as bad as we've all heard? From what you've told me, it seems like gluten for most people is not necessarily bad, despite the huge numbers of people who've been cutting it out of their diets over the last decade.  

[00:10:36] Will Bulsiewicz: Yeah, there's actually, evidence that would suggest that gluten-containing foods should be a part of a healthful. 

There's a 2017 study, Jonathan, of over a hundred thousand participants, and now it's important to point out that these people did not have celiac disease. And when they took a look, they found that there was no association between consuming gluten and the risk of heart disease. You would assume if gluten was truly in inflammatory food, it would increase our risk of these conditions, but, in the study, those people who avoided gluten; actually increased the risk of heart disease.  

Most likely what's happening here is that they're reducing their whole grain consumption when they go gluten-free. This is problematic because whole grains contain many nutrients. They could contain gluten, but they also contain many nutrients like fiber or B vitamins, magnesium, and iron. 

So, believe it or not, even the fructans that, you know, you and I were just speaking about a moment ago and saying, yes, these fructans can cause your symptoms. The fructans are a form of fiber. They're probiotic, and they feed our good gut bugs.  

[00:11:44] Jonathan Wolf: And I think one of the things that are now clear to me that wasn't at all before is that if you. 

Are you diagnosing yourself as needing to eat gluten-free food and that isn't required? That you start to switch to all of these things that you can now buy in the store that say that they're gluten-free. Most of these foods are incredibly processed, so like ultra processes, we would say. And so you are swapping out foods that might. 

Be whole grain that has all of this fiber for these things where we now know that not only you potentially losing some of these nutrients, but these ultra-processed foods can be very bad for you with these emulsifiers and sweetness that can affect your microbiome.  

You know, you're trying to do something really good for your health, right? 

You, you understand this thing is bad. You're actively making these positive choices to buy this food that says it's gluten-free and you are taking something which is gonna turn out for most people to be worse for them. If they hadn't made this swap and I, am I catastrophizing here, or is that, do you think that's fair? 

[00:12:45] Will Bulsiewicz: Yeah. I think that striving towards a diet of abundance where we prioritize getting a wide variety of different foods, particularly plant foods into the diet, is, that's a central philosophy with ZOE. I think one of the other things with ZOE is quality. Quality is important.  

Whether we're talking about gluten-containing foods or gluten-free foods. Either way, one of the central messages that should be taken away from our podcast today is that quality is important. So if you're opting for gluten-containing foods, you want the high-quality gluten-containing foods, you want that whole grain sourdough bread, you want that rye bread, you want that barley. If you're opting for gluten-free foods, this is where, once again, you just need to be cautious not to be opting for those ultra-processed.  

[00:13:29] Jonathan Wolf: That's right. And you're probably not wild on gluten having been separated by the food manufacturing process in order to stick into a bunch of other foods as a glue, right? 

One of my takeaways is there's nothing you're saying here to say like, gluten is a magically good property of food. Is that right Will? It's more that there's no reason to think that it's harmful to most people.  

[00:13:48] Will Bulsiewicz: I Think it's looking at the entirety of the food, Jonathan, and understanding that this food is more than just gluten-containing and so that food matrix contains so many other factors that we've touched on that include fiber and vitamins and polyphenols. And this is why let's not focus so much on the gluten and moose side of the big picture, which is like, what happens when you eat a piece of sour dope bread? Does it nourish your body? Does it feed your gut microbes? The answer is yes, So let's enjoy that.  

[00:14:15] Jonathan Wolf: Wonderful. In my case, not too often, but absolutely. Will, I think the myth about gluten is pervasive. I think that a lot of people will have, like me, learned a lot from this episode. So it's been great to get into the science and I look forward to exploring more of this in the future. 

If you'd be listening to this episode and you'd like to try ZOE's personalized nutrition program to understand your biology and understand what to eat to improve your health. You can get 10% off by going to I'm Jonathan Wolf.  

[00:14:45] Will Bulsiewicz: and I'm Will Bulsiewicz.

[00:14:47] Jonathan Wolf: Join us next week for another ZOE podcast.