Science Vs - Gluten: Should You Give It Up?

Episode Date: June 15, 2023

Going gluten-free is all the rage — we hear it’s the secret hack to being more healthy, even if you don’t have celiac disease. But is gluten actually bad for all of us? And what’s the deal with gluten sensitivity? We talk to immunologist Dr. Armin Alaedini, gastroenterologist Dr. Carolyn Newberry, and nutrition epidemiologist Dr. Natalie Riediger.  Find our transcript here: https://bit.ly/ScienceVsGluten In this episode, we cover: (00:00) Chapter 1: Why the internet hates gluten (02:17) Chapter 2: How gluten can hurt some people (05:21) Chapter 3: What’s up with gluten sensitivity (11:35) Chapter 4: Gluten and the placebo effect (15:27) Chapter 5: Other stuff besides gluten could be to blame (22:05) Chapter 6: Can a gluten-free diet help you lose weight?  (28:03) Chapter 7: Downsides to going gluten free  (29:28) Chapter 8: A love letter to gluten  This episode was produced by Michelle Dang, Wendy Zukerman, Meryl Horn, R.E. Natowicz, Joel Werner, and Rose Rimler. We’re edited by Blythe Terrell. Fact checking by Diane Kelly. Mix and sound design by Bumi Hidaka. Music written by Bobby Lord, Peter Leonard, Emma Munger, and Bumi Hidaka. Thanks to everyone we reached out to for this episode including Dr. Sachin Rustgi, Dr. Robert Anderson, Dr. Jonatan Gomez, Dr. Jessica Biesiekierski, and Zoe Scheier. Special thanks to the Zukerman Family and Joseph Lavelle Wilson.  Science Vs is a Spotify Original Podcast. Follow Science Vs on Spotify, and if you wanna receive notifications every time we put out a new episode, tap the bell icon! Learn more about your ad choices. Visit podcastchoices.com/adchoices

Hi, I'm Wendy Zuckerman and you're listening to Science Versus. Today on the show, we're pitting facts against flour, focaccias, fettuccine. That's right, it's Science Versus Gluten. For years, people have been worried about what gluten is doing to our body. But recently, it's like gluten has transformed into a dietary supervillain. Gluten might be one of the biggest mistakes for your health and longevity. This is not a food for which a little bit here and there tends to be okay. But it's not just the wellness brigade on social media that's got this war against gluten. Gluten.

Gluten. Gluten. Gluten. In the US, surveys show that nearly one in four people are avoiding gluten in some way, which seems like a lot, especially since only about 1% of the population has celiac disease, a condition where gluten can really screw up your gut and make you sick. So what's going on here? Well, people are saying that it's not just those with celiac disease

that need to avoid this stuff. Gluten is incredibly inflammatory for a lot of people. Some people say it can make you feel tired and brain fogged, while others reckon that going gluten-free is the secret to weight loss. Now, without gluten in my life, I've lost fat. So if you cut out gluten to 100%, you will lose weight easier. And you could just brush this aside as just another fad. But the thing is, a lot of people are going gluten-free

and saying they feel better. So what is going on here? Is gluten really bad for all of us? Or is this just the placebo effect gone wild? When it comes to gluten, there's a lot of... Gluten might be one of the biggest mistakes. But then there's science. Science versus gluten is coming. Just after the break. What does the AI revolution mean for jobs, for getting things done? Who are the people creating this technology?

And what do they think? I'm Rana El-Khelyoubi, an AI scientist, entrepreneur, investor, and now host of the new podcast, Pioneers of AI. Think of it as your guide for all things AI, with the most human issues at the center. Join me every Wednesday for Pioneers of AI. And don't forget to subscribe wherever you tune in. That's right. I'm bringing in the A-team. So brace yourselves. Get ready to learn. I'm Jana Levin. I'm Steve Strogatz. And this is... Quantum Magazine's podcast, The Joy of Why.

New episodes drop every other Thursday, starting February 1st. Welcome back. Today, we are talking all about gluten. This fad that just won't die. Or is it a fad? Producer Michelle Dang is here to tell me all about it. Hey, Michelle. Hey, Wendy. I really thought when gluten-free popped up, I don't know, five, ten years ago, it was just going to be like a blip. Yeah.

I don't know. I feel like it emerged in the days of the paleo diet that you just don't hear that much about anymore. And yet this gluten-free thing has persisted, which does make me very curious. Yeah, I was curious too. So, Michelle, first, can we start with a very basic question? What exactly is gluten? Yeah, so gluten is this group of proteins found in wheat, barley, and rye. It's the stuff that gives food like bread and pasta their shape. And fun fact, the word gluten comes from the Latin word for glue.

That is a fun fact. Okay, another fact I want to know, Michelle, is around one of the big claims about gluten-free, which is that gluten messes with your gut. So why would this protein that does this lovely thing to our bread muck up our gut. Yeah, so interestingly, we don't have the enzymes to fully digest gluten. We as in like everyone or just people with celiac disease? Yes, we as in everyone. And if you eat bread, the gluten in the breads basically does not fully break down and then leaves these long chains of protein kind of hanging out in our gut. And so we know that for some of us, the immune system will find

these bits and then start going haywire. That is people with celiac disease. Uh-huh. Yeah, so let me take you inside the gut of someone with celiac disease. What happens is that their bodies, their gut, finds these gluten bits that are left over and start to have this autoimmune reaction. And so the body starts attacking itself. Ground zero for this is in the small intestine, where this immune response ends up destroying these tiny finger-like projections called villi. I spoke to a scientist named Armin Aladini about this. He's an immunologist from Columbia University. Immune cells are being activated. They are attacking the villi. They're

destroying them. And therefore, what you see in celiac disease patients, especially advanced cases of celiac disease, you see no villi. it's completely flat. So you don't see any of those finger-like projections. Wow. Okay. So this is for people who have this condition where their immune system hates the breakdown products of gluten, celiac disease, which we mentioned is only around like 1% of the population, right? Yeah, exactly. So then what is interesting to me is that recently there's been this like growing idea that it's not just people with celiac who need to be avoiding gluten, but like a whole bunch of us do. Particularly people with what's sometimes called gluten sensitivity. What's going on here?

Yeah, I was curious about that too. Because like the weird thing is that these people can have stuff like pain, bloating and diarrhea, but they don't have anything obvious going on inside their guts. Like when doctors do biopsies and take a closer look at the gut, they pretty much see healthy little villi in there. Huh. What is happening with these people? Well, this was a question that Armin had as well. And Armin had been skeptical himself that gluten sensitivity was a thing. And when he started wondering about this more than a decade ago, a lot of doctors were thinking that maybe these symptoms were just in people's heads.

In fact, the patients were even stigmatized. You know, they would go to the clinician, they would say, I think I have celiac disease. They didn't have that. And then there was nothing else to be done for them. So Armin decided to look into it. And, you know, since they can't see obvious damage inside of the gut, he thought maybe the blood could tell us a bit more about what's happening in their bodies. So he found a group of scientists in Italy who were working already with a crap ton of people who felt yucky after eating

gluten-rich foods like wheat, rye, and barley, but they didn't have celiac disease. And Armin asked the scientists if they could do a study together. So then they took the blood from 80 different patients and shipped it off to Armin by plane across the ocean. And, you know, he went to the airport to pick it up and was super excited. But the package got stuck clearing customs at the airport and the dry ice keeping the blood frozen had basically disappeared. So the package was sitting there and all the samples got spoiled. Oh, no. So we were talking about, you know, 200 samples that were, that this had happened to. And so we were extremely disappointed. And I said, we have to see if we can get these samples again. Luckily, the Italian doctors had more samples and he got another package. And this time the samples were okay.

It was like Christmas. I was just ecstatic. I was just ecstatic. So Armin got these blood samples to the lab and started poking around. And he was looking to see if there were any markers of the immune system going haywire in these people of gluten sensitivity. Mm-hmm. And the results of this were truly what changed my mind entirely about what was happening in these patients. What did he find? So what he found was like a host of immune cell activity in the blood. We were detecting such a huge inflammatory response. The battle was raging. So we were extremely surprised. We were really, really surprised and excited at the finding. He also found little traces of gut cells in the blood, which suggested there actually was

a bit of damage to the gut lining. And when Armin looked at blood from the healthy controls in the study, he didn't find these signs of inflammation and damage. The levels of these markers, this inflammation that we were seeing, was so much higher than in healthy individuals. Oh, wow. And we know inflammation in your gut can trigger things like pain and bloating. So do we know what's causing this? Because in people with celiac disease, it's an autoimmune reaction.

But what could be going on in these gluten-sensitive people? Well, Armin has a theory about what's happening. You know how our guts have a ton of bacteria and stuff inside? Yes, yes, yes, yes. Yeah, well, one of the jobs of the gut is to keep that bacteria from getting out. Because you don't want this huge population of microbial organisms to get to the rest of the body, right? Because they'll trigger a very strong immune response. Yes, I want them to stay where they are, in the gut.

Yeah, and one idea is that this bacteria is escaping, getting into the blood, and causing the inflammation markers that Armin saw. Huh. But, like, so many things can cause inflammation. Why does he think it's the bacteria escaping? Yeah, so he basically found antibody responses to bacteria that we do know often are in the gut.

And like we said earlier, he didn't find this inflammation in the healthy controls. Their blood looked totally fine. I mean, that is very curious. I just remember there being so much skepticism about this idea that you could be sensitive to gluten, have a reaction to it when you weren't testing positive for celiac disease. And was this like one of the first times that scientists were able to say, no, no, no, look, we can point to something here? Yeah, this is one of the first studies that helped show that there's actually something going on. And, you know, Armin's still working out what all this means, but the bottom line for Armin

was that people with the sensitivity are experiencing something real. So all of these things really convinced me that we are dealing with a real condition here with a biological mechanism behind it, that this is not something in the patient's heads. This is really something that involves the immune system at a major level. So does everyone who, like, not including people who have celiac disease, but people who are saying they're gluten sensitive, who are saying when I eat gluten I get bloating and these yucky symptoms,

like all those people on TikTok, do they all have that battle going on in their blood? Well, there's a couple other things that might be going on. The first is placebo, right? I talked to Carolyn Newbury about this. She's a gastroenterologist from Weill Cornell Medicine. They've tried to isolate and do like real placebo-controlled trials where they give people, you know, gluten and capsules and capsules without gluten in them and sort of try to isolate whether it's actually the gluten that is causing their symptoms or other components of the foods

that they're eating. I love these kinds of studies because they really get to the heart of this question. Like, is, are you really sensitive to gluten or something else. So what exactly do they do in these trials? Scientists will collect people who report being gluten sensitive, and then they will give them either pills with gluten in it, like pure gluten, or pills without. Or, you know, sometimes they'll give them foods like muffins with gluten and without, and then they'll see what happens. So what do they find? Can people with gluten sensitivity tell which is the real thing? Yeah, what they find is that some people are actually reacting to gluten, but it's not everybody. One meta-analysis rounded up around 200 people from these studies that had the gluten sensitivity and took the placebos or the real thing. And they found that on average,

when they tested them, only 16% reacted to pure gluten. 16%. Interesting. So one in six could actually tell the difference Wow And maybe some of those are like the people in Armand's study Like that's where those people live Yeah, yeah Okay, but that still suggests that of the people out there Listening to this show, talking on TikTok

Who say they have a gluten sensitivity, if we can extrapolate from these studies, actually only one in six may have a gluten sensitivity. So what else could be going on with those five out of six people? I mean, immediately, just because I've done this show for too long, I swear I don't mean to be mean, but like I'm immediately thinking of the Nacebo effect, like that some of these people have just like manifested a fad and they're like, this is, I don't want to say all in their head, but this is a psychological thing. Is that, do we, from these studies, do we have any idea whether that could be going on? Yeah, it could be. So that

meta-analysis I mentioned also found that 40% of people who went through these trials said they felt crappy after they got the placebo. So no gluten at all. Oh, they said they had like bloating and stuff like that, even though they were just taking the placebo pill 40 yeah but the scientists also said that it could be something in the placebos that could have been causing that reaction because often they're you know these pills but there's sometimes also muffins or bars that they use as the vehicle oh Okay. So then zooming out away from that meta-analysis, what else in food might be causing these symptoms then? There are a couple other big culprits. So here's Carolyn. Glutenopin is an innocent bystander of foods that cause bloat. There's other proteins found in wheat. In fact, in Armin's study, his subjects had gone

through these placebo trials already for their belly aches, but the test they used wasn't specific enough to tell if their bodies were reacting to trisgluten or maybe something else in wheat. Now, one of the interesting suspects here is this particular group of sugar chains with a much less sexy name. It's called FODMAPS. It's an acronym and it stands for fermentable, illegal saccharides, disaccharides, monosaccharides, and polyol. Oh, I wonder why they came up with the acronym. That's just so catchy. These are different groups of sugar chains, like big sugar chains. But the key to take away

is that they're fermentable, which means that the bacteria in our gut really like to get at it and start fermenting it and produce a lot of gas. So I've another fun way to put this is wind causing sugars. I like fart causing food. Fart causing food. That is another way to put it. Wind is always felt like such a weird euphemism for farts. Don you think like it doesn't feel like wind to me okay we can say fodmaps the the fart causing foods so fodmaps are in wheat and so they're gonna end up in a lot of the foods that gluten's associated with too your breads your croissants your you know, all those things. Oh, all that good stuff. Yeah, they're also in a bunch of other foods too, like apple, mango, milk, garlic, onion.

So many farty-causing foods. I mean, that doesn't make sense to me. Yeah, I mean, we fart a lot. Now, there's this one FODMAP study that I want to talk about that really tried to work out how many people who thought they were gluten sensitive might actually be sensitive to FODMAPs. Wow, amazing. What did they do? Okay, so researchers recruited around 60 people who said they had gluten sensitivity and had gone gluten free. Then they gave them three types of bars.

One contained gluten, one had a FODMAP called fructans, and then there was a third bar that had neither of them. It was a control bar. All the bars looked and tasted the same, and the people in the study ate each type of bar for one week. So here's what they found. On average, all the bars caused some symptoms. Maybe people were a bit bloated or farty. But the FODMAPS bar made people feel the worst.

Right. To put some numbers on it, the FODMAPS bar made people feel 25% more bloated than the gluten bar. Wow. Wow, wow, wow. And another thing that was sort of surprising here is that the bar with gluten, it didn't make people feel any worse than the control bar. Ha, so it really could be these FODMAPs, this fructan stuff, and we're just blaming gluten because that's the buzzy word right now. Mm-hmm, and other studies have found this sort of thing too.

It's funny because FODMAPs is not a new thing, right? Like it's been in the science world for a while. Yeah, they've particularly been looking into it for IBS. It seems to help that group a lot. Interesting. Oh, it is funny. Maybe they need like a better acronym. You know, maybe FODMAP's not doing it for the kids.

Maybe Farty Sugars. So then my next question, Michelle, is if we're all eating these FODMAPs, these Farty Sugars, and the bacteria in our gut are breaking them down and producing gas, like that's just part of how the human body with our friendly bacteria digest these products. Then why is it that some people feel like bloating and pain as a result of eating them and not others? Yeah, so because we all get wind from those farty sugars, it could be that some people just have a more sensitive gut to that gas.

And so here's Carolin explaining a bit more about how scientists figure that out. And so they've done these really fascinating studies that I would never volunteer for, but they've like blown balloons up in people's like intestines. And they've found that, you know, some people are like, you know, I'm really uncomfortable with this balloon just blowing up a tiny, tiny bit. And other people don't feel it at all. And you get a sense that some people have a lot more higher threshold when they actually feel bloated, distended, uncomfortable than another person. And some of my patients get very frustrated because they happen to be on the spectrum

where they have really sensitive nerves. So even a tiny bit of extra gas makes them very uncomfortable. Oh, that is fascinating. Yeah, I had never thought about that and also doing that kind of study. I really appreciate the volunteers who were up for putting balloons in their cups. So here is where we're at. Michelle, is this right? There are people who have celiac disease, audience knows this. Then there are people who report being gluten sensitive.

What could be happening here is that, yes, indeed, their immune system might be responding in some way to the gluten. It could also be that gluten is an innocent bystander here and their body is reacting nastily to FODMAPs. Yeah, yeah. And for some people, it could be something else altogether. Right. Yeah, the unfortunate thing about all of this is that there's no test to figure out what's actually bothering you.

Oh, that is frustrating. What is up next, Michelle? What's gluten been blamed for this time? Okay, so a lot of people on TikTok are saying that they lost a ton of weight when they went gluten-free. So, can going gluten-free help you lose weight? Coming up! Welcome back. Today we're talking all about going gluten-free. Yes, gluten, the internet's most wanted dietary criminal. Producer Michelle Dagg, so far, I reckon I'm still gonna eat croissants at this point. Unless, have you got a reason I shouldn't? Well, there are people on the internet and on TikTok that say gluten is addictive because it breaks down into a structure that's similar

to endorphins in our body. So, you know, like natural opioids or feel-good chemicals. And is that true? Does it do that? Well, it's true. Yeah. And the idea is that the gluten bits then get absorbed into our blood, go to our brain, and cause that, I want to keep eating. I want to keep eating more of this feeling. Uh-huh. And like, that's why, you know, that piece of bread, that whole loaf of bread is so irresistible. Scientists in the 70s did start looking into this and, you know, proposed the idea that gluten could be like morphine really yeah but

you know more recent research has found that no it's very unlikely that these bits actually pass through and do something to our brain right okay so in our gut when gluten gets broken down it kind of looks a bit like an endorphin, but you just get to crap it out. It doesn't get up into your brain and hijack it. Right, right. And it turns out a lot of foods do this as well, break into these similar structures. Even spinach has a lot of these.

And no one's saying that they're addicted to spinach. No, they are not. Well, I mean, except, of course, everyone's favorite spinach-eating sailor, Popeye, who seems to have been vindicated here. But gluten is not addictive. Very good to hear. Another thing we are hearing all over TikTok and the internet, though, is that going gluten-free can help you lose weight. What is the science here? I want to talk to Natalie Rieniger about this. She's a nutrition epidemiologist from the University of Manitoba. And she had this huge data set from the Canadian government that had surveyed over 20,000 people

on their diet. And so that's a lot of poutine or something. Is that that? Poutine. Poutine. A lot of poutine. And they went to people's houses and had people sit down with one person from the household and had them remember everything they ate in the past 24 hours. And this went like really, really detailed. So if somebody says they had a Tim Hortons sandwich, it can go into the drop down list. It'll search, you know, like you type in Tim Hortons and all of a sudden it'll come up and they can click it. So it'll link to all the nutrient information. Wow. This sounds really fancy. And so in this study, they had also asked whether people were avoiding gluten or not. And so Natalie was able to pull out

the people who were avoiding gluten, and there were about 500 people. And so one of the things she wanted to find out was, did the BMI, was it different between this group of people who were avoiding gluten from the rest of the lot? And what she found... There was no difference between Canadians' body mass index who avoid gluten compared to those who don't avoid gluten. Yeah, it didn't matter if they were eating gluten-free Tim Hortons or regular Tim Hortons. The group of people avoiding weren't any significantly thinner. And other big studies have found the same thing. Like when researchers look at the weight of people who eat gluten versus people who don't eat gluten, they just don't see a difference here. And so, you know, when people say they went gluten-free and they lost a bunch of weight, is it just because they're restricting certain foods from their diet? Like it's not as if they're

replacing a muffin with a gluten-free muffin. They're just not eating muffins anymore. Is that what's happening? Exactly. So we know that avoiding carby stuff like bread and pasta, which is where you might find a lot of gluten, can help people lose weight at least for a while. And so the reason is likely that they're replacing bread with stuff that's just more filling but lower in calories. Yes, of course, of course. Gluten villainized here when it's really just our old friend calories. Yes, yes. And so overall, Natalie says when you look at all the evidence that exists out there, does going gluten-free lead to weight loss?

I'm sure there's somebody who avoids gluten who's like, I lost weight. I don't dispute that. But there's no evidence that avoiding it contributes to weight loss when you take in all other factors into account. I love how Natalie knows the internet so well. I'm not saying, you know, I'm not saying that you've lied on your TikTok. I'm just saying the science. Right, right. And just one more thing that comes up that I want to mention. There's this idea that going gluten-free can help with cognition.

While there is some evidence that this might be the case for people with C-Lac disease, there's not great evidence that it will help those with gluten sensitivity. And just generally, there was this one study that looked at data following over 13,000 women without C-Lac disease. And they looked to see if there were any cognitive differences between low and high gluten eaters. Well, they didn't find any. Okay. All right. So then I think, Michelle, my last question is, if you personally feel like cutting out gluten is good for you and your body,

are there any downsides to cutting it out? I mean, other than missing out on yummy food? Yeah, there have been a lot of big red flags from studies in the past that found that gluten-free diets were like overall lacking certain vitamins and nutrients. So in Natalie's study, the computer system had all the micronutrients broken down. Natalie was able to then analyze that. And she found that when people skipped gluten, they got less folic acid, vitamin D, and calcium. Huh. Why is that?

So folic acid, it's added to wheat flour to prevent neural tube defects in fetuses. You know, important for pregnant people. And if you go gluten-free, you're likely to get less of it because you're just not eating as much. You're not eating wheat. Of course. When it comes to vitamin D and calcium, that might not be related to gluten itself because a lot of people who avoid gluten also avoid dairy. So it's possible that could be a reason. Here's Natalie. I don't think it's, you know, a nutritional disaster. It just requires a bit more thought, perhaps.

So bottom line, gluten is not the big villain in our diets. And Wendy, actually, let's spend a moment just to appreciate gluten foods yes I feel like gluten just gets so much crap let's have this moment Michelle what should we love about gluten filled foods well gluten-rich foods like wheat barley and rye have a ton of fiber. And I know fiber does not sound sexy, but it's so important. Eating a bunch of it lowers the risk for stuff like heart disease and type 2 diabetes, possibly because your gut can't chew up food with a lot of fiber easily, which helps keep your blood sugar from spiking. Oh, interesting. And one big review found that people who eat high-fiber foods

are about 20% less likely to die of cardiovascular disease. 20%? Yeah. Also, fiber can help you pass poo faster, which may lower your risk for colon cancer. Well, thank you, Fiverr, for your services. I know you can get Fiverr from non-gluten-rich foods, which people with celiac disease are very grateful for,

but that is wonderful. So, Michelle, as we're capping off here, as we're sorting out the wheat from the chaff, it feels like the new evidence is telling us that there is this thing called gluten sensitivity that we don't have a test for, but some people, their guts and immune systems don't like gluten, even though they don't have celiac disease. But then the internet has taken that fact and blown it up to say that we should all be avoiding gluten. And there's really no good evidence for that. Yeah. Even Armin, who did that study, but found all those inflammation

markers in people's blood, doesn't think everyone should be avoiding it. Most people do not have a sensitivity to it too. So to make that blanket statement that everybody should go off of it, I think we don't have the evidence for that. We really don't. And you know, I think Natalie said it best here. I believe everybody knows their body best in terms of if that makes you feel better, then do it. But for individuals who have no medical reason for avoiding gluten, there's no evidence to suggest that gluten harms your health in any way. I love gluten. I have no medical reason to avoid it.

So I enjoy it. Well, this is great news. Natalie and I will be cheersing with croissants to this science news. Yes, I'll join you. That's science versus. And Michelle, how many citations

in this week's episode? There are 99 citations this week. 99! That's so many gluten, non-gluten filled citations. If people want to find them, where should they go? They can head over to our show notes and check out the transcript. Yes, and we talked a lot in this episode

about how TikTok is kind of full of bull. So if you are on TikTok and don't want to hear about bull, come find me because I now am making videos on TikTok. I am at Wendy Zuckerman. That's Zuckerman with no C. Next week, our episode on affordable housing. Michelle, are you excited? Ooh.

Will my rent ever go down? That's what we're going to find out. Awesome. Why is rent so expensive? Why is buying a house so expensive? Super fun episode. Thanks, Michelle. Thanks, Wendy.

This episode was produced by Michelle Dang, with help from me, Wendy Zuckerman, Meryl Horne, Ari Natabich, Joel Werner and Rose Rimler. We're edited by Blythe Terrell. Fact-checking by Diane Kelly. Mix and sound design by Bumi Hidaka. Music written by Bobby Lord, Peter Leonard, Emma Munger and Bumi Hidaka.

Thanks to everyone we reached out to for this episode, including Dr Sachin Ruski, Dr Robert Anderson, Dr Jonathan Gomez, Dr. Jessica Bierskirche, and Zoe Shire. Special thanks to the Zuckerman family and Joseph LaValle-Wilson. I'm Wendy Zuckerman. Back to you next time.