Program: Is gluten really the enemy?

Tegan Taylor: Norman, I got a new toy,

Norman Swan: Okay, yeah, what's the toy?

Tegan Taylor: This is the toy. Can you hear it?

Norman Swan: Yeah, your bicycle bell. 

Tegan Taylor: It's the Mediterranean diet ring-ding-ding bell. 

Norman Swan: Oh, so this is every time I say 'Mediterranean diet', okay.

[Bell rings]

Tegan Taylor: I wasn't lying. 

Norman Swan: And what about 'Greek island diet'.

Tegan Taylor: No, that just feels like bragging. But no, if you say…

Norman Swan: 'Mediterranean diet'?

[Bell rings] 

I'm getting a complex now already.

Tegan Taylor: No, I love it. As if anyone needed more marking of the fact that you talk about it all the time. Maybe we can have a little bingo thing for people who can count the dings. And it feels like the right day to bring it along, because even though today we're not talking exactly about the Mediterranean diet…

[Bell rings] 

…we are talking about something…

Norman Swan: You get to ring the bell about yourself, okay, fine.

Tegan Taylor: If it comes up, I'm dinging the bell. If I get a chance to ding my bell, I'm going to ding my bell. 

Norman Swan: Okay, all right.

Tegan Taylor: We are talking about food today, so let's get into it.

Norman Swan: Today's question on What's That Rash? comes from Jill. 

Tegan Taylor: So Jill says among her friendship group it is getting harder and harder to find anyone willing to eat food containing gluten. Jill knows that gluten is very dangerous for people with celiac disease, but most of her friends are talking about having an intolerance rather than actual celiac. And she says this intolerance seems to go beyond what one would expect statistically of the average population. Jill, I love you. Meanwhile, Jill and her partner happily continue to munch on food containing gluten, no apparent ill effects. And so the question Jill is asking is, is gluten really the enemy it's purported to be, or is there something else going on?

Norman Swan: Really good question. 14%…this is work done by Professor Nick Talley at the University of Newcastle, who's a world authority on what's called functional bowel disorders, and things like celiac disease, which is not a functional bowel disorder, these are symptomatic problems in the bowel for which the cause is not entirely clear. Irritable Bowel Syndrome is one of them. So, 14% of the population report wheat sensitivity, but 25% of the population are on a gluten free or reduced gluten diet. So, it's very common. I remember I did a session at the Sydney Writers Festival where there were maybe 800 or 900 people in the audience, and before we got into the panel, I said, 'Well, how many people are on a gluten free or reduced gluten diet?' And far more than 25% put up their hands, although that is a selected population. So what is going on?

Tegan Taylor: And I would say up-front here, if gluten isn't for you then that's fine, don't eat it. But it is interesting, I think, to dig into what might be lying behind why some people feel like gluten is not for them. And then of course I want to talk about celiac, because it's really interesting. 

So I guess what we probably need to start with is gluten. I love making bread. I make pizza dough and focaccia and stuff, and I know that gluten is super important for those processes, because that's what gets the bread to be fluffy and elastic, and gluten is your friend if you are a baker. What I didn't know until recently, because I know that gluten is the protein in bread, but it's actually two different proteins that bind together when you add water to the flour, and then that creates a network which gives the structure to support the dough. So they create long strands of these two proteins, glutenin and gliadin, and they combine together to form gluten, long strands. And then as you knead the dough, you develop this long, stretchy network of strands, and then the yeast breathes out carbon dioxide, forms the bubbles, gluten plus carbon dioxide equals delicious bread.

Norman Swan: My mouth is watering, particularly since I'm on a low carb diet right now, but that's for another story. I think we need to start talking about celiac disease before we get on to gluten sensitivity, because celiac disease is really the main game when it comes to gluten. This is an underdiagnosed autoimmune disease where the body reacts to one of those components of gluten that you talked about, which is gliadin. And about 1.2% of men and about 1.9% of women have celiac disease, although people think that it's actually higher than that, because some…

Tegan Taylor: That's actually still quite a large proportion.

Norman Swan: It is a large number of people in the population, but it's probably more than that, because people don't necessarily get the full range of symptoms, and this is actually a serious…there's no question that celiac disease is a serious condition, and the first thing to say in a show about gluten is that if you think you have some of these symptoms, and if you think that you are sensitive to gluten, you need to go to your GP to get sorted out, because you don't want to have undiagnosed celiac disease. If you've got celiac disease, you need to have it diagnosed and you need to have it properly treated. Gluten sensitivity is something else altogether. But you don't sit on gluten sensitivity where you think you have the symptoms I'm about to describe, you think it's due to gluten and you don't get celiac diagnosed.

Tegan Taylor: Because the thing with celiac disease is basically your body isn't able to absorb food properly. So in your small intestine you've got these little…they're like fingers that sort of stick up onto the inside of your small intestine called villi, and that's providing all this surface area for your body to suck all the good stuff out of the food that's in your digestive tract. And they kind of get gummed up, and then they can't absorb the food, and then you have yucky symptoms, but also you're undernourished because you're not able to absorb those nutrients from food.

Norman Swan: Absolutely right. In fact, it's not just gummed up, you lose these villi. So instead of having a really nicely ruffled bowel, it goes smooth and you don't have the surface area and you've got this irritated surface because you've got this autoimmune process going on. So people with celiac disease can be fatigued, they can show signs that they're not absorbing their food, which means loose motions and maybe fatty loose motions. In kids, they can get growth failure, sometimes constipation. You can get mouth ulcers, weight loss. In women, you can get recurrent miscarriage. You can get B12 iron folate deficiency. So you can get nerve damage, you can lose balance. And the long-term problem with celiac disease is that you're a higher-than-average risk of lymphoma of the bowel, so you can actually get a cancerous change in the bowel from untreated celiac disease. So you've got to get on top of this.

Tegan Taylor: And doing it at home isn't good enough, because if you cut out gluten it can be harder to get an accurate diagnosis. Is that right? 

Norman Swan: Correct. So if you go on a gluten free diet or a reduced gluten diet, it affects the diagnosis. So you can actually cover up the diagnosis by being on a gluten free diet. So before you embark on a gluten free diet, you get checked up. So there are various ways to get checked up. There are blood tests to check for antibodies to gliadin. You can do what's called HLA typing, which is the immune profile that you've been born with in terms of how you react to the world around you. And there are sets of immune profiles associated with celiac disease. 

You can also have, by the way, other autoimmune diseases, such as type one diabetes, autoimmune thyroid disease at the same time as well, at same time as being celiac. And that cuts both ways. But the definitive diagnosis, at least in adults, is a small bowel biopsy. So you biopsy the bowel, and you see this typical pattern in the bowel, and that nails it. And then you go on a gluten free diet, which is really quite rigorously maintained, and it's something that you really do need to be on. And then you find that your symptoms, these serious symptoms, improve. So that's celiac disease. 

Tegan Taylor: So celiac disease, if you think you've got it, talk to your doctor, get it checked out properly. It's not something to mess around with. 

Norman Swan: And don't jump on a gluten free diet, because it's going to make the GP's job harder in terms of diagnosing. And then if the GP suspects it, then you get referred to a specialist who's got an interest in this area.

Tegan Taylor: So you said 1% or 2% of people may be celiac, and then you were talking about the little straw poll that you did and the work of Nick Talley and the 14% or so of people who reckon that they've got some sort of gluten or wheat sensitivity. So where's that rest of the percentage coming from? What's happening there? 

Norman Swan: So this is called non celiac gluten sensitivity, but whether it's gluten sensitivity or not…so I'm not saying that people's symptoms aren't real, they are real, but it tends to be a wide range of symptoms that's not…so I've just given you what the syndrome that goes with celiac disease is like, and that's pretty hard and fast. There's no hard and fast description of what non celiac gluten sensitivity looks like, but it's very, very similar, if not identical to irritable bowel syndrome. So it's alternating bowel habit. It's bloated abdomen at times. It's abdominal pain, abdominal discomfort. 

By the way, if you've got new symptoms…often people with irritable bowel syndrome have had that for quite a long time and it's not new, but if you newly get symptoms like this, which are about bloating, abdominal discomfort, particularly in women, you do need to see your doctor about that because they can be the sign that you've got something serious going on inside the abdomen or pelvis, such as ovarian cancer. So one of the ways that you can diagnose ovarian cancer earlier is new symptoms like this, rather than you've had it for years, and this is just it happening again.

Tegan Taylor: Or bowel cancer. 

Norman Swan: Yeah, there's a lot of difference between things that you've had for many years to something that happens new that you've never had before. And when you've got something new that's never happened before, you've got to make an appointment with your GP and get sort it out. 

Tegan Taylor: Okay, so for someone who…it's not new, it's something that they've felt a bit twingey about for a really long time, gastrointestinal symptoms whenever they have certain foods. It's not celiac, so what could be going on and what is the intervention?

Norman Swan: Often you don't know what foods it is. So, for example, in kids, irritable bowel syndrome is called peas and carrot syndrome.

Tegan Taylor: Because that's what comes out the other end. 

Norman Swan: Got it in one.

Tegan Taylor: I'm a parent.

Norman Swan: And it's not clear that gluten sensitivity…we're not denying the importance of these symptoms, I just want to say that again and again and again, but whether you can blame it on gluten is another matter. So is it gluten? Some people think, well, maybe it's not gluten. Is it wheat? It may be wheat as a whole. Is it fermentable carbohydrates, the FODMAPs, that are causing the problem, maybe causing bloating and gas and so on? And therefore not assuming necessarily that gluten is the issue, because a gluten free diet is not necessarily a healthy diet. It's associated with the metabolic syndrome, weight gain, high fat and sometimes nutritional deficiencies. 

A gluten free diet is not a trivial diet to be on. You need to be on it if you've got celiac disease, but if you haven't got celiac disease, you've just got to be a bit careful about it. So for example, one of the things that some people try is a low FODMAP diet. The interesting thing that Nick Talley and others have found is that when you introduce…let's say you go on a low gluten or gluten free diet, when you give a double-blind challenge where the doctor doesn't know and the patient doesn't know what you're getting, a gluten challenge has no effect. 

Tegan Taylor: Oh, interesting. 

Norman Swan: You don't get a worsening of your symptoms, which is a good thing to find out. It means you don't need to be on a gluten free or reduced gluten diet, and maybe look for other dietary causes with an experienced nutritionist or dietician.

Tegan Taylor: So in terms of the health benefits of cutting out gluten, if you don't have a problem, then…

Norman Swan: You can say categorically there are no health benefits of a gluten free diet, unless you've got celiac disease, or unless you find that you're one of these people who've got such troublesome symptoms that they do disappear, and therefore your quality of life improves. And then, of course there are people who actually have an allergy to wheat, and that's a different set of circumstances.

Tegan Taylor: So let's talk about the negatives of cutting out gluten, because you mentioned before that it's linked to metabolic syndrome, weight gain and that sort of thing, which I'm interested in talking about, because there are lots of traditional ways of eating that are effectively gluten free.

Norman Swan: There are. It doesn't have to be necessarily unhealthy, but you've got to think it through. What Nick Talley and others have shown is you have raised levels of arsenic in a gluten free diet.

Tegan Taylor: What? How?

Norman Swan: They think it's from too much rice.

Tegan Taylor: Really?

Norman Swan: Yeah, but it's not at a toxic level, so it's not something that you would worry about too much, but it's just another indication. You can live quite happily on a reduced gluten diet, but it is pretty restrictive. It's less restrictive now because there are more products on the shelf. But gluten free bread…?

Tegan Taylor: Yeah, it makes me think about…so we were talking about the benefits of being vegetarian a couple of weeks ago, and that sense of what you're replacing it with. If you're taking something out of your diet, then you're necessarily replacing it with something else. And if you're replacing meat with ultra-processed meat alternatives then it's probably not doing you any good, and if you're replacing meat with legumes and more vegetables it's probably doing you good. And similarly if you're replacing bread with ultra-processed imitations trying to be bread versus whole grains that are naturally gluten free, there's a big difference there. 

Norman Swan: But of course it's not just bread. 

Tegan Taylor: Yes, that's absolutely right, gluten is in everything. It's in beer.

Norman Swan: Yeah, which is part of the issue. You can end up with quite a restricted diet if you really want to go to a gluten free diet, which people with celiac disease have to do, but you don't necessarily have to do it if you've got non celiac gluten sensitivity.

Tegan Taylor: So should Jill go back to her friendship group and just slap them and say, 'Get over it'? Or should she be more compassionate towards them? 

Norman Swan: Compassion is probably a strong word here. She could recommend that they subscribe to What's That Rash? and let us take the heat on this rather than her.

Tegan Taylor: I'd love to know how you speak to your friends about the foods that they eat, Norman.

Norman Swan: I don't.

Tegan Taylor: Well, yes, that's probably a good place to start. 

Norman Swan: I leave them to it. My grandmother used to say when I brought friends around for lunch or dinner and she was cooking for them, 'I like that wee boy, he's a pleasure to cook for.' That's the sort of friend you want, who is a pleasure to cook for.

Tegan Taylor: Well, if you would like to be like Jill and judge your friends for what they're eating or ask us a question, you can do that at thatrash@abc.net.au, and also where you can send us any feedback you have. And Norman, we did allude before to our episode on vegetarianism, and Damien has written in with a curious question; should omnivores have a regular deworming regime as part of their healthcare practice? I think Damien is suggesting that people who are omnivores are more likely to contract worms than vegetarians.

Norman Swan: Yeah, but he goes on to say; 'Having grown up with parents who are from country Queensland, we were regularly lined up as children and given our dose of deworming medication. I've got other friends whose parents never did this and find the whole idea absurd.' Really? You shock me, Damien. 'So, what's the best approach? And given all the discussion around a healthy gut microbiome, what's the effect of all these medications on broader gut health? Is it a negative one?'

Okay, so quickly, Damien, you were probably being dewormed because you as a little boy were scratching your bottom and you had pin worms. That's the commonest reason kids get dewormed. It's nothing to do with being an omnivore but getting rid of these pinworms on your bottom. Modern farming practices and animal husbandry has eliminated a lot of the worm diseases from the national herd, and we don't need to worry about that too much, although those who eat raw meat or undercooked processed meat are taking somewhat of a risk. 

Tegan Taylor: What about the question about a healthy gut microbiome? Because the first place my mind went when I read that was the story that I did recently on the Health Report about intentionally infecting people with hookworm to help with their metabolism and…

Norman Swan: Allergy.

Tegan Taylor: Yeah, sensitivity, which I found fascinating. And sorry, just for absolute clarity, this was a clinical study that was done with an ethics approval. Please do not go out and actively try to infect yourself with hookworm or any kind of worm. 

Norman Swan: Yeah, absolutely do not go out and try it. In terms of the microbiome, all we can say is that with a diverse diet with lots of vegetables, like the Mediterranean diet…

[Bell rings] 

Tegan Taylor: I was waiting for it, I've been waiting the whole episode for it!

Norman Swan: Then your microbiome is probably going to be in the best possible shape, and that's with not too much red meat. 

Tegan Taylor: Well, if you have a question or a comment or a love song to the Mediterranean diet…

[Bell rings] 

…email us, we are thatrash@abc.net.au.

Norman Swan: Do subscribe and we'll see you next week. 

Tegan Taylor: See you then.