Program: Should you add snail slime to your skincare routine?

Tegan Taylor: Now, Norman, you and I are in the same room as each other for a rare What's That Rash? recording in-person…

Norman Swan: It is, it's fantastic. 

Tegan Taylor: And I was a little bit nervous, so I brought a chaperone along. Would you like to meet them?

Norman Swan: Yeah.

Tegan Taylor: Look at this guy. Can you please describe to people what I am holding here?

Norman Swan: You are holding a snail, an escargot.

Tegan Taylor: Yuck, it just pooed on me, yuck! 

Norman Swan: Well, is it poo or is it mucin?

Tegan Taylor: Well, it just felt like fate that I saw this little guy…

Norman Swan: It's a slime bag. 

Tegan Taylor: It's a slime bag indeed, which, incredibly, is actually directly relevant to what we're talking about today on What's That Rash?.

Norman Swan: The podcast where we answer the health questions that simply everyone's asking, including escargot.

Tegan Taylor: Not what I thought everyone would be asking about, but truly we have had multiple questions about snail mucin. Lynne says, 'My daughter has discovered snail mucin and believes it has anti-ageing effects. Is there any medical evidence that supports this belief?' And Georgina says, 'I love your show. I listen to it every week since the Coronacast days. I'd like to find out if snail mucin that is found in cosmetics is safe to use.' I can't say that I had heard about this in detail before we got these emails from Lynne and Georgia. 

Norman Swan: It was entirely new to me too. Just shows you what bubbles we live in. 

Tegan Taylor: I know, right? 

Norman Swan: And our skin is just glowing without it.

Tegan Taylor: I mean, yours is, naturally. I've had to bring in my friend. I feel like we should give this guy a name. 

Norman Swan: Oh, just for everybody's benefit here who is not watching this on video, because we are videoing this, it's living in a pot of celery.

Tegan Taylor: I thought it was mean to…we will get into the humaneness, or otherwise, of how you harvest a snail. I'd never really thought before this week, Norman, about how you would milk a snail.

Norman Swan: Yeah, it's a huge issue when it comes to snail snot.

Tegan Taylor: We are actually going to get into it in quite a lot of detail. I suppose a good place to start is…oh no, we were going to name our friend. I feel like Swirly the Snail, because it's got that little…what's it called? 

Norman Swan: And your kids would love that name.

Tegan Taylor: 'Swirly'? They would love that name, actually. All right, so we've got Swirly the Snail in studio. We might ask him or her some questions. Actually, that's quite interesting; snails are true hermaphrodites. We'll ask them some questions in a bit. But I feel like we should probably start with a definition. Snail mucin; is this just a fancy way of saying snot?

Norman Swan: Look, depending on the research that you get in this area, there are probably three different types of glands on the snail that produces this stuff, and I'm not sure that you can say it comes out of the nose. So if your vision of snot is stuff that comes out of your nose, then probably not, but it's mucus, and one function of the mucus is to help the snail traverse the land.

Tegan Taylor: Well, it comes out of their foot, right? Like the body of a snail that we see, most of it, the thing it uses to walk around is called a foot.

Norman Swan: And there are glands that secrete the mucin, which help it get over rough ground and stop it damaging itself. They say that a snail can go across a razor blade without damaging itself because of the mucin.

Tegan Taylor: A razor blade?!

Norman Swan: So they say.

Tegan Taylor: Swirly, you are such an amazing little creature.

Norman Swan: I wouldn't put our lovely little pet here to that challenge.

Tegan Taylor: I'm not gonna put Swirly on a razor blade. So it's a protective thing, it helps it traverse around the place. How on earth have we gotten to a point where we look at something and go, you know what? I'd like to put that on my face. 

Norman Swan: Oh, it's the ancients. A lot of it's the ancients. 

Tegan Taylor: It always comes back to ancient Greece. Yeah, the Greeks did use snail mucin. They actually used it to treat colds and infections. Hippocrates…we cannot have an episode of What's That Rash? without mentioning at least one of the ye olde…

Norman Swan: Did Hippocrates put snails up his nose?

Tegan Taylor: He allegedly crushed snails and used the by-product to treat skin inflammation, so like an irritation. And it's not just the Greeks, in Africa as well, people in southwest Cameroon have used terrestrial molluscs, which is just a fancy way of saying snails and other related creatures, to treat burns, alleviate headaches and prevent infectious diseases such as scabies and ringworm, which makes me think there's something to it here.

Norman Swan: Well, we shouldn't be surprised about that. You know, there are lots of medications, lots of pharmaceuticals that started as natural products. Aspirin is the classic example, anti-malarial cinchona bark. There's no reason to assume that there's nothing in the natural world that's not therapeutic. The question is exactly as What's That Rash?ers have asked; is it safe and is it effective? And there's just beginning to be some research in that area.

Tegan Taylor: So one of the things that I think has made this take off in more recent years, we're not talking that recently, in the 1980s there was some anecdotal evidence from Chilean farmers who noticed their hands became softer and their cuts healed faster when they were handling escargot for the French food market. So they're breeding them for food and they saw this thing happen, and that really kind of set the ball rolling, at least in South America. 

Norman Swan: Well, they created a cosmetic industry around it. 

Tegan Taylor: That's it, exactly. So there's a Chilean skincare brand that launched in 1995 that incorporated snail mucin. And then the skincare capital of the world, South Korea, has also really jumped on board with this. And I think there is something very social media friendly about the idea of putting snails or something from a snail on your face, because it's just a funny image.

Norman Swan: And we'll come back to the question later about is it ethical, because how do you produce the mucin that gets to your face? 

Tegan Taylor: So the other thing is, because I was talking about this with a friend, she was, like, 'Oh, is that like slugging? Is snail mucin like slugging?' And I'm, like, 'That sounds gross and possibly rude.'

Norman Swan: I'm beginning to regret having had lunch before we came into the studio. 

Tegan Taylor: Slugging does not involve molluscs, but it involves mimicking. It's where if you've got super-dry skin…this is another thing that's big on skincare Tok, whatever, and you put, like, a layer of Vaseline on your face to trap the moisture in overnight, so you haven't put snail…

Norman Swan: Oh, so you end up with like a slug skin.

Tegan Taylor: You look like a slug because you're so shiny.

Norman Swan: And there is a form of skin…just on the slugging, in the biology of the snail, they produce a form of mucin that helps them hibernate, go through dry periods. And it is a barrier mucin which keeps the moisture inside the snail. So again, this is not mad stuff. The snail, little Twirly here, whatever you called her, is…

Tegan Taylor: Swirly the Snail is going into hibernation mode at the moment.

Norman Swan: And so in theory there could be a form of mucin that is, in fact, a skin barrier.

Tegan Taylor: Okay, well, let's talk about the science. We've talked a lot about the vibes, now it's time to actually talk about the evidence. So there's a couple of things that I've heard about when it comes to snail mucin. The two questions that we've had are about skin care, broadly I think we could kind of put that in the anti-ageing bucket. There's also claims around it being anti-microbial, there's claims around wound healing. There's even, of course, anti-cancer claims. So let's just step through what's been studied, and what we actually know.

Norman Swan: Some of the research is in reasonable journals, the Nature group of journals, not necessarily from major research institutions. But that's me being a snob. But even if the research is right, a lot of it, if not most of it, is actually test-tube type work, which is the very earliest form of research, which might lead to a human product.

Tegan Taylor: In vitro rather than in vivo. Well, I mean, technically Swirly is in vitro in that he's quite literally in glass right now, so you're saying that this isn't legitimate?

Norman Swan: Swirly would be considered pre-clinical and animal research. But most of the research that is in there in the journals is actually, does it have an effect on bacteria? Does it have an effect on the immune system? And the answer is, unsurprisingly, given that you've got an animal that's creeping over the ground, liable to get infected and wanting to protect itself, there are anti-bacterial, there are anti-microbial compounds in the mucin. So the answer is yes, there are test-tube effects reflecting a lot of the claims, as there are, for example, for anti-ageing compounds. A lot of the anti-ageing supplements that we use are based particularly on test-tube research, some in animal research, but mostly in test tubes, and they haven't made the full transition, in many cases, to animal research.

Tegan Taylor: So even in the in vitro experiments, even in these experiments that are happening in test tubes, what kind of level of an effect are we talking about? Is it a miracle substance? How does it stack up against other things that we might be using?

Norman Swan: So the answer is yes, there are anti-microbial effects. How strong are they? It's unclear from the research. There's not a lot of comparison being done. So here's the interesting thing about the snail. The snail does not have a very effective immune system, so it operates on a snail version of what in humans you'd call the innate immune system. And for those people who've been listening to us for many years through Coronacast, you kind of know there are three levels of the immune system. The first is really a broad barrage that the immune system sets up because it hasn't yet learned what is invading, so that you haven't got the targeting there. Well, the snail doesn't have a targeting immune system, it's just got the barrage. And that barrage is really what we would call inflammation. 

So it would also have concomitantly anti-inflammatory aspects to it, because once the barrage has been set up, it's probably got quite powerful mechanisms for settling it down, because the snail would not want that sort of inflammation, or that its version of inflammation to continue. So it's completely logical that it might have anti-inflammatory effects. 

And so what you may find here is that over time and when they refine these compounds, you might well have some quite potent compounds, particularly if you add medicinal chemistry to change them a little bit to make them quite effective and novel in the area. Whether slapping on snail mucin is actually going to make a difference, quite possibly it could settle down some inflammation. But is it pure? Does it have its own infective organisms in it because you're collecting it off snails? What's the process for manufacturing? There are all sorts of uncomfortable things about this, including how they collect the mucin.

Tegan Taylor: So now is the part of the show where we talk about how to milk a snail, not that we're recommending that you do this at home. In fact I think I am pretty actively recommending not doing it. Just having had a chat with Swirly before, didn't seem to be a massive fan of it. In fact, he's gone right into his shell…they've gone right into their shell.

Norman Swan: Well, Swirly has seen the TikTok videos about how they collect it. 

Tegan Taylor: Yeah, Swirly is very finger-on-the-pulse when it comes to social media. 

Norman Swan: Swirly is shitting themselves.

Tegan Taylor: On my hand! Anyway, the way that it's extracted varies a lot, depending on the brand, depending on the farm. Yes, snail farming is a thing. There's no regulation about it. So most of the slime comes from the common garden snail, which is called Cryptomphalus aspersa, and basically they excrete mucin in response to stress. So the fact that I'm not getting that excreted on right now means that Swirly feels safe with me, and that's great. I love that for them. 

So, like I said, there's all sorts of extraction methods when it comes to getting mucin out of snails. One of them is something called a Mueller machine, which can process up to 4,000 snails an hour, which produce about 11 litres of mucus. If the farm is processing a new batch of snails every hour, they can make like 70 litres a day. But once the snail has had the mucus extracted from them, they need a month to recover, so they go back to the farm for a month to eat, become stronger and be able to produce mucus again.

Norman Swan: Just like a racehorse going out into the meadow.

Tegan Taylor: Just like that. 

Norman Swan: Somehow I don't think it's quite as pleasant.

Tegan Taylor: You don't have to be like a full-on animal rights activist to maybe feel a little bit uncomfortable with the fact that you're really stressing an animal out to collect something that, according to you, there isn't great evidence that it's actually that effective. Curing cancer, maybe the ethics balance of the scales would tip a bit more, but…

Norman Swan: The cracking of the shells just seems gross to me, even though there are many people in the world who will happily eat a snail.

Tegan Taylor: I threw cancer out there at you just now, but there actually is some anti-cancer whiffs about snail mucin.

Norman Swan: Yeah, there's one study of a complex of mucin, which is, again, in cell culture, they were looking at whether or not it kills cancer cells, and it's called cytotoxicity. It doesn't seem to have a cytotoxic effect, which is like a chemotherapeutic effect, but it does seem to have an influence on programmed cell death. And programmed cell death, one explanation for cancer is that cancer is a failure, so cells are programmed to die, and if they don't die, then you risk cancer. So there seems to be an apoptotic effect from one of the compounds in snail mucus.

Tegan Taylor: What kind of cancers are we talking here? 

Norman Swan: So they have looked at melanoma, and there are these immunotherapy drugs which unleash the immune system on the tumour, but they are known in some situations, and melanoma is one of them, as far as I understand it, where you need help to trigger the immunotherapy to work. So you need something alongside it which actually acts as a facilitator for the immune therapy to work. And there's a little bit of evidence in the test tube that some of the components of snail mucin may actually facilitate the immunotherapy to work. So whilst we often cast off at this sort of mad stuff in cosmetics and so on, natural biological material can and often does contain something that is active and fosters the development of something really effective in the future.

Tegan Taylor: And then the other thing I want to talk about, one of the claims is around burns and wound healing. There was some interesting research into that specifically.

Norman Swan: Yeah, so they developed into a burn ointment. And the suggestion was that the ointment with snail mucin in it, compared to a standard preparation, speeded up regeneration, so in other words the growth of the skin cells to close over the wound, and reduced pain.

Tegan Taylor: Okay, whenever I hear something, on one hand 'cancer treatment', and on the other hand 'promote cell proliferation', those two things feel incompatible with each other.

Norman Swan: At odds. So what it could be, and I'm going to sound like the defender of snail mucin here, but there are multiple effects of snail mucin, and if it dampens down the inflammation and the whole reaction of the body to the burn, which gets in the way of healing and dampens that down, then the skin cells might be freer to multiply and heal. So in other words, it may be a facilitation effect. It's a bit like the immunotherapy for melanoma, if indeed that's true, there could be a facilitation here. If it settles things more than the other cream, then it allows the natural processes of the body to take over.

Tegan Taylor: So there's not nothing here. Swirly has the power to change the world. But for our question-askers at the moment who are looking at commercially available skincare products that claim to have cell mucin in them, what's our bottom line?

Norman Swan: The bottom line is we can't find any evidence of harm…

Tegan Taylor: Except to the snails. 

Norman Swan: Sorry, except to the snails, that's absolutely true. Thank you for bringing that up. You've obviously got a strong connection there with Speedy who's now just fallen off your hands…

Tegan Taylor: Swirly!

Norman Swan: Swirly, sorry…

Tegan Taylor: You don't even know our son's name.

Norman Swan: I accept that. You've got to work out do you believe when they tell you it's been humanely produced? How would you know? There is a risk from any cosmetic that there's infection in it, because it comes from animals that are in the wild, although it's not collected in the wild, and there's always the possibility of allergy, because you've got these proteins being produced. So some people will become allergic to it, but there's plenty of other skin cosmetics that you can become allergic to. But I don't think you and I are going to be using any.

Tegan Taylor: So our bottom line to our beautiful question-askers is you're probably naturally beautiful enough on your own, but don't let that put you off using snail mucin if you really, really want to.

Norman Swan: But if you've got cancer, I'd be going for…

Tegan Taylor: Chemotherapy.

Norman Swan: Yeah, I'd be going for the strong stuff.

Tegan Taylor: Well, thank you so much for your questions. You can send your questions to thatrash@abc.net.au.

Norman Swan: So what's in the mailbag? 

Tegan Taylor: So we talked recently about headphones and whether using headphones could cause hearing loss. And on the way through there, you talked about the little tiny hairs in your ears that help conduct sound to your hearing apparatus. Well, Glen is asking whether taking Finasteride for hair loss, so one of the more commonly prescribed hair loss medications, whether taking Finasteride can protect hearing by preserving the little inner-ear hairs.

Norman Swan: So it's a completely logical question, Glen, but the trouble is that the cells inside the cochlea, inside the inner ear, aren't actually real hair. They're just cells that look a bit like hair on the electron microscope. So they're called hair cells because they do waft in the breeze a little bit. They're not they're not real hair. So you don't become bald in the cochlea. Maybe Finasteride can help your hearing in other ways, but not by fixing up your hair cells.

Tegan Taylor: Joshua says, 'Having just listened to your episode on headphones, I can fully vouch for noise cancelling as it helps me have lower volumes when catching up on your podcast on my bus commute to work.' Joshua says, 'I'd like to add that, having worked in a steel yard where the sound of steel pipes or plates being dropped is absolutely deafening, I can advocate wearing ear plugs for any noisy work. My preference is the little cylindrical sponge type. I now use them at live concerts, indoor and outdoor. What I've discovered is that at a live gig,' Joshua says, 'it actually sounds better having them in. The plugs take out the high-end wavelengths, and the music sounds more like the original recording. You'll understand if you give it a go and take the plugs out halfway through a song.'

Norman Swan: It's really interesting. I can't remember whether I mentioned it on the podcast, but if I'm on a plane with noise cancelling headphones, I will put in ear plugs and then put the headphones on top, and for me it seems to improve the sound quality of what I'm hearing.

Tegan Taylor: We also mentioned in the mailbag last week, referring to a previous What's That Rash? episode about doing nothing…

Norman Swan: An incredibly popular episode, yes.

Tegan Taylor: It was really popular, I think because people like to have an excuse to do nothing. Although this particular correspondent I'm speaking of said that his version of doing nothing was riding really hard for 40 minutes in traffic in Sydney on his bike. Well, Mark has messaged in saying, 'Heard the story about the guy who rides to do nothing. Totally agree. Cycling got me through a very rough time in my life where I could detach myself from a terminal illness of a family member for a short time, came back recharged and better able to deal with what the day sent my way. On your bikes.'

Norman Swan: People should go back to that podcast because it's a really, really popular one, and we're talking about mind wandering really, because you never do nothing, and when your mind wanders, it's kind of a refreshing thing.

Tegan Taylor: Well, thank you for listening. Thank you for your questions and your feedback. If you've got anything you'd like to say to us, you can just email us, thatrash@abc.net.au.

Norman Swan: We'll see you next week. 

Tegan Taylor: See you then.