Feeling yuck? Have you ever wondered about the purpose of all that gunk you're coughing up?
At least one of our listeners has … and she wants to know whether there’s any benefit to spitting or swallowing …
In this live episode from the World Science Festival Brisbane, Norman and Tegan take us through the answer.
Norman Swan: Well, it's winter, Tegan.
Tegan Taylor: It sure is. Can you tell from my voice that I'm really feeling it?
Norman Swan: Yeah, you're sounding very phlegmy.
Tegan Taylor: Thank you very much. It's made me think about…we did a live show back at World Science Festival Brisbane, back in March, which feels like a lifetime ago because I was well then and I am now not, but we actually had a phlegm related question.
Norman Swan: Because what happened was we asked our audience to submit their questions ahead of time, and at least one of them was really disgusting.
Tegan Taylor: She was sick, she couldn't actually come along to the event herself, so we asked for a volunteer from the audience to play the part of Rosie who asked this question, and the question-asker was not a stranger to me.
Norman Swan: Playing the role of Rosie there at the beginning of this What's That Rash? was your darling sister.
Tegan Taylor: Yes, it was indeed. She was very excited to have her voice on the radio.
Norman Swan: Stardom awaits her. So, let's get down to it.
Tegan Taylor: Tonight. Raimey, you'll be playing the part of Rosie, who has submitted a question but was not able to be here tonight. Please in your best drama kid voice, read it aloud for us.
Raimey: [reading] I've been in bed with my first bout of covid, lost my 'immunicorn' status, and have been coughing up gunk. It got me thinking about whether or not it's better to spit or swallow the sputum. I assume it's part white blood cells and virus engaged in a holy war in a mucky syrup. So is it better for recovering to keep it in by swallowing or get rid of it?
Tegan Taylor: Great question.
Norman Swan: We like the acting as well. The side effects were fantastic.
Tegan Taylor: There's a couple of words for what we're talking about, mucky syrup, catarrh, that's one of the medical ones. I like to call it phlegm.
Norman Swan: Mucus, sputum.
Tegan Taylor: Hey, look, the list goes on…
Norman Swan: Gob.
Tegan Taylor: I think if we're going to talk about what to do with it, we need to talk about what it is first. What is the recipe for phlegm?
Norman Swan: So the recipe for phlegm is a mixture of proteins and fats in a matrix, it's actually quite complicated, and…
Tegan Taylor: Protein and fats in a matrix actually sounds like something tasty.
Norman Swan: Well, in fact you probably taste it all the time. So mucus is incredibly important for your lung health. So just a little bit of an anatomy lesson. So essentially the cells in the lining of your lungs produce mucus, which is this complicated substance, and you've got these tiny little hairs called cilia, which beat up the mucus and lift it up into our throat. So despite Rosie's question, we actually don't have any choice in the matter. On a day-by-day basis, mucus comes up, picks up all the garbage, literally the physical garbage in our lungs, takes it into our throat, and we swallow it.
Tegan Taylor: Swallowing my lung garbage.
Norman Swan: Swallowing your lung garbage on a daily basis, and breathing does it as well. So then you've got a situation where these cilia are really important for health, and what damages cilia is smoking, any plants, doesn't matter what the plant is, smoke damages cilia, air pollution damages your cilia, and there's certain diseases that damage your cilia. And when mucus is not allowed to be circulated back up into your throat, it gathers, it gets infected, and the lungs become inflamed, and your lungs become damaged.
Tegan Taylor: That's really interesting. So if you're smoking, you're damaging those tiny hairs, and that's one of the reasons why smoking can lead to lung disease.
Norman Swan: Smoking is this vicious cycle where the hairs get damaged, mucus production gets thicker, it's not as fluid as it was, and it gets stuck there, and then you get damage and inflammation, which then causes chronic bronchitis, opens up cavities in the lung. We warned you this was adults only. And that's the smoking cycle. And in fact smoking plants will do it, cannabis will do it, and inhaling fine particulates can do it.
Tegan Taylor: So you mentioned that there's diseases that can do this as well, so you can damage a healthy cilia, or sometimes you said there's diseases that cause this damage.
Norman Swan: Yeah. So the key here with Rose's question is we don't know this is happening on a daily basis, so this is all happening without us knowing it. This gob is coming up, we swallow it, and we just don't know about it. If you produce sputum, then that's actually a sign of disease.
Tegan Taylor: I've always heard that the colour matters, like, if it's green, that's bad, and if it's white, that's okay.
Norman Swan: Yeah. And parents of children want to know, if the stuff coming out of their nose is green, does that mean they need antibiotics? There's very poor correlation between the colour of your gob and whether or not you need antibiotics.
Tegan Taylor: What about if it's red?
Norman Swan: If it's red, that's a sign that you absolutely need to go and see your GP, because blood in your sputum is bad news. So it can be an infection causing blood in the sputum. TB notoriously causes blood in the sputum, but cancer does too. It's not a symptom you ignore.
Tegan Taylor: Okay, so tuberculosis…it comes back to Rose's question about whether you swallow it or not. And I've seen signs around saying 'no spitting', it was sort of a thing back in the day, and part of the reason for that was because of tuberculosis.
Norman Swan: TB, absolutely. So TB is highly infectious, and it can be spread by the sputum. It's probably more spread through the air, but there were rules and fines for people who spat in public. Lovely topic, but the core answer to Rose's question is; you want to cough up your sputum. I suppose if you really want to you could swallow it, but basically you want to cough it up. The cough reflex is a normal reflex to get rid of it.
Now, if you've had major surgery on your chest, it's very hard to cough because it's painful, and physiotherapists have this little device which you blow into which pushes back pressure into the lungs and opens them up and makes it easier to cough up the phlegm. Because if you don't cough up the phlegm, you can actually get collapse of your lungs. So coughing is incredibly important.
Tegan Taylor: How does it do that?
Norman Swan: So what happens is that you get collapse of tiny areas in your lung after the operation, and this device puts back pressure into your lungs and opens those airways up and allows the mucus to come out and circulate. So, better out than in.
Tegan Taylor: Well, I mean, those are words to live by. I think one of the really interesting things about phlegm for me is that there's so many substances in the body that we've sort of discovered in recent times, and there's so much advances in understanding how our body works. But phlegm is one of those things that we've really known about for a really long time because it's so fundamental, and different medical traditions through history have talked about it. So it's a thing in ancient Ayurvedic medicine, it's called kapha, and in Chinese medicine it was called tan. And in ancient Greek and Latin traditions, it was called phlegm, or phlegma…
Norman Swan: Which was one of the four humours.
Tegan Taylor: It was one of the four humours, exactly. And it had a similar sort of thing in Chinese medicine as well, this idea of our understanding of nature and the way the universe worked, but also the way our bodies worked as things needing to be in balance. And so you have phlegm as a humour that kind of represents wet and cold, and it's balanced against sanguine, which is your blood, which is like hot and wet. And then the two biles, the black bile and the yellow bile.
Norman Swan: And they related it to personality and mood. What do you reckon you are?
Tegan Taylor: What do you reckon I am?
Norman Swan: I think you're pretty sanguine.
Tegan Taylor: I think so too. They're the cool ones, right? I reckon you're choleric.
Norman Swan: Yeah, I'm very choleric. Yeah. I'm not phlegmatic.
Tegan Taylor: Well, yeah, being phlegmatic, I think, is associated with being a relatively chill person. So maybe a bit more phlegm in your body is a good thing after all.
Norman Swan: And I just covered something that…some people call this gob, by the way…
Tegan Taylor: Yeah, you mentioned that before, it makes it sound even grosser…
Norman Swan: And the irony is that one of the cells that produce mucus in the lungs called the goblet cell, so that's obviously where it comes from.
Tegan Taylor: Game, set, match. It's like it was meant to be. So, any parting words for Rose?
Norman Swan: Rose, cough it up, Rose, just keep on coughing it up. Clear those lungs.
Tegan Taylor: All right, cool. Rose, did we answer your question?
Raimey: Yes, thank you very much.
Tegan Taylor: So, that was us at World Science Festival Brisbane, and a reminder that it was my sister who read the question submitted by Rosie. She did not, in fact, go to the event with covid. Please don't at me.
Norman Swan: So, as always, we're getting a lot of feedback. We've had a huge amount of feedback on the so-called 'sleepless elite', people who can get by on not very many hours a day. And we've had an email from the assistant treasurer, economist Dr Andrew Leigh.
Tegan Taylor: So some prefacing here. So we did an episode on is it possible to train yourself to sleep less. And there was a bit of an addendum in there about a small proportion of people who seem to be able to get by on not very much sleep, and a large proportion of our audience seems to fall into this category because we've gotten so many emails. Andrew Leigh writes he was fascinated to listen to our episode on the sleepless elite, and he had no idea why in the past, but he's quite comfortable with six hours of sleep each night. If he has less, he can replenish with a 15-minute nap in the middle of the day. And he is very productive, as you said, he is a politician, an economist, and he writes, and I quote, 'I do a fair bit of exercise,' and then he goes on to detail how he's done his third Ironman Triathlon, and is about to train for the Canberra ultra marathon 100k. That's a fair bit of exercise, I'd say.
Norman Swan: So, six hours still seems to work, says Andrew, 'even if I'm doing two to four hours of training a day'. I replied to Andrew Leigh's email saying, 'Andrew, why am I not surprised?'
Tegan Taylor: But Andrew's not the only person that has emailed us about this because…so for people who don't know, What's That Rash? is a podcast which you can and should listen to on the ABC Listen app, and we also play it as part of the Health Report on the radio, which also plays in Canada on their equivalent to the ABC there, and the time that it plays in Canada is three o'clock in the morning. And we have had so many Canadians email us about being sleepless elite…
Norman Swan: It's almost self-defining. If you're listening to us on CBC at 3am then you're probably part of the sleepless elite. So we got an email from Mark and Frank.
Tegan Taylor: They both said that they're short sleepers, and they never had any issues with it.
Norman Swan: And Danny from British Columbia.
Tegan Taylor: Danny says that they can run on six hours sleep, and has been an early morning birder for much of their adult life. They often wake up at 3am and listen to the ABC and other programs.
Norman Swan: And right now he's writing a magazine article on birding in Portugal. So I think we need to put Danny in touch with Andrew Leigh, they've obviously got things together. So a big shout-out for all our Canadian listeners, there's actually quite a lot of Canadian listeners, and our podcast audience everywhere. And send any questions to thatrash@abc.net.au, subscribe, tell your friends about it…
Tegan Taylor: Tell your friends a-boot it, a-boot it. That's Canadian.
Norman Swan: But we will get Sana Qadar in, who's our colleague on All in the Mind, to give us proper training in the Canadian accent. Meantime, see you next week.
Tegan Taylor: See you then.