Vaping Health Impacts: No Smoke Without Fire?

We often talk, metaphorically, about banging our heads against the wall. Luckily, for most of us, talking about it is as far as it goes. But for some animals, really banging your head against something hard, many times a day, is a fact of life. So why don’t woodpeckers - that are masters at this and do it to attract mates and also open up holes in trees to find insects to eat - get headaches and brain damage? The popular theory, for decades, was that these birds have spongy tissue at the base of the beak that soaks up the shockwave of the beak striking the tree, and this avoids transmitting the force to the brain. Surprisingly, it was such an attractive theory that everyone embraced it but no one actually thought to test it. And, speaking with Chris Smith, that’s where Sam Van Wassenbergh comes in…

Sam - Scientists have hypothesised that woodpeckers have a built-in shock absorber in their head to prevent themselves from getting headaches or injuries in their brain. But this hypothesis has never been tested so far, so that's what we wanted to do.

Chris - What sorts of forces, when a woodpecker is striking a tree, will its tissues, including its brain, encounter then?

Sam - When the beak impacts the tree, you have a strong shock. So the brain will suddenly come to a stop and the tissues will be pushed against each other. Where at the back of the head, they will also be pulled away from the brain case. If the shock is too high, you will get a concussion.

Chris - We see this in human athletes, don't we, and people in the sports field when, they have a sudden deceleration injury of their head. So it seems logical to assume that an animal that is repeatedly banging its head against a tree probably is gonna encounter some of the same problems.

Sam - Absolutely. Yes. If you watch woodpeckers smashing their head against trees, it's a very logical idea to think that they have a benefit from having something that cushions this blow. It's definitely a problem for football players or boxers or any kind of people that experience these strong shocks to their head.

Chris - So how did you address this then?

Sam - Well, we went out to zoos where they have woodpeckers and there are not too many in Europe. We took our high speed cameras so we could film up to 4,000 frames per second. And then we played these videos back frame by frame and tracked different points on the head of the woodpeckers, like we would do with crash test dummies. So comparing these different parts on the head and how they experience the shock.

Chris - How did you get them to hammer on demand? Because other people who've studied woodpeckers, because there was a paper a few years ago, where researchers used an old fashioned typewriter and tapped out a few words and the wood pickers would respond by tapping themselves. Did you just wait for them to tap or did you stimulate the tapping in some way?

Sam - No, we just waited for them to tap and this was not such a big problem. These birds really like to hit their head against the wood.

Chris - So you get these pictures, you analyze frame by frame. What are you comparing with what? So you're just seeing the beak hit the tree and then what do you measure?

Sam - So if there would be any cushioning going on between the beak and the brain case, we would see a difference in the movement profiles of the beak and the brain case. So we compared the deceleration values we got out of our data set. And well the result was that there was no difference between the beak and the brain case. So there was no evidence that there's any shock absorption going on. So it's clear that these woodpeckers are not going for this option to absorb the shock.

Chris - You're saying if they did have some kind of spongy tissue that was there to soak up, like a shock absorber, some of that impact so it wasn't transmitted to the brain, which is what other people have speculated. That you would see the beak changing its position relative to these other structures in your pictures. And you just don't see that. So you're ruling that out.

Sam - Yeah, exactly. There's hardly any movement between the beak and the brain case.

Chris - What do we infer is happening to the brain then under those circumstances?

Sam - Well, the brain certainly experiences shock at this moment, but we calculated that it is not strong enough for birds to get a concussion. Birds are just a lot smaller than humans and they just can withstand higher shocks. It's a law in biomechanics that smaller animals can withstand higher shocks. The birds still have some safety margin before they would get any damage to their brain.

Chris - Has anyone gone inside the head of animals like woodpeckers after they've been pecking to see if there are evidences of brain changes and whether this is just an unfortunate cost of this behavioural aspect? Has anyone done that?

Sam - There has been one study, they found some proteins that are involved in damage repair. They call these the Tau proteins and we also see them in humans after they get concussions and things like that. So there is some evidence that there's damage going on. It Is an issue for these woodpeckers to try to minimize their damage.

Fuel prices may be astronomically high at the moment, but this week, we are focusing on fuel which can take us astronomically high: jet fuel. Similar to the petrol we fill our cars with, jet fuel is often sourced from non-sustainable sources giving it a hefty carbon footprint. But researchers at Novo Nordic Foundation Center for Biosustainability in Denmark have found a method to generate power-packing propellant from plants. Julia Ravey spoke to Pablo Cruz-Morales, who told her about a synthetic molecule called “syntyn”, developed as an alternative rocket fuel in the 1960s, which inspired this work…

Pablo - Syntyn is a synthetic fuel as a replacement for rocket fuels, which are typically kerosenes. It was developed by Soviet scientists in the Soviet Union and used successfully in the upper phases of the Soyuz rockets. The process involved the presence of certain chemicals that are explosive and toxic, and the process wasn't very efficient. But it's known that syntyn is a good fuel, it provides higher energy and higher impulses for the rockets than kerosene.

Julia - To get a jet off the ground. I'm guessing you need a fuel that packs a lot of energy, but you are also constrained by the size of the fuel tank. And then there's a problem with if you build a bigger tank, you're carrying more weight. So how can we chemically pack a bigger punch when it comes to the components of jet fuel?

Pablo - The difference between gasolines and jet fuels, for example, is the content of carbon chains that are a circular molecule. So you can have eight member, six member carbon cycles, etc. The shortest is three carbons. And for making these rings so small, you need to bend the carbon-carbon bonds and that requires more energy. When you burn it, you release more energy

Julia - In terms of the volume of fuel, if the components in it are bent into these circular carbon structures, you're essentially getting a similar volume of say, like other fuel, like petrol, where you don't have these things in, but because they have these bent structures in them, they when - burnt - release a lot more energy?

Pablo - That's the idea. In simple words it's called energy density. Higher energy density means that you can have more energy stored in a smaller volume of the fuel.

Julia - The process of making syntyn, which was one of these types of molecules, sounded like it was quite nasty. So is there a way that we can make these higher energy-structured molecules in a more sustainable way?

Pablo - Yes, the idea is to use biology. There are some organisms in the planet that are able to make extraordinary chemistry. So we're looking for potential molecules that look similar to syntin, and then we can take the genes that direct the synthesis of these molecules, put them into a bacteria that we can put in a flask, and then we will produce this. Instead of nasty chemicals, we just add sugars and then we will produce these molecules.

Julia - So you just feed the bacteria sugar and because they have the right enzymes in them, is that right? The right enzymes in them, they then produce these really quite complex structured molecules, which are good for the type of fuel?

Pablo - Yes, that is correct.

Julia - And you said in your process that you fed these bacteria sugar, but could we use say waste products as the substrate for the bacteria in making this fuel and that would then make the process even better for the planet?

Pablo - Yes. At this point in our research, we are feeding sugars because this is a proof of concept level. But if we were to make a sustainable fuel at large scale, the ideal scenario would be to feed substrates that are derived from example from lignocellulosic biomass, from agricultural waste, or maybe plastics that have been broken down using some chemical process, for example, that you can convert into something that the bacteria can eat and then make into this biofuels. A biofuel that is made with lignocellulosic biomass or plastic waste benefits from being sustainable because it's not taking carbon from petroleum, which is a non-renewable resource. Instead of that, if we take lignocellulosic biomass, the carbon is trapped by the plants, and then we convert it into these products. Then if we borrow the products, they will go back the plant. So it's circular

Julia - Is this process scalable?

Pablo - It is possible. And the team in California 's working on it, but it is an important challenge. I will add to that now that we know that we can make the chemistry, it makes sense to put an effort to increase a tighter yield because before we didn't know that it was even possible.

James Tytko sets out to find out why vaping has boomed in recent years. He took a microphone to a pub to discuss the impact of vaping on some people smoking habits...

James - Chris has tasked me with finding some views given the vaping boom we've seen in recent years. I've brought a microphone to a pub to discuss the impact of vaping on some people smoking habits.

James - Will, you've got a vape in your hand there. Before you started vaping, did you smoke cigarettes regularly?

Will - Not regularly, but I would classify myself as a social smoker. Especially on a night out, after having a few drinks, I would definitely say having a few cigarettes was quite nice, but since having recently purchased vapes somewhat regularly, I would say that it's much nicer than having a couple of cigarettes on a night out.

James - How regularly have you been vaping

Will - Past two months? A fair bit. Since then I've maybe purchased four or five. That would be the numbers on it. For me, it's maybe something that I might enjoy through the summer and then I ween myself off it. I just won't buy any and that will kind of be it, I suppose.

James - Then I spoke to Tommy.

James - So Tommy, you were a bit more of a smoker than Will before you started vaping. Would that be fair to say?

Tommy - Yeah, I think that's probably fair.

Will - Obviously.

James - And over the past six months you've picked up vaping?

Tommy - I'd say over the past two months.

James - Similar sort of level to will?

Tommy - No, probably more. You can't really put figures on it. Because each vape has a different amount in.

James - And finally, Sam, you've smoked the odd cigarette. Are you at all tempted to take up vaping?

Sam - No, not vaping.

James - To summarise this less than scientific research into smoking habits, those who were partial to smoking cigarettes have found vaping to be an enticing alternative. Sam, on the other hand, who had never really smoked cigarettes, was not interested in taking it up. I'm interested in what Will had to say especially. A self-proclaimed social smoker, vaping turned his nicotine consumption from a once in a every so often kind of thing into more of a daily habit. Some of the worries surrounding the explosion in popularity in vaping over the past couple of years is that it might coax some younger people, those who aren't that interested in taking up smoking cigarettes, into picking up vapes, given the smaller, but not as yet completely understood health implications. And then there's those like Will who are part-time smokers for whom vapes have become a much easier thing to reach for.

Interested to find out a bit more, James Tytko paid a visit to a few local vape shops in Cambridge. Most didn't want to speak with him, but Andy of E-cig Wizard was happy to talk him through the trends he's noticed developed over the past few years. James started by asking him about the types of products they sell in his shop...

Andy - May 2015 we officially opened, we've been here through the boom. People of all ages, all walks of life, all nationalities. Basically, those that are smoking that have now realised the easiest way to quit is to start vaping. Public Health England have already done the studies and made the announcement that vaping is 95% less harmful than smoking. No one is saying that vaping is necessarily good for you, right. But in comparison to smoking, definitely 95% less harmful...

Chris Smith - And he’s absolutely right. A 2015 review authored by Ann McNeill and Peter Hajek for Public Health England puts the “best estimate” at vapes being 95% less harmful than cigarettes, and, as Linda Bauld points out, people do benefit if they switch. But the data are all short term at the moment, and being 95% less harmful still doesn’t mean they aren’t without health effects at all. Indeed, as many point out, it took decades of following up smoking doctors before Richard Doll could say, definitively, that smoking causes cancer, among other things. Before that, some even believed cigarettes were good for you! So could we be in a similar situation with vaping whereby we’ve not got sufficient data yet to know what the true health harms are?

Following the vape trail through the body, the next stop is the lungs, where there’s mounting evidence that the chemicals in vape smoke might make the cells lining our airways an easier target for infection, as Queen Mary University of London’s Jonathan Grigg explains to Chris Smith…

Jonathan - So, what we do is grow cells that line the airways - the lower airways, deep in the lungs - grow them in the laboratory and put e-cigarette vapour onto them. And what we see is that those cells become stickier for bacteria that can cause really quite serious respiratory lung illnesses. And one of the commonest is called the pneumococcus. It actually causes quite serious pneumonia, actually can get across into the bloodstream. And we see more bugs of these bacteria sticking to the cells when they've been exposed to e-cigarette vapour. And one reason for that is that the e-cigarette vapour causes something called oxidative stress. In other words, it stresses the cells and the cells respond by making themselves stickier for these bugs to infect them.

Chris - Do you know if that stickiness actually has consequences though, because being a bit stickier might not translate into a greater or lesser disease risk? I mean, does it?

Jonathan - Well that's of course the key question of whether this happens in real life. Certainly what we call the receptor that the bugs use to stick onto is really a very important in a range of animal models. If the animals have more of this receptor in their airways, then they get more severe infection. We did follow it up by asking vapers to do a vaping session. And we brush the cells from their nose - and we think that the responses in the nose are probably very similar to the lower airway - and we found that with a vaping session, yes, the particular receptor that the bugs use did get up regulated. There was more of it after a vaping session. So it certainly happens in real life. We're not absolutely sure whether that's going to be translated into more vulnerability to severe infection, but it's certainly worrying to us.

Chris - Do you know how the vape is doing this to the cells? Is it just that oxidative stress reaction or are there specific chemicals in the vape that might be causing this to happen more, which would argue, well, if we don't use those chemicals or don't use those vapes, then we could reduce the risk?

Jonathan - Human vapers use a range of vaping implements, first, second, third generation vaping, different flavours. And we, we saw the same sort of response. We did look at nicotine-containing a nicotine-free vape, the same carrier, and we see the same effects whether nicotine is present or not. So it's not the nicotine itself that's causing it. We're probably certain that it's a generalisable phenomenon

Chris - And just bacteria, or could the effect also extend to fungi and possibly viruses?

Jonathan - We haven't looked. One study, which looked at the effect on a receptor that the SARS-CoV-2 virus uses to enter cells - that's called the ACE II receptor - certainly has been an initial report shown to be up regulated by e-cigarette vapour as well as cigarette smoke of course.

Chris - Now, if this is translating into a shift in clinical risk, given the uptake of vaping among younger people who are never normally smokers, are we seeing a link epidemiologically between vaping and possible more invasive chest infections with things like pneumonia?

Jonathan - The answer is not yet, but of course pneumonia is fortunately pretty rare in healthy young adults. It's taken us a very long time to show that active smoking was associated with pneumonia, invasive disease many, many years after the initial description of cancer. And it's confounded by the fact that people using different types of vape flavours, et cetera. And so epidemiological studies really haven't been done and we'd have, we don't know if there's a signal or not. But I think we have to say that these data are certainly worrying; that there are effects in the lower airway, which will make individuals more vulnerable to bacterial and possibly viral infections. But we haven't seen that signal yet.