Could we end winter illness?; Cold fusion’s comeback; The delicious microbiome of chocolate

0:28This episode is brought to you by Accenture. This episode is sponsored by Wellcome's podcast, When Science Finds A Way. Hello and welcome to The World, The Universe and Us, the weekly news podcast from New Scientist. I'm Penny Sarchet. And I'm Chelsea White. Today on the show, we're revisiting one of the most controversial experiments in physics, the notorious cold fusion of the 1980s, and learning the secrets of how premium chocolate gets its delicious aromatic flavour. But we're starting with an entirely new approach for boosting the immune system that may have the potential to tackle all viral illnesses.

0:59So we're at that back to school time of year. And for many families, this brings an annual sense of dread. We're talking about months of misery as waves of illnesses pass through your family. There's colds, obviously, flu, COVID, but also RSV, hand-foot-mouth disease, slap-cheek syndrome, norovirus. There's so many. Yeah, I can't tell you how many times recently I've heard someone say, well, something's going around. And part of the problem is that viruses are notoriously hard to vaccinate against because they're constantly evolving new variants. But researchers in the U.S. are developing a whole new approach, which they hope will work against any virus.

1:36So the idea here is that one day you'd be able to take regular puffs of an mRNA-based treatment on one of those inhalers that people use for asthma, and that would ensure that any viral infections you get throughout the winter are very mild. It's an amazing concept, and Michael LePage is here to talk to us about it. Michael, this is very early stage, isn't it, before we get too excited? Yes. So the team have only just done the first animal experiments. They've shown that when they gave this to Golden Hamsters that they could protect them from the COVID virus. So any potential treatments still many years away, but it's looking really promising.

2:10And that clearly would be a big breakthrough. But what is this approach? How does it work? So it works by activating the innate defences we have against viruses. So when a cell in our body gets infected by viruses, it sends out this message to other neighbouring cells. It's a molecule called interferon. And basically it's this alarm cord saying, hey guys, there's this virus coming. Get ready. Get your defences prepared. And more specifically, what interferon does is it switches on a thousand genes. So the cell starts producing a thousand proteins. And these do all kinds of different things. So some of them make it harder for the viruses to get into cells.

2:48Some of them make it harder for the virus to replicate once in the cell and so on. And the key thing is that these defenses are not just specific to one virus. They work against just about any virus. And so this is a different branch of the immune system to our so-called adaptive immune system where we produce antibodies and so on. That takes a long time to ramp up. So then if you give people interferon, you can turn on these defenses? Yes, exactly. And in fact, there are already several antiviral treatments that are based on interferon. The trouble is it's a very potent signal. And if people are making these sort of 1 ,000 proteins all the time, you get some quite severe side effects.

3:27So interferon is only used for severe conditions. So what a team at Columbia University have done, they've selected just 10 of the 1 ,000 proteins that are activated by interferon. And then they've delivered these 10 proteins to cells in the form of mRNA. So just like in mRNA vaccines. And what they've shown is that, first of all, they tested this on isolated cells, and they showed it could protect them from a big range of viruses, including flu virus and Zika virus. And then they went on and tested it on the hamsters and COVID, as I mentioned earlier. And in those hamsters, they showed there's a really dramatic reduction in the number of viruses in their lungs.

4:02So this sort of works. The mRNA is like giving ourselves instructions and telling us to make something. But if we already have these 10 genes, these 10 proteins in us, why don't we just activate them all the time if that's a defense that our body has? Yeah, I asked the team exactly that. And their answer is that it's all about timing. So you can think of when we're infected by a virus out of the blue, it's like a surprise attack. Our cells aren't ready. They haven't ramped up any of these defenses yet. They're completely unprepared. And so by the time they start ramping up those defenses, it may be too late.

4:34The viruses may have already got into them. so the key thing is that if you give these cells these mRNAs so they start making these 10 antiviral proteins they've already got some defenses ready and when they get invaded by viruses it may not stop that invasion but it's a bit harder for them and those cells have more time to produce interferon and alert other cells and it gives this body this head start and you know over the course of the infection that that could be crucial so it's like turning a response to a virus into a sort of prevention, you're getting ahead of it. Yeah, you're getting ahead of it and you've got that warning and you think about the difference between a surprise attack and sort of attacking someone who's ready and prepared for that attack.

5:16It's a huge difference. And you multiply that across thousands and millions of cells in the body. That makes a huge difference. So this is not the idea here. This is not going to stop or prevent an infection entirely, but it's slowing it down and it's giving the full immune system lots of time to kick in. Right. And I think we learned with COVID, if you can have like a low viral load, your symptoms are, you might not even notice your symptoms. Exactly. That's a hope. That sounds really great, but it feels like there must be a but here. Yeah. Is there a catch? There's always a but. There's always a but.

5:47So the thing is, for this to work, you've got to get enough mRNAs inside the cells that are at danger of being infected. And so in the case of respiratory viruses, that means the cells are lining our nose and our throat and our lungs. Now, the trick is the delivery part. Now, we're not quite there yet. And there are lots of researchers working on solving this for mRNAs because it's very promising technology. But, you know, we've just had now the U.S. cutting half a billion dollars in funding for mRNA vaccines. And so we've probably now got companies working on this thinking, oh, do you really want to be spending this money on this sort of technology if we're not going to be able to get it approved in the U.S.?

6:26So I think at the moment that that's a potential setback to this kind of approach. Yeah, it's been a real focus of the anti-vaccine movement here in the U.S. These mRNA vaccines, there are several state laws sort of working their way through the system being proposed to limit their use. everything from an outright ban to limiting the use of mRNA vaccines in children to requiring providers to tell patients that the long-term safety of a shot might not be known, even though we have years of data suggesting that the safety is there. Yeah, it's quite incredible. I mean, we've just had the COVID vaccines given to hundreds of millions of people.

7:04We know they're safe and effective. And yet we've seen politicians in the US making these very unscientific, unfounded claims about them. Michael, to return to the promise of this particular line of research, in essence, there's this kind of hypothetical asthma inhaler style puff that gets our cells making these 10 defensive proteins. It's almost like a universal antiviral and it ensures that any subsequent infections are mild. I wondered, you know, while I would love to see this stop children bringing home nasty things from school all winter, this could have real benefits to older people, right?

7:40Winter seasonal viruses can be really deadly for older people. And our immune systems, as they get a lot weaker as we age, would this kind of approach still work in those older immune systems? Well, it hasn't been tested yet. But in theory, it definitely should work. All you need is for those cells to produce the proteins from the RNAs. And that's the sort of the main thrust of it. So that's definitely the expectations. And I think, I mean, obviously, it's early days, but I imagine for the health community, if these treatments do become available the focus is absolutely going to be on the most vulnerable that's the very old as you said and also of course the very young babies and newborns and and so on now time for a word from our sponsor the best science isn't just a laboratory endeavor it changes lives but that link between researchers and the impact they have on people is often forgotten that's the gap filled by welcomes podcast when science finds a way host alicia wainwright is a botanist turned hollywood actor who invites researchers at the cutting edge to tell their inspiring stories alongside the people in communities around the world who are working with science to improve lives and shape their own futures.

8:46Episodes cover topics ranging from cholera prevention in Kenya to wildfire management approaches rooted in indigenous practices. When Science Finds a Way is available now wherever you're listening. Now let's reopen a giant can of worms on one of the most controversial ideas in physics, shall we? Hooray! Yes, let's do that. I'm surprised to say we're talking about cold fusion, are we, Chelsea? Yeah, indeed we are. For those not familiar, there was a brief moment back in 1989 when we thought the world's energy problems might be solved, thanks to scientists who claim to have demonstrated nuclear fusion at room temperature.

9:22But no one could replicate the results, and the phrase cold fusion has become somewhat taboo. However, there's a new experiment in the journal Nature this week, which looks to have somewhat revived the claim. And Alex Wilkins has been reporting on this for us. So, Alex, what is going on here? Are all our energy problems solved? As much as I wish I could say that they have, unfortunately, they have not. No surprise, I guess. Yeah, sadly. Maybe let's just start with what nuclear fusion is. So if you force two atomic nuclei together, when they merge, they release an enormous amount of energy. That process is happening all the time in stars like our sun.

9:57But replicating this process on Earth has proved to be really, really difficult. Despite being suggested first in the 1950s and 60s, we still don't have a functioning commercial fusion reactor. Right, because to get to the extreme temperatures and pressures that we would need to make fusion, that requires so much energy to begin with, right? Exactly. So there was this moment in 1989, as you were talking about, Chelsea, where we thought that maybe we wouldn't actually need all of that energy to kickstart this fusion process. So there were these two chemists at the University of Utah, Stanley Pons and Martin Fleischman, and they claimed to have demonstrated nuclear fusion occurring at room temperature in a tabletop experiment.

10:35And that consisted of basically a rod of palladium that was dunked in heavy water with an electric current passed across it. And they were monitoring how much heat this experiment was giving off and they claimed to find these anomalous heat spikes which they said was beyond what can be produced just by chemical reactions and actually came from nuclear fusion that was happening inside these rods at some significant rate now as you can imagine this experiment attracted a lot of attention quickly got the name cold fusion because it didn't need these really hot temperatures and it showed a possible alternative and a easier path to cheap clean energy production than the conventional hot fusion reactors that at the time were decades away, that they're still maybe decades away.

11:15But sadly, soon after, multiple researchers tried to replicate those claims, and they just couldn't do it. And by the end of the year, the idea was pretty much dead in the water. So this became one of those legendary moments in science. You know, people started using cold fusion as a kind of cautionary tale. You know, don't get too excited over results before they're shown to be solid and replicable. So I guess I'm pretty surprised to be finding ourselves talking about it again this week so why is that it is surprising i agree so the story this week is that some scientists have they claim finally recreated some of the crucial elements of that experiment and shown that at least some of the experiment had merit with with some caveats that we'll get into um but they show that you can you can increase nuclear fusion rates by changing the electrochemistry at room temperature but just nowhere near the rates that ponds and fleischmann were suggesting and also you need a really powerful particle accelerator in the mix.

12:07Just throw that in there. Just on the side. Okay, I'm really intrigued then. How does this work? What's the experiment? So the researchers were at the University of British Columbia in Canada. Curtis Berlinghette was leading the group and he and his team built this tabletop particle accelerator that they called Thunderbird, which they claim is inspired by, but as we said, fundamentally different from this original experiment. Similar to the cold fusion experiment they use deuterium which is a form of hydrogen with an extra neutron added and palladium and it basically consists of a really high energy beam of deuterons which is deuterium nuclei and they're fired into a palladium electrode and as the palladium starts absorbing these deuterons they begin to fuse with more incoming deuterons from the beam and this basically ramps up over a period of half an hour and berlinger and his team they observe these neutrons coming off but But then it seemed to stop.

13:01And that's when they turned on this kind of electrochemical cell that was attached. And that produced deuterium oxide, also known as heavy water. This produced even more deuterons, which then went into this palladium electrode. And they found that this increased the fusion rates by about 15 percent compared to just with the beam switched on. So just to kind of simplify that, in essence, like the original experiment, they used electrochemistry to sort of soup up what is quite a low rate of fusion into a slightly more notable rate of fusion, right? Exactly. Have I got it? Yeah, yeah, yeah. They found that these neutrons are coming off that suggested fusion was happening, and all it took was a bit of electrochemistry at room temperature.

13:40But of course, that beam that's being fired in, that's very much not at room temperature. That's got enormous energies involved. So even with that said, in essence, we've got some room temperature fusion going on here? Kind of, yeah. But the big caveat here is that even with the electrochemical enhancement, the amount of energy being produced is tiny. So the particle accelerator takes about 15 watts to run, and the amount of fusion that's happening from this electrochemical enhancement is equivalent to about a billionth of a watt of energy, which is many, many orders of magnitude below what you would need for positive energy production.

14:15And even the author admitted that they're not claiming any energy miracles in their work. But it is worth noting that Berlinghut told me he's optimistic that the fusion rate could be enhanced more. And he says that one of his students has been playing around with the shape of the electrode, which has improved things by four orders of magnitude. Even that obviously is a lot below usable levels, but he's optimistic they might be able to increase things somewhat. Right. So I guess my skepticism wasn't totally out of line. But is there anything we can take from this? Like, is it just this tabletop trick or is there a wider significance here for making fusion energy really happen?

14:49So I spoke with Anthony Kuchenak at Imperial College London, and he was actually still active in research in 1989 when this original experiment came out. And he was one of the first groups to try and replicate the result and failed to. So he really kind of knows this whole story to start to finish. And he did think the work was really interesting, but not as a potential future energy source. Instead, he thought the way this electrochemistry works could potentially help us build things like room temperature superconductors because they all use metals that have a lot of hydrogen or other hydrogen-like species in them, like deuterium.

15:24And so he thought maybe this could help us kind of build these materials which one day could help us build room temperature superconductors, which really would solve a lot of our energy problems. That's a bit of a twist. I wasn't expecting that. No, it would be a real vindication for the original research, just not in the way that researchers thought. God, that really is a blast from the past. I've forgotten all about cold fusion. Wow. It's the most surprising 80s trend comeback since the mullet, I think.

15:54Fermented foods are increasingly popular as we continue to uncover the huge role that the microbiome plays in our health. But this week, there's news about how we also have microbes to thank for one of the greatest foods on Earth, which is, of course, chocolate. Sam Wong, our resident expert on kimchi and other fermented foods, can you tell us a little bit more? Yeah, so as you say, when we talk about fermented food, we're normally talking about things like kimchi, cheese, sourdough bread. But people may not realize that chocolate is also made by fermentation. So the growers harvest the cocoa pods.

16:26They extract the cocoa beans, which are the seeds inside the pod, and the pulp inside the pods as well. They leave all of that to ferment for about six to ten days, and then it's dried and roasted. Then you get your chocolate flavor. But the unfermented cocoa beans have a really bitter, astringent taste. it's not very nice. So that fermentation is really crucial to the flavour that we all love, but not very much as known about the bacteria and fungi involved. So recently a team from the University of Nottingham went to cocoa farms in Colombia and they carried out genetic tests to identify the microbes that are responsible.

17:00So like you say, I don't think it's very well known that there's this six to ten day fermentation and that's kind of an essential step in chocolate flavour. How does that fermentation work? How do they do it? So typically the cocoa beans are just piled up in boxes or baskets and then naturally occurring microbes find their way in there from the air or from the hands of the people working there or maybe from insects. The microbes, they start to digest the pulp, which is rich in sugars, and they produce all these flavour compounds. Usually they produce what the researcher David Salt describes as dark, woody flavours, but premium chocolate also has these more fruity flavours, which is down to different microbes in the fermentation.

17:43So then were they able to identify which microbes are responsible then for these different flavours, especially those kind of finer, lovely aromatic ones in premium chocolate? Yeah, so they pinpointed five species of bacteria and four fungi that are consistently found in batches of beans that produce the high quality chocolate. And they tested this combination of microbes on cocoa beans that were sterilised so they contained no microbes. And then after fermentation, they ground them up to make this liquid called cocoa liquor. and they got some expert chocolate tasters to try it. And they said it had fruity flavors that you don't normally find in cocoa liquor, like citrus, berry, tropical fruit, caramel notes, these kinds of things.

18:23Expert chocolate tasters, what a job. So can they use these microbes to make all chocolate taste like the fancy stuff? Potentially, yeah. So growers could use a starter culture with these microbes in to improve the flavor of their chocolate. But there are other things they can control too, like the pH and the temperature, which might help to standardize the process and predict what flavor you'll end up with. So techniques like this are used all the time. They're quite advanced in the beer and cheese industries, for example. But chocolate is playing catch up. So perhaps knowing more about the microbial diversity involved in chocolate fermentation and designing different starter cultures will even help us develop entirely new kinds of chocolate with flavors we've never tried before.

19:06So I think, you know, if Willy Wonka was around, he would be experimenting with this stuff. For sure. Michael, this reminds me of an article you wrote earlier this year about chocolate being made entirely in the lab. So no need for plants, just culturing it. You tasted some, didn't you? Yes. So this is the idea here is you take the bean cells and you grow them in vats of liquid rather than getting them from trees. So, yeah, the sample I tried, it was very small, but the flavour was great. Actually, I was surprised by how good it was. Where it was lacking was in that melt-in-the-mouth factor because the sort of cocoa butter levels were a bit low and the teams that they're working on that, so hopefully that will improve.

19:42But I think, you know, discovering these microbes will be particularly helpful for that sort of cultured chocolate producers because they can control every aspect of the process. So it's all sort of, you know, done in sort of sterilized vats. So they'll be able to use exactly the microbes that they wanted and get sort of precise control of those flavors. Delicious. us. That's all from us this week on the world, the universe and us. Thanks to all our guests today and to you for listening. Do subscribe or follow us wherever you watch or listen. Leave us a comment or a review. We love to hear from you and we'll see you next week.

20:16Bye. Bye. Bye. This episode was sponsored by Wellcome's podcast, When Science Finds A Way, available on all podcast platforms.

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