Short Wave - News Round Up: Chocolate, A Solar Valentine And Fly Pheromones

Episode Date: February 17, 2023

After reading the science headlines this week, we have A LOT of questions. Is chocolate really that good for your health? How do solar flares affect life on earth? And what's the big deal about scientists identifying the chemical motivation for tsetse fly sex? Luckily, it's the job of Short Wave co-hosts Emily Kwong and Aaron Scott and Scientist in Residence Regina G. Barber to decipher the science behind the headlines. Hang out with us as we dish on some of the coolest science stories in this Valentines-themed installment of our regular newsy get-togethers! Have suggestions for what we should cover in our next news roundup? Email us at [e-mail] pcm.adswizz.com for information about our collection and use of personal data for sponsorship and to manage your podcast sponsorship preferences.NPR Privacy Policy

You're listening to Shortwave from NPR. Heather Shortwavers, Aaron Scott here with Regina Barber and Emily Kwong. And today we're back with another roundtable discussion of science in the news. Where we look to social media, academic journals, and the headlines for science nuggets that catch our eyes. And in honor of the recent holiday, today's theme is all things Valentine's, love and romance. We've got stories about how chocolate may be good for you with some major kids. caveats. The science behind the most recent massive solar flare. And a pheromone discovery in Tzzi flies, also known as Tetsi flies that could help rain in the diseases they spread by

controlling their mating. Those all roughly fit into the Valentine's Day theme, right? Yeah, for science nerds. So today on the show, science love straight from Cupid's Bo. You're listening to Shortwave, the Daily Science Lovecast from NPR. Okay, Emily Regina, let us start. this with a highly scientific poll. What is objectively the best part about Valentine's Day? I'm not a big Valentine's Day fan. I'm a huge Valentine's Day fan. It's 100% flowers out of nowhere. I love a good arrangement or just like a single statement rose, very beauty and the beast, but less tragic. I mean, I love chocolate, though. I love dark chocolate. I love it. Fair. Thank you, Regina. That was the correct answer. objectively. Best part. scientifically of Valentine's Day is the chocolate, which, you know, in recent years has kind of gotten this reputation as a superfood. I'm sure you've heard all the claims about how it's full of bioactive compounds called flavonels.

They're antioxidants. They're anti-inflammatory. They can help lower your blood pressure. I mean, there is one big study that found that people who consumed 500 milligrams of cocoa flavanols each day for several years actually saw a 27% reduction in cardiovascular. Discular disease. Oh, I see this heart relationship. It's feel good science where chocolate is like going to save us all, right? So given all these studies, it's no surprise that chocolate companies, of course, want to be able to make health claims on their labels. And so a couple years ago, one petition the U.S. Food and Drug Administration. And as MPR's own Alison Aubrey reported earlier this week, the FDA has finally released a ruling about the health benefits of chocolate. Oh, the top dogs have waited. Okay. So what does the FDA say? I totally want to know. You want to know what it does for your heart, huh? So Valentine's Day E. So in that language of love, the FDA ruled it's complicated. Of course. They found that there is very limited, credible scientific evidence that high flavinole cocoa powder may reduce cardiovascular disease if it contains at least 4% of naturally conserved cocoa flavanols.

Oh, so best case scenario, it has to be 4%. What kind of chocolate is that? Yeah, so what that means is like dark, bitter cocoa powder. Like we're not talking most of the chocolate bars you buy off the shelf. In fact, the FDA says that this ruling doesn't apply even to chocolate, that it applies to high flavanol cocoa powder. Dark, dark, bitter stuff that will probably start to see companies adding to their products. but really what it comes down to is most of the chocolate we buy on the shelves contain a lot of sugar, fat, and calories that many other studies have shown can lead to weight gain.

So, I mean, I hate to say it, but heart health is really not an excuse to eat chocolate after all. Yeah, I knew this had to be too good to be true. And when I would pass by the dark chocolate Hershey's Kisses bowls at the doctor's office and stuff myself silly with them, I felt so good. like, oh, yeah, you've just extended your life by a few more days. That's not true at all. It sounds like... I hate to say it, Emily, but no.

Nope, not going to be any FDA health claims behind those Hershey kisses. No, it's too good to be true, of course. But sticking with our theme, Gina, you have a story about one of the most cosmically romantic things that happened on Valentine's Day, right? Yeah, the sun put on a little show on Valentine's Day. Oh, it happened. It was a light show, actually, and it started over the weekend. February 11th, with a couple of solar events. Like, first, there was this major solar flare.

You know, an explosion of energy or light from the surface of the sun. Sounds hot. How major are we talking? So there are a few classifications that go from, like, weakest to strongest. It goes A, B, C, and then M, and then X. And this X-class flare was the strongest class. In these solar flares, I mean, this one sounded a, pretty powerful. Did it affect anything on Earth? Yeah, it actually affected radio communication

in South America. I talked to Alex Young and Alexa Hawford at NASA about this, and they said that the radiation from these bursts, they travel from the sun at the speed of light to Earth. That's about eight minutes. And the amount of radiation actually heats up the ionosphere. This is the upper part of the atmosphere that reflects radio waves. So shortwave radios, don't work when these large flares happen. Shortwave radio. Bringing it home, Gina. Yes, I'm amazing.

And I mean, you did an episode about how these solar flares actually create the northern lights, right? Yeah, that relates to the second event that happened this weekend. After the flare, there can be a coronal mass ejection. And that's when the sun shoots matter, not just light towards Earth. And it can take days for that matter to get to Earth. And this happened on February 11th. It was another event, a filament, like those ribbons or loops that you see on the sun and it broke. And that matter comes to Earth.

It gets stuck in the magnetic field and it smashes into our atmosphere, which produces the northern lights. Gorgeous. So I'm guessing that means they were like just in time to put on this beautiful light show for any lovers strolling out in, you know, the far of the northern hemisphere. Aaron's always looking for date ideas. Here we go. Yeah, so a couple days after February 11th, you know, all this matter hit our atmosphere, just in time for Aurora to happen on the night of Valentine's Day. So love is clearly in the air.

Yes, it clearly is for us. And seamless transition for flies. Nothing says romance like flies. Have you heard of the Tetsy fly? They are the ones that cause sleeping sickness. Yeah, I've heard of them too. Did you really know that? I did actually know that.

What? Okay, well, I did not. So for people who are not as knowledgeable, these are large, biting, bloodthirsty flies. They are kind of horrible. They're common in tropical regions throughout the continent of Africa. Super romantic. Yeah. Where is this going?

Okay, I promise. I'll bring it all around. First, though, we have to talk about these flies because they live off the blood of vertebrates. And that's a serious problem because as they're nibbling, they are spreading disease. Like you mentioned, Erin, most seriously, Tetsi flies can cause life-threatening human diseases if untreated. And they kill approximately three million cattle each year in sub-Saharan Africa. Yeah, this is definitely not Valentine's material, Emily. Thank you.

This sounds like a very big problem. Yes, it's a big problem that kind of has a love solution. Okay, hear me out. So for more than a century, scientists have been trying to. to figure out how Tetsi flies find each other to mate because if there's less of them making babies, there's less disease to go around. Okay. Right?

Yes, yes. Yes. So what happened is this? A group of researchers at Yale University published a paper in science this week, which named down to the chemical how these flies are attracting and finding a suitable mate. They figured out several pheromones that elicited, quote, strong behavioral responses from the male. I will let you use your imagination as to what those strong behavioral responses were.

I want to know what the... And if your kids are listening, I apologize, but I'm just doing my job because this is a science podcast. What does love smell like to a fly? Is it like rotting meat? Is that the smell of love for a fly? Excellent question. I don't think it can be given a human approximation, but I will give you this metaphor. So how they figured this out is by creating a fly perfume. Yeah, that makes sense. Metaphorically speaking, okay. Real marketing potential. So what they did is they took these virgin female tetsy flies and they soaked them to extract their pheromones and then they doused decoy

flies like fake flies with the pheromone concoction and they put the decoy flies into a chamber with a male fly and measured what happened. And most of the flies within seconds were on that decoy. And a lot of them actually stayed there for an hour, just hoping something would happen. Wow. If Calvin Klein could bottle this, they'd make themselves a fortune. Right? Like, what is going on?

The human variety, of course. Yeah, yeah. So, like, right, what are these chemicals? They used something called gas chromatography mass spectrometry to figure out the identity of the pheromones. And one of the strongest was called methylpomitoliate, methylpamatolyate, or MPO, which the paper said acted like an aphrodisiac. Wow. And to pair the chemical with its receptor, the researchers actually looked at the antenna of the Tetsi fly, and they identified a class of neurons that respond to the MPO.

So this like aphrodisiac is real. They figured out the chemical. It worked on the fake flies. And they figured out the neurons in the receptors of the male flies. And so what are they going to do with this research? Yeah. Well, you know, this discovery is exciting because, like I said, we didn't really know how these flies were chemically communicating to mate before.

And now that we do know, this can be added to strategies for controlling their population and the spread of disease, maybe using the chemical to lure flies into traps. With all those decoy flies that you want to hang out with all the time. Pretty flies. Yeah. Something like that. Pretty fly at the bar. The paper was done by people who are primarily a biologist, not people working on the ground as epidemiologists.

But with climate change, the range of the tessie flies expected to increase. So it's all the more pressing to be, you know, doing this work on the level of chemistry. By chemistry, I mean chemistry. You know what I mean? The chemistry of love. That's right. Thank you for bringing that back for us, Emily, to our theme. Listeners, if you have science news you want us to dig into it, Shortwave, email us at Shortwave at npr.org.

This episode was produced by Burley McCoy, edited by our supervising producer Rebecca Ramirez, and fact-checked by Anil Oza. The audio engineer was Josh Newell. Brennan Crump is our podcast coordinator. Beth Donovan is the senior director of programming, and Anya Grundman is the senior vice president of programming. I'm Emily Kwong. I'm Regina Barber. And I'm Aaron Scott.

Thanks for listening to Shoev. shortwave from NPR.