Short Wave - Eating alone may be secretly spiking your blood sugar

Episode Date: October 2, 2026

Being more social has a ton of benefits: lower stress, decreased inflammation – even living a longer life! Recently, some scientists have added lowering your blood sugar to the list. To figure it out, researchers had people break bread both in duos and alone. And they think the results could tell us something about the roots of our social nature. Consider it another reason to prioritize our social lives. Interested in more science in the news? Email us your question at [e-mail] public media with NPR+ and enjoy perks for over 25 podcasts like this one. This show’s perks include sponsor-free listening. Learn more at plus.npr.org. See 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

Hey, Regina Barber here to ask if you'll follow Shortwave on the NPR app or whichever one you're using. It's a little action that goes a long way for our small team. Okay, here's the show. You're listening to Shortwave from NPR. I'm here with Ari Daniel and Sasha Pfeiffer. Hey, Ari. Hey, Sasha. Hi.

Hi, Regina. So I have a question for you. What are your guys' habits around eating? Like, do you do it purely for fuel, like for your body and your mind? Do you like to treat it as a ritual? Well, it's certainly a source of fuel, Regina, but I do think of it as a kind of ritual, both the making of it and then the eating of it. Family meals are really important where we eat all together with our kids.

I don't know that I'd call it a ritual, but I do love to eat, and I'm certainly aware that how I eat can make my brain or body feel or look different. So I think of food in all sorts of ways. Yeah, I think of it as a ritual, but like a fun ritual. patrol, you know, like I'm looking forward to this thing that we always do to keep me grounded. I love it. So the reason I ask about food habits is because our first story in this biweekly Science News Roundup episode is about how eating with friends and family could actually lower your blood sugar. Oh, that's an interesting one. I'm interested to hear if there's something about communal eating that has some physiological effect. Yeah. And we also got two others, very different stories, one about how loudbirds can get and what contributes to that variety. Plus, how samples from the asteroid Benu could help us answer questions about life's origins right here on Earth. You're listening to Shortwave, the Science Podcast from NPR. Okay, Sasha, as promised, we're going to start with the eating with or without company and how it might help your blood sugar.

Yes, tell us why in the world those two things are related. Yeah, so researchers and Israel gave participants the same amount of carbs to eat. So in this case, it was bread. then they measured their blood glucose levels. And they found compared to people who ate alone, people who ate together were better at regulating their blood sugar. Regulating like it didn't spike as high. Yeah, and their blood sugar came back down to baseline quicker. Basically, they recovered faster from the sugar high.

Researchers calculated the social group was 24% more efficient at clearing glucose from their blood. The results are published in the journal Science advances. And why? Why would eating not by yourself but with other people or another person make a difference? Yeah, so lead author Shear Adseal thinks one possibility is that our brains associate other people with eating. And that social cue might push our brains to start the metabolizing process earlier, like by releasing insulin sooner, which helps regulate blood sugar. And behavioral neuroscientist James Cohn offered another idea to support these results, that our brains could interpret company as help is here if we need it. And so your body may not require as much sugar at the ready, and you could use it elsewhere, like to grow hair or store it.

You can do other things with it than dump it into your bloodstream. You know, this is very relevant to me today because I went to NPR's in-house cafeteria, a little cafe. I got food, brought it to my desk, and ate it all by myself. And it sounds like you're saying, maybe I shouldn't do that all the time. Maybe, yeah. Both James and Shear say this is a reason to prioritize our friendships and social lives. and Shear also thinks this is evidence that our social nature as humans is rooted in our biology. Maybe social bonds are actually rooted in the most basic physiological processes or what I call homeostasis.

So what I'm saying, Sasha, is I'm happy to eat lunch with you when I see you. Next time we'll go to the cafeteria together, Regina. Yeah. All right. Tell me about your next topic, which is loud birds. Right. So scientists have been studying bird vocalizations for well over a century, Sasha, and there's a ton of variation between species, says Jeff Podos, a behavioral ecologist at UMass Amherst.

Because they're all communicating about the same sort of stuff, about being territorial or trying to attract mates. That raises questions as to why we have all that diversity. Most studies have focused on pitch and rhythm, but hardly ever on volume. I would have thought that maybe volume would be the first thing they study. It seems like it's so straightforward. it's the thing we most focus on. Yeah, you would think, but it hasn't been easy to do it in the wild until recently, with devices like sound level meters and laser range finders.

All right. So if scientists can figure out the volume of birdsong, what can they learn from that? Well, what they want to do is they want to try to figure out how some birds sing louder than others and perhaps why. So several years back, POTOS and his Ph.D. student at the time, Jual Menezes set out to do just that. They recorded birds in western Massachusetts and fields and swamps and suburbia and all across Brazil, Zhuas home country, from the top of a more than mile-high mountain to his balcony in Sao Paulo. Even in your backyard, you feel like an early naturalist measuring something for the first time. In a paper they published in the journal Evolution, they collected the volumes of 123 different species.

So they got a really large range. It was staggering. There was an 800-fold difference between. the softest species, a kind of hummingbird you can barely hear, all the way up to a very loud trio. Comparable to the level of a jackhammer? Including two species that are new contenders for world's loudest bird, the bare-throated bellbird, and the red-legged seriama.

They really did their homework, didn't they? Yeah, and they found that larger species and those with wider mouth openings tend to seeing louder. All right. I get if you have a wider mouth opening that anatomically, maybe you can belt it out more, any idea why there is so much variety among all this? They don't have that answer just yet. The scientists couldn't find any clear patterns, but here is a cool fact. Some of these birds are actually louder than the published values of certain mammals, like lions and wolves and elephants. You know, that initially seems hard to believe, but then I think about the times I've been woken up by crows in the morning. So yes, maybe birds can

out loud an elephant at certain times. Yeah. Better than being woken up by a lion. True. We chatted with Sue Ann Zollinger, an ornithologist at Manchester Metropolitan University in the U.K., who wasn't involved in the research. She was impressed with the study, but acknowledged it's natural for such a broad survey to have its constraints. You can't really go into a lot of detail about the mechanics that might underlie these differences. Oh, scientist studies such interesting things.

Yeah. All right. For our last topic, it was something to do with asteroid samples. Tell us about that one. Yeah, it's something that truly boggles my mind. NASA sent a spacecraft to Benu. This is an asteroid that comes pretty close to Earth every six years to collect samples. And they brought those samples back to Earth. The samples landed in the Utah Desert in September of 2023. And these precious rocks and dust grains were sent to scientists around the world to study. We talked to one of those researchers, Larry Nittler at Arizona State University. Literally, I get in the mail a box and inside it is a little glass container with a little tiny, tiny black rock. And I'm like, this came from outer space. And so what did those little black rocks tell them?

Yeah, a lot. Another chemist named Maria Schoenbechler also got a little stash of these rocks. She and our team looked at the chemical signatures and compositions of these samples, and they determined that Benu actually formed a lot closer to the... the Sun than previously thought. And this has huge implications. It goes back to very, very basic questions. Where are we coming from? How did life emerge on earth? And if we want to answer this question, it can actually, but we need more of this material. That's why we need these samples here on Earth in the labs.

They wrote about all of this in the journal Science Advances. We just heard her say that these samples could help answer the question of how life emerged on Earth. How could it tell us that? Well, the origins of this asteroid could give us some hints. The study suggests Benu formed in the part of the solar system called the water ice line, basically right before you hit Jupiter. If that's true, that could mean that when the solar system was just forming, asteroids like Benu could have brought water and possibly organic material to the young Earth.

And Sasha, I want to say that getting these samples from Benu and another asteroid Ryugu is crucial. because the only space rocks that scientists have studied before were meteorites that survived the fiery journey through our atmosphere and crashed into Earth. But just studying stuff that falls to Earth means we might be missing a huge part of the picture of what's really going on out there. So as is often the case with science, a lot more still to be learned. We just need more space rocks. Sasha, thank you so much for spending time with us and, you know, being a science enthusiast with us just for a little while. It's always fun. Thanks. Good to talk to both of you. You too, Sasha.

You're always welcome here. You can hear more of Sasha on Consider This and PIR's afternoon podcast about what the news means for you. This episode was produced by Burley McCoy and Kai McNamee. It was edited by Rebecca Ramirez and Christopher and Taliatta. Tyler Jones checked the facts. Jimmy Keely, Aowin Fain, and Tiffany Vera Castro were the audio engineers. I'm Ari Daniel. And I'm Regina Barber. Thank you for listening to Shorewave, the science podcast from NPR.