Short Wave - Science Says Quitting Smoking At Any Age Is Good For The Brain

Episode Date: October 17, 2025

The rate of smoking cigarettes has steadily declined since the 1960s – when Congress required warnings on cigarette boxes. Research shows that people are more likely to try to quit smoking when they’re under 40. But a new study in the journal The Lancet Healthy Longevity shows that quitting later in life can still be beneficial – and could possibly lower your risk for dementia. For this and more news from the science journals, Short Wave hosts Regina G. Barber and Emily Kwong talk with All Things Considered host Mary Louise Kelly.Interested in knowing more about science behind the headlines? Email us your question at [e-mail] to every episode of Short Wave sponsor-free and support our work at NPR by signing up for Short Wave+ at plus.npr.org/shortwave.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

You're listening to Shortwave from NPR. Hey, Shortwaivers, Regina Barber here. And Emily Kwong. With our biweekly science news roundup this time featuring, and this is what I always say, because it's true, the legendary. Mary Louise Kelly, of all things considered, welcome to the show again. I'm delighted to be here. I will try to live up to that billing. Okay, I hear we're going to be talking about why quitting smoking at any age is good for you.

That's right. You hear that, Dad? It's important. Did you hear that? Okay. And we're also going to talk about a new way to support the language development of preterm babies. Plus an urban animal mystery. Animal who'd done it.

Yes. Let's go. You're listening to Shorewave, the science podcast from NPR. Okay. Let's start with smoking and memory. I didn't know there was a link. Gina kicks off. Yeah.

So the rate of smoking cigarettes has declined since the 1960s. That's when Congress required warnings on cigarette boxes. And researchers have found that people are more likely to try to quit smoking when they're under 40. However, a new study in the Lancet Health Longevity Journal shows quitting later in life can still be beneficial. And it could possibly lower your risk for dementia. And that's the interesting thing. I didn't realize there was a link between our brains, our memory, and smoking. Yeah.

Yeah. So for that, we spoke to Michaela Bloomberg, an epidemiologist and lead author of the study. And Michaela said that smoking can damage small blood vessels in the brain. That can restrict oxygen flow, which can affect cognitive decline and lead to possible strokes. And was her study looking at the question of even if you quit well into adulthood, it's still beneficial? Yeah, Michaela and her team looked at survey data of over 9,000 smokers from 12 different countries for almost two decades. Half of them quit smoking and the other half continued. And the survey included cognitive test participants took over the years.

And what the results showed is that people who quit smoking in middle age or even older age scored better than those who never quit. So even quitting later in life, it can help your brain. And I guess there's been research showing that quitting smoking can be beneficial for other parts of your health as well, even later in life. Yes. Yeah, quitting smoking is better for your heart health later in life. A study in 2024 show that even quitting around the age of 75 can extend life expectancy and reduce your risk of heart disease. And so, Michaela, she wasn't surprised that quitting smoking would help the brain too. What's good for your heart is good for your brain. And so it's not an overly surprising results, but it's surprising in that we didn't see that the effect kind of weakened with age.

Meaning quitting at any age seems to show a benefit. Now, Michaela points out that the study can't definitively say good cognitive scores mean like a lower risk of dementia. But I talked to a physician who didn't work on the study, Neil Benowitz, and he's very optimistic about the finding, saying that cognitive tests are good predictors of dementia later on. Topic two, the far other extreme end of life. Tell me about language development in premature babies. Yeah, so a full pregnancy term is about 40 weeks, and in the womb, a lot happens. And hearing develops very early. The fetal auditory system actually starts to become functional at 24 weeks.

And as the weeks go by, the fetus can hear the sounds of the person carrying them. Here's how Melissa Scala put it. She's at Lucille Packard Children's Hospital at Stanford. You can hear mom talking all day long, right? Because they're sort of a captive audience. Totally a captive audience. You're stuck in your mom's tongue the whole day long. I mean, that's true of all babies.

Is there something distinct here about preemies? Yeah, so preemie babies, those are born before 37 weeks. They're at a higher risk for delays in language development. Among very preterm babies, up to one-third can have problems with reading or speaking later on. And scientists suspect that one of the reasons that one of the reasons that is that one of the reasons may be that because preemies come out earlier, they're in the NICU and not getting to constantly eavesdrop on the sounds of speech like they would in the womb. The NICU sounds nothing like the womb. And parents do visit, right, to do skin-to-skin contact, but they can't be in the NICU around the clock. So Melissa and her colleagues tried an intervention using sound. Sound. As a sound person, as a radio person, I'm totally intrigued. What kind of sound?

They played a recording of their mom's reading the book, Paddington Bear. Oh, I know. For 160 minutes every night. 46 preemies already in the hospital's care were signed up for this. Some got this intervention. Some did it. The book starts, Mr. and Mrs. Brown first met Paddington on a railway platform. I love this.

I want to listen to my mom for 160 minutes. I feel reading me, Paddington, Barry. How did the preemie babies react? How did it affect their language development? Yeah, so it did help, like, compared to the control group, who didn't get the recordings. The babies in the intervention group had more mature white matter. in key language areas of the brain.

And the researchers publish these results in the journal Frontiers in Human Neuroscience this week. Now, scientists don't know the effect of this intervention long term. The study wasn't designed for that. It was a small cohort, just 46 babies. So Melissa says the plan is to repeat this intervention with a larger cohort of children who are even more premature and with whom the hospital can follow up in a year, in two years to see how their language develops. And research like this has changed preemie care at the hospital. They now give all preemie parents free books to read and the chance to record their voices.

I've got to think that's beneficial for the parents, too. That's a whole other study we need to do. Okay, last one. Let's wrap up the urban animal mystery. Yes. I'm so excited about this. Okay, Mary Louise, do you remember the 2024 viral sensation, the Chicago rat hole? I'm so happy to tell you, I do not.

You're living life offline. We love that for you. Okay. All right. So you know when someone makes a handprint in wet concrete? it hardens into a shape. Yeah. Picture a Chicago sidewalk where there's a whole imprint shape kind of like a rat.

That's what it is. Comedian Winslow Dumain posted about visiting this so-called rat hole on social media, and people started flocking to it, leaving offerings, and there was even a wedding. We are gathered here today to marry man and man in front of the honorable Chicago rat hole. Yeah. And all this caught the attention of zoologist Michael Granitowski at the University of Tennessee. He studies how animals evolved their movements. And in his scientific opinion, it looks a whole lot like a rat. And so it's a good guess. A good guess. Was it the right guess? Well, that's where this mystery comes in, right? Like Michael was seen post on social media where people were guessing it could be a squirrel because it was next to a tree. And he thought, what a great way to actually. try and show the public that, you know, all of us are doing science when we take guesses. So Michael's team decided to turn this event into a research project, whodunit.

Which is blowing my mind because I'm thinking, how do you scientifically prove that this was a rat that imprinted in the Chicago cement? Right. Science is amazing, right? So they collected pictures of the rat hole from the internet since the actual imprint was actually removed last year. And using these pictures, they took a bunch of like body measurements. And they compared these measurements to tax sederoming animals from the American Museum of Natural History, from rats and squirrels to mice and muskrats. And they ran a bunch of statistics and they found. It is not a rat. It's definitely not a rat. It was a squirrel. A squirrel? Yeah, Chicago squirrel. Hole. Yeah. What are we supposed to take

away from this? Yeah. There is science. There's something to take away here. So other scientists we talk to say it's like a really clever way of highlighting how science is. done. And Michael hopes it will encourage more people to explore the natural world. Explore the natural world, as we'd love to do. Yes. And we love when you come on the show. It's true. I love it. I'll come back anytime. You can hear more of Mary Louise Kelly on Consider This and Pierr's afternoon podcast about what the news means for you. This episode was produced by Kai McNamee and Burley McCoy. It was edited by Rebecca Ramirez and Christopher and Taliyadh. Tyler Jones, check the facts. The audio engineer with Simon Laslo Jansson. I'm Emily Kwong.

And I'm Regina Barber. Thank you for listening to Shorewave, the science podcast from NPR.