SOPHIE BUSHWICK: This is Science Friday. I’m Sophie Bushwick in for Ira Flatow this week. I’m technology editor at Scientific American, and I’m glad to be back on your radios today.

A bit later in the hour, we’ll talk about how extreme heat affects the human body, and we’ll take you on a beach vacation to visit homes of piping plovers. But first, Alzheimer’s disease is a devastating brain disorder that targets the brain’s ability to hold on to memories and thinking skills.

For people worried about their loved ones or themselves getting Alzheimer’s, research provides hope that the disease could someday be a thing of the past. But a massive report from Science Magazine highlights a startling discovery, that decades of Alzheimer’s research may be based on faulty data. Researchers are grappling with the revelation and what it means for the future of studying the disease.

Joining me today to talk about this and other science stories of the week is my guest, Maggie Koerth, science writer for FiveThirtyEight, based in Minneapolis, Minnesota. Welcome back to the show, Maggie.

MAGGIE KOERTH: Thanks for having me.

SOPHIE BUSHWICK: Let’s start with this big story about Alzheimer’s written by Charles Pillar. What does the story say?

MAGGIE KOERTH: Well, first off, I want to give a brief recap of this amyloid hypothesis of Alzheimer’s because this is really at the center of what’s going on. And the basic idea with this is that this degenerative brain disease happens when something causes a protein called amyloid beta to clump up in the brain, kind of like a hairball in your shower drain.

This is an idea that’s gotten a ton of attention. It’s gotten the bulk of the investment money over the last three decades. It’s basically sucked all the air out of the room in the field of Alzheimer’s research. And that’s even though, as multiple drugs that were designed to kind of Drano out all that amyloid beta buildup, have really failed to help patients.

So this is something that’s not standing by itself when we’re looking at this report in science that is showing that there’s probably some kind of malfeasance happening. That’s not an isolated issue with this hypothesis. There’s also other people who have long thought that maybe this was not a correct understanding of how Alzheimer’s works.

SOPHIE BUSHWICK: Tell us a little more about the protein that’s implicated, amyloid beta. What is this protein, and what does it typically do in the brain?

MAGGIE KOERTH: So this is a protein that can occur when a bigger protein, called an amyloid precursor protein, gets cleaved in a certain way. And people are still trying to understand what that precursor protein does in your brain, exactly, just like they’re trying to figure out still what beta amyloid does. What we do know is that beta amyloid is sticky. There was a blog entry that an organic chemist called Derek Lowe wrote for science where he really described it as something that was just really hard to work with and synthesize because it’s just this gummy thing that sticks to everything.

And we know it’s definitely found in these plaque-like clumps in the brains of people who’ve been autopsied after dying from Alzheimer’s. So there are good reasons why people think it’s involved. It’s just not super clear whether it’s the causative agent.

SOPHIE BUSHWICK: And what seems to be the origin of this misinformation about the cause of Alzheimer’s?

MAGGIE KOERTH: Yeah, so the science piece is basically this whistleblower went public with evidence that suggests at least a couple of the studies important to beta amyloid hypothesis have been deeply flawed. The whistleblower, who is a Vanderbilt neuroscientist named Dr. Matthew Schrag, he does not describe this as proof of fraud or misconduct. But he’s basically identified a bunch of red flags that really point in that direction.

And one of these issues involves Sylvain Lesné. He’s a researcher at the University of Minnesota, and his work appeared to show that beta amyloid could cause dementia in rats. This is something that was supposed to be kind of the silver bullet that proved beta amyloid hypothesis was right, and it really went unquestioned for about 16 years until Schrag found tons of evidence that Lesné’s data and images have been altered, including situations where it looks like images of results were pasted together from different experiments to produce a more favorable outcome. And these findings affect about 20 papers that Lesné has been involved with over the years.

SOPHIE BUSHWICK: Have we heard anything from the people responsible for these iffy papers?

MAGGIE KOERTH: Lesné does not seem to have publicly commented. One of his co-authors on that 2006 paper, she said that she wants to retract the study in its entirety. The confidence in it’s been undermined. But she also said that she still thinks the beta amyloid hypothesis is not flawed in itself.

SOPHIE BUSHWICK: And do we know just how much Alzheimer’s research may be impacted?

MAGGIE KOERTH: I think we’re still trying to figure that out. This is definitely something that really is going to be a challenge for people going forward. There’s a lot of other theories about how Alzheimer’s works. And there have been other reasons to suspect that maybe the beta amyloid hypothesis doesn’t fully explain it for a long time. And this is going to give more of an opening to people who really feel like their work has been ignored and that other hypotheses have been ignored.

SOPHIE BUSHWICK: What happens next?

MAGGIE KOERTH: Next I think the big thing that needs to happen is somebody needs to go into the raw data in those Lesné papers. So one of the reasons why Schrag doesn’t want to describe this as fraud yet is because all he’s seen is these images that were published. He has not seen the raw data. So this is basically a red flag that says we need to dig a little bit deeper into what’s going on.

SOPHIE BUSHWICK: And let’s move on to another health-related story. We know that the COVID-19 pandemic disrupted a lot of things in our lives– work schedules, child care arrangements, dog ownership. But it turns out that childhood vaccine schedules have been really impacted by this, too. Tell us about that.

MAGGIE KOERTH: Yeah. So there’s been a decrease in uptake of childhood vaccines that’s happening globally. And this is something that got onto my radar a little bit because we had a polio case in the US last week that was announced. It happened earlier this year. But a man actually was paralyzed by polio in Rockland County, New York. And this is the first time that there’s been a polio case in the US in a decade.

It’s also happening in a county that has been home to vaccine resistance in recent years. And this is also the county where, back in 2018, 2019, they had that big measles outbreak. So this is kind of something that probably is tied into vaccine resistance.

This single case is also significant because it calls attention to this larger problem that extends well beyond Rockland County. So, globally, childhood vaccination rates have decreased or stagnated during the COVID pandemic. It depends how much based on which vaccine you’re talking about. But, for example, the one that covers diphtheria and tetanus, that’s fallen by five percentage points, which is the largest decrease in uptake in 30 years.

Experts are blaming a combination, of factors and that includes supply chain issues, economic problems, natural disasters that have happened around the same time, but also these efforts to undermine trust in public health campaigns that have been tied to how people feel about COVID.

SOPHIE BUSHWICK: How do we get back on track to make sure that kids are adequately protected against disease?

MAGGIE KOERTH: Get them vaccinated.

SOPHIE BUSHWICK: Yeah. That seems like a good solution to this.

MAGGIE KOERTH: When I come up with a deeper solution, I will have a higher pay grade, and I will let you know.

SOPHIE BUSHWICK: Let’s head to space for our next story, specifically, the moon. It turns out that there are some places up there that are actually pretty comfortable. Tell us about that.

MAGGIE KOERTH: Yeah. So one of the big issues with lunar exploration, and particularly any kind of long-term habitation plans, has always been temperature. The moon has these huge swings in the temperature on its surface because it doesn’t have an atmosphere.

So temperatures can be as high as, like, 250 degrees Fahrenheit. Days are two weeks long. And when the two-week nighttime comes, that can drop to -208 degrees Fahrenheit. And these temperatures are even higher and lower on the surface of the moon depending on what location you’re at.

So when we sent astronauts to the moon years ago, they were surviving there partly because their trips were timed to be at lunar dawn, when it wasn’t too hot or too cold. So this has always been a big, big issue. And now NASA has found these pits on the moon’s surface that they are finding the temperature hovers around 63 degrees Fahrenheit all the time.

These pits are probably collapsed lava tubes. And at least a couple of them look like they might lead into the mouth of a cave, which is really exciting because it could be a great place to locate a base for future exploration for space tourism. But– there is always a great big but– a different study came out the same week that found that rocket travel, especially the kind of frequency of rocket travel you would need if you were doing space tourism, is real, real bad for this planet.

So that study looked at air pollutants that were released during the 103 space launches that happened in 2019. And it found chemicals that can damage the ozone layer, other chemicals that are enhancing climate change. To give you an example, the study concluded that soot released directly into the upper atmosphere by a rocket launch is 500 times as efficient at heating the planet as soot released during when you’re burning fuel in an airplane. And it also concluded that a decade of regular space tourism could claw back 16% of the improvements made to the hole in the ozone layer since 1987.

SOPHIE BUSHWICK: Oh, Wow.

MAGGIE KOERTH: Yeah.

SOPHIE BUSHWICK: I guess I should cancel my trip to hang out in a 63-degree moon pit.

MAGGIE KOERTH: Yeah. Yeah. Maybe it’s not time for moon cave people.

SOPHIE BUSHWICK: Well, let’s end with a very summery story that will be pretty relevant to anyone who likes an outdoor grill. It turns out that there is a mathematically optimal number of times to flip a burger on the grill. So what’s the magic number?

MAGGIE KOERTH: Yeah. So the summer is more than half over. But mathematician Jean-Luc Thiffeault has published calculations that will help you cook burgers faster in the time you have left.

And his calculations are based on the fact that you have a piece of meat on a grill. One side is always gaining heat. That’s the side facing the fire. And one side is always losing heat, the side facing the sky. So regular flipping means more even heat and faster grilling.

And he found that flipping a burger three or four times can reduce the cook time by as much as 29%. If you flip more than that, you aren’t really gaining any more cooking speed. There’s a limit to this. You can’t infinitely flip a burger and infinitely get it to cook instantaneously. So it’s that three to four times that seems to make the difference.

Now, this work is theoretical. And, even worse, it is based on a theoretical burger that is well done.

SOPHIE BUSHWICK: So I know that there will be a lot of quibbles with that decision.

MAGGIE KOERTH: Right, right– three or four. It may be less than that if you want a burger that’s actually edible. But it does line up with real-world cooking analysis that J. Kenji López-Alt did at Serious Eats back in 2019, when he found that flipping a burger every 15 seconds reduced the cooking time by nearly a third.

SOPHIE BUSHWICK: That’s all the time we have for now. I’d like to thank my guest, Maggie Koerth, science writer for FiveThirtyEight, based in Minneapolis, Minnesota. Thank you for joining us.

MAGGIE KOERTH: Yeah. Thank you so much.

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