IRA FLATOW: This is Science Friday. I’m Ira Flatow.

Do you revel in red meat, or bask in the crispy goodness of bacon? If so, I bet this week’s World Health Organization announcement was a real bummer. The organization’s International Agency for Research on Cancer classified red meat as quote– “probably carcinogenic to humans.” And processed meat as carcinogenic to humans. Oh, double whammy.

However, clear guidelines like how much meat may or may not be OK to eat, well, they weren’t provided. Joining me now to decipher this announcement and other selected short subjects in science is Ed Yong. He’s a science writer for The Atlantic. He’s based in London. Welcome back.

ED YONG: Hi, Ira.

IRA FLATOW: Hi, Ed. So saying that red meat and processed meat could cause cancer seems like a big deal. But haven’t we heard this before?

ED YONG: Right. So there have been large studies before showing that some people who eat lots of these foods have a higher risk of bowel cancer than people who don’t eat any at all. And some studies from laboratories showing the biochemical means through which these foods could lead to cancer.

So we have definitely heard about this potential association before. What’s happened here is that the World Health Organization has this arm whose job it is to look at things that could potentially lead to cancer and say, how strong is the evidence that they could do so. And that’s what they mean when they make that their rulings.

But I think the way this information is presented is deeply confusing and misleading to people. If you hear, like, red meat probably causes cancer, what you think is, OK. So if I eat lots of steak, that’s probably going to cause cancer in me. And that’s absolutely not what they’re saying.

They’re saying that the evidence suggests that these things have the potential to cause cancer. Don’t say anything about what the actual risks are. And if you eat more of this stuff, what are your risks of developing bowel cancer? They don’t say. If you cut down and become vegetarian, do your odds decrease? They don’t say.

IRA FLATOW: Yeah. I can’t give up that hot dog during World Series. I’m sorry, Phil. And you’re right. It just sort of validates the idea. But it doesn’t tell you if there’s a dose-related thing or not. How much it is.

ED YONG: Right. Right. Or how much you should– really what people want is good information with which they can make informed choices about their own lifestyle. And you know, when it comes to meat– like I’ve cut down meat a lot in the last year or so. I only eat it maybe once a week or once every couple of weeks.

But that’s because I’m trying to lose weight. I have environmental concerns about the impact of red meat. And whether something affects my risk of cancer or not is just one part of that. But I think because cancer is so scary to people, it behooves organizations that give out information about it to make that information as clear as possible. And that’s not what’s happened here.

IRA FLATOW: That’s why we have you here today, Ed, to talk about it.

ED YONG: Thank you.

IRA FLATOW: Next up, you’ve got a look at genetic studies that focus on indigenous peoples. What has the relationship between researchers and indigenous peoples been like in the past? And what does your research show?

ED YONG: Well, it’s been pretty fractious. So there have been some famous cases where scientists have taken blood samples from Native American groups under the auspices of doing research on things like type 2 diabetes, which affects them. But instead, used those samples to study things like schizophrenia or inbreeding, or migration patterns that contradict the tribe’s own origin stories. And that’s created an atmosphere of distrust among Native Americans for the genetics community as a whole.

But I heard about a different story which took a more positive spin. So it starts in the same way. A Native American group called the Pima who have been long studied because of the high risk of diabetes, but who have always been passive participants in that work, and who’ve never really received the preventive services or educational services that were promised to them.

So they took matters into their own hands. They started a partnership with a private nonprofit research organization. And they became equal and active partners in that work. They decided what questions should be asked.

When they gave blood samples, they did it on loan. And the researchers were actually more like consultants than people who steered the project.

IRA FLATOW: You know, there was a recent play by Deborah Zoe Laufer called Informed Consent, which is exactly about this. And we had her on talking about it. It’s still a very interesting subject.

You know, we hear so much about how TV screens and smartphones are ruining how we sleep. But is that really the case? Because there’s some interesting studies out about what a good night’s sleep was like for our hunter/gatherers who never had that kind of stuff.

ED YONG: Right. So this study looked at hunter/gatherer groups from Namibia and Tanzania, and hunter/farmers from Bolivia. And they found that they contradicted a lot of these myths about the way people used to sleep. Now obviously these are modern people. But they give a sense of what life was like before the advent of light bulbs and TV screens and so on.

So they sleep about the same as we do. No more. They don’t have a lot of naps in the afternoon, like some people have said. And they sleep in a continuous stretch throughout the evening like we do. Like there’s this idea that some people used to sleep in separate blocks and woke up for a bit in the middle of the night. That’s not what we see here.

So there’s this tendency to assume that the way things used to be before the advent of modern life was so much better and aren’t things like televisions and modern technology ruining our health. And I think you need solid data to back up those assertions, rather than just going to some magical fantasy about the way people use to live.

IRA FLATOW: Speaking about something really magical. You’re bringing us a tale of murder. Tell us about those electric eels.

ED YONG: A shocking tale of murder.

IRA FLATOW: A shocking– take it away.

ED YONG: OK. So. Happy Halloween.

So electric eels are a two-meter long fish, live in the Amazon, and they pack a hefty electric charge. They can create up to 600 volts from their own bodies.

And this guy called Ken Catania has been doing a lot of work looking at how they actually use these shocks. First, they use it to make their prey give away their position. They produce small pulses that cause muscles to twitch. And prey fish will twitch and reveal itself to the hunting eel.

The eel then delivers a volley of very fast, very intense pulses. And that acts on the nerves that feed into its prey’s muscles, causing all of them to contract. So it basically paralyzes a fish by forcing all its muscles to contract, very much like a taser firing into a person.

And then it eats it, which is quite terrifying. But there’s more. Do you have time?

IRA FLATOW: Yeah. Go ahead. You got about 30 seconds. Go ahead.

ED YONG: All right. All right. So if the prey somehow resists it, the eel then curls its body to pinion the victim between its head and tail. And because it’s like a battery– the head’s the positive end and the tail’s the negative end– this doubles the electric field experienced by the prey. And it basically wears out all of its muscles. It causes its muscles to contract so intensely that it duplicates the effect of like a full-body workout in the space of a second, and allowing the eel to just take its time and swallow the victim.

IRA FLATOW: Wow. This is a true Halloween story. In fact, [INAUDIBLE] to tell us. Ed Yong, science writer for The Atlantic, based in London, England.

And now it’s time to play good thing/bad thing. Because every story has a flip side. And as we’ve been talking about, Halloween is here. And for some, it’s all about the perfect costume, right? Or decorating your lawn with the right balance of ghost headstones and ghouls.

But to others, this spooktacular day means one thing above all else. And that’s candy. Fistfuls of chocolates and caramels and gummy bears, which means we’re all going to be eating a lot of sugar. And we all know how bad sugar is for us.

So can there be any positives? Here to talk about the pluses and minuses of this annual candy binge is Roberto Ferdman. He’s a reporter for the Washington Post who covers food, culture, and economics. He joins us from the paper’s office in Washington. Welcome back.

ROBERTO FERDMAN: Thanks for having me.

IRA FLATOW: Is there anything good about eating a ton of candy on Halloween?

ROBERTO FERDMAN: Well, the good thing about Halloween, while it entails eating tons of sugary treats, which we know aren’t exactly great for us, is that we’re conscious of the fact that we’re eating things that aren’t very good for us. You know what? We actually don’t eat that much candy in perspective over the course of the year on Halloween.

About 4% of all candy consumed in the United States is eaten on Halloween. That might sound like a lot. But it’s OK given that it’s this temporary binge that doesn’t continue. We don’t continue to eat candy through the following month. And it doesn’t bring up our candy consumption over the rest of the year.

So the good thing about Halloween is that we’re conscious of the fact that we’re eating candy.

IRA FLATOW: And the bad thing about it is it’s still sugar, I guess.

ROBERTO FERDMAN: The bad thing about it is that it’s still sugar. The bad thing really about sugar is that it is in our diets more than it has been before. And it is in our diets in subversive ways, in ways that it hasn’t been before.

So what’s interesting about added sugar consumption in the United States is that the typical American only gets about 6% of their added sugar from candy. What that means is that tons of the sugar that we get is from things like juice and sweetened drinks, and granola bars– which have candy– and fruit snacks, which some people and some institutions like the Center for Science in the Public Interest have contended shouldn’t be called fruit snacks. They should be called candy.

IRA FLATOW: So at least when you’re eating the Halloween stuff, you know, as you say, that you’re eating the sugar. But when you think you’re eating more wholesome stuff, it’s really loaded with sugar.

ROBERTO FERDMAN: That’s exactly what I’m saying.

IRA FLATOW: And so you’re not saying that we shouldn’t be eating candy, we shouldn’t be binging out on this. You’re saying that we should be aware of the other stuff we’re eating during the year.

ROBERTO FERDMAN: Right. So it’s not to say– if you were to ask a nutritionist, would it be better if this child ate no candy, or ate candy, the answer would almost always be ate no candy. But the answer is always that it would be better if the child ate candy knowing that they were eating candy, than ate something thinking that it was good for them, but had just as much sugar as that candy.

IRA FLATOW: Do have a favorite candy, Roberto?

ROBERTO FERDMAN: I really like dark chocolate. So I like dark chocolate versions of pretty much anything, especially when there’s peanut butter in it too, which means dark chocolate Reese’s Pieces are a weakness of mine.

IRA FLATOW: Yeah. I’m a Hershey’s Kisses guy myself. Happy Halloween, Roberto. Thanks for taking down a view with us today.

ROBERTO FERDMAN: Thanks for having me.

IRA FLATOW: Roberto Ferdman is a reporter for the Washington Post who covers food, culture, and economics.

After the break we’re going to be continuing with our spooky Science Friday with a look at the microbiomes of monsters. Yeah! They gotta have microbiomes too, right? We’ll talk about what’s inside them. Speculate on these fictional monsters after the break.

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