Air Date: Week of March 3, 2000

Janet Raloff of Science News magazine, and Ira Flatow of NPR’s Science Friday join host Steve Curwood to discuss recent findings that shed new light -- and new uncertainty -- on old issues, from the health effects of chocolate to disappearing frogs. When a science discovery makes the headlines, we often assume that researchers have found the truth about a subject. But Raloff and Flatow say that good science builds on, or even contradicts previous work.

Transcript

CURWOOD: It's Living on Earth. I'm Steve Curwood. You might remember that old Woody Allen movie "Sleeper," in which a twentieth-century health food store owner wakes up after being frozen 200 years, only to find that dietary guidelines have changed a bit.

WOMAN: And he's fully recovered, except for a few minor kinks.

MAN: Has he asked for anything special?

WOMAN: Yes. This morning for breakfast he requested something called wheat germ, organic honey, and tiger's milk.

MAN: (Laughs) Oh yes, those are the charmed substances that some years ago were felt to contain life-preserving properties.

WOMAN: You mean there was no deep fat? No steak or cream pies or hot fudge?

MAN: Those were thought to be unhealthy, precisely the opposite of what we now know to be true.

WOMAN: Incredible.

CURWOOD: Well, don't break out the cream pies just yet. But there is new research that brings into question a couple of long-held dietary assumptions. The findings were presented at the recent meeting of the American Association for the Advancement of Science. Other topics discussed at the gathering illustrate the difficulty of honing in on a scientific truth. We're joined now by two journalists who attended the meeting. Ira Flatow, host of NPR's Science Friday is with us from the studios of WSHU in Fairfield, Connecticut. Thanks for joining us today, Ira.

FLATOW: My pleasure, Steve.

CURWOOD: And Janet Raloff is senior editor at Science News, and she speaks to us from Washington. Hi, Janet.

RALOFF: Hi, Steve.

CURWOOD: Now, let's start with you, Janet Raloff. It seems that we might have to do some rethinking about what we include in our diets. And I'm especially thrilled to hear about this new research on chocolate as medicine.

RALOFF: Yeah, no more thrilled than I am, I'll tell you. Turns out that people have been using chocolate therapeutically in the Americas for at least 600 years, and it's been used for almost everything you can think of. It's sort of good for what ails you -- if it's bad digestion, diarrhea, TB, even sexual dysfunction. It turned out in more recent years, anyway, medicine looked at it and said there wasn't an awful lot of science to back that up, and so it ended up being just a really delightful snack. More recently, as in the last three to five years, a number of studies have started showing that there are constituents in chocolate that actually seem to be beneficial for a number of attributes of your cardiovascular system.

CURWOOD: So what does chocolate do for you? What's this stuff and how is it good for you?

RALOFF: Well, these are a family of antioxidants, flavonoids, and they seem to prevent your LDL from oxidizing. That's good, because oxidized LDL contributes to the development of atherosclerosis.

CURWOOD: This is low-density --

RALOFF: Lipoproteins, uh huh. Things that carry cholesterol into your blood vessels.

CURWOOD: Right.

RALOFF: They also relax your blood vessels, which is the same kind of thing that nitroglycerine does for people, trying to help them lower blood pressure. It sort of works a little bit like a mild aspirin to reduce the risk of blood clots.

CURWOOD: So this means we can indulge in our chocolate cravings now, right?

RALOFF: Well, not too much. It still should be kept in moderation. There is the fat; calories overall matter. But it turns out chocolate has very good fat in it for you, and if you eat dark chocolate you don't need to eat as much to get the same effect.

CURWOOD: Now, there's change in a dietary law that's been ingrained in the U.S. for the last couple of years. And this is the one that tells us, reduce salt intake to reduce high blood pressure. Janet, at the AAAS meeting, people are saying that's not true?

RALOFF: Those original recommendations came out 20 years ago. They were based on data that were two to four decades old at that time. And the more studies they've done since the new recommendations came out, the less support they find for this idea that salt is actually a problem for blood pressure. It is a problem for a small share of people, maybe 15 to 20 percent. But that means that for 80 to 85 percent, it's not a problem. And, in fact, a few studies have even suggested that for some people lowering salt can increase the risk of heart disease and stroke, sexual dysfunction, and a number of other things.

CURWOOD: Now, this is an instance in which the initial work has been proven to be wrong. There are some other issues that were presented at the conference that ended up being, well, much more complex than we had first thought. And let's talk about the latest research on the frogs. Ira Flatow, I want to turn to you for this discussion. Frogs are in deep trouble. They seem to be dying. They have malformed or missing limbs. What's going on here?

FLATOW: Scientists have known for over the past 15 years that frogs and amphibians, the whole class of amphibians, have been dying off all over the world. And they would love to say there is one cause for all these frogs dying off. Possibly it's global warming, possibly it's the ozone hole. And they've been looking for one kind, something they can pin on it, but they haven't been able to find any. And in fact, they have found all different reasons for these frogs dying off. So it makes it a very complex situation. Sometimes they find there's a fungus where the frogs died. Sometimes there are parasites. Sometimes there is water pollution and runoff into a stream or a river from the nitrates that are in fertilizers. Things that would kill your aquarium fish, for example, might be killing the frogs also. And it's a very complex situation where there are lots of different reasons, instead of one big reason that everybody would love to have.

CURWOOD: Well, I see a huge problem here. What we've been saying, Janet and Ira, is that from salt intake to chocolate, things that we knew in the past aren't true any more. Or they're so complex it's hard to figure out the exact cause of something. So how do we as non-scientists put all this research and changing science into the proper context? I mean, how do you make a personal health decision? How do you make a public policy decision when things are uncertain or are going to change, or are so complex that it's unclear? Ira, maybe you go first on this one.

FLATOW: You know, we as journalists, we face the same problem that everybody else does trying to sift through all of this and figure out what we do in our own personal lives. And you know, it drives public officials crazy also, this uncertainty. I remember many years ago, on a hearing on Capitol Hill that I covered when the supersonic transport was first coming into the country and they were trying to decide whether it would create these giant holes in the ozone layer. And Senator Ed Muskie had a big hearing on Capitol Hill, and he called all these scientists together. And they had a blue ribbon panel that was presenting their findings, and they said, "Our findings show this, that the preponderance of data is that it won't cause any danger. On the other hand, our data shows just the opposite, also, that we need to do more research." And I remember Ed Muskie getting up and saying, "Will somebody please find me a one-handed scientist?" Because they didn't know how to deal with this ambiguity themselves.

CURWOOD: But who's responsible here? I mean, is it the public's fault that their expectations can get dashed when a health study comes out that contradicts a previous one? Of course, I don't want the study that comes out that says that chocolate's lousy for you.

(Laughs with Raloff) Is it the media's or even the scientist's fault?

RALOFF: Well, I think it's certainly human nature that we want things to be black and white. And as a journalist, when we see people asking for those black and white answers, we have to tell people no, really, the whole universe is gray. Now it's an uphill struggle to keep this message, because every time you find five studies that show one thing, people are ready to say, aha, that's the answer, that's the truth. So we have to keep harping on our audience and telling them that it's never black and white.

CURWOOD: Okay. Well, there's a new field of science that on the surface seems to be, well, the quintessential gray, uncertain, unclear discipline. And this is the one called ecological forecasting. Janet Raloff, help us understand what this is all about, ecological forecasting.

RALOFF: Well, this is taking the big picture view of how the environment works. It turns out that in the last several decades humans have really started to dominate the planet. They are changing everything in a big way. And for the most part, science has only been looking at little corners of the world to try and see what's happening. Eco-forecasting tries to take that global overview, and by nature it's going to be a real broad-brush view. But it helps people figure out where the big pressure points are, where you need to home in on your research to find out what's likely to happen. You may be off by, you know, 50 percent or even 100 percent, but at least you know that these are the areas that are likely to be changed or heavily impacted by mankind's footprint on the planet.

CURWOOD: Ira, I have to ask this question. It's a bit of a million dollar one. What kind of certainty can we expect from eco-forecasting?

FLATOW: I'm skeptical on this, because I have trouble believing the five-day forecast of the weather. I think that the further out we go, especially five, ten, 50 years, the more lucky we're going to be if it gets to be right. So I'm a little skeptical about this.

CURWOOD: We have just a moment before we have to go. But your predictions, both of you, on how the chocolate research will hold up over the years.

FLATOW: (Laughs) I hope that we can eat a lot of it. But food, nutrition is the hardest thing to predict, of all the sciences I've ever covered, that research goes. There are so many factors involved, it's very hard to predict. But I'm hoping we can get to eat a lot of chocolate.

CURWOOD: Janet?

RALOFF: Well, among other things, eating chocolate makes you feel good. And that's good for your health, too. So if it does nothing else, at least we can go out being happy.

CURWOOD: (Laughs) So we can just not worry about all that other uncertainty, huh?

(Raloff laughs)

FLATOW: I go for the dark chocolate, and you take the milk chocolate.

CURWOOD: (Laughs) There you go, Ira. Ira Flatow and Janet Raloff, thanks to both of you for joining us today.

FLATOW: Thank you, Steve.

RALOFF: Thanks, Steve.

CURWOOD: Janet Raloff is senior editor with Science News, and Ira Flatow is host of National Public Radio's Science Friday.