GWEN IFILL: Now: how the sugar industry paid experts to downplay health risks.

Researchers have discovered documents showing the industry tried to influence scientific studies back in the 1960s. Early studies had found a link between sugar and fat and heart disease, but it now appears that the sugar industry paid two Harvard professors to point the finger elsewhere.

At the time, it wasn’t routine to disclose such conflicts.

Marion Nestle wrote an editorial about the latest research in “JAMA,” “The Journal of the American Medical Association.” She’s an author and professor of nutrition, food studies, and public health at New York University.

Welcome, Marion Nestle.

Let’s start by a few…

MARION NESTLE, New York University: Well, glad to be here.

GWEN IFILL: Let’s start with a few definitions.

What was the Sugar Research Foundation?

MARION NESTLE: Well, this was a trade association for the growers of sugarcane and sugar beets. It’s new called the Sugar Association. So it’s a trade group.

Its job is to promote the sales of sugar and to lobby to make sure that nobody does anything regulatory to reduce the consumption of sugar. It’s a trade group.

GWEN IFILL: So, yes. So, when all the years when we were being told that fat and cholesterol were the prime culprits in obesity and early death and heart disease, it turns out that sugar also played a big role.

MARION NESTLE: Well, it did.

If you look at the epidemiology, at the time, it was clear that both sugar and fat were risk factors for coronary artery disease. But these investigators at Harvard who were paid by the Sugar Research Foundation kind of cherry-picked the data and minimized the problems with sugar and maximized the problems with saturated fat. And that was exactly what the Sugar Association wanted them to do, as the documents show.

GWEN IFILL: So, the goal here was to sway public opinion, in much the same way that the tobacco industry did?

MARION NESTLE: Yes, it followed the playbook of the tobacco industry.

The number one playbook rule is, the first thing you do is you attack the science, you cast doubt on the science. “Merchants of Doubt,” the book and the movie, explain all that. And the Sugar Association was doing exactly that.

It was trying to get researchers to produce research that would minimize a role for sugar and shift the blame elsewhere. And they were very frank about what they wanted, and the investigators agreed that that was what they were going to do. Pretty shocking.

GWEN IFILL: If they could shop for experts for something like this, to find someone at Harvard who could tell them what they needed in order to preserve the industry, how do we know that hasn’t happened or maybe it has happened in other nutrition areas?

MARION NESTLE: Well, it has happened.

And The New York Times last year had a big investigative report about Coca-Cola’s funding of thee Global Energy Balance Network, in which they had e-mails that showed that there were very close associations between the researchers who were doing some of this work and executives at Coca-Cola.

But it’s very hard to get documentary evidence of this. But I do want to say one thing about it. It’s not a simple matter of buying investigators. These Harvard investigators, at least one of them, was really pretty well-known for his work linking fat to heart disease risk.

And so he probably believed that that was what it was, didn’t think that sugar was nearly as important, and believed that. So it wasn’t as simple as the Sugar Research Foundation just saying, this is what we want and we’re going to pay for it.

GWEN IFILL: When you say it’s not as simple, I’m going to ask you a question that is a little — leans towards simplicity. What is the smoking gun? Is it sugar? Is it fat?

MARION NESTLE: Oh, I think it’s both, because both of them are nutrients.

And we don’t eat nutrients. Most people don’t eat sugar on its own, and nobody eats saturated fat on its own. We eat foods that contain sugars and saturated fats. Diets are much more complicated to study than individual nutrients. But that’s really what everybody ought to be looking at.

And dietary guidelines tell you, reduce consumption of foods containing a lot of added sugars, and don’t eat so much meat, which is a major source of saturated fat. So, I say it’s both, and you have to always take the number of calories into consideration when you’re talking about these things.

GWEN IFILL: How skeptical could consumers be about these reports, which every year seem to tell them to worry about a different thing?

MARION NESTLE: Well, I think they should be very skeptical.

The first line of defense is always to say, does this research contradict what I thought I knew? If it does, you want to be a little skeptical about it and wait for some more studies to come out.

The science is cumulative. Nutrition science is extremely difficult to do, because people are terrible experimental animals, and diets are so complicated. There are lots of different ways to put together healthy diets. And we know that diets that have a lot of vegetables, that balance calories, and don’t have a lot of junk food are really good for health. We know that.

GWEN IFILL: Marion Nestle, we know it. It’s a question of paying attention to it.

Marion Nestle, professor of nutrition, food studies and public health at New York University, thank you very much.

MARION NESTLE: My pleasure.