喝未加工的生牛奶更有益?

生奶是否比加工过的奶更为健康？口感是否会更好？一起来听听专家们都是怎么说的。

 GUY RAZ, host:

This is ALL THINGS CONSIDERED from NPR News. I'm Guy Raz.

Have you ever met someone who drinks raw milk? Maybe you do. Well, the thing I always hear is how much better it tastes and then, of course, how much healthier it is.

Well, the science on that is in dispute, and so is the safety. We'll hear why in a few moments. But first, the story. And this story is told by volunteers from a raw foods co-op in Venice, California. It's called Rawesome Foods. There's Lela Buttery.

Ms. LELA BUTTERY (Volunteer, Rawesome Foods): I work with the membership services, and I'm a biologist. I answer a lot of technical questions that a lot of members have.

RAZ: Lela works with Arnell Lingren(ph).

Mr. ARNELL LINGREN (Volunteer, Rawesome Foods): I have a background over two decades in clinical nutrition.

RAZ: And then there's Jim.

Mr. JIM PHILLIPS (Volunteer, Rawesome Foods): Jim Phillips. And I set up the produce on our open days.

RAZ: And that's where the story starts, on a recent Wednesday morning at Rawesome Foods.

Ms. BUTTERY: In the morning, we have a crew that comes in probably about 4 or 5 a.m. They get there pretty early. And they literally what time?

Mr. LINGREN: 7:30.

Ms. BUTTERY: Really?

Mr. LINGREN: 7:30...

Ms. BUTTERY: She told me she was there at 5:30 the other morning.

RAZ: But anyway, the workers there at 7:30 in the morning are a part of what's called the coconut crew.

Mr. PHILLIPS: So we're setting up all the produce, getting everything ready for the day.

Mr. LINGREN: They're breaking up coconuts.

Ms. BUTTERY: They're breaking up coconuts, man. I mean, they literally get the coconut, extract water, extract the meat.

Mr. PHILLIPS: There's a knock at the back gate.

(Soundbite of knocking)

Mr. PHILLIPS: And I went back there to see who it was.

Ms. BUTTERY: Armed...

Mr. PHILLIPS: Police with...

Ms. BUTTERY: Full-on gear.

Mr. PHILLIPS: We asked them what they wanted, and they said we have a search warrant.

(Soundbite of music)

Mr. PHILLIPS: And it was to the effect of you guys are selling improper items. The police actually grabbed five or six of us volunteers, pulled us to the side by the back gate, got our name, numbers, patted us down, proceeded to go on the lot. The guns were out, and they were walking through the containers.

RAZ: And it turned out the LAPD wasn't after a stash of heroin or cocaine. They were looking for dairy products, unpasteurized dairy products.

Ms. BUTTERY: In particular, it was for a goat milk that we get from a farm.

RAZ: Now, you can sell unpasteurized milk in California, but you need a permit. And the cops said Rawesome didn't have the right one, which it turns out is in dispute.

But anyway, the police confiscated about $10,000 worth of dairy products, and it didn't make a whole lot of sense to Lela Buttery.

Ms. BUTTERY: There's a marijuana dispensary down the street from my house. There's - I can buy as much alcohol as I want, but I can't drink this enzymatic, nutrient-rich superfood?

RAZ: Now, people who eat a raw diet don't just eat raw nuts, fruits and vegetables. Most of us do that anyway. What government regulators worry about is meat and milk, foods, they say, more susceptible to bacteria like E. coli and salmonella.

But raw food advocates say that's nonsense, that raw foods contain essential bacteria and nutrients that are lost when foods are pasteurized and homogenized, which is why when you join Rawesome co-op, you sign a form that says:

Ms. BUTTERY: I reject the government's rules for pasteurization, homogenization; all these things on my food. And I want E. coli, listeria, salmonella in my food.

(Soundbite of laughter)

Ms. BUTTERY: Aside from that, in your gut right now, you have salmonella. You have E. coli. You have listeria. We've evolved with it, and it's what our immunity is made out of.

RAZ: Except for Bill Marler, it's not that simple. He's a lawyer and a well-known food safety advocate who represents clients who've suffered from food-borne illness.

Mr. BILL MARLER (Attorney): I completely understand where so many of these folks are coming from because my wife and I, we have a garden. We buy locally. We buy at our farmers market. My daughter just turned 18. She's never had a hamburger. We don't serve hamburger in our home. But sometimes people can take things to a little bit to an extreme.

I see the other end of it, and it's sometimes not very pretty.

RAZ: Bill Marler, why do you think there has been such an upsurge in interest in consuming raw foods and raw milk in the United States? And why do you think the people who consume those foods are so passionate about them and about the availability of them?

Mr. MARLER: Well, this is where I sort of understand, and I agree with their assessment of our food system as we see more and more diabetes, heart. And that's why I think you saw the incredible upsurge in organic.

Of course, big business then got into organic. Then people got disgusted with big business getting into organic, and they started doing the locavore. It's continued to sort of push the edge.

And I think, frankly, raw milk consumption, raw food movements, are really a direct result of people who've been disgusted by corporations putting profits before health, by governments failing to combat that.

RAZ: I mean, so you're essentially saying you don't blame them, but that you disagree with them.

Mr. MARLER: One of the things that proponents of raw milk fail to deal with is, is that bugs that exist today - E. coli 0157, antibiotic resistant salmonellas and campylobacters, listeria. Those bugs didn't exist in the way they exist today 50 years ago.

RAZ: I mean, you would argue that raw milk is not safe for human consumption?

Mr. MARLER: I think it's very difficult. E. coli, salmonella, campylobacter are all fecal bacteria. It's very difficult to create a sanitary environment when cows don't wear diapers when they're being milked.

Fecal bacteria can kill at about 10 to 50 bacteria. Over 100,000 of them can fit on a head of a pin. There's a very little margin of error for these bugs.

RAZ: Do you believe that raw milk and unpasteurized dairy products should be available to people who want to consume them?

Mr. MARLER: I think the reality is, is that there have been nine reported raw milk outbreaks since January of this year, sickening dozens of people. And if the beef industry had had nine outbreaks in this year, you know, we'd be calling for the head of the USDA.

I think if people want to consume raw milk, they need to go and look that farmer directly in the eye. They need to see the facility. And it also needs to be regulated by state and local authorities.

RAZ: There's a food safety bill now in the Senate. It could pass before the summer recess. How would that change the rules if it does pass?

Mr. MARLER: Raw milk advocates are worried that Senate bill 510, and the House version that's already passed, will have some impact on raw milk sales. But frankly, it won't.

The bill primarily is focused on mass-manufactured foods to try to make them safer, creating a much more rigorous inspection system.

RAZ: That's lawyer and food safety specialist Bill Marler.

Bill Marler, thank you so much.

Mr. MARLER: Thank you.

RAZ: Now, we should point out that at Rawesome, the place in Venice, California that was recently raided, the food is probably about as safe as it can be. The volunteers know exactly where it comes from.

So we called up Marion Nestle. She's a food scientist at NYU. And we asked her if there's any scientific evidence to back up the claims made by raw foodists.

Dr. MARION NESTLE (Professor of Nutrition, Food Studies and Public Health, New York University): If they feel better, I think that's great for them, and I can understand why they would continue wanting to eat it and to have that choice. I think they should have that choice.

RAZ: Marion Nestle has written several books on nutrition. Her most recent is called "Food Politics." She says that while the raw food movement is taking off now, its origins go back to the 1930s.

Dr. NESTLE: A dentist named Weston Price visited a lot of third world countries and was enormously impressed by how healthy people were, particularly their teeth. He was a dentist, so he cared about teeth.

And he went around and took photographs of these gorgeous people - radiant is the word that's used - and attributed their good health to their eating natural foods, foods that were uNPRocessed. And, of course, that tracks very well with what we know about sugars and the effect of sugars on tooth decay.

And then his work has been incorporated into something called the Weston Price Foundation. They have a website in which they talk about you're happy if you eat butter. And I must say, I'm happy if I eat butter.

RAZ: Who isn't?

Dr. NESTLE: And who isn't? And they propose that you would be healthy if you ate high-fat meat, dairy products, fish, anything that is natural and uNPRocessed, including raw milk. And they become the major political arm of the raw food movement with many, many followers.

RAZ: So it began with this dentist's visit to third world countries. Presumably, he saw people consuming raw, unpasteurized milk. What does the science say about let's start with raw milk? I mean, could there be benefits from drinking it?

Dr. NESTLE: Well, what gets killed in pasteurization is the question. Pasteurization is a process in which milk is heated very, very quickly, in just seconds, to high temperatures. You know, it's considered to be one of the triumphs of public health.

And the heating, depending on how long it is and how hot it is, certainly destroys some of the more labile vitamins, particularly Vitamin C and folate. But milk is not a major source of either of those vitamins. Those vitamins mainly come from fruits and vegetables.

Proponents of raw milk argue that it inactivates enzymes, but those enzymes will be inactivated when you eat the food anyway because the stomach acid inactivates them. And if that doesn't work, they're taken apart by digestive enzymes in the digestive tract.

So the kinds of arguments that are made for the nutritional benefits of raw milk really don't hold up very well to scientific scrutiny.

RAZ: So what you're saying is there's no evidence that raw milk carries any kind of health benefits, I mean, microbes or...

Dr. NESTLE: If you want to talk about the microbial issues, those are more complicated. Milk is not a sterile product. It's going to pick up whatever bacteria are on the cow.

Now, some of those may be helpful bacteria, lactobacilli and the kinds of bacteria that go into making yogurt, for example. But if there are pathogens on the cow, they're going to be picked up.

The idea bacteria in raw milk have substantial health benefits, I think it's theoretically possible, but I haven't seen any substantial evidence that shows that that's the case.

RAZ: That's Marion Nestle. She teaches nutrition, food studies and public health at New York University.

Marion Nestle, thank you so much.

Dr. NESTLE: You're very welcome.