Pollan's new book, In Defense of Food, is a scathing indictment of the food industry and a call for a return to unprocessed food.

The human digestive tract has about the same number of neurons as the spinal column. What are they there for? The final word isn't in yet, but Michael Pollan thinks their existence suggests that digestion may be more than the rather mundane process of breaking down food into chemicals. And, keeping those numerous digestive neurons in mind, Pollan's new book In Defense of Food: An Eater's Manifesto entreaties us to follow our knowledgeable guts when it comes to figuring out what to eat.

Nutrition science and the food industry have been changing their minds about what Americans should eat for years. Low fat, no fat, low carb, high protein. In In Defense of Food, Pollan argues that all of these fixations amount to a uniquely American disease: orthorexia -- an unhealthy obsession with eating. And as statistics on diabetes and obesity can attest, obsessing doesn't seem to be getting us anywhere. Pollan takes the reader on a journey through the science of food and reveals how it is that we've ignored our guts and followed the ever-changing tune of food science. At once a scathing indictment of the food industry, and a call for a return to real food, Pollan's latest book reveals how Americans have been dangerously misled into adopting "low fat" as a fundamental food mantra, and how most of the products on our supermarket shelves should be called "imitation."

Pollan recently sat down with AlterNet to explain why cooking from scratch has become a subversive act, and to tell us things our guts probably already knew.

Onnesha Roychoudhuri: At the very beginning of the book, you indict your own field -- journalism. You write, "The story of how the most basic questions about what to eat ever got so complicated reveals a great deal about the institutional imperatives of the food industry, nutrition science, and -- ahem -- journalism ..."

Michael Pollan: The way journalists report on science contributes to the confusion about nutrition. We over-report the latest findings. Science is this process where hypotheses are advanced, and then they get knocked down. But you lose track of that when they run the big story on page 1: "Study of Low-Fat Diets Finds They Don't Really Work." That makes it sound like a consensus has formed. You look more closely and you realize, well, that's not really what that proved. It really proved that it's very hard to get people to go on a low-fat diet. The people in that study didn't really reduce their fat intake that much. We've tended to amplify a very uncertain science.

The larger issue is that the very nature of journalism and the nature of food don't make a good fit. Food is a really old story. The foods that we do best on are the ones we evolved eating over many thousands of years. But journalism needs a new story every week, and so we tend to play up novelty and surprise. The classic methods are to eat more fruits and vegetables. How are you going to interest an editor in that story? But in fact, that is the story. Nutritionists haven't changed their points of view nearly as much as you would gather from reading the journalism about them.

On the other hand, there is a very good fit between journalism and the food industry, which needs lots of change. The food industry needs to know that the blueberry is the food of the moment and that there's very exciting research showing that it's a "superfood" so they can put blueberries in all their products. That suits both journalism, which needs a new story every week, and the food industry, which puts out 15,000 new products every year.

OR: This constant influx of food products seems to be the result, in part, of this rise in the prominence of focusing on "nutrients." Can you explain how we became fixated on nutrients?

MP: In 1977, Sen. McGovern, who had convened this select committee on nutrition, was looking at why there was so much heart disease post-WWII. The thinking then was that people were eating too much animal protein. So his initial recommendation, quite plain-spoken, was to eat less red meat. Turns out the industry would not let the government say "eat less" of any particular food, so there was a firestorm of criticism. He was forced to compromise on that language. He changed it in a way that would prove quite fateful in many ways. He changed "eat less red meat" to "choose meats that will reduce your saturated fat intake."

There are a couple noteworthy things about that. One is it's a lot less clear and a lot of people aren't going to understand it, which certainly suits the food industry. The other is, it's affirmative. It's saying "choose meats." In other words, eat more of something that will have less of the bad nutrient -- saturated fat. We're no longer talking about eating more or less of a particular food; we're saying eat more or less of a particular nutrient. That became the acceptable way for everyone to talk about food. It didn't offend the food industry because they could always change their products to have more of the good nutrient, less of the bad. And I think it was very confusing to people: Foods are not merely the sum of their nutrient parts.

OR: Can you explain how this focus on nutrients impacts medical studies as well?

MP: The focus on single nutrients, which is to say single variables, is necessary to science. This is part of the nature of reductive science and it's part of its power. But, it is not the way that the rest of us need to look at food. When a scientist learns from the epidemiology that diets high in vegetables, fruit and whole grains seems to confer some protection against cancer, the scientist needs to figure out what in that diet is responsible. So, he or she immediately is going to look for the "x" factor. Is it beta carotene, is it vitamin E? Then they break down the food into its component parts and study them all individually to see if they can find an effect.

As it turns out it's been very hard to do that and, often, when we isolate these nutrients, they don't seem to work the way they do in whole foods. Maybe they'll figure out what's going on. But the point is, for us eaters, it doesn't matter. All we need to know is that eating lots of fruits, vegetables and whole grains confers some protection against cancer. Who cares what the mechanism is. They want the mechanism because they're curious and it's the nature of science to satisfy curiosity, and the industry wants to know the mechanism because then they can make a supplement or they can fortify foods with that magic ingredient.

But, for now, stick with the foods. We know it works.

I'm not a Luddite; I'm not anti-science. I'm fascinated by nutritional science. But I've also acquired a healthy skepticism about how much and how little they know. It has only been around for about 175 years. Its history is of one overlooked nutrient after another. As I see it, nutrition science is kind of where surgery was in the year 1650, which is to say very interesting and promising, but do you really want to get on the table yet?

OR: You describe nutrition science as being, in some respects, "parking lot science." Can you explain this?

MP: You measure what you can see, and you inevitably decide that what you can see is what matters. Cholesterol is a classic example. It's the first factor related to heart disease that we could measure. So, the science got obsessed with cholesterol, and cholesterol became the cause of heart disease, and dietary cholesterol was what you had to eliminate. This is parking lot science. It's based on the parable of a man who loses his key in a parking lot at night. He spends all his time looking for it under the lights even though he knows that's not where he lost it, because that's where he can see best.

We have a science that often proceeds that way. But then new factors emerge. Now we know about triglycerides and C-reactive protein and homocysteine, and we're studying those as well. Scientists understand this about themselves better than the journalists who write about science do. They understand the limitations. They've come out and made recommendations that perhaps were less than helpful, such as get off animal fats and get onto margarine and trans fats, but on the other hand, they understand that what they're doing is still very provisional. It's the rest of us that have taken what are very partial, imperfect findings and tried to organize a food supply around them, such as when we took all the fat out of the foods.

OR: Everyone has heard about the low-fat diet. In the book, you talk about how little evidence there is that this diet -- bolstered by the lipid hypothesis -- is the magic bullet.

MP: I was very surprised when I started delving into that. The big message from nutrition science and public health since the 1970s has been that the great dietary evil is fat -- saturated fat in particular. In the years since, this hypothesis has gradually melted away. There are still people who think that saturated fats are a problem because they do raise bad cholesterol, but they also raise good cholesterol. But there are very few people left who think that dietary cholesterol is a problem. There is a link between saturated fat and cholesterol in the blood. There is a link between cholesterol in the blood and heart disease. But the proof that saturated fat leads to heart disease in a causal way is very tenuous. In one review of the literature I read, only two studies suggested that, and a great many more failed to find that link. Yet the public is still operating on this basis that we shouldn't be eating cholesterol.

In fact, when the government decided to tell people to stop eating fat or cut down on saturated fat, the science was very thin then. But the net result of that public health campaign was to essentially get people off of saturated fat or try to get them onto trans fats, and we've since learned that that was really bad advice because the link between trans fats and heart disease is the strongest link we have of any fat to heart disease. They told us butter is evil and margarine is good, and it turned out to be the opposite.

You still see all these no cholesterol products and no saturated fat, and the American Heart Association is still bestowing its heart-healthy seal of approval to any products that get rid of fat no matter how many carbohydrates they contain. The science has moved on. The science now is much more curious about things like inflammation as a cause of heart disease and the fact that refined carbohydrates appear to increase inflammation and metabolic syndrome. These assaults on the insulin metabolism from refined carbohydrates are perhaps a culprit.

I was surprised at how few scientists would defend this lipid hypothesis as the great answer to the questions of diet and health. Nevertheless, they move on because scientists don't stop and come out and say, "You know, we were really all wrong about that." They just keep moving forward. That's the way science should work. But there should be a big disclaimer saying, "Wait till we figure this all out before you change the way you eat and before the government issues proclamations."

OR: You write that, "Foods that lie to our senses are one of the most challenging features of the Western diet." This is in a discussion of the "imitation food rule" -- can you talk about his?

MP: That was another red-letter day in the rise of nutritionism. Basically, the Food and Drug Administration was started in 1938 with the Food and Drug Act and as part of that was this rule that basically held that there are certain traditional foods that everyone knows like bread and pasta and yogurt and sour cream and if you're going to fundamentally change their identity by substituting one nutrient for another, you had to call them imitations. If you look at the ingredients of something like no-fat sour cream, you will find all sorts of things that have nothing to do with sour cream. You will find carrageenan and guar gum. These are parts of seaweed and beans. These are all substitutes for the fat in sour cream. It is not sour cream, and the law used to require you to say as much, but in 1973, the FDA -- without going to Congress -- simply repealed the imitation rule.

They did it at the behest of organizations like the American Heart Association, who thought that this would be a good thing. That the imitation rule was standing in the way of reengineering the food supply to make it contain less fat. Because no one would buy products called "imitation sour cream." Would you buy imitation pasta? No. But "low-carb pasta" might sound more appealing.

Throwing out the imitation rule essentially allowed the food companies to do what they wanted with things like yogurt or sour cream -- fundamentally change the identities of food without having to disclose it. We've moved from real foods like sour cream to edible food-like substances like low-fat sour cream that I refuse to call food. I think we should restore the imitation rule. We still have it for certain products.

So for example, if you want to sell chocolate, you have to use cocoa butter as the fat in the chocolate. But now there's a move to get that changed. The Hershey's Co. has petitioned the government to change the standard of identity of chocolate so that you could use corn oil or soy oil, which would be cheaper. Fortunately, Mars, Inc. is holding out to let chocolate be chocolate. But this is why I felt I needed to write a defense of food. Food is under assault by industry and nutrition science, who think they can improve on the foods we've had for hundreds of thousands of years. My contention is, they can't.

OR: It was interesting that the FDA, and not Congress, repealed this. What's the legality of that?

MP: I think they were acting without authority. This happens more than you may think. It happened with the organic rules. The original legislation in 1990 that began the process that led to organic certification said that you could use no synthetics in organic processed food. It was very clear-cut. But the industry, when they started writing these rules said, we need these synthetics, we can't possibly make all this wonderfully organic junk food without certain synthetic ingredients.

So the USDA's organic standards board just went ahead and created a list of the law of synthetics. This was completely extralegal. Then this blueberry farmer from Maine sued and he won. Then the industry went to Congress and got them to change the law. It would be wonderful if some enterprising public interest lawyer decided to sue to restore the imitation rule. My guess is Kraft, General Mills, Frito Lay and Pepsi-Cola would all go to Congress, and some very obscure provision would be attached to a very obscure spending bill, and we'd be back where we are today.

OR: You talk about how corn, soy, wheat and rice account for over two-thirds of the calories we eat and how these crops have taken the place of more diverse crops. What's ironic is that while we're seeing a shift to nutritionism -- as we try to supplement foods with the supplements naturally found in foods -- supplements in natural foods are declining.

MP: Over time the nutritional quality of many of our foodstuffs has gone down for a couple different reasons. One is we have been breeding for qualities other than nutrition. We've been breeding for yield, looks and ship-ability. Also, over time, our soils have been simplified by the use of chemical fertilizers. For plants to create all these interesting phytochemicals that nourish us, they need a complex soil. So crops that get lots of nitrogen fertilizer and little else tend to be less complex and less nutritious. In a way, this gives the advantage to the food scientists because they can add as much nutrients as they want to their processed foods. But on the other hand, there is this trend towards organic foods, which restore a lot of those nutrients partly by nourishing the soil with organic matter and party by using older varieties that are often more nutritious.

OR: You explain that weeds are actually some of the most nutritious plants because they haven't been cultivated and that the natural pesticides they develop can be converted into positive qualities once consumed.

MP: They don't even have to be converted. The defensive compounds that plants produce to deal with diseases and pests turn out to be some of the most nourishing things in them. That's what a lot of those phytochemicals are. They're plant pesticides, in effect. They happen to be very useful to us and our bodies. One theory is that since organic plants have to defend themselves, they produce more of those compounds. Whereas, if a plant is pampered and gets lots of pesticides, and the farmer takes care of the pests and the disease, the plant doesn't produce all these chemicals that are good for us. There is a theory that stressed vegetables in various ways are more tasty. If you stress a tomato and don't give it enough water and make it fend for itself, it will taste better, and those compounds that make plants taste good are also the same ones that we're talking about here. A certain level of stress in the plant kingdom is good for us.

OR: And maybe a little stress in our attempts to obtain the food makes it taste better to us?

MP: Well if you work hard to grow that tomato, it will taste better. So maybe there's something to that.

OR: In some ways, this book seemed to make the case for the "shock doctrine" of the food industry. There's this notion that what's bad for us is good for the industry.

MP: There is a disconnect between the economic imperatives of the food industry and the biological imperatives of the human eater. You make money in the food industry by processing food as much as possible. It's very hard to make money selling whole foods as they grow. They're too cheap and common; farmers are too productive. The price of commodities is always falling.

But if you process food, you then have a way to add value to it. For example, it's very hard to make money selling oats. Very simple grain, really good for you. I can buy organic oats for .79 cents a pound. That's a big bag of oats. But there's little money in it for anyone. If you turn those oats into Cheerios, there's a lot more money in it. Suddenly, you have your intellectual property, your little design, donut-shaped cereal, you have a convenience food, you just have to add milk, you don't have to cook it anymore and you can charge about four or five dollars for much less than a pound of oats. So that's a good business.

But in fact, over time, those Cheerios will turn into a commodity, too, and all the supermarkets will have their store brand and it will be hard to expand your market and grow. So what do you do? You go up the next level of processing, and you make honey nut Cheerios cereal bars. These new bars that have a layer of synthetic milk through the middle and the idea is that it's a bowl of cereal that you could eat dry in the school bus or in the car.

OR: You have a way of making that sound really unappealing.

MP: They really are. Look at the ingredients on the label -- it will say "made with real milk." Check out what the real milk is. It's ten ingredients that include some powdered milk and a lot of other strange things. But then you're selling a few ounces of oats for a great many dollars. By the pound, you've taken that 79 cents, and my guess is you're up to 10 or 20 dollars a pound for your oats because you've added all of this excitement and novelty.

And then you go up another level: Now you have these cereal straws. You take that oat material, and you extrude it through some machine that turns it into a straw and then you line that with that fake milk product. Then your children sip milk through it and you feel virtuous because you're increasing their milk consumption. But at every step of the way, this food has gotten less nutritious. None of them are as healthy as that bowl of oatmeal, and the reason is, the more you process food, the less nutrients it has unless you add them back in. And even if you try to add them back in, you're only going to add in the stuff you know is missing. There are other things you don't know about because nutrition science doesn't see them yet.

So that's the capitalist imperative behind food. The fact is we would be better off with the oatmeal. The industry has many tricks to make sure we don't eat the oatmeal. One is to market the wonders of these processed products. The other is to convince us we're too busy to cook. And they're very good at that. If you look at the picture of American life, family life on view in food commercials for television, you would think it's this frenetic madhouse in every household in America, where the idea of cooking is absolutely inconceivable.

Yet, at the same time, there are images of people lounging in front of the television, doing their email and doing all sorts of other things, but there's simply no time to cook. I think we've been sold this bill of goods that cooking is this heroic thing that only happens on special occasions.

OR: The industry spin isn't especially vague or nuanced -- you cite a trade magazine called the Packer, in which an author asserts that declining nutrients in foods is good news because it just means people will have to eat more food.

MP: You realize that they can spin anything. If the nutritional content of carrots has gone down, that just means that people are going to need to eat three carrots instead of one. I'm full of admiration for the ingenuity of capitalism. It can turn any mess it creates into a wonderful, new business.

OR: Your book draws on scientific studies and provides an incredible amount of information about nutrition science, but it's also a manifesto of sorts. You say that "in our time cooking from scratch and growing any of your own food qualify as subversive acts."

MP: It's funny to think of something as domestic as cooking and gardening as subversive, but it is. It is the beginning of taking back control from a system that would much rather do everything for you. The food industry wants to cook for you, shop for you, they want to do everything but digest for you and if they could figure out a way to do that profitably, they would. It's all about making money. They need to convince you that you can't do this stuff on your own. That gardening is hard, growing your own food is old-fashioned. Cooking is just so hard, we have to cook for you.

I think it's really an important thing to do. The fact is we've had 50 years of letting corporations cook our meals, and it appears now that they were not doing a very good job of it. The food they're cooking is making people sick. It is one of the reasons that we have the obesity and diabetes epidemics that we do. And it's not surprising because they do not take as much care of our health and welfare as our parents do when they cook for us.

If you're going to let industries decide how much salt, sugar and fat is in your food, they're going to put as much as they possibly can. Why? Because they want to sell as much of it as they possibly can and we are hard-wired to like sugar, fat and salt. They will push those buttons until we scream or die. That's in the nature of things. If you want to sell a lot of products, you make it as appealing as possible, but that's not the same as cooking with an eye toward our health. We have responsibility for our health. We shouldn't expect them to look out for us. And indeed, they don't.

OR: It seems like an incredible irony that we Americans are so obsessed with eating, and yet we're eating so poorly. I'm interested in your emphasis throughout the book on the importance of pleasure in food.

MP: I think we've lost track of just how peculiar our view of food has become. We think the only question is health. Historically, people have eaten for a great many other reasons: for pleasure, community, to express their identity, to commune with nature. There are so many equally good reasons to eat than to either improve or ruin your health. But we've narrowed it down to this one thing.

Paul Rozin is a psychologist at the University of Pennsylvania, and I call him the psychoanalyst of our eating disorder in America. He's done wonderfully creative experiments like conducting word/image association tests with different cultures. For example, he showed a picture of a slice of chocolate cake to an American audience and a French audience. The Americans look at it and their response is "guilt" or "calories," and that seems very understandable to us until you realize that there's another way to look at that. When he shows it to a French audience, their first response is "celebration." How much healthier is that?

We have this very narrow lens through which we're looking at our food, and I think it's robbing us of pleasure. Perhaps it would be worth looking at food in this guilt/health way if it actually made us healthier, but there is no evidence that worrying about your nutritional health makes you any healthier. In fact, we are the great food worriers of the world, and our nutritional health is really very poor. Why is that? I think a lot of our obsession with nutrients ends up becoming just another license for eating badly. When all those products became no-fat, people felt they could eat as much of them as possible, and we ended up getting very fat on that low-fat diet.

OR: I think you refer to a related phenomenon in our relationship with food -- this Puritan bias that "bad things happen to people who eat bad things."

MP: We moralize our food choices. This as an example of how science is more influenced by ideology than perhaps we realize. We've tended to focus on the evil nutrients as the cause of our problems, but of course, it's just as possible that it's the lack of beneficial nutrients. In other words, it may be the problem with meat is not the saturated fat, i.e., the evil nutrient, but the fact that the meat is pushing other foods out of the diet, such as vegetables, fruit and whole grain. You see, that's the complexity of nutritional science: There's always a zero sum relationship. If you're eating more of something, you've got to be eating less of something else. Our tendency has been to focus on the bad nutrients, because we do assume if you get sick, you did something wrong by eating a bad thing, but in fact, maybe you just didn't eat enough good things.

OR: And there are many diets throughout the word that you address in the book -- even diets based heavily on animal proteins -- and nearly every single diet is better than the Western diet.

MP: Weston Price and the researchers from the early 20th century that I look at in this book found many examples of people who were eating almost exclusively animal protein diets and were actually very healthy. There is a great range of nutritional diets to which the human body appears to be very well adapted. You go from the Inuit in Greenland eating their seal blubber and lichens to the Masai in Africa, who eat cattle blood and milk, or the Central American corn and beans. Traditional diets have kept people healthy for a long time with whatever was at hand locally -- as long as they were real foods.

The one diet to which we appear to be very poorly adapted on the evidence of how sick it make us is the Western diet of processed food, refined grain, not that many fruits and vegetables, and lots of meat. After thousands of years, we have invented the one diet that makes people sick and rejected the thousands of diets that make them healthy. How did that happen? Well, it's hard to make money on those traditional diets. We're programmed to like refined grain, sugars and fats. When technology could make them common, we weren't going to reject that. I think that's just the nature of things. We have this reward system in our brains, and if you can figure out a way to trip it with a drug, with a food, you're going to do it, and people are going to fall for it.

OR: In terms of guidelines on how we can eat better, you write that we should keep in mind that "you are what what you eat eats, too."

MP: I assure you that sentence is grammatical. Essentially, the idea is that we're part of the food chain, and in the food chain creatures eat other creatures, and so you can't just say, "This is beef." It's a very different food depending on what that cow or steer ate. A steer that was finished on grass is a completely different food than one that was finished on corn and industrial by-products in a feed lot. We don't pay enough attention to that. If you're eating from a grass-based food chain, you're getting a very different diet than if you're getting a corn-based diet.

If you're concerned about your health when you're eating beef, you should really look at grass-finished beef, because it's got very different kinds of fats. It has lots of omega-3 fatty acids, which are in short supply in the American diet, and it has a lot more minerals. Finally, it has a much happier story in terms of the animal's life. It's worth paying attention to not just where your food comes from, but what your food ate. If you've ever had eggs from chickens that got to eat grass in their life, it's a completely different food: The yolks are bright orange, they're much more flavorful, and as it turns out, they're more nutritious. They have more beta carotene and more omega-3 fatty acids.

OR: You also suggest focusing more on leaves rather than seeds.

MP: Leaves are very important to both our health and the health of animals. Even if you don't eat leaves yourself, and you eat lots of meat, well then eat some leaf eaters and you will be better off. We don't think of leaves as a place to get fats, but in fact you do get omega-3 fatty acids and you get lots of vitamins and antioxidants. Leaves are in the business of collecting solar energy, and that process produces oxygen. The plants need antioxidants to protect themselves from all that oxygen.

Over time, we have moved from a diet with lots of leaves to a diet that's based on seeds. Seeds are very nutritious: they're plant storage devices, so they're very rich and contain lots of stable fats that have a long shelf life. That's the omega-6 fatty acids. We need to correct the balance and get more leaves in our diets and less seeds. Basically, if you limit the seeds in your diet -- and again, I'm not saying eliminate them -- because they're very important and they're really tasty, but if you rebalance toward the leaf side, you're going to find that it will contribute to your health. You're going to get a lot of good nutrients that way. The antioxidants generally aren't in the seeds as much as they are in the leaves, because the seeds are not participating in photosynthesis.

OR: There has been a whole revolution in fake meat soy products. Reading the book definitely gave me a new perspective on soy in terms of how healthy it really is and how much of it are we eating in our diet without consciously being aware of it.

MP: I have a couple basic principles about food, and one is to diversify our diet. We are omnivores. We need to eat a great many different nutrients -- between 50 and a hundred are the estimates that I've seen. Yet, we're really getting most of our calories from four plants, and soy is one of them. Twenty percent of the American diet comes from soy or soy oil. I think that that's putting all your eggs in one basket.

There are two ways to process soy products: There are traditional ways of processing, such as when you ferment and make tofu, and these have been proven to keep populations healthy and alive for a long time. But we have some very novel ways of processing soy. We're isolating the protein and using soy isoflavone as an additive. These are novel and untested, and there is science to suggest that you might not want to eat too much of that. I don't know that we've found real harms, but there are questions.

Soy isoflavones, and soy products in general, closely resemble estrogen in the body. It isn't really clear whether that's a good or bad thing. They may be fooling the estrogen receptors into thinking they're estrogen and blocking estrogen response, which might be a good thing, or they may be acting like estrogen and doing what estrogen does, which would be a bad thing because estrogen promotes certain cancers. There are way too many estrogen compounds already circulating in our bodies, because we get it from plastics and other things. So going crazy over soy might not be such a wonderful idea.

In general, I have more confidence in the traditional ways of processing soy than the new ways. Novelty in biology is guilty until proven innocent. Mutations are novelties, and every now and then there's a great mutation that confers an advantage on the creature. But 99 out of 100 mutations are disasters. So when we come up with a completely new way of using a food, combining a food or processing a food, I'd just as soon watch some other people eat it for a couple hundred years before I try it.