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Podcast: Is There a Single Paleo Diet?

By The Paleo Diet Team
February 27, 2014
Podcast: Is There a Single Paleo Diet? image

Dr. Loren Cordain: I'm Loren Cordain, founder of the Paleo Diet Movement.

Shelley Schlender: I'm Shelley Schlender. This is the Paleo Diet Podcast for October 2014.

Loren Cordain, Paleo has become so popular. A lot of people use that term Paleo Diet for a lot of different diets. Do you have some concerns about that?

Dr. Loren Cordain: I do and I actually, I'm probably at fault. I coined the term back in 2002 and maybe we should’ve called it something else. It riles up some anthropologists. It goes under the umbrella of Paleo. I think people now realize that means Stone Age, so it riles up some anthropologists.

It has connotations to nutritionists that it's an all meat, all male, animal killing type diet. I think there's a lot of misinformation about what the actual umbrella of this concept is. I've written numerous scientific papers in which we tried to outline what is the broad umbrella of the concept.

First off, there is no single Paleo diet that our ancestors ate. They were opportunists. They ate a wide variety of wild plant and animal foods, a wide percentage of plant to animal ratios. It was dependent upon geography. It was dependent upon time. It was dependent upon season. It was dependent upon cultural biases and multiple factors.

Shelley Schlender: A wide variety of carbohydrate to fat to protein ratios as well.

Dr. Loren Cordain: It was, but there were limits in terms of the macro nutrients. What many nutritionists and anthropologists don’t recognize is that we have a physiologic protein ceiling, so we can't eat all the lean protein we want.

Shelley Schlender: Those concepts of Paleo diet is Fred Flintstone going out and eating lots of burgers. If he's healthy he eats the ones without any fat in them. You can wipe that out of your mind. That's not a Paleo diet.


Dr. Loren Cordain: We live here in Colorado and in the fall we have a deer and an elk hunting season. If you were to kill the deer and the elk in the late winter or early spring, February or March, and that was the only food that you had to eat, you would die. They're depleted of fat and they basically have only muscle tissue and maybe a tiny bit of carbohydrate and glucose in their blood and glycogen in their liver, but just an incredibly small amount.

Protein itself is actually toxic and we know this from historical studies of frontiersmen and physicians and other folks that lived in the frontiers in North America. Is that if that's all they had to eat, they were done because we can only process so much protein, so protein becomes toxic.

That physiologic protein ceiling is roughly 35 to 40% of the normal caloric intake which was call U caloric intake. If that's all you had the liver simply cannot process that much protein and the nitrogen in the protein is turned into urea.

Shelley Schlender: That's ammonia. That doesn’t sound very good to eat.

Dr. Loren Cordain: That's right, there a few modern studies done in the ‘70’s and a little bit earlier, showing that humans can't eat pure protein. We either have to dilute the protein with fat or carbohydrate.

Shelley Schlender: Just not eat too much of it. I've noticed people who go on all protein diet thinking it's healthy they often say that they have to take breath mints because they tend to have and breath. Could it be that eat so much protein that the ammonia smell gets into their breath?

Dr. Loren Cordain: We only had a single study done by Rudman’s Group dating back to the ‘70’s and that’s the only study that we know that establishes physiologic protein from a scientific prospective.


Shelley Schlender: They didn’t study halitosis as part of that, bad breath.

Dr. Loren Cordain: That was not part of it. We need further studies, but the best available evidence tells us that you can't eat pure protein. I don’t care what any body builder thinks. If I were to give you a chicken breast that has no skin on it or water packed tuna and I said that's all you can eat from now and the next 30 days.

You would be in serious shape after about three or four days. You would be hurting. I actually anecdotally have tried it. You feel awful. After about two days I couldn’t go in. it was just absurd. I just felt very, very bad. That's an anecdotal evidence, but I wanted to see for myself if there really is science to this.

The strategy then that our hunter/gatherer ancestors did is that if you’re going to eat animal food you need to selectively butcher the animals. You need to get the parts of the animal that has more fat in it.

We can go back to the very get go to the first time we start seeing humans butchering animals in East Africa two and half million years ago. One of the first things that they realized was that the long bones of all mammals they either scavenged or hunted contained marrow. Marrow is a very good source of fat.

Shelley Schlender: That long ago it could be that our ancestors were not actually hunting animals. They were scavenging what was left after the hyenas and the lions or whatever the big predators were, sabre tooth tigers, had eaten. It may be that what was in the bones was the most available food for them. It may have been the fat.

Dr. Loren Cordain: That's our bias and I've actually, our group has written at least one scientific paper on that concept that you can get at my website, The, you can download that paper.

I think we published it in 2002, so the scientific articles are organized by year and if you go to 2002 you can see that paper. Indeed, the archeologic evidence that is dug up is very much suggestive that they probably weren’t good hunters. They were primarily scavengers at that early stage.


The deflesh long bones that were available that were abandoned by hyenas and lions and leopards and what have you. Our ancestors realized that if they took those long bones and they put them on an anvil stone, a flat stone, and smacked it with another big stone they could crack open a bone, extract the marrow. They also did it to the skull. Skulls could be a lot more difficult to get into, but they eventually did it.

Shelley Schlender: After you told me this once I tried this at home with a soup bone. It's not that easy.

Dr. Loren Cordain: It's a difficult process even with modern tools like you can take a big steel hammer and put it on a flat stone. What happens, and I've tried it myself, is that the bone squishes away. You have to be dedicated, but it can be done.
The trick is to get a larger hammer stone, so don’t hit it with a one pound hammer, get yourself a ten pound hammer stone and drop it. Then, you can start to have success.

Shelley Schlender: It took our ancestors being pretty clever to be able to figure out how to get this resource, the fat inside of bones that, the big, strong animals were not able to get as quickly anyway. That’s one part of Paleo is yes there has been some meat as part of Paleo and there's also been fat from the very beginning.

Dr. Loren Cordain: Mm-hmm (affirmative).

Shelley Schlender: It's never been a low fat diet.

Dr. Loren Cordain: That's right and one of the distinctions is the average person doesn’t understand what a fat is. There's a subtlety here that we probably should address. Brain contains a lot of fatty acids, but it contains no fat. They were very much interested in eating brains.

Shelley Schlender: I'm pausing on this because having tasted things like sweetbreads. I don’t know if I've ever been brave enough to taste a brain, but it tastes kind of fatty.


Dr. Loren Cordain: That's right, it's tastes very fatty. The reason that it tastes fatty is that when you look at a fat; a fat is technically called an acyl glycerol. It's a glycerol molecule attached to a fatty acid.

Fats are triglycerides, so it's a combination of a glycerol, ol, any time you see ol at the end of a statement it means alcohol, like cholesterol. It's a fatty alcohol.

They cracked open long bones to get at marrow and marrow is a good source of fat. Marrow contains anywhere from 60 to 90% fat or acyl glycerols. Primarily it contains monounsaturated fats like what we find in olive oil and nuts and what have you. It tastes good; marrow tastes pretty good. Monounsaturates seem to taste better than saturated fats to most people.
Let's move on now to brain. They also realized that they could crack open skulls and extract brain. That was even tougher still particularly with large antelope. They have these very thick skulls and it takes quite a bit of smashing to get into the brain. They did, they endured and they figured that out.

Then, when they were eating brain, brain, as I mentioned, contains no fat or almost no fat i.e. triglycerides. It contains a lot of fatty acids in what's called the phospholipid traction. The fatty acids then are attached to a different molecule. They're not attached to a glycerol molecule only. They are attached to glycerols, but they also are attached to phospate molecules. They're what are called structural fats rather than storage fats.

Shelley Schlender: What do they taste like?

Dr. Loren Cordain: I've only had brain once or twice in my life. It needs to be cooked carefully in the Western world and we have to worry about Prion disease and what have you. Brain typically is not consumed in the Western world, but it's a very good source of fatty acids.

Shelley Schlender: Did it taste good or bad?


Dr. Loren Cordain: It's been so long I can't really remember, but it's a very rich source of omega-3 fats particularly DHA. We know that DHA is very helpful in terms of cardiovascular disease; in terms of brain function. We believe then that the best terrestrial source for DHA came from brains. We think that consumption of DHA is how humans got DHA that allowed them to build bigger brains.

Shelley Schlender: Loren Cordain, so brains were not one of your favorite meals when you had them years and years ago. From a study of health and nutrition if our ancestors ate brains as one of their foods they would've gotten really good nutrition from it.

Dr. Loren Cordain: That's right, brains are the, as I mentioned, the best terrestrial source of a fatty acid and omega-3, along chain of omega-3 fatty acid called DHA. When we think about omega-3 fats, particularly the long chain omega-3 fats, we think about EPA and DHA and we think about fatty fish as the source.

Unfortunately, the archeologic evidence shows that our ancestors were not very good fisherman, so they didn’t exploit the aquatic environment to the degree in which they were getting their DHA from fish. We believe that they were getting their primary DHA source from brains.

Shelley Schlender: That's another thing that is part of ty real Paleo diet from your perspective. Now, there are people today who would describe their Paleo diet as being one that’s got beans in it, cheese in it. What do you think?

Dr. Loren Cordain: First off, let's define what the Paleo diet really should be. I need to pin this one down because I'm the guy that coined the term. First off, let's make sure that we’re all on the same page.

None of us in the Western world can eat like our ancestral hunter/gatherers. It's impossible to eat wild plant and animal foods exclusively. We don’t have the time. We don’t have the cultural proclivity for consuming these foods.


Secondly, it's illegal. You can't kill wild animals in North America and sell them, so it's completely beyond our ability to eat exclusively like out hunter/gatherer ancestors ate.

What can we do, and this is what I've always suggested, is that we should mimic the types of food that they ate with modern foods. Let's mimic the foods and the food groups that they consumed. They didn’t consume cereal grains. They didn’t consume dairy and they didn’t consume processed foods.

They ate wild plant and animal food0s. We can easily mimic that nutritional pattern by doing our shopping in the outside aisles. When you go the supermarket, let's get our fruits and vegetables in the produce. Let's get our meats and our poultry and our eggs in that section and fish and what have you. Let's avoid the midsection where all the grains are; the mid aisles where the grains and the breads and the cookies and the processed foods are.

That's really the essence of this concept is to mimic the foods and the food groups that they ate with modern foods and avoid the foods that they didn’t eat.

Seventy percent of the calories in a typical Western and US diet come from four foods refined sugar, refined grains, refined vegetable oils and dairy products. It could be called bread, cereal, pizza, donuts, cookies, cakes, potato chips. You can call it whatever you want, but we eat those same four foods and that comprises 70% of our calories.

The major idea with this quote/unquote Paleo diet, maybe I should’ve named it something else, is to severely reduce or eliminate those types of foods and replace them with real, living foods. Replace them with fresh fruits and vegetables and meat and fish and eggs and poultry. When we do that numerous nutritional characteristics of that type of a diet improve our health and wellbeing.


Shelley Schlender: That sounds pretty delicious. Some people who say that they have a Paleo diet who are professionals advocating different kinds of health products would say that soy is part of that for a Paleo diet. You're shaking your head. Are you shaking your head because you don’t think people do that or because you wish they wouldn’t?

Dr. Loren Cordain: I'm sure that they do and there are people that are involved in the Paleo movement that advocate the consumption of those foods. If you want to draw a line in the sand what foods and food groups shaped the human genome you have to look at the development and the advent of fire?

Shelley Schlender: I was at the ancestral health conference that happened in Berkley in August. There were presenters explaining how fire began for humans and cooking things more than a million years ago.

Dr. Loren Cordain: The Devil’s always in the details and you know I don’t know if these were legitimate scientists or not. The best available evidence from scientists who are studying fire would suggest that's rubbish. Richard Wrangham at Harvard, I am completely in disagreement with him.

Shelley Schlender: When does he say that fire was used by humans?

Dr. Loren Cordain: He goes back to the very get go.

Shelley Schlender: Meaning three million years ago?

Dr. Loren Cordain: Yeah, there's a cave in South Africa where they actually have found fire. Let’s talk reality, take a reality check here. One is what's called control a fire and two is called starting fires at will.

Control of fire is completely different than starting fire at will. What is controlling fire? If you have to be near a lightning strike or a volcano you can take fire and move it around and control it.


Those are very opportunistic events. When is the last time you saw a volcano erupt here in North America? It happens very irregularly in and in a very specific geographic locale, so it's almost nonexistent.

Lightning tends to be more frequent, but here in Colorado and everywhere else in the United States we have a lightening season. The lightning season doesn’t occur in the dead of winter. It occurs primarily in the spring and the summer time.
Even here in Colorado where we have multiple lightning strikes, when was the last time you saw a strike that formed fire that you could get to without a car or a vehicle? Maybe there's a lightning strike over here in the Rocky Mountains and its 35 miles away and it starts a fire. You probably can't get to it.

If lightning occurred we could probably control the fire, but it also means that you have to keep the fire going for long, long periods, six months, a year, through the winter very difficult to do.

The next key is the voluntary ability to make a fire. Unless we have some survivalists that are listening here, I'd be willing to bet there's not a single person that will hear this broadcast that can make fire just by walking out into the wilderness. If you can start a fire I’ll give you $10,000.

Shelley Schlender: To a normal person, we’re not talking …

Dr. Loren Cordain: To a normal person, right.

Shelley Schlender: Not the survivalists.

Dr. Loren Cordain: A survivalist knows how to do it. Even if you know how to do it, even if the told you how to do it you probably can't do it because it's a very difficult. It's requires skill and patience to be able to do it. It's called a fire drill.
We think that a fire drill was probably the first way or perhaps with percussion. We don’t really know. It was either percussion or a fire drill was the way in which it was done. The best available evidence shows that in Europe when we first start to see fire about 300,000 years ago that is was control of lightning and it wasn’t produced at will.


How do we know that? Because we can look at caves where Neanderthals lived and we know the season. They suffered in these caves in the winter time with no fire. Why is that? If they had the ability to make fire they would.

Can you imagine being in France or in Germany and you're in the middle of a brutal winter and you're huddling in a cave and you don’t use fire? Why don’t you use fire? Because you can't start a fire, you don’t have the technological ability to start it. The best available evidence now suggests that Neanderthals collected fire and they certainly used it, but it was a sporadic situation.

Shelley Schlender: All right, then, Loren Cordain, you're suggesting that it wasn’t until there could be creation of fire that it couldn't be a consistent part of cooking food.

Dr. Loren Cordain: That's right and so legumes, as our cereal grains, are inedible in their raw state. We've talked about this. That is the defining line in the sand. Until you can make fire certain foods are unavailable to you. I hate to tell Richard Wrangham this is that most tubers also are inedible unless you cook them.

Shelley Schlender: Richard Wrangham is the guy at Harvard?

Dr. Loren Cordain: He's my colleague at Harvard. He's a good guy and we actually get along quite well. We just disagree on this issue.

Let me just give one more detail. How do you make fire? You make fire with a drill, a fire drill. You get a long, thin, cylindrical piece of wood.

Shelley Schlender: I finally bought one of those. I have it at home and I'm trying, as hard as I can, to make fire. Haven’t done it yet.

Dr. Loren Cordain: Yeah, it's very difficult to do and, as I mentioned, even if you have the technology and someone show you how to do it, you have to be very persistent. It takes a lot of skill to be able to do it.

The questions comes up why would you do that in the first place because if you haven’t seen it done it's not self-evident that taking a drill and doing this will produce fire. Why would you do it in the first place?

It was done accidentally. They were interested and this was done by Homo sapiens, our direct ancestors, 70,000 to 100,000 years ago. They were interested in drilling holes in objects for necklaces and ...


Shelley Schlender: They were artists.

Dr. Loren Cordain: They were artists. They were interested in putting a hole and stringing things through it and maybe making a grommet for a tent made out of animal hide or whatever.

Shelley Schlender: Okay, so they were also civil engineers.

Dr. Loren Cordain: They were civil engineers. They were interested in drilling. We see this in the archeologic record is that the first drilling doesn’t occur with Neanderthals. It occurs with our own genus, Home sapiens.

Once we start to see drilling, probably an accident, a byproduct of drilling holes through something was fire. Somebody accidently was trying to drill a hole into whatever, a piece of wood or a bone or a shell or what have you. They noticed that it got really hot. They saw smoke arising.

That's how it first happened was it was an accident of drilling holes through objects and not this genius who said, “I can make fire by drilling.” It came about as an accident and people noticed it. Even if you coach extensively a chimpanzee or a gorilla or lemur anything, they couldn’t make a fire to save their life because they simply don’t have the dexterity to do it. Obviously, didn’t have the knowledge.

What it tells us is that all Hominins prior to our own genus Homo sapiens could not make fire at will. The defining line in the sand for what a Paleo diet is is what our ancestors were able to eat, which was wild plant and animal foods that were essentially uncooked.

Shelley Schlender: All right, when did that happen? How long ago was that that humans could actually make a fire from scratch?


Dr. Loren Cordain: We really don’t know. There's a couple lines of evidence. We can look for hearths, areas in which fire was controlled. The very first hearths that we see definitively in the fossil record occur in Europe perhaps 300 to 250,000 years ago which are suggestive that the Neanderthals were the first guys that were interested in controlling fires.

As I mentioned, even though they had these hearths, and we can identify them in Europe, they suffered through winters without fire. Why would you do that? In the dead of winter, in February, in France or Germany, when it's -10 degrees why wouldn’t you build a fire? Because you don’t have the ability to start a fire in the dead of winter if you have lost that fire that you collected from lightning. In all likelihood that's probably how the whole thing worked.

Shelley Schlender: No beans.

Dr. Loren Cordain: No beans and no grains and no tubers; some tubers that they're edible in their raw state depending on their starch content and actually their anti-nutrients.

Legumes and grains and tubers, they have starch and protein that's unavailable unless it's hydrolyzed. The way you hydrolyze it is by cooking it. If you can't hydrolyze the starch then the starch is unavailable.

Shelley Schlender: Couldn’t you just soak it for a long time and let fermentation make it into something you could eat?

Dr. Loren Cordain: The starch is not broken down. It's not hydrolyzed without heat. What has to happen is the actual cell walls that contain the starch granules have to be broken down and that takes heat. Unless you have fire, those foods are inedible.
It's not just the starch that is unavailable they contain what are called anti-nutrients. The anti-nutrients have a variety of adverse effects even after cooking. These are the reproductive material of plants.

Plants don’t want to give you their reproductive material for free because if they did then they don’t reproduce. That's over the course of hundreds of thousands of years, then they become extinct. Plants have evolved these anti-nutrients to help protect their reproductive materials.

Shelley Schlender: This has been a basic part of what you’ve said a Paleo diet is for over 15 years. You think it inevitable that as more people examine this from their perspectives every now and then somebody will get to an idea that really has nothing to do with your original idea?

Dr. Loren Cordain: I'm not saying that my original idea was infallible, but I'm saying that's what the data points to. As a scientist, unless we have better data, then we need to base our hypotheses and our theories and our projections upon the data. Let the data speak for itself, forget any evangelical or charismatic individual, it should always be the data that speaks for itself.

Another element that many of these Paleo folks, and I've got to show you downstairs, I've got hundreds of these books now these copycat books that have come out, is they suggest that in the recipes you should include sea salt. They like to put sea salt in it because we have this proclivity for salt in all of pour modern processed foods.

Shelley Schlender: Let's look at that the next time we talk because I think we might want to talk about that more than a minute.

Dr. Loren Cordain: Yeah, the sea salt issue. That can go a long, long ways and so this is a topic that I haven’t written about yet, but I have collected hundreds of papers on.

Shelley Schlender: Let's talk about that next time.

Dr. Loren Cordain: We’ll talk about that later.

That's all for this edition of the Paleo Diet Podcast.

Shelley Schlender: Our theme music is by Chapman Stick soloist, Bob Culbertson.

Dr. Loren Cordain: Visit my website for past episodes and for hot links to my research studies, books and latest writings. For questions or comments the place to go is

Shelley Schlender: For the Paleo Diet Podcast I'm Shelley Schlender.

Dr. Loren Cordain: I'm Loren Cordain.


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