The Paleo Diet
Diets come, and diets go. And like fashion, if you wait long enough, what is now out will eventually return -- but with a twist, so you can't dust off the old books, but instead have to buy new ones. And when you think about it, that only makes sense. After all, food really falls into one of only three groups: proteins, fats, and carbohydrates. So all diets are pretty much restricted to mixing things up within those three groups -- thus the repetition. Ahh, but given those limitations, there is still infinite variety -- thus the ever new diet programs.
And now it is the turn of the Paleo Diet (also known as the Paleolithic Diet, or Caveman Diet) to sweep the nation. In fact, the Baseline of Health Foundation has been literally bombarded with requests for me to explore the topic over the last several months. But in truth, it's not actually new. It was first popularized by Walter Voegtlin in the 1970's and is close cousin to the Atkins diet and the Meat Lovers Diets that rose to popularity about ten years ago. And in truth, there is much to like in the diet, but also some things that give me pause and a couple of "are you kidding me's" along the way.
With that in mind, let's take a look at the Paleo Diet.
The theory behind the Paleo Diet
As I mentioned, the Paleo Diet has its roots in Walter Voegtlin's book, The Stone Age Diet, which was published in the mid 70's. Originally, it was referred to as the caveman diet, or the stone age diet. "Paleolithic," by the way, is just the scientific term for "old stone age." The theory is that without access to modern diets, cavemen ate more naturally than we do today. They didn't eat Twinkies® and chips and Big Macs®. They were hunter-gatherers and ate as the human body was designed to eat…theoretically. They had no agriculture, no storage facilities, no grocery stores, and no processed foods. They ate wild plants and fresh meat as they found it.
And they were healthy…again, so the theory goes. There was no arthritis, no cancer, no osteoporosis, and no heart disease. They were strong-boned, hearty and healthy, and if they died young, it was not because of disease but because of accidents and a hard environment. Otherwise, they were all veritable Methuselahs. And although there are few remains of cavemen to verify the claims, there are a couple of small studies that do indeed show health benefits for those who follow the diet. But mostly there are testimonials. Now please understand, I do not make light of testimonials. I find them potentially as valid as many so-called scientific studies. However, I am quite aware of how testimonials can be ruled by emotion and run totally out of control, totally invalidating themselves. Another problem is that when giving testimonials, people tend to generalize their experiences -- if I feel better because of it, then everyone in the world will feel better. That said, the primary argument on behalf of the Paleo Diet is that there are select populations living in the world today that have followed the Paleolithic diet for generations and show none of the signs of modern disease…maybe. [Incidentally, new evidence has come to light that non-farming, prehistoric people who ate the paleo hunter/gatherer diet were not necessarily free of diseases such as arthritis and artherosclereosis. Ed.]
For about 30 years, the Paleo Diet struggled along, taking a back seat to the Atkins Diet®, the Blood Type Diet, the Nutritional Type Diet, Jenny Craig®, Nutrisystem®, the Hollywood Diet®, Volumetrics®, the Mediterranean Diet, the South Beach Diet®, the Carb Lovers Diet, and on and on. It was not until 2005 that the Paleo Diet came into its own, with the publication of Loren Cordain's The Paleo Diet for Athletes: A Nutritional Formula for Peak Athletic Performance. With athletes beginning to endorse the diet, it gained momentum, hitting the big time in 2010, with the publication of Cordain's next book, The Paleo Diet and Rob Wolf's book, The Paleo Solution.
So what exactly does the Paleo Diet advocate, and is it as good as claimed?
The tenets of the Paleo Diet
The primary tenet of the Paleo Diet is that diets and health started to go downhill the moment agriculture started to gain traction. Farming, the foods it produces, and food processing -- which are the cornerstones of the modern diet -- are the enemies of health. If you want to be healthy, you have to eat the diet your body was designed for -- the diet that cavemen ate, the diet that is natural to man. Of course, what that diet actually is, is open to question. It's not as if Grog the caveman left behind cookbooks. Cave paintings, yes! Cookbooks, no! And of course, the diet has to make do with certain "alternatives" since fresh, grass-fed mammoth meat is no longer available for the killing right down the street.
To summarize, the Paleo Diet is based on what we "think" cavemen ate, based on some historical data and studies of modern-day hunter-gatherers, as well as trace evidence found in archeological digs and a whole lot of guess work and theory. And since true caveman foods are no longer available to us, it is also based on modern food "equivalents" that have been refined over centuries and that are commonly available in today's supermarkets. That means that, for the most part, the meat you eat comes from domesticated animals raised using modern mass production methods, even if grass-fed, and the so called "forage" that you eat is based on cultivated hybrids nurtured on artificial fertilizers and possibly pesticides.
But that's only part of the story. The Paleo Diet is defined as much by what you cannot eat, as by what you can eat. Or more specifically, the philosophy behind the diet is that you are only allowed to eat what was "natural" to the human diet during the Paleolithic era, not the "artificial" foods that have been added to the diet since then as a result of the agricultural revolution and the introduction of urbanization and mass manufacturing. That means that all crops that only became viable parts of the diet because of the agricultural revolution (grains, beans, and peanuts, for example) and the byproducts of domesticated livestock (i.e., dairy) are taboo. Sugar is not allowed. And alcoholic beverages and fermented foods are also off the table. Incidentally, I find this particularly amusing since alcoholic beverages and fermented foods seem to have been part of man's diet since the beginning of time. As Bob Dylan once sang, "Everybody must get stoned." But forget about cavemen, as it turns out, the consumption of alcoholic over-ripe fruit for the purpose of getting blitzed predates even the first cavemen and is common to many species. See for yourself how animals find ways to "party hearty" without a brewmaster in the bunch.
I think it's pretty much safe to say that if Paleolithic men and women abstained from alcohol, they would have been pretty much alone in the practice -- which brings up an interesting contradiction in the Paleolithic diet. If cave-people ate fermented foods, and yet you choose to exclude those foods from the Paleo Diet, which is supposed to be based on what they ate, then you've opened up a fundamental hole in the logic behind the diet. But there's no need to dwell on that now.
One problem we face when looking at the Paleo Diet is that there are multiple versions of it among its many adherents. For example, some insist on organic, grass-fed beef, others barely mention it. Some say no oils are allowed. Others say low omega 6/high omega 3 oils such as canola oil are okay. And others disagree as to which fruits and vegetables are allowed. This brings up a second fundamental problem when discussing the Paleo Diet, with so many variations, what exactly is it? But in general, here is a list of the do's and don'ts of the Paleo Diet.
No grains, beans, potatoes, or dairy
This is numero uno! As the theory goes, for millions of years, humans and their relatives ate meat, fish, poultry, and the leaves, roots, and fruits of many plants. That was their natural diet, and that was their sole diet. Grains, beans, and potatoes were not eaten because uncooked, they are inedible -- in fact, according to the theory, they are toxic if eaten raw. (We'll get back to this later, because it's actually not quite true.)
Around 10,000 years ago, two things happened that changed the way we eat. First, humans learned that they could eat the three demon foods -- grains, beans, and potatoes -- as long as they are thoroughly cooked. Cooking destroys "most" of the toxins that made them inedible. "Most" is the important word here for Paleo's. In any event, these discoveries changed the course of history. No longer did people have to chase animals across the plains and scavenge for roots and berries in harsh winter landscapes. Now they could grow food, store it in granaries for times of famine, and have a source of abundant calories in a stable environment. In addition, they could start raising herds of animals and introduce dairy products into the diet. Once the hunt for food was no longer the driving factor in life, people could devote themselves to the things that make for civilization: science, the arts, building cities, gangsta rap, and war. This is the point in history that divides Paleolithic man from modern man (or so the theory goes).
Unfortunately, according to the Paleo diet, our bodies are not designed to handle these "new foods." We're not genetically equipped to handle a diet heavy in grains, legumes, and potatoes. And the development of the culinary arts has only exacerbated the problem by introducing salt and sugar to our diets. And now, with the introduction of artificial flavors and colors, preservatives, pesticides, excipients, and whatnot, it is more than our bodies can handle. Chronic illness and obesity are the inevitable result.
So what do grains, beans, potatoes, and dairy have in common that makes them so unhealthy that we have been unable to adapt to them over the last 10,000 years? Two things according to the theory: enzyme blockers and lectins. Plants use enzyme blockers to stop plant seeds from sprouting prematurely. And lectins are natural pesticides used by plants to defend against bacteria, insects, worms, rodents, and other pests that threaten their existence. And when you think about it, from the plants' POV, humans are just another pest that threatens their existence -- and thus lectins, defend against people too. Theoretically then, plant lectins are harmful to people. As for dairy, milk contains lectins because the cows eat foods that contain them -- and so they are passed on in the milk. I know that the Paleo banishing of milk will certainly draw the ire of the raw milk aficionados who regularly write into the Foundation espousing the virtues of raw milk -- most of which I acknowledge. But I find that complaint secondary to the fact that lectins are present in meat for the same reason they're present in dairy -- because the cattle eat them as part of their diet. So if you can't have dairy for that reason, how does meat get a free pass? In any case, this argument is somewhat specious since every living thing has defense mechanisms to protect itself from being devoured by predators large and small. For example, humans have immune systems (and antibiotics of their own creation) to defend against bacteria. How can anything "eat" those defenses, figuratively speaking? Because, quite simply, species are constantly adapting to be able to overcome other species' defenses and so use them for food. It is the way of life. But let's not dwell on the negatives; let's move on.
Since lectins are so fundamental to the Paleo Diet, let's explore them in a little more detail. Incidentally, this is not the first time I've explored lectins in some detail. Back in 2007, I discussed the validity of the Blood Type Diet, in which lectins play a prominent role in its theoretical underpinnings -- much as with the Paleo Diet.
Lectins are carbohydrate-binding proteins that are found in most plants, particularly grains, potatoes, and beans. The problem is that some lectins ape the glycoproteins on red blood cells, thus triggering immune reactions in sensitive individuals. And yes, there is no question that different foods definitely have high allergy potential for many people, but the problem appears to be less with the lectins, than with the ability of the digestive tract to fully break down the proteins in the food. And beyond that, lectins are not exclusive to plants. All foods contain lectins. Not all are harmful. Some are actually beneficial. In animals, lectins serve a number of biological functions, from the control of protein levels in the blood to removing harmful glycoproteins from the circulatory system to recognizing carbohydrates that are found exclusively on certain pathogens and thus targeting them for elimination.
For example, guava lectin may be useful in the prevention of E. coli infection of the gut.1 Even better, some studies have shown that lectins can neutralize cancer cells. Soy and peanut lectins appear to be particularly good in this regard.2
But not all lectins are good. Curiously, soy and peanut lectins, which may target cancer cells, are also among the most allergenic lectins in nature. One lectin with an especially bad rep that has been much in the news over the last few years is gluten. Like most lectins, gluten is resistant to stomach acid and digestive enzymes and does not break down easily in the gut. Once in the gut, it may attach to the intestinal wall and damage its lining. Gluten has been implicated in a whole range of intestinal diseases such as irritable bowel syndrome, colitis, Crohn's, and of course, Celiac-Sprue. More specifically, gluten, in those susceptible, can break down the surface of the small intestine, stripping it of mucus and causing the gut to leak -- allowing undigested proteins to pass into the bloodstream.
According to some proponents of the Paleo Diet, lectins may also play a role in diabetes by tricking cells into thinking they've been stimulated by insulin and also by causing the beta cells of the pancreas to release insulin. Yet other lectins may play a role in rheumatoid arthritis by attaching to cell surfaces and tricking the immune system into thinking that cells are actually pathogens, thus triggering the immune system to attack the body -- an autoimmune response. And to be sure, there is no question that certain foods definitely have high allergy potential for many people, but the problem appears to be less with the lectins, than with the ability of the digestive tract to fully break down the proteins in the food. As I've discussed in several newsletters, the use of digestive enzymes with meals and proteolytic enzymes between meals can often help reduce food allergies dramatically. In fact, there is little evidence that lectins, other than a handful of exceptions, present a problem for most people.
To conclude our discussion of lectins, let me offer some perspective. If the argument is that because "some" lectins are toxic to "some" people, then "all" people should avoid "all" lectins, we have a problem. We live in a world where food exists as part of a chain, with predators eating prey – and the prey develops defenses to protect itself from being eaten. Lectins are part of the circle of life and can’t be avoided; they permeate the food chain as predator eats prey. This means that if you wish to avoid all lectins, you would have to avoid all food, since all food contains lectins. To do otherwise implies selective belief in your theory. At least the Blood Type Diet acknowledges this issue and says that at least some groups of people have adapted to eating grains, beans, potatoes, and dairy.
So what should we eat on the Paleo Diet?
Meat (particularly organ meats such as liver and kidneys), poultry, and fish top the list. Remember, we're talking about "hunter" gatherers. In fact, according to some proponents, flesh should provide upwards of 65% of the calories in a Paleo Diet, with fruits and vegetables providing only about 35%. Eggs are also big on the diet.
Fruits and vegetables
Fruit and root vegetables such as carrots, turnips, and beets are okay, but not tubers such as potatoes, sweet potatoes, and yams. Incidentally, I find the exclusion of tubers requires a bit of theoretical bending. The argument is that potatoes are a "new world" crop and humans have only been eating them for maybe the last 35,000 years. But in truth, yams are an African crop that people have been eating since the dawn of time. So why are they excluded? And if that's your logic for excluding potatoes, then why is turkey okay? After all, turkey is a "new world" species, not even introduced into Europe until the 16th Century. Not that I personally think it matters, but I'm just saying.
As for fruits, berries of all kinds are good -- strawberries, blueberries, and raspberries etc. are good. From there, differences in Paleo's abound. Tree fruits are controversial. For example, some say apples are great. Others call them "bags of sugar." And still others say they're okay if you eat the low sugar varieties. And yet, if the theory is based on eating what hunter-gathers ate, then tree fruits would have to be top of the charts. Not to go Biblical, but I think it's pretty safe to say that tree fruits such as apples and pomegranates have been part of the human diet since the very first man and woman walked the earth. And I don't believe hunter gatherers selected their fruit based on the glycemic index. Again, I'm just saying.
Also, fruits contain lectins3 -- just like grains. Apricots, bananas, cherries, kiwis, melons, papayas, peaches, pineapples, plums, and even berries are all known to contain lectins and cause allergies. In fact, fruit allergies make up about 10 percent of all food related allergies. So why are fruits allowed? Incidentally, new research has shown that allergies to fruit are actually made possible by pectin, the soluble fiber found in fruit. The pectin surrounds the fruit allergens in the digestive tract so that they don't get broken down and enter the bloodstream intact. Using a digestive enzyme supplement that contains added pectinase can help moderate that problem by breaking down the fruit pectin, which then exposes the allergens to digestive juices and enzymes.
Nuts and legumes
Curiously, nuts are cool on the diet -- pretty much all nuts except cashews and peanuts, which are actually beans. Yes, I understand that people have eaten gathered nuts since the beginning of the human race, but if allergenic lectins are your thing, nuts should be a "no no." Tree nuts including macadamia nuts, brazil nuts, almonds, walnuts, pecans, pistachios, chestnuts, hazelnuts, and pine nuts are high in allergenic lectins. And unlike grain allergies, which tend to be low level and chronic, tree nut allergies tend to be severe, and are strongly associated with anaphylaxis and even death. Walnuts (and cashews) top the list for the tree nuts most likely to cause an allergic reaction. Peanuts, incidentally, are legumes, which is why they are on the Paleo no-no list. As legumes, they are biologically unrelated to tree nuts; nevertheless, there is a high level of cross-allergenic reactivity between peanuts and tree nuts. So again, if peanuts are not allowed, why are tree nuts okay? I'm just looking for consistency in the theory behind the Paleo Diet and its application in the real world.
Another factor to consider is that tree nuts have the same enzyme blockers that seeds and grains have, and for the same reason -- to prevent premature sprouting. And like seeds, grains, and legumes, those enzymes are neutralized by soaking in water and exposure to heat. But that goes against the premise behind the Paleo Diet. So once again, we have to ask, "Why nuts?"
Incidentally, sprouting nuts will eliminate most of the blocking enzymes as well as many of the allergenic lectins.
Legumes, or beans, present much the same problem. They have blocking enzymes to prevent premature sprouting and toxins to keep predators away. Soaking and cooking will pretty much eliminate that problem, but because they have to be cooked, they violate the "Paleolithic theory" of no cooking and so are not allowed.
Are you kidding me?
I find the theory behind the Paleo Diet to be somewhat distorting of facts and highly inconsistent within its own logic. We've discussed a number of those inconsistencies already and will explore several more in a moment. However, it is important to keep in mind that just because an underlying theory may be wrong does not mean that the program itself is without value. For example, at one time, people believed that the sun was a golden chariot driven by a god that crossed the sky -- a theory that many scientists now believe to be flawed. Nevertheless, belief in that flawed theory didn't stop ancient peoples from being able to track the sun so accurately that they could determine the vernal equinoxes to the day hundreds of years in advance -- knowledge essential for agricultural societies. So once again, let me state that theory aside, the Paleo Diet has much to recommend it. But before we go there, let's examine a few more of the theoretical inconsistencies.
Location, location, location
The assumed diet of the hunter-gatherers modeled by the Paleo's is reflective of cave people living in Northern Europe in cold climes where plants did not readily grow. But the simple truth is that hunter-gatherer societies in other locations ate decidedly different diets. As Katharine Milton points out in an editorial in the American Journal of Clinical Nutrition:
"The !Kung might live in conditions close to the "ideal" hunting and gathering environment. What do the !Kung eat? Animal foods are estimated to contribute 33% and plant foods 67% of their daily energy intakes. Fifty percent (by wt) of their plant-based diet comes from the mongongo nut, which is available throughout the year in massive quantities. Similarly, the hunter-gatherer Hadza of Tanzania consume "the bulk of their diet" as wild plants, although they live in an area with an exceptional abundance of game animals and refer to themselves as hunters."4
And it's not just modern examples of hunter-gatherer tribes. There is solid evidence that suggests that Paleolithic peoples commonly ate grain, and even flour, as far back as 30,000 years ago.5 In fact, there is quite reasonable evidence that people were processing cereal grains for food as much as 200,000 years ago.6 The bottom line is that the fundamental premise that Paleolithic peoples did not eat grains and that they ate large amounts of meat is only "suggested" by historical records, not necessarily supported by them.
Another example is salt. Salt is a taboo in most Paleo Diets, and yet the evidence is that the people of the Lenggong Valley in Malaysia were not only eating salt 200,000 years ago, but had created tools for grinding it. And animals will eat/lick salt whenever they find it. Virtually all animals consume it. Salt is actually an interesting test for the Paleo Diet. Animals eat it. Cavemen ate it. And yet, it's taboo in the Paleo Diet. Obviously, the Paleo Dieters' faith in their ancestors' food choices only goes so far. And in this case, It appears they bought into a "golden chariot" theory. I wrote several years ago (and appeared on numerous radio shows) trying to tell people that the case against salt was largely misguided. And on May 4th 2011, the Journal of the American Medical Association published the results of a study corroborating that position.7 Stunningly, the study found that participants with the lowest salt intake had the highest rate of death from heart disease during the follow up (4 percent), and people who ate the most salt had the lowest (less than 1 percent). In the case of salt, cavemen really did know better; unfortunately, advocates of the Paleo diet, despite their professed belief in the caveman diet, backed the wrong horse: bad science.
Another problem I have is that just because people ate certain foods does not necessarily mean that those were the best foods to eat -- merely that those were most likely the foods that were easiest to obtain in their local environment. If you were living in Europe on the edge of a glacier, mangoes were not part of your diet, not because they were unhealthy, but because they were not readily available. On the other hand, if you grew up in the Indus valley 100,000 years ago, a vegetarian diet would have been a strong option because fruits and vegetables would have been readily available.
As anyone who has been to college knows, you don't live on pizza and beer while attending school because they are a "natural" part of your diet; you live on them because they are readily available on campus and all your friends are eating them.
To me, a much better indicator of what foods we are designed to eat is your digestive tract -- from your mouth to your anus. Animals that eat particular foods have digestive tracts designed to handle those foods. Carnivores have sharp teeth for ripping and tearing flesh, and short digestive tracts for quickly eliminating waste once digested in the stomach -- so it doesn't have time to putrefy in the intestines. (Meat putrefies.) Animals that eat plants have flat teeth for grinding and long digestive systems to allow time to extract nutrients from plant matter, which does not putrefy. Human digestive systems largely match Chimpanzees, who eat mostly fruits and nuts and termites, but will eat a small amount of monkey meat when they can get it. For more on this issue, you can check out my series examining the digestive system.
Premise of health is arbitrary
The idea that the so-called Paleo Diet is inherently healthier is simply not supported by the evidence, either ancient or modern. What is supported is that eating modern highly processed, high-glycemic foods is unhealthy. Diabetes was virtually unknown in China until people began eating the modern Western diet. But before people started eating modern diets in China, they weren't eating anything remotely close to the Paleo Diet. They were eating a largely vegetarian diet grounded in rice and noodles. For centuries, they ate grains without problems. It was the introduction of refined sugars and oils and processed fast foods "what done em in," to quote Eliza Doolittle. As a side note, although meat consumption has gone up dramatically in China, with disease rates climbing right alongside them, it's probably not the meat that's causing the problem. It's most likely all of the refined, processed, fast food that's killing them. Then again, one of the most comprehensive diet studies ever conducted, known as the China Study, touched on this issue in some detail -- coming down in favor of the vegetarian diet.
India is another example of a largely vegetarian society that had few health problems until Western civilization moved in and hooked people on the modern diet. In fact, India is now known as the diabetes capital of the world. But again, the problem isn't grains, tubers, and beans -- the almost exclusive diet of India's poor. On the contrary, it isn't until people earn enough money to move away from that diet that they are afflicted with diabetes.8
If eating meat were a prerequisite for health, then vegetarians as a group would have to be unhealthier than heavy meat eaters, and that just isn't true. Study after study has shown that vegetarians (on a good vegetarian diet) tend to be healthier. On the other hand, eating meat by itself doesn't make you unhealthy. It is quite possible to eat meat and have radiant health. As I have explained many times before, health is determined less by the vegetarian/carnivore question than by other dietary concerns. In the end, the issue of meat is less a health choice than a personal choice. That said, let's examine the issue of meat a bit more.
What meat are we talking about?
The meat promoted in the Paleo Diet is not necessarily the same as the meat that was available way back when. While it is true that some Paleo advocates advise eating only lean cuts of meat that are either hunted in the wild, or grass-fed, most do not. And in fact, most people following the diet opt for lean cuts bought in regular grocery stores -- primarily because of convenience and cost. But grocery store meat, pork, and poultry come with a wide range of "bonus" goodies not found in Paleolithic times, including:
- Growth hormones
- High pesticide concentrations
- Heavy metals
- Toxicity from over 100,000 manmade chemicals now found in the environment
- High levels of omega-6 fatty acids as a result of being grain fattened
- Not to mention the fact that cancerous and tumorous meat is not necessarily removed at the slaughterhouse, and may quite easily find its way to the butcher's shop. If you think the USDA is actively preventing sick animals from entering the food supply, think again. Unbelievable abuses have been documented happening under the very noses of USDA inspectors.
As for fish, even if you catch it yourself, you're now looking at mercury contamination, dioxin, and sex altering hormones -- things Paleo fishermen never had to deal with.
Germs in meat
And now there's something else to watch for in today's meat. Scientists from Arizona's Translational Genomics Research Institute recently announced that 47 percent of samples of beef, pork, and poultry obtained from supermarkets around the country tested positive for Staphylococcus aureus, the bacteria that causes staff infections -- and 52% of those bugs were resistant to at least three kinds of antibiotics. S. Aureus already kills about 11,000 people in the U.S. every year. Thanks to contaminated meat, we can look for that number to climb.9
Most Paleos cook their meat, even though cooking is the knock against grains -- one of those inconsistencies we try not to think too much about. Nevertheless, there is a small subset of Paleo's who believe that humans have not adapted to cooked foods, even though the evidence is that cavemen were cooking their meat almost since day one. And so this subset of Paleo's eats only foods which are both raw and early Paleolithic. Actresses such as Uma Thurman, Demi Moore, and Natalie Portman are/were believers. The concept is not without science. Cooking meat creates heterocyclic amines (HCAs), which have been linked to cancer. The higher the temperature used in cooking and the more the meat is cooked, the greater the risk. One study out of the National Cancer Institute's Division of Cancer Epidemiology and Genetics found that people who eat their beef medium-well or well-done have more than a 300% greater risk of stomach cancer than those who eat their beef rare or medium-rare.10 And yet another study linked the consumption of well-done meat to higher rates of breast cancer.11 But there's good news for diehard carnivores who love a cook-out or a tailgate party. More recent studies have confirmed that marinating meat sharply reduces the level of HCAs when you are cooking -- making it much safer. I'll bet that's something cavemen didn't know.
In any case, the evidence for when man first started cooking with fire ranges from 230,000 years ago (confirmed) to evidence at archeological sites in Spain and France that strongly indicate dates ranging from 300,000 to as many as 500,000 years ago -- with cooked rhinoceros meat on the menu.12
All in all, this brings up three conundrums.
- Since most cave people cooked their meat, eating raw meat denies the foundation of the Paleo Diet -- i.e., eating what cavemen ate.
- On the other hand, if you do cook your meat, then you're doing something potentially unhealthy, which denies the premise of the Paleo Diet -- that if cavemen did it, it's good for you.
- And when did people first start marinating meat, which makes cooked meat healthier -- something that certainly started happening after the Paleolithic era?
So after all is said and done, where do I stand on the Paleo Diet?
As I said at the outset, there is much to recommend it. I'm all for cutting back on sugar and dairy. And as for grains, I'm all for cutting way back on those too. Considering the negatives associated with the excessive consumption of grains (most notably associated with high glycemic responses and allergies), I cannot argue with the basic premise espoused in the Paleo Diet for eliminating grains altogether. On the other hand, consumption of certain grains in moderation, if selected carefully, can provide significant health benefits with little downside. For example, sprouted grains and cereal grasses have all the positives associated with grains and virtually none of the negatives. Think wheatgrass juice. And let's quickly single out barley, maybe the king of grains. It's high in beta-glucans; it's one of the least acidic grains; and it's one of the lowest of all foods on the glycemic index. And when consumed in its sprouted, pre-sprouted, or cereal grass forms, it's a monster of nutrition.
I also have a fundamental problem with the consumption of high levels of meat. All meats, fish, poultry, and eggs are acid forming in the body. When metabolized, the proteins produce sulfuric acid and phosphoric acid. And fats produce acetic acid. The way the body handles them is to neutralize them by converting them into acid salts by combining them with the minerals sodium, calcium, potassium, and magnesium. Of these, calcium is the most important.
Now, here's the key: your body uses a priority system if there are not enough available minerals to neutralize all of the acids present. After extracting what it can from urine and soft tissues (creating a rich environment for the spread of cancer), your body turns to its great mineral bank -- your bones. So, if your diet is too acid-forming, your body will fairly quickly begin to leach calcium from your bones to balance the low pH and avoid death. In effect, your body says osteoporosis is preferable to death.
And in fact, osteoporosis is seen to start earlier in "pre-contact" Inuit, who relied heavily on whale and seal meat, than in the Eskimos eating a more modern diet, "post-contact."13 Even better, Masai warriors in Africa also partake of a high meat diet and begin developing osteoporosis in their 20's. The women of the tribe do not share in the high meat diet, and do not show early signs of osteoporosis. But keep in mind, meat is by no means the sole determinant of osteoporosis, and in fact its negative effects can be easily mitigated by higher consumption of offsetting minerals such as calcium, potassium, and magnesium, and through the use of weight bearing exercise to strengthen the bones. But high meat consumption is a contributing factor.
And one last issue concerns intestinal flora. High levels of meat in the diet disrupt the balance of beneficial bacteria in the intestinal tract. First, virtually all meat, chicken, and pork that you eat (other than organic) is loaded with antibiotics, which destroy all of the beneficial bacteria in your gastrointestinal tract. But that aside, heavy consumption of meat (of any purity) significantly compromises beneficial bacteria in the colon, resulting in a 1,000 percent increase in the levels of harmful bacteria and a concomitant 90 percent drop in the levels of beneficial bacteria.
In addition, epidemiological studies done at Harvard Medical School show that, "Men who eat red meat as a main dish five or more times a week have four times the risk of colon cancer than men who eat red meat less than once a month." They are also more than twice as likely to get prostate cancer. And a recent study found that women who had more than one-and-a-half servings of red meat a day doubled their risk of hormone receptor--positive breast cancer.14 To be sure, studies such as these do not differentiate between the consumption of hormone-laced commercial beef and organic grass-fed beef, which might produce decidedly different results. But a cautionary flag has certainly been raised.
As I said, just because the theory behind the diet may be questionable, does not mean that there is not much to take from the diet. I absolutely agree with the following:
- Cut way back or eliminate all grains. And if you eat grains, opt for hypoallergenic grains that have been soaked, sprouted, or well cooked.
- Eliminate all high omega-6 store bought oils from your diet. For low temperature cooking, use olive oil and coconut oil. For high temperature cooking, use avocado oil, grape seed oil, or rice bran oil. Supplement with omega-3 fatty acids.
- Eliminate all added sugars.
- When eating fruit, lean more towards berries than tree fruit; they're higher in antioxidants. But there's no need to be afraid of eating tree fruit, which tends to be higher in soluble fiber.
- Cut back or eliminate all beans, and if you eat them, make sure you soak them before cooking, and then cook them well before eating.
- Nuts are fine if you're not allergic. Use whole fresh nuts that have been soaked/sprouted. Do not use pasteurized or "roasted" nuts -- especially those roasted in oil.
- Cut way back on white potatoes, but yams and sweet potatoes are okay in moderation.
- Eliminate all commercial dairy from your diet. And if you do opt for some dairy, choose raw dairy despite what the government says -- or at the very least opt for organic, grass-fed dairy.
- If you eat meat, use only organic, grass-fed meat. And keep consumption to less than 4 oz a day. And don't overcook it. (And here you're faced with another conundrum if you eat commercial meat. If you undercook it, you face the risk of bacterial infection (see above). If you overcook it, you face the risk of cancer (see above). If you want to eat medium rare meat, you're going to have to buy organic, grass-fed meat from a supplier you trust.)
As I said before, the Paleo Diet has much to recommend it. But then again, isn't what we've described above really just a very clean Mediterranean Diet -- light on grains, meat and dairy -- heavy on fresh vegetables, clean fish, and fruit.
Sounds good to me.
For more on diets, check out:
- 1. Peter D'Adamo. "Fruit Lectins and E. Coli." Ask Dr. D'Adamo. Eat Right for Your Type. 3 May 2011. <http://www.dadamo.com/B2blogs/blogs/index.php/2009/08/15/fruit-lectins-and-e-coli?blog=27>
- 2. Peter D'Adamo, Catherine Whitney. "Eat Right for Your Type." G.P. Putnam's Sons. 1996. P 318 <http://books.google.com/books?id=jvyMgMec6mIC&pg=PA318&lpg=PA318&dq=Soy+and+peanut+lectins +cancer&source=bl&ots=cArfgE8v2y&sig=nq3hEer1Op7IhEUrVO0zjEAXQvA&hl=en&ei=z8TATcf4O-_SiAKJo7 GuAw&sa=X&oi=book_result&ct=result& resnum=2&ved=0CB0Q6AEwAQ#v=onepage&q&f=false>
- 3. Roci´o Coutiño-Rodriguez, Pedro Hernández-Cruz, Héctor Giles-Rios. Lectins in Fruits Having Gastrointestinal Activity: Their Participation in the Hemagglutinating Property of Escherichia coli 0157:H7. Archives of Medical Research. Volume 32, Issue 4, Pages 251-257 (July 2001). <http://www.arcmedres.com/article/S0188-4409(01)00287-9/abstract#AFF1>
- 4. Katharine Milton. "Hunter-gatherer diets -- a different perspective." American Journal of Clinical Nutrition, Vol. 71, No. 3, 665-667, March 2000. <http://www.ajcn.org/content/71/3/665.full>
- 5. Anna Revedina, Biancamaria Arangurenb, Roberto Becattini, et al. "Thirty thousand-year-old evidence of plant food processing." PNAS. Published online before print October 18, 2010. <http://www.pnas.org/content/early/2010/10/08/1006993107>
- 6. Murphy, D. "People, Plants and Genes: The Story of Crops and Humanity." Oxford: Oxford University Press. 2007. <http://ukcatalogue.oup.com/product/9780199207145.do>
- 7. Katarzyna Stolarz-Skrzypek, MD, PhD, Tatiana Kuznetsova, MD, PhD, Lutgarde Thijs, MSc, et al. "Fatal and Nonfatal Outcomes, Incidence of Hypertension, and Blood Pressure Changes in Relation to Urinary Sodium Excretion." JAMA. May 4, 2011, Vol 305, No. 17, pp 1733-1824 <http://jama.ama-assn.org/content/305/17/1777.abstract>
- 8. Jason Gale. "India's Diabetes Epidemic Cuts Down Millions Who Escape Poverty." 7 November 2010. Bloomberg Markets Magazine. 3 May 2011. <http://www.bloomberg.com/news/2010-11-07/india-s-deadly-diabetes-scourge-cuts-down-millions-rising-to-middle-class.html>
- 9. "Nationwide study finds U.S. meat and poultry is widely contaminated." 15 April 2011. Translational Genomics Research Institute. 3 May 2011. <http://www.tgen.org/news/index.cfm?newsid=1948>
- 10. Ward MH, Sinha R, Heineman EF, Rothman N, et al. "Risk of adenocarcinoma of the stomach and esophagus with meat cooking method and doneness preference." Int J Cancer. 1997 Mar 28;71(1):14-9. <http://www.ncbi.nlm.nih.gov/pubmed/9096659>
- 11. Wei Zheng, Deborah R. Gustafson, Derek Moore, et al. "Well-Done Meat Intake and the Risk of Breast Cancer." JNCI J Natl Cancer Inst(1998) 90 (22): 1724-1729. <http://jnci.oxfordjournals.org/content/90/22/1724.full>
- 12. Megarry, Tim (1995) "Society in Prehistory: The Origins of Human Culture." New York: New York University Press. <>
- 13. Mazess RB and Mather W. Bone Mineral Content of North Alaskan Eskimos. AJCN (1974) 27:916-925 <www.ajcn.org/content/27/9/916.abstract>
- 14. Cho, E., W.Y. Chen, D.J. Hunter, et al. "Red Meat Intake and Risk of Breast Cancer among Premenopausal Women." Arch Intern Med166 (2006): 2253--2259. <www.ncbi.nlm.nih.gov/pubmed/17101944>