Primitive Nutrition 14:
Define "Healthful"?, Part I
Let's turn now from the theoretical justifications of Paleo to its purported health benefits.
Cordain's book contains a section that is de rigueur in diet books. A contrast is drawn between the proposed diet and the current disastrous eating habits of a lot of us in the United States. The problem with this comparison is that these awful diets, justified by cost, cravings, and convenience, are not planned for their nutritional benefits, and no one claims they are healthy, although hamburgers might find defenders among the low carbers if the bun is removed. Yes, Cordain is right that some of us are failing nutritionally. Practically any reasonable planned diet, and even some unreasonable ones like Paleo, will probably compare well to a junk food diet. Comparing your diet to a diet composed of cheap, fatty, highly marketed industrial foods is just like shooting fish in a barrel.
Cordain shows his lack of confidence in his own diet by choosing to compare it to an imaginary nightmarish incarnation of the junk food diet, which includes a danish for breakfast with coffee and sugar. To make sure the corn flakes look bad, he adds extra sugar to them, too. He wants you to remember, as you read about this slow-motion suicide diet, that the USDA wants you to eat lots of grains, implying the danish is what they have in mind. To be fair to Cordain, other grains consumed in this imaginary day come in the form of a glazed doughnut, a cheese pizza, and yes, a hamburger bun.
Somehow this imaginary worst-case-scenario diet mustered 8 grams of fiber. I guess this is what it takes to make Paleo look good, in it’s creator’s mind.
Cordain actually asserts, "Many nutritionists would say the example diet is healthful because it contains large amounts of carbohydrates." Dr Cordain, can you name a single professional nutritionist who would call a diet with only 8 grams of fiber healthful? With this absurd statement, Cordain demonstrates his total insincerity in matters of public health.
The average American is only consuming 12-18 grams of fiber, so even for the nutritionally oblivious, Cordain's comparison diet is pathetic.
Cordain has his Paleo diet reach 47 grams of fiber, and this indeed is one of its better features.
It is unimpressive, however, compared to examples of past populations. Here, it is stated that hunter gatherers had diets that were mainly fiber.
This researcher asserts that fiber often exceeded 100 grams per day.
At his Paleobiotics web site, he relates the enormous quantities of fiber that prehistoric peoples have been estimated to have consumed, along with the amazing variety of plants they enjoyed.
Funnily enough, the Paleo diet proposed by Cordain's primitive nutrition partner S Boyd Eaton in 1988 had 150 grams of fiber, well in line with these references. So why is Cordain so impressed with his 47 grams?
I should mention that there are people out there who say high fiber consumption is harmful. If you encounter advice along these lines, a little skepticism might be in order.
It seems to me the primitive nutrition promoters engage in some obvious motivated reasoning to justify their beliefs.
Here is a scholarly article Cordain wrote to construct a tenuous argument against grains. He seems concerned about the ill effects experienced by bakers who inhale flour. What if he applied a similar standard to meat?
A litany of cancers are linked to workers in poultry plants. Recall that in a previous video I showed you that zoonotic diseases increased with the advent of agriculture as animals were domesticated. This study demonstrates the cancer-causing effects of zoonotic virus infections, passed from animal to man.
These viruses are likely some of the same that cause butchers' warts.
There is also a paralyzing illness caused by contact with aerosolized pig brains.
Occupational exposure to meat is linked to lung cancer.
When you read Cordain’s concerns about baker’s asthma, you should bear in mind there is a range of illnesses associated with breathing things you shouldn’t breathe. Flour can contaminate the lungs if you breathe enough of it, just like any other airborne debris. The serious risks to those who process meats make particles of flour seem rather innocent by comparison, but Cordain doesn’t seem concerned about those.---
Cordain likes to point to a handful of human diet studies that he thinks prove how great Paleo is. In the next video, I’ll show you those.
They are disappointing, to put it mildly.
Primitive Nutrition 15:
Define "Healthful"?, Part II
Go to the Paleo Diet website and you will see that Loren Cordain references five studies as the primary evidence for the health-promoting power of his diet.
These are the same studies named in this very interesting rebuttal letter written by Cordain to US News, who found the Paleo diet unimpressive in comparison to other diets.
At last place out of 20 diets for weight loss, you can see why this was a disappointment for him. It was also last place overall.
These are actual quotes from Cordain's rebuttal.
“This comment shows just how uninformed this writer really is.”
“Once again, this statement shows the writer’s ignorance and blatant disregard for the facts.”
“Here is another example of irresponsible and biased journalism, which doesn’t let the facts speak for themselves.”
Cordain's bluster and condescension belie the strength of these studies. Let's have a look at them so we can decide who is really biased, irresponsible, and uninformed.
Before I begin, I must acknowledge the one big plus for the primitive diet idea. They advocate the consumption of vegetables, and for some proponents, fruits as well. This slide is just a token to remind you of the benefits of plant foods. Any favorable outcomes for these Paleo diet studies I attribute at least in part to the plant-based element of the diet.
Here's the first one. Amazingly, this paper from 1983, two years before the original Boyd Eaton article, is one of the studies Cordain touts as supportive of Paleo. It is simply a demonstration of the improved health of Aboriginal Australians once reintroduced to their traditional diets, after having eaten a diet that you can be sure was typical of impoverished, lower-status people. Read a bit of Aboriginal history and you'll see why that is a safe assumption. Therefore, any whole natural foods of decent quality were likely to be an improvement from their prior foods. What nutrients made the difference for them? The paper doesn't say. It does say, however, that they were only consuming 1200 calories per day, which would certainly normalize blood glucose and cholesterol. It would also guarantee weight loss. Paleo dieters should note this diet was low fat. Less dietary fat, greater physical activity, and weight loss would have virtually guaranteed improved insulin sensitivity. This is hardly a compelling argument for Cordain's diet. Normal factors such as calorie restriction and exercise explain the results here better than any magical effects from the recreation of their Paleolithic milieu.
Here is another Paleo study. The most serious weakness in this one is the small cohort - only six [***correction: fourteen, not six] subjects for whom they have data. They started with 20. It appears six of them dropped out. Next, we can see this was only a short term intervention. We don't know how these people would have fared over the long term. Also, we don't know what the comparison diet was. These people could have been eating anything before going on Paleo, so a study of this nature can't prove much. All we know is they consumed 36% fewer calories in these three weeks, which easily accounts for the improvements noted. Antioxidant status improved, no doubt due to the consumption of fruits and vegetables. Finally, the authors are up front in acknowledging the lack of a control group in this one. The contents of this article are behind a pay wall, so this is all I have to go by, but it’s still apparent that this one is hardly impressive.
The next study relies on the fish-in-a-barrel technique, as the subjects' terrible normal diets were the basis of comparison. These diets were not informed by modern nutrition science, as these folks had been consuming nearly 500 milligrams of cholesterol daily. Thanks to this dismal number, the 311 milligrams consumed on their experimental primitive diet seem pretty reasonable. This excess of dietary cholesterol, along with the 16 grams of saturated fat they consumed, is hard to avoid with animal protein intake at this level.
311 is still a high number for daily cholesterol intake. Cordain believes very low blood cholesterol concentrations are right and proper, yet this study which he touts falls far short of conventional recommendations for dietary cholesterol. It seems inferior by his own standards.
Knowing that success is defined in this study as an improvement on a diet that had almost 500 milligrams of cholesterol and 32 grams of saturated fat, I'm not sure who should be impressed with this one. Notice also the intervention diet only contained 5 fewer grams of carbohydrate. Therefore, this study hardly tells us anything on that subject. We aren’t told what the fiber content was in either diet. All we are told is fiber was increased on the Paleo diet, which was probably very easy to accomplish considering the prior diets of the sedentary, cholesterol-filled individuals used in the study.
The lack of specificity in describing the baseline diet and the lack of a control group render this study useless for drawing important conclusions. Yes, cut saturated fat and refined carbs and increase fruits and vegetables and you will see better health. Once again, there is no need for a Paleo idea to explain what happened here.
The title of this one says it all. This is a victory won on very narrow grounds. If the world was clamoring for a way to make patients with reduced blood supply to their hearts feel full from a meal sooner, we may have an answer with this one. Notice that the authors of this study, one of whom is a high-profile Paleo promoter, characterize the so-called Paleolithic diet as low-carb. Low carb is just plain bad nutrition and I'll show you why later. Also note that the claimed satiating effects of protein were not observed in this study. Also notice the pathetic 22 grams of fiber consumed, far below recommended levels. Their Mediterranean comparison diet was below recommended levels as well. This matters if you care about satiety.
Some types of dietary fiber have been shown to increase satiety.
Several types of grains have been shown to increase satiety with their fiber intact. What is often missed in the discussion of whole grains is that dietary fiber seems to have different effects when it is milled into tiny particles, as you find in most whole grain breads.
Also, carbohydrates generally have different effects on satiety depending on whether they are in solid or liquid form, with liquids being less satiating.
Maybe the authors knew this and factored this into the design of their study. You can see here that the Paleo-style diet benefited from a greater share of whole fruits and vegetables, whereas the Mediterranean diet was loaded with sweet soft drinks, sugary juice, sugary milk, and sauces. In other words, lots of less-satiating liquid carbs.
As you can see in this graphic from the film, Forks Over Knives, foods of equivalent calories expand the stomach and signal satiety differently depending on their energy density. Rob carbs of their fiber and they won’t fill you up as much. Again, we didn't need a Paleo diet idea to tell us what nutrition science already knows. There was no magic here.
We're back to patients with ischemic heart disease in our last study. Here they are investigating glucose tolerance. As you will see in my low carb videos, glucose metabolism is damaged by high-fat diets and is dramatically improved with low fat, whole food, plant-based diets. Once again, fruits and vegetables probably played a role here. Let's look at the details.
Here you see changes in body composition between the Paleo diet and what they are calling a consensus Mediterranean-like diet. It's interesting that the Mediterranean diet did a better job preserving fat-free mass. Also, notice the relative loss of water weight, common in high protein diets.
Here you see what they ate. Pretty interesting stuff. You see the Paleo diet was much lower in calories and saturated fat, which once again is adequate to explain any observed benefits. Both diets were again high in cholesterol, but it was especially high in the Paleo diet. Their so-called "consensus" diet was also much higher in glycemic load, and while it was over 70% higher in carbs, it was only 5 grams higher in fiber, telling us they were not particularly healthy carbs. Still, it bested the Paleo diet's embarrassing 21 grams of fiber. Yes, refined carbs and sweets are unhealthy. That's hardly new. So there was no Paleo solution here, either, folks. Just one bad diet doing better than another bad diet. If you are going to eat poorly, eat fewer calories. That's the message I take away from this one.
Now that you've seen these studies, I ask you, should anyone make a big deal of Paleo based on these results alone? Do you really think the Paleo diet promoters see in this a Copernican Revolution for nutrition? Or do you see people with an agenda to peddle a fad diet grasping at any thread of support they can find?
Paleo promoters seem to care about a variety of modern health afflictions. As we look at a few of them in the next section, perhaps you can see a pattern for what might really help these health challenges. The pattern is not a primitive diet.
Primitive Nutrition 16:
Define "Healthful"?, Part III
Paleo promoters say their fad diet is good for some specific health issues. Let's look at a few of them.
They seem to talk a lot about various bowel problems. If they cared about those problems more than their Paleo agenda, maybe they would draw our attention to some non-Paleo studies. Here you see that vegetarians have a much lower risk for developing diverticular disease.
Inflammatory bowel diseases are recognized to be genetic disorders yet there are dietary interventions that might combat them that are not Paleo.
Here a patient with Crohn's disease managed to avoid relapse with a semi-vegetarian diet.
Similar benefits with this plant-based approach were later observed in a group of 16 patients over two years.
On the other hand, increased intake of animal protein was the single strongest independent risk factor for Crohn's disease in this study in Japan.
Rural West African children have much healthier intestinal microbes than heavy meat eaters in Italy because of their cereal- and legume-heavy diets. It seems to me that these healthy foods from the Paleo banned foods list actually improve bowel health.
Paleo promoters also express concern about autoimmune diseases. Rheumatoid arthritis gets some mentions in The Paleo Diet book, but the findings revealed in this article are ignored. It seems the iron and fat in meat are not helpful for RA.
Changing to a diet that reduces arachidonic acid might help RA as well. Meats are high in arachidonic acid.
A vegan diet improves the composition of gut microflora, and consequently the symptoms of RA patients.
As I have shown you, Cordain has chosen to promote his hunter gatherer diet as producing a net base balance, only to have the idea taken seriously by other researchers, who reached a different judgment. Without entertaining the merits pro or con of the acid diet idea, this was a strange claim for him to make.
Here you can see that generally speaking, animal products are quite acid-producing. Egg yolks are a big offender. In comparison, many of Cordain's forbidden foods look pretty good. With white sugar registering as slightly base-producing, I think we shouldn't invest ourselves too much in this particular issue.
I'll just add here that if you care about acidity, whey protein may not be a good choice.
Vegetarianism would be a great choice, though. Now that you've seen where meats are on the acidity chart, you know why.
The more plant-based your diet, the less acid your body must eliminate.
Loren Cordain seems interested in cancer and insulin-like growth factor 1. Large amounts of refined grains are the easy target for him in this excerpt.
Cancer prevention is an interesting place to go for a diet guru promoting the consumption of lots of meat. Normally, in discussions of diet and cancer prevention, fruits and vegetables are seen as a way of neutralizing the risks associated with meats.
Doesn't Cordain know that high protein diets promote IGF-1?
Doesn't he know IGF-1 is lower in vegans?
Maybe that's one reason why highly nutrient-dense vegetarian diets are considered protective against cancer.
And it might be why animal products can be linked to some cancers.
The Paleo Diet is also sold as a solution to general metabolic dysfunction in the forms of metabolic syndrome and diabetes. But increased conformity to a plant-based diet correlates to better Body Mass Index and lower vulnerability to diabetes. The 5 unit advantage in BMI for the vegans in this study was called substantial.
This was an eight week trial with great results for diabetics eating high carb, high fiber and plant-based, which meant cereals and legumes in this one.
Studies like that are why the WHO and FAO recommend lots of fruits and vegetables, with carbs as high as 75 percent of calories and protein as low as 10 percent to control chronic disease.
Many of the foods I've mentioned that seem to promote health are on the Paleo banned foods list. I think Paleo dieters are concerned about these healthy foods because they don't understand plants. I'll try to set them straight in the next section.