Is Paleo just another fad diet? If you follow an ancestral approach to dieting of one kind or another, the answer is probably a resounding, no. But, what about those who are curious about paleo, or those who have heard very little about it?
Eating paleo -and other ancestral approaches to dieting- has become increasingly popular in the last few years, and those who have benefited from eating paleo have been its best promoters. Because the paleo diet has been so successful, it has also garnered its fair share of critics. Paleo criticism has hit a fever pitch this year, and the misinformation that results from this criticism can influence peoples perception of paleo in a negative way.
Recently there was an article in Scientific American that kept with trend of creating a version of paleo, and then proceeding to debunk it. There was also three separate papers that had numerous paleo critics grasping at straws and rejoicing in the light of new scientific revelations that our human ancestors ate grass! A few months before these more recent events, Marlene Zuk’s Paleofantasy rolled off the shelves, creating quite a stir. However, none of this is to be outdone by Christina Warinners Ted Talk at the beginning of the year.
The paleo genie is out of the bottle, and it ain’t going back in! We’ve reached a tipping point. Too many individuals have had success with paleo for it to be whisked away by the proponents of conventional dietary wisdom.
All of the positive health results people have achieved by eating paleo, otherwise known as anecdotal evidence, is increasing paleo’s awareness among healthcare professionals. And, whether they like it or not, the results merit their attention.
So, what about these critiques?
Loren Cordain wrote a great paper concerning the three papers I mentioned earlier. I will use some of his general points to address those who claim there is scientific evidence that our human ancestors ate grass. I’ll then address Christina Warinners Ted Talk.
Most of these criticisms are the same. Essentially, a version of the paleo diet is created by the critic, then the created version is debunked. At no time, however, are the benefits of eating paleo refuted or taken to task. They are creating, as Robb Wolf said, their own “Paleo Fantasy”.
Three papers published recently measured carbon isotopes in our hominid ancestors and found that the presence of particular isotopes represented a change in the diet of our ancestors. The papers show that our human ancestors either began to eat grass, or eat animals that ate grass about 2.5 million years ago.
Cereal grains are essentially grass, so I can see why many felt the urge to be prompt in letting us know that grass has been a big part of the human diet all along.
The problem is that there really isn’t any scientific evidence which supports human grass consumption as a dietary staple until about 10,000 years ago, and as Dr. Cordain points out in his response, there is plenty of scientific evidence that suggests that humans were eating the animals that ate grass, not the grass itself.
Dr. Cordain notes that interpreting these papers in ways that suggests humans began consuming grass as part of their diet 2.5 million years ago presents a number of “logical shortcomings”, and here are a few of those:
- The point at which humans supposedly began to eat grass coincides with “the earliest known use of stone tools to cut flesh from animal carcasses and to extract morrow from their bones.”
- the “human gastrointestinal tract is only about 60% of that expected for a similar-sized primate. Consequently, the increase in brain size that occurred in hominins starting 2.5 million years ago was balanced by an almost identical reduction in the size of the gastrointestinal tract.”
- Larger brains “are attributed to an improvement in dietary quality that occurred largely as a result of increased consumption of animal foods…”
- A diet with more animal foods naturally “contains less structural plant parts and more animal material…”
- “Grass leaves and seeds maintain a low dietary quality, and are high in fiber and cellulose and are indigestible in their raw, unprocessed state in modern humans.”
- “All great apes (chimps, gorillas, orangutans, and gibbons) living in their natural environment” show a reliance on fruits and leafy vegetation, not grass.
- “All vertebrates lack the enzyme cellulase which is required to breakdown cellulose and hemicellulose found in grass leaves and seeds…”
Much of plant nutrition simply can’t be assimilated by humans, and with the loss of much of our digestive tract over our evolutionary history, the task of fermentation has played less of a role in the digestion of plant foods, which highly suggests that we replaced a significant amount of our calories from plants with calories from animal products.
However, many paleo detractors won’t see eating paleo as anything other than a fad diet any time soon. In February of this year Christina Warinner gave a Ted Talk titled “Debunking the Paleo Diet.” Like the other critics, Warinner doesn’t provide many reasons why we shouldn’t eat paleo (Fresh meats, fruits, and vegetables) in her presentation, but she is highly critical of the “Paleo Fantasy” she creates.
Christina Warinner is a researcher at the University of Oklahoma as well as the University of Zurich, and she has a Ph.D in Anthropology from Harvard University. If you’ve seen her Ted Talk, you may be annoyed by the rudimentary presentation, and clearly this Ted Talk received its share of snickers and giggles. But, whenever a person of Warinners stature gives a presentation using a well respected forum like Ted, it must be taken seriously, and I feel obligated to address it now, if only briefly.
Warinner uses the first two minutes of her presentation promoting a visceral bias toward things unrelated to “debunking paleo.” She starts off by referring to the paleo diet as “one of Americas fastest growing diet fads.” Then she begins to debunk her very own “Paleo Fantasy.”
First the visceral qualifiers: The paleo diet “seems targeted at men” and it calls for us to “eat lots of red meat”! Interpretation: The paleo diet is sexist and promotes eating that red meat we all know will kill us.
She then states that, “now that we know the paleo diet is sexist, we can talk about the science”…No! I’m kidding, she didn’t say that. But, she didn’t have to.
No where does she provide evidence that the paleo diet is sexist, nor any evidence that those that eat paleo are predominately male. As Robb Wolf points out, a Google search for “paleo diet before and after” brings up images that are not only a good mix of males and females, but may even have more females than males. This evidence is anecdotal, but it’s more evidence than Warinner provides.
While I love and champion red meat, I’ve rarely heard red meat being championed any more or less than other meats in the paleo community. Nor could I find any evidence for this in publications.
Warinner piggybacks her “red meat” qualifier with an example of how fatty red meat is today, and how our ancestors would have eaten leaner meats. That’s certainly true, but what makes the red meat of today, particularly beef, more fatty than the red meat our ancestors ate? The answer is grains. The same thing that has been fattening humans is also fattening our livestock, but that shouldn’t come as a surprise, after all, there is a reason for the term “cornfed”.
Stating that feedlot beef isn’t the beef of yesteryear hardly begins to debunk the paleo diet.
However, it’s important to keep in mind what’s being debunked here, and that’s Warinner’s very own “Paleo Fantasy”:
Myth #1: Humans evolved to eat meat
According to Warinner, this is not true. Why? Because, we lost our ability to make our own vitamin C, which means plants are our only source for vitamin C. We also have larger digestive tracts than carnivores, which suggests we didn’t evolve to eat meat.
However, virtually all primates share the vitamin C trait with humans, and this trait existed millions of years before humans started eating meat. We also require very little vitamin C to build collagen and prevent scurvy, it’s not like we have to sit around eating plants all day so we can get enough vitamin C.
Also, we are not carnivores, we are omnivores, so while our digestive tracts are larger than that of carnivores, that doesn’t mean we didn’t evolve to eat meat. The human digestive system, from the mouth to the other end, resembles that of carnivores more than it does a herbivores.
Myth #2: Paleolithic peoples did not eat whole grains and legumes
According to Warinner, we ate grains as early as 30,000 years ago, well before the 10,000 year marker paleo eaters put forth.
Evidence for grain consumption 30,000 years ago is fresh science. But, nowhere does it suggest that humans ate grains as a large part of their diet. Clearly the earliest evidence for grain consumption as a dietary staple is 10,000 years ago. Moreover, grains are an inferior nutritional source to fresh meat, fruits, and vegetables.
Myth #3: Paleo diet foods are what our paleolithic ancestors ate
Warinner states that most fruits, vegetables, and even the meats we eat are mostly from domesticated versions, and these versions wouldn’t have been what paleolithic humans would have ate. They would have eaten much more fibrous and bitter tasting fruits and vegetables.
Just because our foods are domesticated dosen’t make them less desirable compared to other foods that aren’t paleo, so this does little to debunk the paleo diet. In fact, it does just the opposite in my opinion.
When Warinner pointed out to the audience that brocoli, kale, cabbage, cauliflower, and brussel sprouts, were all domesticated, and that none of them were available to our paleolithic ancestors, she got quite a shock from the audience, and a snicker from me. To me, the audience reaction was a clear sign of their preconceived notions. Many of them probably believe that a plant based diet is the optimal human diet, and just assumed that humans had been eating things like kale, cabbage, and brocoli since the beginning. Warinner also states that the plant foods we put on our plates often come from different parts of the world, and most paleolithic people would never have eaten them together, if at all.
Warinner accurately gives examples of how seedy and tasteless the plant foods of old were. All of this is true, but does that mean we should go back and eat those types of foods? Could we even do that if we wanted to? Who knows? What is clear though, is that the plant life of old was different, not only was it less tasty and more fibrous, but it also contained more antinutrients
After hearing myth #3, I thought to myself: “She just told the audience how difficult it would have been for humans to eat a plant based diet in the paleolithic.” Of course, this point most likely didn’t take with most of the audience, who were filling up their preconceived notion bowls with all of the red meat the speaker was throwing their way (pun intended).
Warinner also took time during myth #3 to remind her audience that the paleo diet is a fad diet. She didn’t want her audience to forget it, and I don’t want you to forget that’s what she calls it!
Warinner goes on to make the observation that paleolithic peoples who lived in different parts of the world ate different foods in different macronutrient ratios. Which was a relief to me, because I was sure that the audience thought that paleolithic humans just got their food from the grocery store.
Nonetheless, amongst studied hunter-gatherers, where animal food is laking, fatty animals tend to be treasured. And, where animal food is abundant, fatty animals tend to be treasured. Be it pork in papua or caribou in the Arctic, fatty animals are the foods of choice.
Through most of the world the plants we eat are seasonal, but something eats virtually everything, and what we can’t eat, another animal most likely can, and in doing so they turn the food we can’t eat into the protein and fat we can.
At the end of her Ted Talk, Warinner states that “we evolved to eat fresh foods”, a point upon which I couldn’t agree with her more, and a point that inspired me to grill up a fresh t-bone!