The Five Failings of Paleo

Unless you’ve been living under a 24 Hour Fitness, you’ve probably noticed that this whole Paleo thing is blowing up in a big way.

From the New York Times to ABC Nightline and the Atlantic to Dr. Oz, eating like a caveman has never been more in the public eye, and it shows no sign of slowing down any time soon.

The good news is that meat and eggs are back on the table. The bad news is that, like many other diets, highly-processed stuff is out, as well as less-refined foods such as grains, legumes, and (sometimes) dairy.

I hopped onto the Paleo bandwagon several years ago, before it really started to take off. (As both a health nut and a scientist, it was inevitable that I’d eventually research the diet that humans evolved eating.)

I expected to find something resembling a raw vegan diet based on readings I had done previously when I was a vegetarian, but what I found instead was pro-meat and the easiest diet I had ever followed. It also gave me the best results as far as my health and fitness were concerned. Suffice it to say I am a BIG Paleo fan, and predict it will keep growing for the foreseeable future.

But I’ve got some beefs with it–as I do with every other diet–and it’s time to get a few things off my chest.

Arguments That Hold No Water

First off, there’s a couple of objections that often come up when debating the health merits of replicating our ancestors’s diet:

Cavemen died at 30 years old. Our modern diet allows us to live much longer. Food was scarce for our ancestors. They had to burn a lot of calories to get relatively low-calorie food.

I’ve addressed both of these claims elsewhere on this site, but here’s a brief refresher.

The idea that our caveman forebears died at a much earlier age than us is undeniable. But of the millions (or billions?) of things that have changed in our lives since then, why give all the credit to diet?

It is far more likely that the unbelievable advances in medicine and medical care are the major causes of our dramatically increased lifespans. Before this technology was available what today are everyday injuries and illnesses would prove fatal… or worse!

And among modern hunter-gatherers, we see that the average lifespan is brought down by factors such as infant mortality, and that those who are lucky enough to avoid the injuries and illnesses so easily cured by modern medicine live to an old age without the “inevitable” mental and physical decline we now take for granted.

That we evolved under mainly famine conditions is a “just-so story” that has no scientific merit. The idea of living off the land horrifies most inhabitants of industrialized societies, which is where this idea originates from. Again, when we look at modern hunter-gatherers, we see that they spend far less time getting food each week than most of us spend at our day jobs.

Humans, like all successful species, have had to weather famine conditions at one point or another. But if this were to have been a permanent environment, we would have either gone extinct or adapted to a different food source. That’s how the brute force of evolution works.

Instead, we are adapted to both times of famine and times of plenty. To claim otherwise would mean that we are an outlier in this sense from the animal kingdom, and would require supporting evidence that is simply not there.

But enough with the lame criticisms of Paleo, let’s move on to the REAL problems.

Fail #1: We Don’t REALLY Know What Our Ancestors Ate

By studying the unique characteristics of the human body, modern hunter-gatherers, and our closest primate relatives, we can figure out with a high degree of accuracy what the diet of our ancestors prior to the advent of agriculture was.

In short, we are best adapted to run on two sources of fuel:

Animal Fat Plant Starches

Prehistoric humans almost certainly ate a diet high in meat and vegetables, with some eggs, fruit, nuts, and seeds when available. And this is, in basic terms, the kind of diet I think most of us should eat.

But when it comes down to it, we can’t know with 100% accuracy how we ate. We have yet to find a magic phone booth that will transfer us back through time–Bill and Ted notwithstanding–to directly observe how our great-times-450-grandparents lived. Yes, we’ve found animal bones with knife scrape marks on them, and fossilized poop with plant matter, but we’ll never be able to go all National Geographic and directly study our caveman forebears in detail.

Although we clearly couldn’t have eaten dairy, grains, and legumes in large volumes, there is plenty of evidence that some of our ancestors consumed a little bit. It’s hard to believe that they disposed of the mammary glands of female aurochs when modern tribes such as the Hadza characteristically make use of every last bit of the animal.

A recent study has even suggested that we were grinding flour up to 30,000 years ago! (Shock! Horror!)

And if all that wasn’t enough, even if we knew exactly what we ate back then, most of those species of animals and plants likely no longer exist today. They have all almost certainly either:

Gone extinct, or

Drastically changed as the result of domestication.

We might have a pretty good idea of how our ancestors ate, but not a good enough idea to say that all people would be better off if they avoided grains, legumes, and dairy completely. It’s much better to test these types of food out on yourself to see how you do before you decide to completely avoid them.

Fail #2: There Is No ONE Paleo Diet

By the time the Paleolithic era had ended, about 10,000 years ago, humans had already spread across the entire planet. With the exception of some very hard-to-get-to places, we were hanging out everywhere from the frigid arctic to the sweltering tropics and from coastal areas to remote mountaintops.

There is no ONE diet, with strict macronutrient ratios and lists of things not to eat, that could have conceivably sustained the human population at this point. Instead, we would have had to learn how to thrive in environments with vastly different food sources. Some of us would have eaten hardly any plants during our lifetimes, while others would have rarely tasted meat.

Focusing solely on the Paleolithic to analyze the optimal human diet is more than a little bit arbitrary, and is likely to be the result of marketing efforts just as much as science.

Most modern anthropologists agree that the earliest primates ate primarily fruits and insects. The first “true humans” (Homo Habbilis) then started scavenging meat, which allowed us to start standing upright and grow the massive brains that now consume 20% of our energy.

There is no one magic diet for humans.Throughout the history of our species, we have proved ourselves remarkably adept omnivores, thriving off a wide variety of foods.

Fail #3: Yes, We HAVE Evolved Since the Paleolithic

One of the basic tenets of Paleo diets is that our genome is optimally designed to a nomadic hunter-gatherer lifestyle, and that evolution moves so slow that it has not been able to evolve to suit our modern environments.

As it turns out, recent scientific evidence suggests that, not only have we been evolving since the advent of agriculture, we are doing so at a rate that is about 100 times greater than during the Paleolithic!

This can be most evident in the physical characteristics of different races. Humans scattered all over the globe and slowly evolved to suit their environments better, and we can now see the vast physical differences that characterize us. For example, those of us who remained in the tropics kept the dark skin that would prevent sunburn while those of us that moved to cooler destinations got paler skin that could more easily synthesize vitamin D from limited sunlight.

One well-studied phenomenon is the pattern of lactose tolerance. Most mammals lose the enzyme necessary to break down the sugar in milk as they grow up, but there is a minority of humans that still produce this enzyme their entire life and are able to consume dairy with no major issues. These people are almost invariably descended from people in chillier climates, where dairy would have been a crucial form of food due to the lack of vegetation.

Although we are very much a product of preagricultural evolutionary forces, the rapid evolution that has occurred since then should not be ignored. From the standpoint of diet, it suggests that many of us, depending on our ethnic roots, should expect to handle the Neolithic foods of dairy, grains, and legumes much more effectively than others.

Fail #4: What Is Natural Is Not Necessarily Optimal

The argument known as the Naturalistic Fallacy states that it is illogical to claim that something is good or right just because it is natural.

In other words, just because we probably didn’t consume very much dairy, grains, and legumes during the bulk of our evolution doesn’t mean they are inherently unhealthy for us.

Similarly, just because we didn’t eat frozen pizza, microwave mac and cheese, and White Castle burgers during our evolution doesn’t mean they are inherently unhealthy to us!

Note that the opposite is not necessarily true. This doesn’t prove that these types of foods ARE inherently healthy. It just means that you need to draw your conclusions from different sources.

It makes a ton of intuitive sense that foods new to our diet are detrimental to our health. But from a scientific perspective, this observation is only the first part of the scientific method: formulating a hypothesis that must then be tested.

Fail #5: Nutritionism Is a Horrible Basis For a Healthy Diet

Perhaps the biggest threat facing Paleo today, the one most likely to get it thrown into the “fad diet bin” by most people, is the insistence of most of its practitioners to justify it on the basis of nutritionism.

In the late 90’s and early 00’s, the Paleo diet was a low-carb, low-fat, and high-protein diet. This has been lovingly labeled the “Faileo” diet by many today due to the incredible difficulty of eating little more than salads and chicken breasts (not to mention the silliness of thinking that our ancestors actually ate like this.)

More recently, Paleo shook off the low-fat title and went strictly low-carb. This is the version of the diet most followed during its current explosion. It has been popularly dubbed as the second coming of Atkins and has been criticized on the same points.

The hypothesis that a traditional diet of meat, vegetables, fruit, eggs, nuts, and seeds causes us to be more healthy and fit meshes perfectly with all observations, but it still needs to be tested in order to meet strict scientific scrutiny.

I hate to break it to you, but our ancestors didn’t eat a strict low-carb diet. The power of Paleo comes from focusing on food quality rather than food quantity.

Most diets attempt to earn their authority by demonizing some nutrient(s) while holding other nutrient(s) up on a pedestal, all the while quoting different scientific studies they claim support their hypothesis. So you’ve got low-carb/high-fat diets, high-fat/low-carb diets, high-polyunsaturated fat/low-saturated fat diets and just about every other combination you can think of. This nutritionism may be a great way to cause a sensation and sell books, but it is a horrible way to create and defend a good diet.

As I have bemoaned before, nutritionism is a very young science and as a result many (if not most) of the findings are inherently flawed and will eventually be superceded by more accurate information. This is similar to how early astronomy viewed the Earth as the center of the world until more rigorous testing found that it orbited the sun, which was a part of the Milky Way Galaxy, which is a tiny part in a much larger universe.

Just as you shouldn’t let observations be the only basis for how you eat, you shouldn’t let scientific studies either. These two things are ultimately most beneficial for separating the wheat from the chaff and doing the most important thing of all: testing things out on yourself to see what works. You should always try things out for yourself–for at least 28 days–to give yourself the best idea of what you should and shouldn’t do in regards to your health and fitness.

The Future of Paleo

So where do I see Paleo going in the future? To be honest, I think it hasn’t even started to peak yet. It seems to be popping up in the media more and more, and lots of regular folk (i.e. non-health nuts) are giving it a shot each and every day.

I see more and more mainstream media attention coming in the future. The bulk of the articles so far have simply derided it for its emphasis on meat, to point and make laugh at the “modern cavemen,” or to compare it disparagingly to the Atkins diet. As more and more people succeed with it, you can expect the media’s view to shift from “look at these silly cavemen killing themselves with arterycloggingsaturatedfat” to “holy hell, look how healthy these people are despite not eating healthywholegrains!”

People will start capitalizing off of it. The bookstores will become flooded with crappy Paleo books (as opposed to the small handful of excellent ones currently available). You’ll see Paleo microwave dinners and supplements start creeping in. But after a certain point the wave will crest and it will no longer be the big thing.

But it won’t die out completely. Like vegetarianism, Paleo is a diet that will be around for a LONG time if for no other reason than that it is fundamentally based on much more than a scattering of half-assed scientific studies.

At the end of the day, I think Paleo is the most intelligent and effective diet that has ever been advocated. Focusing on the types of food that our ancestors evolved on is an excellent hack to making health and fitness as automatic as possible.

On the other hand, I don’t think we should be too hasty to outright hate on all grains, legumes, and dairy products. Although they are far from essential parts of our diet, I think they can still have their place if you go about it intelligently. (Hint: 7-11 servings per day is craziness for almost everyone!)

Although I agree that our modern diet is to blame for the wave of obesity and other diseases of civilization, I think it’s far more likely to be the result of such things as sugar, flour, and highly-processed vegetable oils–the things that NO ONE has eaten in large amounts until relatively recently.

And so, most of the criticism leveled at Paleo-style diets are completely asinine and based on really bad science. Which is not to say that Paleo is above the fray. There are some failings in the ways that Paleo is commonly practiced and justified, but these things likely won’t stop its momentum.

We’re definitely entering the age of Paleo, and despite its problems, I couldn’t be happier.