Today I bring you another post by the remarkable “Duck Dodgers.” It’s part overview of the current state of the anthropological science in terms of hunter-gatherer diets, part critique of the current state of the low-carbohydrate Paleo fantasy that refuses to keep up with said advances in scientific understanding. In typical Duck style, he does his homework, so this is heavily referenced—posts from this blog (some of which he wrote), articles, and the scientific literature. I hope you don’t skip over them.
Over the past year we discovered early hominids ate a raw, sweet and starchy sedge tuber that is more nutrient-dense than red meat. We dug up evidence of starch consumption during the peak of the ice age. We detected starch granules all over the hand tools of North American Paleo-Indians—including granules from the same sedge tubers found all over the African savanna. We found that even the most carnivorous indigenous cultures consumed sufficient levels of carbohydrates and were not in ketosis, when fed their native diet. We learned that VLC advocates developed a false diabetes while being unable to reproduce the diet of the carnivorous cultures that they championed. And, we learned that fermentable carbohydrates are essential for our health and our microbiome.
And just this past month, National Geographic—you know, the magazine that spends each issue examining the latest research on cultures and ancient anthropology—ridiculed the notion of a highly-carnivorous Paleolithic Diet. Times have certainly changed.
Despite all this new knowledge, the old-guard VLC advocates are still promoting their outdated theories. Case in point, Nora Gedgaudas in a recent podcast with Jimmy Moore:
Nora: To me, what our ancestors relied on as the most consistently available food sources throughout our evolutionary history, has to be a starting place, when we’re trying to evaluate what’s essential to us now…All the research in paleo early on, almost all of it, started out in support of a very low carbohydrate approach. Because that was really the only rational way to see it.
Ah, to live in a simpler time when people still thought that our ancestors sat around and only ate fatty slabs of meat all day. Apparently the high fat/low carb advocates haven’t noticed that if you open your mouth and look in the mirror, you will find that—unlike a carnivore—Homo Sapiens evolved with omnivorous dental features. At no point in evolutionary history has the dental morphology of hominids ever presented as highly carnivorous. In fact, the canine teeth of hominids have only gotten shorter over the course of evolutionary history, and even the earliest hominids had canine teeth that were shorter than those of living apes and chimpanzees.
Interestingly, the saliva of true carnivorous animals do not contain digestive enzymes. Since liberating their proteolytic (protein-digesting) enzymes in the mouth would induce autodigestion (damaging the oral cavity), carnivores do not mix their food with saliva—they simply swallow huge chunks of meat. As you might guess, we omnivores tend to do things a little differently. Our mouths and throats are much smaller. We masticate and we evolved to liberate salivary amylase—a carbohydrate-digesting enzyme in our saliva. If we don’t masticate well enough, we tend to choke.
Keep in mind that our carbohydrate-degrading enzymes are secreted into every bite we take, even when we are only eating meat. In fact, you are secreting salivary amylase 24 hours a day, seven days a week until the day you die.
So, did our ancestors purposefully shun the nutrient-dense starchy tubers that were all over the African savanna? It’s highly unlikely given their high nutrient density, extremely easy harvesting, their year round availability and long-term shelf life. They were invasive too, with a single tuber able to produce 2,000 plants and 7,000 tubers in a single growing season. No hunting spears or tools were required to eat them—just a human-like grip to dislodge the tubers, by pulling up on the blades of grass, and an omnivorous mouth with a few molars for mastication. Easy peasy.
And, in fact, the clear lack of carnivorous dental morphology, combined with the isotopic signatures discovered across a wide range of hominid fossils, has now led anthropologists to believe that early hominids were thriving on these starchy sedge tubers.
Given all these clues, it should come as no surprise that—as National Geographic pointed out last month—virtually all of the documented indigenous cultures and hunter-gatherer societies across the planet have relied heavily on plants and carbohydrates.
Anyhow, back to the show!
Nora: …But, somehow, you know, people…like…carbs. They like sugar. And they want to be able to believe that they can enjoy these things. They want to be able to rationalize that idea that these are somehow good for them in some way or another. And it’s really, really hard to, ummm, you know it’s become very PC to say, “well…you know, it’s ok. As long as it’s real food, it’s ok.
Jimmy: And they make up problems with very low carb diets that aren’t true.
Nora: Exactly. Right like, ‘This is going to destroy your thyroid.’ That’s a real gem.
If we can look past Nora and Jimmy’s outright dismissal of any potential for health issues from a VLC diet, you have to wonder where Nora thinks the universal human desire for craving sweetness ever evolved from, if we supposedly shunned carbohydrates while we evolved as humans. She seems completely mystified.
Does she think this natural desire for sweet tastes is some flaw in our evolution? We “somehow” evolved liking carbs. We “somehow” evolved with omnivorous dental morphology and continuous salivary amylase secretion. We “somehow” have highly-sensitive tastebuds for sensing sweets on our tongues with strong cravings for carbohydrates after supposedly evolving for millions of years eating buckets of fatty meat?
There’s a tremendous irony in having a discussion of human evolution while telling people to completely ignore their own anatomical features and universally-innate cravings.
Skipping ahead a bit…
Nora: There’s also the whole issue that a lot of people just really, what they think they’re doing as a ketogenic approach may not be. We both know of instances, it’s very easy to underestimate the amount of carbohydrates you’re getting. It’s very easy to underestimate the amount of protein you’re consuming. Or to over… yeah, to underestimate the amount of protein you’re consuming.
Jimmy: Or assuming that you’re ketogenic just because you’re low carb, without really testing to see where you are.
The thought of our Paleolithic ancestors avoiding all of the invasive energy-positive plants around them and having to test their blood and urine in order to stay in ketosis is just too hysterical for words. I can just imagine the diorama at the Natural History Museum showing cavemen stressing and obsessing about their ketone levels.
You can see where this is going. They want you to believe that people will only have problems on low carb diets if they aren’t in ketosis.
And sure enough…
Jimmy: Nora, I have a theory why people feel better when they added carbohydrate back into their diet when they do a quote-unquote ketogenic diet…
Nora: Opiate centers?
Jimmy: Well, obviously that’s part of it. But, I think they haven’t fully gotten ketogenic. They’re stuck between a low carb and a ketogenic diet and they’re not really keto-adapted.
Nora: Yes, I actually agree with you and I had the same thought myself and I ran it past Ron Rosedale and I was thinking it occurred to me that a lot of people who failed on an Atkins diet early on, for instance, might have failed because they never really did stop relying on sugar as their primary source of fuel.
Nora: They were deriving it from the excess protein consumption, which is less carbs certainly, than they were getting before, but at the same time still carbohydrate dependence. And that makes it really dicey…
Jimmy: Still a sugar burner.
Nora: Right, still a sugar burner. And therefore, more likely to experience carbohydrate cravings as a result of that, if they’re not eating regularly enough. You can go longer on a more protein-based diet. But it’s still not a ketogenic approach. And high fat, and high protein, still does not ketogenic make. And that’s the rub.
And there we go.
Did you catch the massive flaw in their logic? If you consistently fall out of ketosis—whether it be from accidentally eating too much protein, or from consuming a few starchy tubers, and not eating regularly enough—you are likely to feel worse, and you’ll burn sugar, crave carbohydrates and then feel better as you eat more carbohydrates. At this point, the listener should be left wondering how our ancestors—who obviously couldn’t test their ketone levels—didn’t just start craving more carbohydrates whenever they executed ketosis incorrectly and then concluded that consuming more carbohydrates made them feel better.
Let’s keep listening…
Nora: It helps to reinforce what’s already kind of an addictive predisposition. Or an addictive tendency, I should say. I don’t think we’re at all predisposed to rely on carbohydrates as our primary source of fuel. We’re actually born in a state of ketosis. We’re born to rely on fat as our primary source of fuel. We would not have the brains we have were it not for the enormous amount of fat that we consumed in our evolutionary history. When we had access to more of it. When we were hunting the great big megafauna. The Pleistocene megafauna. Umm.. you know, once they died out, we had comparatively leaner animals to hunt. Umm, and but fat was always even among more Neolithic societies fat has always been coveted and central to our umm.. to our tastes and was always considered probably the most important dietary inclusion. Certainly Weston Price found that consistently, that those were the sacred foods among every society that he studied no matter how different they were. Umm.. most sacred foods among all cultures were fat-based foods.
Nora: Milk is fundamentally a very high carbohydrate food…
Let’s recap. Humans are born in ketosis but grow with substantial amounts of carbohydrate (39%) from their mother’s milk. Supposedly, as adults, we evolved over millions of years only eating lots of fatty megafauna all day and somehow stayed in ketosis all the time (forget that virtually no anthropologists actually believe this and the latest data doesn’t support it). At some point in our life span, we should naturally come to the realization to begin shunning those tasty carbohydrates and only crave lots of fat, but not too much protein. And we should have no desire to eat sweets with the caveat that those who consistently fall out of ketosis will likely feel worse and crave more carbohydrates to feel better. And we also simultaneously evolved with the ability to develop an “addictive tendency” toward carbohydrates when we fall out of ketosis, thanks to those darn “opiate centers”.
So, now we are all left wondering how billions of our ancestors made this perfectly-engineered transition from a child who is carbohydrate-adapted to an adult that is expected to ignore their innate cravings for sweets when anything slightly off a ketogenic diet causes our brains to reinforce its own desire for carbohydrates.
No, no.. Don’t think too hard about it people! Ignore that natural desire in you for carbohydrates. It’s just the devil on your shoulder—a miswiring of the brain. You have to fight those instinctual tendencies. It’s simply a design flaw that you’re supposed to know to resist for your entire adult life.
Incidentally, 50 years ago, Norman Jolliffe’s “Prudent Diet” only furthered to scare Americans into believing that animal fats were the cause of all their health problems. Jimmy and Nora worked hard to undo those fears, and they sensibly cited our innate craving for fat as a reason for adding animal fats back into Western diets. However, in a strange twist of fate, they are now the ones scaring people into believing that an entire macronutrient is the root of all their health problems—despite everyone’s obvious cravings for it. Nevermind that nearly all hunter-gatherer societies and indigenous cultures thrived on whole foods carbohydrates. Indeed, VLC is the new “Prudent Diet”—simply replacing animal fats with carbohydrates and blood cholesterol with blood glucose. The message from 50 years ago is the very same message Jimmy and Nora are telling us today: ignore your own tastebuds and your cravings for “optimal” health.
Duck Disclaimer: I do not discount that ketogenic diets are therapeutic for some health conditions. However, I do not believe that we should be persuaded by VLC advocates that ketogenic diets are “optimal” based on their shoddy interpretation of a Paleolithic diet that is widely rejected by anthropologists and deviates from the overwhelming majority of documented hunter-gatherer societies.