I suspected my post about the real Inuit diet would draw a few howls online, and I was right. There are people in the low-carb world I think of as vegans-in-reverse: instead of insisting that humans aren’t designed to eat meat, nobody actually needs meat, and eating any kind of meat is bad for you, they insist that humans aren’t designed to eat plants, nobody actually needs any plant foods, and eating any kind of plant food is bad for you.
If you’re on all-meat diet and it’s working for you, great. But it’s one thing to say an all-meat diet works for you and quite another to insist that our paleo ancestors didn’t eat plants and therefore nobody – absolutely NOBODY, you understand – needs any plant foods to be healthy. When I commented on Facebook that many plants provide micronutrients we need to be healthy, someone even labeled it as an excuse to eat carbs.
An excuse to eat carbs? Seriously? We don’t need an “excuse” to eat whole, unprocessed plant foods that contain carbohydrates any more than we need an “excuse” to eat meat. That’s what I mean by the vegan-in-reverse mentality: in the eyes of some people, eating any plant foods at all is apparently a moral failure. Give me a break.
Short of building a time machine and zipping on back to paleo times, I don’t suppose we can prove what paleo humans ate or didn’t eat. But I’m convinced Paleo Man included plants in his diet. Here are a few reasons:
Our nearest relatives
Humans share about 99% of our DNA with chimpanzees. We’re not directly descended from them, but according to the genome project, we almost certainly split off from a common ancestor. Vegans like to insist that chimps are vegetarians, and therefore we should be vegetarians too. That’s wrong, of course. Chimps hunt and eat meat. But they’re still omnivores who get most of their calories from plant foods.
Eating meat allowed us to develop bigger brains and become human. But I find it difficult to believe that after evolving from plant-eating apes, we rejected plant foods entirely once we became proficient hunters, and then suddenly started eating plants again 15,000 years ago. It seems a wee bit more logical to assume we added meat to a diet that continued to include plants.
More than 200 hunter-gatherer societies were discovered and studied in relatively modern times. These were people who hadn’t previously been exposed to civilization and were living a stone-age lifestyle. They all ate meat or fish or both. They also gathered and ate plants – even the Inuit ate certain plants when they could find them.
According to Loren Cordain’s studies, carbohydrates made up 20% to 40% of the diet in most hunter-gatherer societies. Good luck doing that eating nothing but meat. So once again, I find it more than a little difficult to believe that Paleo Man ate no plants whatsoever, but people living essentially a paleo lifestyle in modern times did.
Yes, yes, yes, I can hear the reply in cyberspace already: yeah, but humans only ate plants when they hunted the big game to extinction and ran short of meat!
Sorry, but that is simply not true.
As I’ve mentioned before, I was fascinated with Native Americans for years and read a ton of books about them. I still read one now and then. A book I read a couple of years ago described how the buffalo-hunting Sioux would get together with their Eastern cousins and trade buffalo meat and hides for foods like pumpkins and squash.
If you’re trading away meat for squash, it means you want the squash. It’s not a meat-shortage survival strategy. Until the “civilized” buffalo-hunters came along and nearly wiped out the herds, there were a shootload of buffalo living on the Great Plains. I doubt the Sioux ever ran short of meat. I’ve also read that the buffalo-hunting Sioux ate wild berries, spinach, turnips and potatoes. No meat shortage, and yet they ate plant foods.
One reader on Facebook suggested I watch a speech by Dr. Mike Eades, claiming it provides slam-dunk evidence that early humans lived on an all-meat diet. So I watched the speech, which was excellent, of course. But the evidence Dr. Eades presented (much of which focused on analysis of stable isotopes) only proves that early humans ate a heck of a lot of meat, both from herbivores and carnivores. It proves they were top-level hunters. It doesn’t prove – and wasn’t intended to prove – that they stopped eating plants.
In fact, in one section of the speech, Dr. Eades talked about a study of Native American skeletons found in Kentucky. One group of skeletons came from hunters who lived nearly 3,500 years ago – 3,000 years before Europeans showed up. Another group of skeletons came from agriculturalists who lived 1,500 years ago and ate a lot of maize. The hunters were healthier in all kinds of ways – watch the speech if you’re interested. But what struck me was this slide:
The hunters ate a variety of meats, but also gathered and ate grapes, acorns, blackberries, sunflowers and hickory nuts. Again, I sincerely doubt they only gathered those foods when they ran short of meat, because I doubt they ever ran out of meat.
Kentucky and Tennessee have similar weather and terrain. Even with the encroachment of civilization, we have plenty of deer and other animals tromping around our area year-round. Heck, we hit a deer recently while driving home. Lots of people around here end up with damaged vehicles because of deer collisions. Just this week, Chareva spotted three deer carcasses along the highway near our home. And as you know if you read my farm-report posts, there’s no shortage of raccoons around here.
In Good Calories, Bad Calories, Gary Taubes describes how early European explorers described much of the planet as a “paradise for hunting,” with large and small game present in almost unimaginable numbers. I’m pretty sure that applied to the dense forest that’s now Kentucky. The Native American hunters in that area didn’t eat grapes and blackberries because they ran out of meat. They ate them because of …
Our taste buds
If you’ve seen Fat Head, you may remember this line: Mother Nature isn’t stupid. She didn’t make human beings the only species on earth who prefers foods that will kill us.
The whole idea behind paleo diets is that we have to eat the kinds of foods that Nature, through evolution, designed us to eat. We put it this way in the Fat Head Kids book:
The Nautilus was programmed to choose the right fuels and building materials automatically. Inside the FUD hatch, special sensors send messages to The Brain that say This is what the ship needs. You experience those messages as This Tastes Good.
When humans hunted and gathered their food, this app worked perfectly. Our taste for sweets told us to eat fruits and sweet-tasting vegetables like carrots and squashes. Our taste for fats told us to eat olives, nuts, eggs and meats. Our taste for salts told us to eat meats and seafood. Our taste for spices told us to eat plants that were full of vitamins and minerals.
Those are the flavors we naturally seek: sweet, fatty, salty and spicy. Good luck finding sweet and spicy flavors in an all-animal-foods diet. We like sweet and spicy foods because in a natural environment (not a processed-food environment), those tastes lead to us foods that provide micronutrients.
Here’s a slide from a lecture by Chris Kresser on the nutrient density of foods:
Yup, meats – especially organ meats – are nutrient-dense, which is why we should eat them. But please notice that herbs, spices, nuts and seeds are more nutrient-dense than beef, seafood and wild game. Many vegetables are more nutrient-dense than pork, eggs and poultry.
When I mentioned our natural desire for sweet and spicy foods, a reader on Facebook retorted with something along the lines of, Well, we only like fruits and other sweet foods now because we bred them over the centuries to be bigger and sweeter than they were in paleo times.
So let’s think about this …. you’re Paleo Man, supposedly a pure carnivore with no inborn desire for sweet foods. And yet you decide to breed fruit to contain even more of a flavor you don’t naturally like. How does that make any sense?
Humans don’t eat tree bark because it’s not a natural food for us and therefore doesn’t have a flavor we naturally enjoy. Would we start eating (and perhaps over-eating) tree bark if someone bred trees that grew really, really big and chewy bark? I’m pretty sure we wouldn’t. We bred animals to be fatter because we naturally love the taste of fat, and we bred fruit to be sweeter because we naturally like sweet foods.
Yes, the makers of processed foods have hijacked our taste for sweet foods to sell us donuts, candies, sodas, Pop-Tarts, Frosted Flakes, Twizzlers, gummy bears and countless other junk. But you can’t hijack a desire that doesn’t already exist.
My cat is an actual carnivore. He wouldn’t touch a donut if I offered it to him. Heck, even though he loves meat, he won’t touch spicy meats like pepperoni. Why? BECAUSE HE’S AN ACTUAL CARNIVORE. His brain tells him not to bother with sweet or spicy flavors, which come from plants.
Someone pointed out that his cat will eat dry cat food made from grains. Yup, so will mine. But only because the food-taste scientists managed make grain-based cat food appeal to a carnivore’s taste buds. If you don’t believe me, take a bite of some dry cat food. I promise it won’t taste sweet or spicy. You could fill my cat’s plate with bananas, berries, potatoes, bread sticks, tomatoes and broccoli drizzled with butter and he wouldn’t eat any of it. He wouldn’t eat gummy bears either, even though they’re super-sweet. Once again, you can’t hijack a desire that doesn’t already exist.
If Nature designed humans to be pure carnivores, we wouldn’t like sweet and spicy foods. And yet we do. And therefore it makes no sense to insist that paleo humans wouldn’t have gathered and eaten plant foods that were available, tasted good, and provided nutrients.
The AMY1 gene
All humans carry the AMY1 gene, which enables our bodies to digest starch. Some people have just one copy of the gene, while others carry up to 15 copies. The average among humans is six copies, whereas the average among chimpanzees is two. If we share a common ancestor with chimps, but then evolved into our human form on plant-free diets, why the heck would most humans carry more copies of the starch-eating gene than chimps, who live mostly on plant foods? That makes no sense.
Research strongly suggests that people with fewer copies of the AMY1 gene are more likely to have blood-sugar problems and gain weight on a starchy diet. Fair enough. That’s evidence that some of us have to limit our intake of starches. But if we’re all descended from paleo ancestors who lived on meat-only diets, there’s no logical reason we’d carry the AMY1 gene at all – and certainly no reason for some people to carry 15 copies.
If the reply is something like Well, humans probably only started carrying more copies of the AMY1 gene after we started farming, then it means our bodies were reprogrammed rather dramatically in the past 15,000 years. The whole idea behind paleo, of course, is that we’re virtually the same as our paleo ancestors and therefore need to eat like them.
Can’t have it both ways. Biologically, we’re either nearly identical to our paleo ancestors, or we’re not. If we are, then Paleo Man carried the genes to digest starch. If we’re not, then what Paleo Man did or didn’t eat doesn’t matter all that much.
The effects of zero-carb diets
Some people do well on zero-carb diets. But other people don’t. They get the symptoms Paul Jaminet described in his Perfect Health Diet book. They get dry eyes. Their thyroids slow down. Their cortisol levels go up. Their production of sex hormones declines.
I didn’t read the back-and-forth debate between Jaminet and Dr. Ron Rosedale on safe starches until a few years ago, but when I did read it, I found Jaminet’s arguments more convincing.
Rosedale, for example, doesn’t deny that a glucose deficiency can slow down the thyroid, but offered this explanation:
Glucose scarcity (deficiency may be a misnomer) elicits an evolutionary response to perceived low fuel availability. This results in a shift in genetic expression to allow that organism to better survive the perceived famine…. As part of this genetic expression, and as part and parcel of nature’s mechanism to allow the maintenance of health and actually reduce the rate of aging, certain events will take place as seen in caloric restricted animals. These include a reduction in serum glucose, insulin, leptin, and free T3. The reduction in free T3 is of great benefit, reducing temperature, metabolic damage and decreasing catabolism.
So yes, your thyroid may slow down, but Rosedale insists that’s good for longevity. Hmmm. If you’re struggling to lose that last 50 pounds, a “healthy” slower thyroid isn’t going to help. Neither is the reduction in leptin. Losing weight requires being in a catabolic state, so you can guess what “decreasing catabolism” means as far as weight loss.
As for the reduction in sex hormones, Rosedale replied with this:
If we evolved in a certain way and with certain physiologic responses to the way we eat, it was not for a long, healthy, post-reproductive lifespan. It was for reproductive success. The two are not at all synonymous, in fact often antagonistic.
Just roll that one around in your brain for a minute. Rosedale doesn’t deny that your sex hormones will decline, but insists it’s a worthwhile tradeoff for longevity. Jaminet does a good job of disputing that lower-is-always-better when it comes to glucose and longevity, but that’s not the point. If long-term, drastic restriction of glucose doesn’t support “reproductive success,” it can’t be the diet that allowed us to win the game called Survival of The Fittest.
If we’re all descended from and virtually identical to paleo ancestors who lived on all-meat diets, then almost nobody would suffer ill effects from a zero-carb diet – which, of course, is what an all-meat diet is. And yet many people don’t do well at all on a diet that includes no plants and no carbohydrates.
That’s because their paleo ancestors ate plants and at least some carbohydrates. Jumping up and down and insisting that anyone who doesn’t feel awesome and healthy on all-meat diet just isn’t doing it right! is thinking and acting like a vegan-in-reverse. That doesn’t help the cause.
Now if you’ll excuse me, I’m about to go enjoy a dinner of beef, broccoli and roasted squash with onions … but if you happen to have any buffalo meat, I’ll trade you some squash for it.