Have you ever thought that we need to eat animal products to be healthy, because, after all, we were designed to eat them? It’s been on my mind for quite some time to write on this topic. But, wow is it controversial!
William C. Roberts, MD responded here to the question, “Are human beings herbivores, carnivores, or omnivores?” Dr. Roberts worked at the National Institute for Health (NIH) for 30 years, and currently is a cardiac pathologist at Baylor University Medical Center. He’s been the editor-in-chief of the American College of Cardiology for several decades. His response:
“Although most of us conduct our lives as omnivores, in that we eat flesh as well as vegetables and fruits, human beings have characteristics of herbivores, not carnivores (2). The appendages of carnivores are claws; those of herbivores are hands or hooves. The teeth of carnivores are sharp; those of herbivores are mainly flat (for grinding). The intestinal tract of carnivores is short (3 times body length); that of herbivores, long (12 times body length). Body cooling of carnivores is done by panting; herbivores, by sweating. Carnivores drink fluids by lapping; herbivores, by sipping. Carnivores produce their own vitamin C, whereas herbivores obtain it from their diet. Thus, humans have characteristics of herbivores, not carnivores.”
Dr. Roberts also stated that atherosclerosis affects only herbivores, which caught my attention. “Dogs, cats, tigers, and lions can be saturated with fat and cholesterol, and atherosclerotic plaques do not develop (1, 2).” Atherosclerosis is a disease in which plaque builds up inside our arteries, and can lead to serious problems, including heart attack and stroke. Indeed, cardiovascular disease is our second leading cause of death.
If we have characteristics of herbivores and not carnivores, it sheds light on the fundamental reason we achieve healthier outcomes when we eat more plants and fewer animal products. As physician and plant-based advocate Milton Mills puts it, it’s often the missing piece in the healthy-diet conversation.
If you haven’t yet seen the investigative documentary What the Health (available on Netflix and here), you may want to check it out and see why it has caused a stir. Dr. Mills is one of many interviewed in the film. Having earned his medical degree at Stanford, he’s an internist who practises in the Washington DC area. For years he’s been drawing attention to the ways we are anatomically and physiologically closer to herbivores than carnivores or omnivores. Check out some of his comparisons:
Even if doubt remains in our mind about whether humans can physically thrive for the long term while still eating both plant and animal products, it’s my perspective that our herbivorous characteristics help explain why the scientific evidence has shown that a diet high in saturated fat (found largely in animal products) and low in fibre (found exclusively in plants) simply spells trouble for our health.
Please, do yourself a favor and visit the Paleolithic caves in France, Spain, Bulgaria, Libya, Argentina and the Aboriginal caves in Australia. One look at cave paintings dating back 40,000+ years will show you what we ate. There’s not a single one depicting broccoli farming, berry gathering, nut cracking, or potato planting. They depict animals (buffalo, elk, deer, boar, and Mammoths), humans with spears, bows and arrows, chasing, hunting down big game. Fires, cooking captured game. And eating animals, flesh. There were no shamans glorifying apples, figs or tomatoes in their artwork. They worshipped the animal prey, as part of the natural environment, as part of what they needed to feed off of. To survive and evolve. When there was a shortage of this, we supplemented with berries and nuts. But, we have always eaten meat as our primary source of calories
Thanks so much for your comment. I appreciate your point and will definitely visit some of those caves when I can. Historical evidence does reveal that people were eating meat in early cultures, however this does not prove we were designed to eat meat. It does speak to the availability of certain foods at that time and those locations.
Cave paintings are not strong evidence of dietary habits, and more recent evidence does show that prehistoric humans ate grains and seeds. That doesn’t mean white bread, but that we can find any evidence at all of these foods after so long is remarkable. Bones last much longer, so one would expect to see more evidence of meat consumption.
I don’t think anyone reputable is going to claim that humans didn’t eat meat, although that is not as important as you think it is. People eating mainly meat and people eating mainly plants all survive long enough to reproduce, so any direct evolutionary pressures from diet past that point do not exist. Your dietary viewpoint stops arbitrarily at paleolithic humans, but what of our more distant ancestors? We have a much longer history of frugivores/herbivores compared to ancient humans. Using the same logic of the paleo diet it makes perfect sense that we would be more adapted to plant consumption than to meat consumption. Sure, we are also adapted to meat consumption, but only relatively recently. Sounds a lot like how we are recently adapted to consuming milk from other species.
Much of the strong evidence against meat consumption is related to the long-term health effects, which would be easily ignored by evolutionary pressures. Humans have a remarkably adaptable digestive system, primarily because we can cook things. I find it doubtful that early humans stopped at flesh when they discovered cooking.
I was once big into the paleo diet (a decade ago), but one big thing about that diet is that you really can’t afford to eat a lot of meat (at least for a college student and then recent grad). ALL of your meat should come from clean sources, grass fed/pastured, cage free, and let’s not forget no dairy. Much of my fat intake was from plants (coconut oil, coconut milk, nuts/seeds, avocados). This even held true after I graduated and started working full time. Also, let’s not forget that many of the “antinutrients” in legumes and grains are also present in nuts. Also, there was no single paleolithic diet, but many different diets depending on where people lived.
No matter where in the spectrum a diet falls, it is always fallacious to claim that any diet is the “optimal” diet for humans unless you have hard scientific evidence for what you are talking about. “Because cave men did it like this” is not a valid argument (naturalistic fallacy), and even if it were valid you are arbitrarily choosing a golden time in our history to say that we should all eat like that.
I think that the only reasonable position to take is one backed by hard scientific evidence, and that is largely lacking in most named diet circles. I do fear that industry-funded studies are making this task much more difficult to take, though. But that being said, there is no big food corporation set to make billions off of whole food plant based dieters. The same is not true for meat-based diets, or diets including heavily processed meat alternatives.
LW, your comment also makes a couple of assumptions about the cave paintings that I think aren’t reasonable assumptions to make given our historical knowledge of human cultures.
You assume that humans hunted animals primarily for meat. This is untrue, given archeological evidence. Animals were hunted largely for furs, hides, and bones, or to protect a tribe against predators or competitors.
You also assume that food would have been a significant influence of art… This assumption really only works in times of famine. Mostly, artists through history have depicted significant events, stories, or cultural symbols. Historically, it’s only fairly recently that humans had the luxury of valuing art for purely aesthetic purposes. A hunt would have been a significant event worth recording, but a simple meal of plants and grains may have been mundane and unworthy of note.
Finally, we do have archeological evidence of our ancestors eating plants, just not in paintings. Mostly in the form of fossilized grains, or grinding stones.
D0E8R, archeological evidence is overwhelming that our ancestors for the past 2 million years have hunted and eaten meat. To imply that all these hundreds (perhaps thousands) of hunting images have been painted because humans were only after furs and hides – and not ONE is for food – flies in the face of reason and evidence. Additionally, there are multiple drawings depicting the cooking of these animals. And these are outside the physical forensic evidence for cooking and meat eating. I’m not saying we didn’t also eat plants, of course we did, but for sustenance we required meat. And they likely worshipped and honored these animals (perhaps with some of the paintings even) for the nourishment they provided us for survival.
With the advent of agriculture, some 10,000 years ago, we moved to a plant-based diet. It allowed for the propagation of the species and the expansion of culture and society – which is where we are today: a society on a plant-based diet. One look at a busy person’s day, will show you what he/she eats. Breakfast: swing by Starbucks for a coffee (plant based) and a muffin or donut (plant based) before work. In the office, maybe some nuts (plant based) to snack on. Lunch? Salad (it’s a light meal not to get too sleepy). Back at the office, more coffee, maybe some biscuits or indulging in a Kit-Kat bar (both plant based). Then for dinner, some bread to start off (plant based), add some meat (finally) to the spaghetti or pizza (plant based), with some wine (plant based) and finish off with dessert (plant based). This is not atypical of American diets (I’m not saying it’s yours).
And what are we left with? A society that is exploding with obesity, diabetes, and metabolic syndrome. This is caused by plant-based food/sources. Sure, call it an unhealthy diet of sugar, high fructose corn syrup, white bread, candy and candy bars, processed “health” protein bars, huge portions of pasta, etc (all plant based, and not all necessarily bad, mind you). But, the fact remains that none of these products contain one iota of meat, fish, pork, or fowl. All the “bad”, insulin-spiking, diabetes triggering, autoimmune-causing foods come from plants. All of them. And I bring this up not to rail against plants, but because of the outcries over how bad meat is for you.
But the truth is, you will not spike your insulin or get obese if you only eat meat (I’m not necessarily saying it’s all you should eat either). But, there is no way to eat enough of it – it is simply too dense and too carbohydrate scarce. The problem is that the pyramid is inverted. We went from primarily meat, supplemented by plants to a diet that is now almost entirely plant-based with some meat thrown in. And now there’s a movement to eradicate meat altogether… and leading the charge is this notion of what eating meat does to the environment?
When we were nothing but hunter-gatherers, the earth was in balance. Human population was outnumbered tens-of-thousands to one by animals. We could not hunt or eat them all – it was just not possible. What has caused the earth to become unbalanced was the advent of agriculture, and artificially being able to support and propagate an exploding population of humans that required more and more food, energy, shelter, and comfort than the earth was really capable of sustaining.
Don’t get me wrong – I love civilization and the comforts that come with it. But we should be careful about tipping the scales any further. Let’s not forget the lessons of the Dust Bowl where we over-farmed and drained the land – and it’s happened many times all around the world. There is balance in everything, including what we eat. And meat is part of that balance. Has been for 2 million years.
LW thank you for your comment. A few thoughts that come to mind:
– North Americans eat more meat than you think. In 2013, on average each person in the US ate 106 kg (233 lbs) of meat (see http://www.earth-policy.org data center tab). That’s about three quarters of a pound per day!
– The World Health Organization issued a press release in 2015 stating that the consumption of processed meat is carcinogen to humans “based on sufficient evidence in humans that the consumption of processed meat causes colorectal cancer”. In the same press release they stated that the consumption of red meat is probably carcinogenic to humans.
– I’m happy that you’re not thinking that eating mostly meat or protein is a healthy dietary pattern. Studies are showing that high protein/low carb diets are worthy of concern. For example, a study entitled, “Dietary carbohydrate intake and mortality: a prospective cohort study and meta-analysis” published in Lancet Public Health in 2018 and funded by NIH concluded, “Both high and low percentages of carbohydrate diets were associated with increased mortality, with minimal risk observed at 50–55% carbohydrate intake”. A plant-based dietary pattern happens to be comprised of approximately 50% carbohydrate.