3

votes

Are humans "naturally" herbivores?

Answered on September 12, 2014
Created March 07, 2010 at 3:12 PM

Having spent so much time as a vegan, one argument I heard frequently was that humans are naturally herbivores, so consuming meat is harmful and "unnatural." Unfortunately this also seems to have seeped into pop culture as well and I've also heard it from garden variety vegetarians. So what's the evidence for human omnivory (or carnivory)?

32f5749fa6cf7adbeb0b0b031ba82b46

(41747)

on June 16, 2013
at 11:16 PM

What a shitty copy-paste job this is.

9d43f6873107e17ca4d1a5055aa7a2ad

on November 21, 2010
at 08:29 PM

Hey, which study is that? I'd love to see the reference.

34d0dfe6cb1a477bd2b5f984c2af29a9

(493)

on November 21, 2010
at 01:21 PM

I'm reticent to edit for this, but I've heard that our two-leggedness and posture evolved because it was beneficial for catching prey.

C1fb8666b1ae085507a76a4c494e4f0a

on July 06, 2010
at 12:43 AM

Even orangutans occasionally eat live fish... at least on orangutan island :)

431274eafd914ee34d9c57262c1f617a

on May 10, 2010
at 11:13 PM

"Could we be considered primarily carnivores with streak of opportunistic omnivorism?" Yep, that's what I think. I believe we are designed to live on meat....meaning protein and fat...as the majority of our calories. Our calories should come from animals and use vegetables, fruit, spices, etc as enhancers.

93f44e8673d3ea2294cce085ebc96e13

(10502)

on March 08, 2010
at 08:00 PM

@Melissa -- Love your word-smithing. Tweeting this now.

5cd18bfcafadc56292971e59f2f1faf6

(2475)

on March 07, 2010
at 07:21 PM

Cool, the community wiki thing works!

9d43f6873107e17ca4d1a5055aa7a2ad

on March 07, 2010
at 05:47 PM

Hey, I marked this as a community wiki...I wonder if that means you can edit too?

5cd18bfcafadc56292971e59f2f1faf6

(2475)

on March 07, 2010
at 05:26 PM

Great question and nice list! Dr Eades had a great post on this subject. Maybe The Expensive-Tissue Hypothesis is worth adding to the list? http://www.proteinpower.com/drmike/low-carb-library/are-we-meat-eaters-or-vegetarians-part-ii/

9d43f6873107e17ca4d1a5055aa7a2ad

on March 07, 2010
at 04:23 PM

I think the paper is agreeing with you, since they say there is no evidence for it being a recent acquisition. Even the peacenik Bonobos have a taste for blooood http://www.sciencedaily.com/releases/2008/10/081013124416.htm

58a55f0986b8f49a8bc5666e10492569

on March 07, 2010
at 04:18 PM

Goodall observed chimps in the wild. Does it make sense that after millions of years they would suddenly adopt meat eating habits, just by coincidence when scientists are there to observe?

9d43f6873107e17ca4d1a5055aa7a2ad

on March 07, 2010
at 04:11 PM

http://beyondveg.com/billings-t/comp-anat/comp-anat-2a.shtml "[T]he Gombe chimpanzees removed 8% of the local baboon population in 1968-1969 (Teleki, 1973a) and 8-13% of the local colobus population in 1973-1974 (Busse, 1977). How is it possible, then, that the primates serving as prey to chimpanzees in Gombe National Park, and possibly also at other sites, have not developed more successful defensive tactics? Any answer other than the proposition that chimpanzees have only recently acquired predatory inclinations, for which there is no supportive evidence at all (Teleki, 1973a)"

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8 Answers

30
9d43f6873107e17ca4d1a5055aa7a2ad

on March 07, 2010
at 03:20 PM

YOU can add to this Community Wiki...simply click "edit"!

  • Comparing us to Great Apes ignores that they have the ability to ferment the tough foliage that they eat into free fatty acids, which account for 57% of calories consumed in gorillas. Their colon is 50% of gut volume and our colon is 17% of gut volume.

  • Humans are a fairly unusual species. Contrary to popular misconception, gorillas and chimps are our relatives, not our ancestors. Re the latest fossil evidence "indeed, the new evidence suggests that the study of chimpanzee anatomy and behavior???long used to infer the nature of the earliest human ancestors???is largely irrelevant to understanding our beginnings." It also means that comparing our digestive system to lions and cows is pretty pointless since we are a unique clade.

    Observing that human gut proportions are different from those found in carnivores, herbivores, swine (an omnivore), and even most other primates, including the anthropoid apes, Milton [1987, p. 101] notes that "...the size of the human gut relative to body mass is small in comparison with other anthropoids (R.D. Martin, pers. comm.)." Milton [1987] includes a table (3.2, p. 99) that compares the relative volumes of the different parts of the gut for selected hominid species. The table shows the stomach at 10-24% of total gut volume in humans, while for orangs and chimps it is 17-20%. The small intestine is 56-67% of total gut volume in humans, 23-28% in orangs and chimps. And the colon is 17-23% of total gut volume in humans, while it is 52-54% in orangs and chimps. The percentages quoted in the preceding sentence are unscaled, i.e. are not scaled for inter-specific differences in body size. Despite this, the figures are useful to compare patterns of gut proportions, and the general pattern is clear: humans have "large" intestines, while chimps and orangs have "large" colons.

  • Humans are the longest lived primates. A diet high in sugary fruits cannot support this longevity. Without modern dental-care, humans eating high sugar diets would not live very long because they would lose all their teeth. Our "natural" diet would not be the one that makes our teeth fall out. Apes experience tooth decay in the wild, but it matters less since they don't live as long.

  • Our brains require nutrients like Vit B-12, iodine and DHA that simply can't be found on a diet of forest foods. Furthermore, our brains are big and hungry for calories. While modern fruit eaters can survive because of the wealth of sugar-rich fruit at the grocery store, there is no evidence that a homo sapien could survive by foraging for only wild fruit. In fact, there is strong evidence that homo sapiens could not survive in a forest environment at all without access to cultivated foods. The argument that vegans can make babies doesn't hold much water, as this argument is about optimal brain development throughout generations.

  • [T]here is evidence that some people have a genetic defect which renders them unable to convert beta-carotene to retinol [Blomstrand & Werner, 1967; McLaren & Zekian 1971].]6

  • Humans have low rates of taurine synthesis, an important part of human breastmilk and essential for children's development. Vegan levels are often 1/4 of omnivorous levels. "Animals that are more herbivorous (e.g., the rat) have a greater ability to synthesize taurine than humans do (they synthesize taurine with three times greater efficiency."

  • "Heme iron receptors: an adaptation to animal foods in the diet. The information that the human intestine has receptors specifically for absorption of heme iron is significant. Heme iron is found almost exclusively in animal foods. Plant foods may contain heme iron as well, as cytochrome c, a protein found in plants, reportedly contains a heme group. However, the level of heme iron in plants is extremely low, and not nutritionally significant. (Most of the standard references, such as NRC [1989, p. 198], report that all of the iron in plants is in non-heme form)."

  • Isotopic analysis of earliest members of the homo genus showed they consumed significant quantities of meat.

  • "Comparative analyses of archaeological bone assemblages from Olduvai Gorge and Koobi Fora and of various modern bone assemblages with known taphonomic histories reveal direct evidence of early hominid butchering and marrow-processing activities" between 2 and 1.5 Myr ago.

  • The Expensive-Tissue Hypothesis "suggests that the metabolic requirements of relatively large brains are offset by a corresponding reduction of the gut."

    No matter what is selecting for relatively large brains in humans and other primates, they cannot be achieved without a shift to a high-quality diet unless there is a rise in the metabolic rate. Therefore the incorporation of increasingly greater amounts of animal products into the diet was essential in the evolution of the large human brain.

    Dr Eades discusses this at great length in Are we meat eaters or vegetarians? Part II.

  • "In contrast [to australopithecines], members of the genus Homo show thinner molar enamel, a dramatic reduction in cheek tooth size, and considerable cranial expansion (Grine 1981; McHenry 1982; S. Ambrose, pers. comm.). In combination, these dental and cranial features, as well as an increase in body size, apparently with no loss of mobility or sociality, strongly imply that early members of the genus Homo made a dramatic breakthrough with respect to diet--a breakthrough that enabled them to circumvent the nutritional constraints imposed on body size increases in the apes."

  • And let's not forget one of our ancestors, Homo Ergaster: "It lived during the Lower Pleistocene epoch (dated at between 1.51 and 1.56 million years old), with fossils dated between 1.8 and 1.2 million years old... As a clue to a part of our evolutionary history, scientists have studied the evolutionary relationships of our host-specific taeniid tapeworms... A tapeworm's life cycle is adapted to its parasitic existence. For taeniids, this centres upon a predator-prey relationship, with a carnivore carrying the adult tapeworm and a herbivore hosting the infective larvae. Evolutionary relatives of our tapeworm are usually found in intestines of carnivores such as lions, hyenas or African wild dogs... Homo ergaster displays a set of features that support the adoption of a new meat-eating or scavenging type niche as opposed to the largely vegetarian diet of the Australopithecines."

5cd18bfcafadc56292971e59f2f1faf6

(2475)

on March 07, 2010
at 05:26 PM

Great question and nice list! Dr Eades had a great post on this subject. Maybe The Expensive-Tissue Hypothesis is worth adding to the list? http://www.proteinpower.com/drmike/low-carb-library/are-we-meat-eaters-or-vegetarians-part-ii/

5cd18bfcafadc56292971e59f2f1faf6

(2475)

on March 07, 2010
at 07:21 PM

Cool, the community wiki thing works!

9d43f6873107e17ca4d1a5055aa7a2ad

on March 07, 2010
at 05:47 PM

Hey, I marked this as a community wiki...I wonder if that means you can edit too?

34d0dfe6cb1a477bd2b5f984c2af29a9

(493)

on November 21, 2010
at 01:21 PM

I'm reticent to edit for this, but I've heard that our two-leggedness and posture evolved because it was beneficial for catching prey.

4
5ebeec76e20738d0a17cd724d64b1e0f

on March 07, 2010
at 10:24 PM

One simple argument against humans being herbivores is that we require Vit B-12 to live, and B-12 is not widely available in plant material. Sure, you can get it from seaweed, but that clearly wasn't a common staple in the Paleolithic period. The best source is meat.

We also require Omega-3 fatty acids, which are available from fish and some animals, and again there are relatively few plant sources.

Another thing about herbivores is that they tend to spend many, many hours every day chewing their food in order to get maximum nutrition from it.

2
691f120a3e7a1a036845d105d86c99a3

(3641)

on March 08, 2010
at 07:34 PM

Could we be considered primarily carnivores with streak of opportunistic omnivorism? if plant material spikes insulin and messes with the blood sugar and we can get everything we need from animal flesh including vitamins, i feel like we should be more carnivore.

also the expansion of homo sapiens from the original habitat would mean we couldn't really be reliant on plant matter for food because of the diversity of the places we all ended up. a strange new habitat with new plant matter would be unknowns to migrating humans. we had to be able to get all of our nutrients from a consistent source-- game meats!

431274eafd914ee34d9c57262c1f617a

on May 10, 2010
at 11:13 PM

"Could we be considered primarily carnivores with streak of opportunistic omnivorism?" Yep, that's what I think. I believe we are designed to live on meat....meaning protein and fat...as the majority of our calories. Our calories should come from animals and use vegetables, fruit, spices, etc as enhancers.

2
58a55f0986b8f49a8bc5666e10492569

on March 07, 2010
at 04:13 PM

And let's not forget one of our ancestors, Homo Ergaster: "It lived during the Lower Pleistocene epoch (dated at between 1.51 and 1.56 million years old), with fossils dated between 1.8 and 1.2 million years old... As a clue to a part of our evolutionary history, scientists have studied the evolutionary relationships of our host-specific taeniid tapeworms... A tapeworm's life cycle is adapted to its parasitic existence. For taeniids, this centres upon a predator-prey relationship, with a carnivore carrying the adult tapeworm and a herbivore hosting the infective larvae. Evolutionary relatives of our tapeworm are usually found in intestines of carnivores such as lions, hyenas or African wild dogs... Homo ergaster displays a set of features that support the adoption of a new meat-eating or scavenging type niche as opposed to the largely vegetarian diet of the Australopithecines."

0
Ce0b5fd94b1034e96cf710b6f138c29d

on November 21, 2010
at 05:29 PM

The short answer is no. There are too many kill sites, shell middens, butchered bones, hunting tools, etc. in the fossil record, going too far back in time, for that statement to carry any weight with anybody with any anthropological training.

0
58a55f0986b8f49a8bc5666e10492569

on March 07, 2010
at 04:06 PM

Let's not forget Jane Goodall: "David Greybeard was eating meat. This astounded Jane; chimpanzees had been thought of as herbivores, who occasionally ate small bugs. Chimpanzees had never before been seen or recorded as eating meat. Like humans, chimps are omnivores (Goodall 1971)."

9d43f6873107e17ca4d1a5055aa7a2ad

on March 07, 2010
at 04:11 PM

http://beyondveg.com/billings-t/comp-anat/comp-anat-2a.shtml "[T]he Gombe chimpanzees removed 8% of the local baboon population in 1968-1969 (Teleki, 1973a) and 8-13% of the local colobus population in 1973-1974 (Busse, 1977). How is it possible, then, that the primates serving as prey to chimpanzees in Gombe National Park, and possibly also at other sites, have not developed more successful defensive tactics? Any answer other than the proposition that chimpanzees have only recently acquired predatory inclinations, for which there is no supportive evidence at all (Teleki, 1973a)"

58a55f0986b8f49a8bc5666e10492569

on March 07, 2010
at 04:18 PM

Goodall observed chimps in the wild. Does it make sense that after millions of years they would suddenly adopt meat eating habits, just by coincidence when scientists are there to observe?

9d43f6873107e17ca4d1a5055aa7a2ad

on March 07, 2010
at 04:23 PM

I think the paper is agreeing with you, since they say there is no evidence for it being a recent acquisition. Even the peacenik Bonobos have a taste for blooood http://www.sciencedaily.com/releases/2008/10/081013124416.htm

93f44e8673d3ea2294cce085ebc96e13

(10502)

on March 08, 2010
at 08:00 PM

@Melissa -- Love your word-smithing. Tweeting this now.

C1fb8666b1ae085507a76a4c494e4f0a

on July 06, 2010
at 12:43 AM

Even orangutans occasionally eat live fish... at least on orangutan island :)

-1
29c0fd71f20d762225dbae8caf609c8e

on June 16, 2013
at 08:16 PM

Yes, Well You Are Correct And The Great Debate About That- Is Because Of The Soil...If You Would Please Take The Time To Watch All That Video Above You Would See That...This Is Not About Winning Or Losing...You Already Lost, Because It Is 100% Proven. I Hate To Say That Too, Because I USED TO LOVE MEAT FLAVORING> 36 minutes ago ?? Like

Eric Plott The major causes of death in Western countries are cardiovascular diseases and cancers. Abundant medical research linking these diseases to dietary and lifestyle factors, guidelines advanced by the American Heart Association, the American Cancer Society, and the Surgeon General, among others, counsel Americans to sharply reduce animal foods consumed and replace them with fruits, vegetables, and whole grains. In effect, they are recommending a more plant-based diet, which begs the question: Are humans designed to eat meat?

Milton Mills, M.D. has an extensive background in nutrition research, focusing on the role nutrition plays in the development of chronic diseases. He is a graduate of the Stanford University School of Medicine and is a practicing physician in the Washington, D.C. area. He also serves as the Associate Director of Preventive Medicine for the health policy group Physicians Committee for Responsible Medicine. He has lectured extensively throughout North America and is a Nutrition Health Education Video Spokesperson for the Discovery Health Channel.

Filming and editing by Dr William Harris M.D. on November 12, 2005 at McCoy Pavilion, Ala Moana Beach Park, Honolulu, Hawaii Sponsored by: Vegetarian Society of Hawaii

And They Told Me It Wasn't Possible, Well I Am Proving Them Wrong & We Are PUSHING To Greater Lengths Than Ever Before, An Incredible Mark In Midwestern History , Introducing A Great Concept To Change The Environment For The Better. Accenting The Midwestern Beauty, We Now KNOW Without A Doubt That Palm Trees Live Here And Are Here To Stay! Go Missourah! Go Tigers! We Are The Sub-Tropics!

http://www.youtube.com/watch?v=lAzYxz4bc3g

32f5749fa6cf7adbeb0b0b031ba82b46

(41747)

on June 16, 2013
at 11:16 PM

What a shitty copy-paste job this is.

-1
Dd8e802e33f3bb6fc156fdd2d8d5805f

on November 21, 2010
at 10:56 AM

I happened on this page looking for something else and felt the desire to chime in one thing - saying that meat is the "best source" of b12 is not sound. The average adult needs but 0.000876 grams of b12 per year and studies of Asian vegans (I know this only secondhand and have not seen the research) have shown that soil traces on produce served this need adequately. Surely there are stronger arguments in favor of meat eating (some mentioned here). But if anyone is going to turn to natural/evolutionary arguments that identify the human animal as a carnivore, it seems only fair to point out that there are parallel historical logistics that absolutely would've provided adequate nutrition to evolving humans. Great site btw.

9d43f6873107e17ca4d1a5055aa7a2ad

on November 21, 2010
at 08:29 PM

Hey, which study is that? I'd love to see the reference.

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