Because this is my first post, I should
clarify how I conduct my research. I consider a few things: the
theoretical framework, the validity of the data presented, the generalisability
of the study and the research methods. What does this all mean? Firstly, I look
at what type of paper am I reading. Google is a search engine and Wikipedia,
for example, can be edited by anyone. Google results and Wikipedia entries are
starting points; they give me ideas. But, I don’t take these things at face
value. Anyone can publish stuff on the internet (I am writing a blog for
example). After I found a topic I want to know more about, I search for scholar
articles. Sometimes I have been given clues by Wikipedia (see the references at
the bottom on each page) or in an article I read. Then I check out the
theoretical framework, the ideas behind the research conducted. I am trying to
answer questions like “Have they considered pros and cons?”, “Can I follow the
logic from the general topic to the hypothesis, the question the researchers
are trying to answer?” and “Have they tried to explain their findings with an
alternative answer?” At this point, I often start to find discrepancies. I find
that most research is done very narrow-mindedly. These people are experts in
one particular field and their research is streamlined to this one subject.
Only some researchers do link several fields together as it should be when it
comes to something as complex as the human body … The next step is a
closer look at the methods. I look for things like in vitro vs in vivo
(research in a Petri dish vs research in a living organism), placebo controlled
or not, how the participants were selected and if I think I could replicate the
study setup. This partially influences the other two points, the validity and generalisability. A study about
diabetes in rats which have been bred to be diabetes predisposed and have then
be made diabetic through medication is of a lesser value for human application
than a double-blind, controlled study with human diabetics with various length
and severity of the disease. The number and selection of participants is also important (a handful versus a representative sample), as is the way the data was obtained. An experiment or observational setup is more objective than a retrospective interview/questionnaire. If I asked you what you had for lunch the Wednesday the week before last, you will probably find this hard to remember. I will add all my sources at the end of each post,
so you can read for yourself – and make up your own mind. I simply don’t believe
everything people tell me, I go and look for myself!
Back to the meat. Bad or good? One of the
apparent culprits that make meat in general, but red meat in particular, bad
for us, is carnitine. Carnitine is a protein known for its role in transporting
long-chain fatty to the mitochondria (the cell’s ‘powerhouse’) where they are
burnt for energy. The health food gurus claim that carnitine is responsible for
the build up of fat in the arterial walls, known as atherosclerosis. What’s up
with that? According to the meat opponents, carnitine raises the levels of TMAO
(trimethylamine N-oxide). TMAO reduces the reuptake of cholsterol into the liver
where it is metabolized to HDL (the ‘good’ cholesterol), sterol and other
compounds. But, I find it ludicrous to conclude that the reduction of this
pathway automatically leads to a higher incidence of atherosclerosis. Sorry, I
cannot find any studies that would confirm such assumptions, probably because
these studies look at one component of the entire (cholesterol) metabolism, not
the whole. Other studies around carnitine suggest that it lowers
insulin-resistance and improves blood glucose levels. My verdict on the
carnitine debate? Researchers haven’t completely deciphered the metabolic
cholesterol pathway; only 10% of variation in HDL levels can be explained by
genetic predisposition and there is no established link between carnitine,
TMAO and atherosclerosis. The
Another reason not to eat meat, in
particular grilled meat, is heterocyclic amine. Guess what, they are linked to
cancer. When you cook your meat at high temperature for a prolonged time or
char it on the barbecue, heterocyclic amines form in the meat. But here’s the
problem. The studies undertaken to prove the cancer-promoting properties of
these compounds have been undertaken in vitro or in animals. Plus the doses
used have been thousand fold to what you would eat, even if your steak was a bit
charred on the outside. Even less convincing to give up meat is the fact that
heterocyclic amines are common; they are found in hemoglobin, myoglobin,
chlorophyll, vitamins B1, B3, B6 and B12. I bet if the researchers would take
thousand fold amounts of these compounds, they would find adverse affects for
those too …
What else? Environmental arguments are
often held against eating meat. One of them is the argument that you could feed
more people per land area if you farmed crops instead of animals. I have a few
issues with this argument. You can farm animals on steep hillsides, but you
will have to terraform if you would like to grow crops there. Secondly, water:
in dry areas you would have to irrigate while nomadic herding or pastoral
husbandry is sustainable without the need for extra water even in arid
conditions. Crop farming depletes the soil and monocultures without crop
rotation require fertilization to keep production up. On the other hand, I use
sheep poop (alongside crop rotation and companion planting) in my vege garden.
If you want to argue deforestation now, please leave it. Deforestation is not
just done for husbandry, but for crop farming as well. I know cows and sheep produce carbon dioxide and worse methane. But plants need carbon dioxide to survive, so if there were only plants and no carbon dioxide producers, the plants would plain and simple suffocate. I am sorry to say that a diet shift alone would not reduce methane emissions, they would still go up! As far as the
environment goes, I am all for pastoral agriculture, and sorry that includes animals.
Next on the list would be antibiotics and
pesticides. I’ll make that very painless: herbicides, insecticides,
plant-specific pesticides, fertilizers, lack of phosphorus and other trace
elements due to depleted/poor soils, genetically modified crops ... I rest my
case. If you weren’t the person who grew that crop, you won’t know what went in/on there. And yes, it’s the same for the piece of meat in front of me. In this
regard alone, we have the choice between eating toxins related to animal
husbandry and well, eating toxins related to crop farming.
But I saved the ’best’ argument against eating
meat for last. Apparently we are not designed to eat meat. There are three
major groups in regards to diet: plant eaters or herbivores, meat eaters or
carnivores and the mix of the two, omnivores. The trouble with the
argumentation against eating meat is that it presumes an exclusively
carnivorous diet – rather than the omnivorous diet most human meat-eaters actually
have. But we aren’t carnivores. Nor are we herbivores. Technically, we are
omnivores, we eat both and yes, we are adapted to this mixed diet.
Let’s start off with something not so food
related. Meat opponents argue that carnivores don’t have sweat glands. Wrong!
There are two types of sweat glands, eccrine and apocrine sweat glands. Eccrine
sweat glands are ducted directly to the surface of the skin while apocrine
sweat glands are ducted into hair follicles. Humans and carnivores possess both
types of sweat glands. While we use perspiration (sweating) as a measure to
cool down, carnivores will do so by panting. Carnivores’ sweat glands are
designed to provide moisture for a better grip (eccrine glands in the palms) or
help maintain healthy skin and hair (apocrine glands). Just because the sweat
glands have different functions, it doesn’t mean they are absent. The only
carnivorous mammal, which would fulfill this criterion, is the whale. They
don’t possess sweat glands at all. And if anyone wants to argue all carnivores lap water, ask someone with a cat if you can film it when it drinks. Cats don't lap, they suck very gracefully (they use physics to their advantage). Not to mention whales; ever seen a whale lap or a seal? Cows lap sometimes, even bunnies do. Get a pet and an education, if you're fooled that easily!
Presumably, we have evolved from apes;
therefore our nutrition should be the same. Should it really? Let’s take a look
at genus onychomys, the grasshopper mouse. These mice are carnivorous, eating
insects and even scorpions. A close relative (similar relation as between us
and the great apes) is the packrat and this mouse is herbivorous. If mice are
not universally herbivores or carnivores, why should human or apes? Besides
that, chimpanzees may be primarily frugivores, but they also eat insects, eggs
and even small mammals (see Jane Goodall). Gorillas eat predominantly leafy
greens, supplemented with fruit and insects. Orangutans are opportunistic; in
the growing season they will eat mostly fruit, but if fruit is not abundant
they will whatever is available including young leaves, shoots, bark, insects,
honey and bird eggs. If the great apes don’t share a common diet, why are we
bound to have the same diet as one of those species?
Other apparent hints why we are not
designed to be carnivores are our teeth and the absence of claws apparently.
Some carnivores do have claws, but others like hyena and weasel don’t. On the
other hand, herbivores such as panda, koala and sloth do have claws, even
though they are herbivores. As for the teeth: almost all herbivorous mammals
have a large gap, or diastema, between their incisors and molars. Most herbivores
miss their canine teeth, but a good number have vestigial canines such as
camels, pandas or koalas. I don’t recommend annoying a male camel, except if
you like teeth leaving deep puncture wounds! Some herbivores like sheep miss
their upper incisors altogether; they have a rough pad instead. Humans don’t
have carnivore teeth either. We do have canines, but ours are small. We don’t
have jagged molars like cats or dogs; ours are rather flat. So where do we fit? In the middle as omnivores. Another argument is
that herbivores can move their jaws side to side. Have you lately tried to chew
something moving your jaw side to side? You can move your jaw sideways when
your mouth is open, but you can chew side to side as your canines and incisors
won’t let you move the jaw this way. Also both, masseter and temporalis
muscles, are used to move the jaw, whether the aminal in question is herbivore,
carnivore or omnivore. Don’t get me started on the mouth opening versus the
headsize. If a cat yawns being bored by this discussion, I can still make out
the size of its head. If I would discuss this subject with a hippopotamus
though …
Teeth and claws are rather easy to see, but
what about our internal make-up? Meat opponents argue we secret salivary
amylase, an enzyme that aids the breakdown of starches. Why on earth would a
tiger need amylase when he doesn’t eat grains or fruit that contain
carbohydrates? Studies have shown that the saliva of omnivorous animals like
rats and even humans adapts based on the primary diet. More carbohydrates, more
amylase. Let’s stay with digestive enzymes for a moment. My dear M.D. Milton R.
Mills, you should return your degree papers. I have no idea where you sourced
the humbug about the pH in the stomach. The pH in the stomach I directly
correlated to the presence or absence of protein. Protein rich foods, whether
plant or animal derived, requires pepsin. Pepsin is activated from pepsinogen
by excretion of hydrochloric acid. The more protein, the more pepsin needed,
the more hydrochloric acid produced, the lower the pH while food is present.
You obviously slept through your anatomy class! And of course it is not a
surprise that the pH of a tiger’s stomach is going to be much lower than that
of a cow’s. But I doubt that the pH level of an omnivorous organism is
consistently as low as that of the tiger, or the pH level of a herbivore
primarily eating seeds and nuts is as high as that of a cow!
And what about the anatomy of the stomach
and intestines? We don’t have a rumen and our cecum is much smaller than the
cecum of a horse. It’s also smaller than the cecum of the omnivorous pig for
that matter. You’ll probably be surprised to hear that whales, all carnivores
(even those that only eat krill), have multi-compartmental stomachs just like a
cow. The length of the intestines? Now some really smart food guru will
tell you that the small intestines of a herbivore are about 10 to 12 times of
the body length, while small intestines of a carnivore are about 3 to 6 times
its’ body length. The human small intestines are about 4 metres long (body
length 1.8m), the herbivorous elephant’s small intestines are 19 metres long
(body length 3.3m) and those of carnivorous sea otters are 11 metres long (body
length 1.2m) … I’ll let you do the
maths alone! By the way, you may find varying numbers for the length of the
small intestines. That’s mostly due to the fact that muscle tone prevents the
small intestines to fully stretch while you are still alive. If you were dead I
could stretch your small intestine to a total length of 7 metres. But the
numbers still don’t stack up. There aren’t too many human beings around that
are 70 cms short. Right? In other words, anatomy alone does not prove whether
or not an animal (or human) is a herbivore, omnivore or carnivore. If you
ignore the relation between anatomy, the structure, and physiology, the
function, you simply don’t see the big picture. You need to take into account
the type of cells, the digestive enzymes and the structure and function
of other body parts.
So shall we eat meat? If you like meat,
there is no reason why you shouldn’t or can’t. I know meat is rich in saturated
fat and cholesterol, but I will give this subject some separate attention (let
me say for now eating eggs or steak won’t be the primary reason why you may
have high cholesterol levels). If you don’t like meat or can’t stand the idea
of some innocent creature being kidnapped from its mother, then force-fed and
raised to serve the one purpose of being slaughtered to be eaten, go
vegan/vegetarian! Even though your kind gesture won’t change the food chain,
this is the only reason that makes any sense.
