Meat - To Eat Or Not To Eat?

 I do eat meat, but I don’t have to have it every day. I rather prefer fish and seafood. But in both my pregnancies I graved red meat though and the only explanation I have is my low hematocrit and my body’s need for iron. But I keep hearing that meat is sooo bad for me and I am actually designed to be a herbivore anyway. So I decided to do my own research whether or not meat is bad for me.

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.