salivary amylase

Regulation of Digestion

All aspects of the GI processes are controlled by neural, hormonal and paracrine controls, specific control systems include

  •  Long & Short Reflexes 
  • GI peptide reflexes 
  • The autonomous function of the enteric nervous system (ENS) 

Long Reflexes 

  • Integrated within in the CNS 
  • May originate in or outside of the GI tract 
  • Feedforward & emotional reflexes are initiated and integrated entirely outside the GI tract 
  • Called cephalic reflexes 

Short Reflexes 

  • Integrated in the enteric nervous system
  • Initiated by changes in pH, distension, osmolarity, products of digestion 
  • Submucosal plexus contains the sensory neurons 
  • Afferent information to ganglia 
  • Efferent information to submucosal and myenteric plexuses for control of secretion, motility and growth 

GI Peptide Reflexes 

Peptides released by the GI tract may act: 

  • as hormones 
  • Secreted into the blood 
  • Act on accessory organs, other parts of the GI tract or the brain 
  • As paracrine signals 
  • Secreted into the lumen or extracellular fluid 
  • Lumenal signals bind to apical epithelial receptors 
  • ECF signals act in the immediate vicinity of secretion 

Effect:

  • Peptides alter secretion and motility 
  • Alter behaviour related to eating 

Enteric Nervous System 

  • Allows for the autonomous behaviour of the digestive system 
  • CNS control is not required for digestive functioning 

Commonalities between ENS and CNS:

  •  Intrinsic neurons – similar to interneurons of CNS 
  • Extrinsic neurons – composed of autonomic neurons 
  • Neurotransmitters and neuropeptides 
  • Nonadrenergic and noncholinergic receptors - same as adrenergic and cholinergic in CNS 
  • Glial support cells – similar to astrocytes in CNS 
  • Diffusion barrier – cells around capillaries in the ganglia are tight, just as the capillaries in the brain, forming the BBB 
  • ENS acts as its own integrating centre, just as the CNS does 

Cephalic phase

  • Stimulus-CNS-Vagus nerve-ANSSalivary glands-salivary amylase & lingual lipase 
  • Enteric Nervous system-increased gastric secretions and motility 

Gastric phase  

  • Stores food; digests into chyme 
  • Protects (mucus and HCl)

Intestinal phase

  • Digestion of proteins, formation of chime in ileum 
  • Controlled entry of chyme into ileum 
  • Concentration of waste and digestion in colon 
youtube
  • fistula 瘻孔 ろうこう
  • gastric juice 胃液 いえき
  • oral cavity 口腔 こうくう 
  • buccal cavity 頬側口腔 きょうそくこうくう,
  • hard palate 硬口蓋 こうこうがい
  • soft palate 軟口蓋 なんこうがい
  • uvula 口蓋垂 こうがいすい
    • (the colloquial term is 喉ちんこ のどちんこ)
  • nasopharynx 鼻咽頭 びいんとう
  • nasal cavity 鼻腔 びくう
  • teeth
    • incisor 門歯 もんし or 切歯 せっし
    • canine 犬歯 けんし
    • premolar 小臼歯 しょうきゅうし
    • molar 臼歯 きゅうし or 大臼歯 だいきゅうし
      • (the chemical term is molar モル濃度 もるのうど)
  • masticate 噛み砕く かみくだく
  • bolus 食塊 しょっかい
  • parotid gland 耳下腺 じかせん
  • sublingual gland 舌下腺 ぜっかせん
  • submandibular gland 顎下腺 がっかせん
  • saliva 唾液 だえき
    • salivary amylase 唾液アミラーゼ
  • gastric pit 胃小窩 いしょうか
  • gastric gland 胃腺 いせん
  • secretory cell 分泌細胞 ぶんぴつさいぼう
  • parietal cell 壁細胞 へきさいぼう
  • hydrochloric acid 塩酸 えんさん 
  • denature 変性させる へんせいさせる
  • pepsinogen ペプシノーゲン
  • chief cell 主細胞 しゅさいぼう
  • pepsin ペプシン
  • enteroendocrine cell 腸管内分泌細胞 ちょうかんないぶんぴさいぼう or 腸内分泌細胞 ちょうないぶんぴさいぼう
  • regulatory hormone 調節ホルモン ちょうせつホルモン
    • serotonin セロトニン
    • histamine ヒスタミン
    • somatostatin ソマトスタチン
  • G cell G細胞 じーさいぼう
  • gastrin ガストリン
  • cephalic phase 脳相 のうそう or 頭相 とうそう
  • gastric phase 胃相 いそう
  • reflex arc 反射弓 はんしゃきゅう
  • intestinal phase 腸相 ちょうそう
  • chyme 粥状液 かゆじょうえき or 消化粥 しょうかがゆ or 糜粥 びじゅく
  • vomit 嘔吐 おうと
Vegan Cats: A Masterpost Against.

This writing will contain a mass of information as to why plant based diets are inappropriate for cats. I know why many of you desperately want to cling to the hope that your cat can safely be fed a plant based diet. I’ve went through the same dilemma. However, feeding a cat a plant based diet is not the answer. 

If you want a TL;DR, it’s because plants and meats are digested differently, and a cat’s system is optimized to extract nutrition from meat and lacks the necessary components to digest plant matter efficiently. Plants are hard on their system and difficult to digest. Plant based diets will lead to accelerated dental problems, and will likely induce kidney and pancreatic problems. Let’s begin!

- Pancreatic health: A cat’s body is not meant to be fueled by carbs like ours, so when they eat plant matter, especially dry plant matter, their pancreas has to work very hard to correct the glucose spike. Not only that, but cats do not produce amylase in their saliva, the enzyme that breaks down starches, so their pancreas must produce much more than their body was ever intended to produce. Pancreatitis is extremely common in cats, and so are plant based diets. It’s from the pancreas being overworked by plant matter.

Insulinomas are cancerous pancreatic tumors. Insulinoma is very rare in raw fed ferrets and ferrets fed a very high meat wet food, but extremely common in kibble fed ferrets. Why? Because plant matter is really rough on their pancreas.  I have no idea how common insulinoma is in cats, but I’ve heard pancreatitis is, and when most cats are fed a high plant matter diet, you begin to wonder. I mention ferrets because they are physiologically similar and have similar nutritional needs to cats, similar enough that they can eat each others food. Most people feed ferrets cat food, because there’s few ferret foods that are very good out there and accessible. 

- Urinary tract health: There are two big problems with plant based diets: Crystals and dehydration. Cats originate from desert regions, and in nature get most of their water intake from prey. The average mouse is 70% water, yet the average vegan dry food is 8% moisture. Cats do not have a strong thirst mechanism, and will not drink enough on their own. UTI’s are dismissed as being a cat thing, but the real reason for the epidemic is dry food doesn’t hydrate them properly. Crystals occur due to plant based diets alkalizing their urine. Crystals can be extremely painful and lead to blocking their urethra. Due to the high risk of crystals, a cat on a plant based diet must have their urine Ph monitored weekly or even daily in some cats.  If we need to take an otherwise healthy cat and monitor them often due to their diet, is the diet really that safe? 

- Intestinal Length: Did you know that an herbivore will have an intestinal length 9-20x their body length? Did you know carnivore’s will be 1.5-3x their body length? Why is that, you may be asking? Cats have a short digestive tract because their system is optimized for meat. A cat’s intestines specifically are around 2.5 times their body length. IIRC, it help prevent bacteria from growing in their intestine. Herbivores have long intestines because plant matter is actually pretty hard to break down and extract nutrients from. 

- The cecum: The cecum is a portion of the large intestine which, “ hosting a large number of bacteria, which aid in the enzymatic breakdown of plant materials such as cellulose.“ Most herbivores have a large, well developed cecum. Carnivores either have small, underdeveloped ones in comparison, or in the case of obligate carnivores like cats, will completely lack one. 

- Dental health and digestion in the mouth: Cats do not have the salivary amylase that herbivores do to break down starches during digestion in the mouth. This can be pretty hard on their stomachs. Not only that, but starches are extremely bad for their dental health. It accelerates tooth and gum problems. In contrast, raw meat and bones clean teeth and stimulate the gums. The gnawing on raw meat also aids in digestions. In high quality kibble and wet food fed cats, they still experience dental problems, but at a much slower rate. Dental problems are severe and epidemic in plant based fed cats, to the point where cleanings and tooth removal are usually inevitable by the time they’re seniors, but not uncommonly even younger. 

- Mental health: You know how rotting meat might taste bad to us, but great for a vulture? Or how warm, fresh, bloody meat would be gross to us, but awesome to a wolf? Their system is wired to bring pleasure from food their physiology is adapted for. I’ve personally tasted vegan dog food, as I used to feed it as a base to my rats, and it’s pretty bland. It’d definitely be very unpalatable to a cat. Palatable food provides mental stimulation necessary for their well being. That’s a big point on raw feeding actually, they have to work at their food and chew and gnaw, which provides additional mental stimulation. Many raw feeders report their animals are very excited during feeding times, and report less signs of bored or under stimulated induced behavior.

- DIabetes:  Plant based diets, vegan or not, are extremely heavy in carbs. Diabetes has been on the rise in cats, it’s an epidemic. Pet food companies are putting increasing amounts of fillers like corn and wheat into foods to reduce cost, and this has created a rise in obesity and diabetes, Diabetic cats are put on low carb, high protein meat based diets, and often times the diabetes reverses and the cats no longer need insulin.

- More anatomical & physiological info?:  Here’s another link going further in depth about the anatomy and physiology of carnivores: [Link]

- Argument ~ Look at this study!: The most common study by Lorelai Wakefield in 2006 is highly flawed. Read more on the criticisms here: [Link]. TL;DR? -  35%, just over 1/3, of cats were not kept strictly indoors, the study has a very small sample size, this study only followed cats for a year, the study only looks at Taurine and Cobalamin levels, and blood was only obtained from 17 cats. Please do not rest your companion’s health and well being on this study and anecdotes

- Argument ~ Obligate carnivore just means they eat a lot of meat in the wild!: Where did people even get this from? Obligate carnivores, also known as true carnivores, have characteristics different from herbivores and omnivores, and even other carnivores such as dogs. For instance, a true carnivore like a cat will lack a cecum, but a dog has one. True carnivores need preformed vitamins like Retinol for Vitamin A, they can’t convert Beta-Carotene to vitamin A. True carnivores cannot efficiently digest plant matter, and some even use it to vomit. 
“[Certain] animals became obligate carnivores as a result of their ancestral diets. Because eating a meat-only diet provides some vitamins and fatty acids in their pre-formed state, cats and many other obligate carnivores have lost the ability to make these amino acids and vitamins in their own bodies the way herbivores or omnivores do. They don’t need to since the animals they are eating have already done it for them. For example, cats require vitamin A in its pre-formed state, they can’t make it from beta-carotene the way humans or dogs or rabbits can. They have little ability to form niacin from tryptophan.⁴ They have a high requirement for taurine, which is found almost exclusively in animal flesh.⁵ Arginine, also found in animal flesh, is so critical to the cat that a meal without it can lead to death.”  

- Argument ~ Commercial cat food is also highly supplemented and high in plants!: Yes, big name commercial cat foods are highly fortified as well due to the fact that that these foods are also borderline vegan diets and the little meat in them is rendered at high temps from injured animals, sick animals, and even euthanized pets. These foods are not good for cats. There are not “tons of cats eating these foods and doing just fine”. Eventually these diets catch up to them, but it’s usually dismissed as just aging. Not to mention, again, cats are stoic and will not show for a long time when something is wrong with them. Even in higher quality foods with supplementation: You must consider though what I said above in regards to pancreatic health, digestibility, palatibility/mental health, and dental health.

- Argument ~ Commercial cat food is full of bad stuff like organs and euthanized pets and fillers!: While it’s true many of the commonly fed cat food brands out there contain sketchy ingredients, vegan cat food is NOT the answer to this, education is! There are high quality, meat based cat foods out there that don’t have sketchy ingredients in them. Some can even be found in places like Walmart, Petco, and Petsmart. People simply don’t know what’s in their cat’s food, and don’t think about it because these poor quality foods are so commonly fed. We need to educate people, and encourage people to research proper companion animal nutrition, and what foods and ingredients to buy and avoid. Also, vegan cat food is literally just filler and vitamins. 

- Argument ~ There are plenty of cats on plant based diets, so clearly cats can survive on it!: So yes, there are cats currently on plant based diets. I’m not interested in whether or not they can survive on it. To survive is not the same as to thrive. Survival can mean illness and pain, but it’s still survival. Look at how many cats are on poor diets such as friskies, Fancy feast, meow mix, etc. They survive on it, but eventually it catches up to them and they often have problems later in life. There will always be exceptions to the rule. Just like there are humans who lived to 90-100+ smoking cigarettes and eating red meat daily, there may be some cats that live long lives on plant based diets. That doesn’t mean most cats and humans won’t succumb to that though. Not to mention that plenty of these cats are indoor/outdoor cats, meaning they’re most likely supplementing with whole prey, which is one of the best things for them.

- Argument ~ Plant based diets may not be natural for cats, but neither is beef or tuna or chicken!: Meat of any kind is more natural to them than plant matter, as we can see by their anatomy and physiology their system is designed to consume mostly meat. The thing is, if there was a tuna on the shore the cat would likely eat it, but if they came across ground corn or wheat, they probably wouldn’t sniff it. 

- Argument ~ The food is AAFCO approved!: Please read my link on why AAFCO approval or meeting AAFCO guidelines doesn’t equal healthy or safe. Those same foods many of you trash for having sketchy ingredients in them also meet AAFCO guidelines. There are AAFCO approved foods out there causing all sorts of health problems due to their carb content. [Link]

- Argument ~ I switched my cat and he’s doing great!:  One of the things I don’t trust about people’s anecdotes is that 1) Cats are stoic animals; 2) Most people, quite frankly, feed their cats complete garbage. It’s not their fault. Animal food companies are super good at marketing and exploit people’s lack of animal nutritional knowledge. The most commonly fed foods are glorified vegan diets with little meat in them. So when you switch from that to vegan, you’re not making much of a change, so you probably won’t see much a difference.

- The ferret story: One story I love to tell my personal experience with a borderline plant based ferret and my raw fed ones. Ferrets are also obligate carnivores and have similar physiology and nutritional requirements to cats, mind you. A vegetarian girl I knew fed her ferret a food with the least amount of meat she could find, and as I said before, mind were fed a mix of raw meat, bones, and organs, and a 90% meat kibble with no starches or grains. Her ferret was small, skinny, had coarse fur, smelled awful and extremely musky, had constant, massive defecations with frequent bouts of diarrhea, and his fecal matter smelled vile. Poop is a very strong indicator of ferret health. Mine were large, muscley, had soft soft fur, smelled like corn chips, had a few small bowel movements per day, and it didn’t smell too bad. Which ferret sounds healthy and which sounds like it’s surviving?

- Equivalences: To finish this off, vegan cat food is roughly the equivalent of feeding a human tofu for protein and vitamin supplements, and not even really because at least our systems can properly digest tofu. Would you be skeptical of how healthy that is? Last thing, let me ask you a question: Would you think it’s healthy for a human to eat only meat? What about an obligate herbivore like a cow being fed only meat? No? So then why would it be healthy for a cat, an obligate carnivore, to eat plant based?

- Vet Opinions: The vast majority of vets and feline nutritionists do not support a vegan diet for cats. Please read this link for vet opinions, which includes the problems with vegan cat food brands:  [Link]

There is virtually no reputable evidence or expert approval to support the long term safety and healthfulness of fully plant based diets for cats, yet tons of evidence against and expert disapproval on fully plant based diets for cats. The only evidence that supports plant based cats is anecdotal, and there’s even plenty of negative anecdotes. If you feed your cat a plant based diet, you are taking a shot in the dark. Please don’t let confirmation bias guide your evidence. Please feed your cat a high quality meat based diet, and advocate that everyone else as well.

Hopefully this proves that a plant based diet is physiologically inappropriate for a cat, and will become detrimental to their health with time.

anonymous asked:

How to respond to people that say we're meant to eat meat and that is the way we have evolved?

The neanderthal were better adapted for a diet higher in protein, but not much, homo sapiens are starchivores, that is what we are!  Its simply a lack of a quality education that you have to deal with people who don’t understand this difference.  

There is a limit, considered to be 35–40%, to the amount of energy requirements humans can derive from proteins; above this ceiling protein toxicity can occur, which can cause death quite rapidly (Speth 2010).  = not a carnivore

Modern humans require a reliable source of glycemic carbohydrate to support the normal functioning of our brain, kidney medulla, red blood cells, and reproductive tissues. The brain alone accounts for 20–25% of adult basal metabolic expenditure (Fonseca-Azevedo and Herculano-Houzel 2012). In addition to the demands of the brain, red blood cells require approximately 20 g glucose per day directly from the bloodstream (Mulquiney et al. 1999). 

Read this entire paper on carbohydrate and human evolution

You have taken on a colossal job of trying to reeducate someone in a single conversation.  


Glucose is the main energy source for fetal growth, and low glucose availability can compromise fetal survival (Herrera 2000; Baumann et al. 2002). During pregnancy a woman has a minimal requirement for 70 –130 g/day of preformed glucose or glucose equivalents to maintain optimum cognitive function in the mother and to nourish the fetus.

At peak lactation, mammary glands require an additional 70 g glucose/day for synthesis of lactose, the main sugar in milk (Institute of Medicine 2006).

The rapid growth in hominin brain size during the Middle Pleistocene will have required an increased supply of preformed glucose. Such increased demands can be met through a range of biologically and culturally driven dietary adaptations. Noting that there is considerable overlap in date estimates for the origins of controlled fire use and the origins of AMY1 CNV, we hypothesize a gene-culture coadaptation scenario whereby cooking starch-rich plant foods coevolved with increased salivary amylase activity in the human lineage. Without cooking, the consumption of starch-rich plant foods is unlikely to have met the high demands for preformed glucose noted in modern humans.

So people who don’t get this and think they are Neanderthal…  well maybe they are, they are surely headed for extinction!  

We cooked starch therefore we became large brained world dominators.  Those trying to restrict glucose are going to be small brained.

You can go into all the anatomical differences, but anyone arguing is probably not intelligent enough to grasp that they aren’t cats on their own, your help will not convince them.  Maybe dare them to eat a can of cat food every day for a week to prove that they are carnivorous and you will eat a bowl of oatmeal to prove you are not. 

anonymous asked:

Humans r carnivores so we can eat meat

Sigh. I think the time has come to explain as thoroughly as possible.

DISCLAIMER: I am not here to tell anyone to stop eating meat. I am not here to shit on your lifestyle, and I am not here to ‘force my beliefs down your throat’. I am merely educating those who are interested. I am stating facts, based off of research that does not come from the internet (which could be written by anyone like you and I) but from real scientific research, doctors, and books (whom are, of course, not allowed to promote fake facts). What you do with this information is your own choice.

Our anatomy, physiology, biochemistry, and psychology all indicate that we are in fact not carnivores. Carnivores eat raw meat, straight from the carcass, and not only the flesh, but eating the muscle meat as well as the organs. They make sure they lap up the warm, fresh blood as well as other bodily fluids without hesitation.

Most of us love animals. We do not salivate when we see a little pig - in fact, we wanna play with it! Most of us do not salivate at the idea of crushing the life out of that pig, or gnawing on its insides. We can not imagine slurping the hot blood while ripping out its intestines, getting it all over our faces, hands, and bodies. These behaviors are not moral to humanity, perhaps are even sickening.

Slaughterhouses have the scents of those of death and blood. People who have been in one find them unspeakably abhorrent - in fact, no one is allowed to visit anymore. Employees find slaughterhouse conditions impossible to be okay with, which shows up in slaughterhouses having the highest employee turnover rate of any industry. Slaughterhouses do not fit in with our concepts of kindness and compassion.

We buy our meat off the shelf, packed neatly, without veins or bones or a carcass. Majority of adults agree that if they had to kill the animal themselves in order to eat it, they wouldn’t do it. We disguise animal flesh by only eating small cuts of the muscle and some organ meats. However, even then we are told not to eat them raw, but instead cook them and camouflage them with condiments.

Now, lets see an incomplete list of the major biological differences between humans and carnivorous creatures.

Humans vs. Carnivores, shall we?

  1. Walking: We have two hands and two feet, and we walk erect. All of the carnivores have four feet and perform their locomotion using all fours.
  2. Tails: Carnivores have tails.
  3. Tongues: Only the truly carnivorous animals have rasping tongues. All other creatures have smooth tongues.
  4. Claws: Our lack of claws make ripping through skin or tough flesh extremely difficult. We possess much weaker, flat fingernails instead.
  5. Opposable thumbs: Our opposable thumbs make us extremely well equipped to collect a meal of fruit in a matter of a few seconds. Most people find the process effortless. All we have to do, is pick it. The claws of carnivores allow them to catch their prey in a matter of seconds as well. We could no more catch and rip the skin or tough flesh of a deer or bear barehanded than a lion could pick mangos or bananas.
  6. Births: Humans usually have children one or two at a time. Carnivores typically give birth to litters.
  7. Colon formation: Our convulated colons are quite different in design from the smooth colons of carnivorous animals.
  8. Intestinal length: Our intestinal tracts measure roughly 12 times the length of our torsos (about 30 feet).This allows for the slow absorption of sugars and other water-borne nutrients from fruit. In contrast, the digestive tract of a carnivore is only 3 times the length of its torso. This is necessary to avoid rotting or decomposition of flesh inside the animal. The carnivore depends upon highly acidic secretions to facilitate rapid digestion and absorption in its very short tube. Still, the putrefaction of proteins and the rancidity of fats is evident in their feces.
  9. Mammary glands: The multiple teats of abdomens on carnivores do not coincide with the pair of mammary glands on the chest of humans.
  10. Sleep: Humans roughly spend two thirds of every 24-hour cycle actively awake. Carnivores typically sleep and rest from 18 to 20 hours a day and sometimes more.
  11. Microbial tolerance: Most carnivores can digest microbes that would be deadly for humans, such as those that cause botulism.
  12. Perspiration: Humans sweat from pores on their entire body. Carnivores sweat from the tongues only.
  13. Vision: Our sense of vision responds to the full spectrum of color, making it possible to distinguish ripe from unripe fruit at a distance. Meat eaters do not typically see in full color.
  14. Meal size: Fruit is in scale to our food requirements. It fits our hands. A few pieces of fruit is enough to make a meal, leaving no waste. Carnivores typically eat the entire animal when they kill it.
  15. Drinking: Should we need to drink water or any liquid substance, we can suck it with our lips, but we cannot lap it up. Carnivores’ tongues protrude outward so they can lap water when they need to drink.
  16. Placenta: We have a discoid-style placenta, whereas the carnivores have zonary placentas.
  17. Vitamin C: Carnivores manufacture their own vitamin C. For us, vitamin C is an essential nutrient we must get from our fruit.
  18. Jaw movement: Our ability to grind our food is unique to plant eaters. Meat eaters have no lateral movement in their jaws.
  19. Dental formula: Mammalogists use a system called the “dental formula” to describe arrangement of teeth in each quadrant of the jaws in an animal’s mouth. This refers to the number of incisors, canines, and molars in each of the four quadrants. Starting from the center and moving outwards, our formula, and that of most anthropoids, is 2/1/5. The dental formula for carnivores is 3/1/5-to-8.
  20. Teeth: The molars of a carnivore are pointed and sharp. Ours are primarily flat, for mashing food. Our “canine” teeth bear no resemblance to true fangs. Nor do we have a mouth full of them, as a true carnivore does. 
  21. Tolerance for fat: We do not handle more than small quantities of fat well. Meat eaters thrive on a high-fat diet.
  22. Saliva and urine pH: All of the plant-eating creatures (including healthy humans) maintain alkaline saliva and urine most of the time. The saliva and urine of the meat eating animals, however, is acidic.
  23. Diet pH: Carnivores thrive on a diet of acid-forming foods, whereas such a diet is deadly to humans, setting the stage for a wide variety of disease states. Our preferred foods are all alkaline forming.
  24. Stomach acid pH: The pH level of hydrochloric acid that humans produce in their stomachs generally ranges about 3 to 4 or higher but can go as low as to 2 (0 = most acidic, 7 = neutral, 14 = most alkaline). The stomach acid of cats and other meat eaters can be in the 1+ range and usually runs in the 2s. Because the pH scale is logarithmic, this means the stomach acid of a carnivore is at least 10 times stronger than that of a human and can be even 100, or even 1,000 times stronger.
  25. Uricase: True carnivores secrete an enzyme called uricase to metabolize the urid acid in their flesh. We secrete none and so must neutralize this strong acide with our alkaline minerals, primarily calcium. The resulting calcium urate crystals are one of the many pathogens of meat eating, in this case giving rise to or contributing to gout, arthritis, rheumatism, and bursitis.
  26. Digestive enzymes: Our digestive enzymes are geared to make for easy fruit digestion. We produce ptyalin - also known as salivary amylase - to initiate the digestion of fruit. Meat-eating animals do not produce any ptyalin and have completely different digestive enzyme ratios. 
  27. Sugar metabolism: The glucose and fructose in fruits fuel our cells without straining our pancreas (unless we eat a high-fat diet). Meat eaters do not handle sugars well. They are prone to diabetes if they eat a diet that is predominated by fruit.
  28. Intestinal flora: Humans have different bacterial colonies (flora) living in their intestines than those found in carnivorous animals. The ones that are similar, such as lactobacillus and e. coli are found in different rations in the plant eaters’ intestines as compared to those of carnivores.
  29. Liver size: Carnivores  have proportionately larger livers in comparison to their body size than humans.
  30. Cleanliness: We are the most particular of all creatures about the cleanliness of our food. Carnivores are the least picky, and will eat dirt, bugs, organic debris, and other items along with their just killed food.
  31. Natural appetite: Our mouths water at the sights and smells of the produce market. These are living foods, the source of our sustenance. But the smell of animal usually puts us off. Meat eaters’ mouths water at the sight of prey, and they react to the smell of animals as though they sense food, unlike humans.

When we weigh the evidence, we can see that too many considerations exist in physiology, anatomy, aesthetic disposition, and psychology for us to seriously entertain the notion that we were designed to eat flesh.

And yes, we used to hunt to survive, but we also used to hit each other over the head with clubs and smack rocks together to make a fire. We have alternatives now, and we do not need to cause harm in order to survive, unlike animals, who do need meat to survive. The choice is ours.

I highly recommend ANYONE to read ‘The 80/10/10 Diet’ by Dr. Douglas N. Graham, which has been adopted by several olympic stars. It is extremely educative as in what fruit does to the body and how it stands in comparison to meat, as well as going straight through myths. 

On the Subject of Vegan/Vegetarian Cats and Dogs

I’ve been seeing this issue come up on my dashboard a lot lately and felt I should say something about it.

I’ll be blunt: your cat and dog CANNOT live on a vegan diet.

There is no reputable veterinary medical source which would recommend this diet for your pet. None. Oh, the field of veterinary medicine is well aware some people are trying to force these lifestyle choices on their pets and has been doing as much as it can to inform people of how detrimental such a diet is to their pets.

People might think they have a decent argument for feeding their pets a vegan/vegetarian diet. Fine. Bring it on. In the meantime, let me teach you a few things about animal nutrition.

In nature, carbohydrates are most commonly found as polysaccharides. In animal and plant tissue alike, polysaccharides are the major form of carbohydrate. Thus, most carbs ingested by animals are in the form of polysaccharides which, as complex molecules, must be broken down before they can be absorbed/utilized. To do this, monogastric animals like cats and dogs depend on endogenous enzymes.

The major forms of polysaccharides ingested are starches (mostly seen in plants) and glycogen (aka animal starch). Starches are formed by alpha-linkages into substances like amylose, which require amylase to break down.

Humans have amylase in our saliva (salivary amylase doesn’t do much but it still exists). This is why if you hold a complex carbohydrate in your mouth, it becomes sweeter over time (the enzyme is producing sugars from the carbs). We secrete additional amylase and other enzymes in the stomach and (most significantly) in the intestinal tract to digest and absorb these molecules.

Cats have almost no amylase in their digestive systems (less than 5% of what dogs produce) and are deficient in other enzymes (sucrase & others) required to utlize carbohydrates (especially carbohydrate sources of protein) efficiently. They lack hepatic fructokinase, which means they cannot digest foods high in surcrose. A high sucrose meal will cause fructosuria (fructose in the urine, which is NOT normal). They have little to no glucokinase activity, and this activity does NOT increase in response to feeding more carbohydrates (as it does in dogs). The digestive tract of the cat is significantly shorter than ours, which further limits their ability to digest and absorb carbohydrates.

At least 17-20% of a cat’s diet must be composed of animal protein (this requirement is higher in kittens, who need about 26%). A single meal deficient in the amino acid arginine will result in hyperamonemia (excessive ammonia in the blood). Ammonia is TOXIC to a lot of things, especially brain cells. A cat without arginine will die, quickly. And guess what? Arginine is found abundantly in animal protein and not so much in milk/plant proteins. Additionally, cats cannot synthesize the amino acid taurine, which is found in animal proteins. Cats without taurine can develop issues with their eyes and can even become blind. Taurine can be found in soy and other protein sources BUT as we’ve already discussed, cats are not good at utilizing non-animal sources of protein.

So, if your cat doesn’t get animal protein, they are going to be nutritionally deficient, period. No ifs, ands or buts. A vegan/vegetarian diet is unacceptable.

There are two commercially available vegan/vegetarian diets for cats. NEITHER OF THESE has been found to meet the basic dietary standards set up by AAFCO or the AVMA. They are not adequate.

Now, let’s talk about dogs. First thing is first: dogs are NOT wolves. Dogs are descended from wolves, yes, but their digestive systems are somewhat different from the wild wolf (wolves do have SOME amylase but not as much as dogs tend to, according to what I’ve read). Recent genetic studies (attempting to trace the genetic point of domestication in dogs) suggest that most dogs descended from a now-extinct variety of the wolf and that at the time of their domestication, dogs were not scavenging off of man. Dogs may have actually served as hunting partners and came to us in our hunter-gatherer days. Interestingly, those breeds of dog who evolved near humans with agricultural societies developed larger amounts of amylase-producing genes than breeds whose people were less agricultural (huskies are one example).

Dogs CAN digest carbohydrates and feeding more carbs to them will increase the activity of certain enzymes. HOWEVER, they still have a minimum protein requirement (around 4% of their diet, 12% for puppies). ALSO, dogs can digest naturally occurring carbohydrates and fats. They are not, however, very efficient at deriving protein from non-animal sources. Are they better than cats at it? Yes. But they are still not as good at it as we are and a dog fed only non-animal protein will almost definitely suffer from a protein deficiency, particularly as there are no vegan/vegetarian diets which meat the basic AAFCO standards. Just because a dog CAN live on a starch-based diet, does not mean they will thrive on it.. 4% of their diet is the BARE MINIMUM FOR SURVIVAL, they need more to do well. Dogs who eat mainly plant proteins suffer from a whole slew of problems. There are, to my knowledge, no reputable vets/organizations who would recommend a vegan/veterinarian diet for a dog.

You are most likely NOT a veterinary nutritionist. You have not taken courses in nutritional physiology and therefore do not have the training necessary to formulate a vegan/vegetarian diet which is not incomplete in some way. Commercial dog foods might not be the best thing, but they at least meet the minimum standards (again, minimum does not equate to best but in comparison to the vegan diets, it’s better).

Animals depend on us for their nutritional needs. It is up to us to provide them with what they have to have in order to thrive. It is fine if you, as a human being with a choice, choose to live as a vegan/vegetarian. But our pets do not have a choice. They should not be forced to live that way.