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Plant-based diet (vegan/vegetarian) vs. meat-eating diet (predan) from a medical perspective

Nyomtatás By : on : 2013-09-24 comments : (0)

Vegetarians do not eat meat. Fish is also considered meat. Vegans do not eat or drink any animal products such as milk or other dairy, they do not take eggs and may avoid honey too.    What do they eat then? Vegetables, fruits, grains, nuts, legumes, spices, herbs, vegetable milk, vegetable fat, mushrooms. A vegan who takes a lot of pasta and bread, may not necessarily have enough vegetables and fruits. Such a diet is still not ideal. Predan is a person who also eats meat regularly and/or takes little vegetables/fruits. It may be that such a person eats meat only occasionally, but since he/she eats a lot of pasta and bread, there is not enough vegetables in his/her diet. The opposite of vegan/vegetarian is not a meat-eating diet, as all persons who eat meat also eat vegetables, and in general the only difference would be the frequency of meat-eating. There are people who eat meat more than once a day (cold cuts, sausages for breakfast), cooked or fried meat for lunch, and leftover meat for dinner, but there are also predans who eat meat only 1-2 times a week.

There are a variety of reasons for being vegetarian: ethical (to protect animals), religious, environmental, to achieve a greater physical output (ie. in sports), and there is also a health reason which I will discuss herewith.

So the reason behind a predan diet (eating meat regularly) may be habit, current social norms, family traditions, misleading propaganda of scientific records, depreciation of animal life, as well as the fact that the abuses made by food industry generally take place behind the scenes, thus killing in slaughterhouses is completely hidden before the eyes of an average person. Knowing this much less people would eat meat.

What type of a diet would better suit human anatomy?

Wrong question! Although this question is often asked and discussed, it is still wrong because based on the human body and intelligence, a human being is capable of following many types of diets. This however does not mean that humans can go on following any of them without repercussions later. Human dentition, a long gastrointestinal system, the abdomen, digestive fluids, intestinal bacterial flora are capable of handling a mixed diet. In other words:

  • We are capable of eating meat, dairy and eggs, but anatomically there is no reason to consume all of these despite our capability
  • We are capable of eating plant materials, in fact we can eat them alone. An exclusively plant diet will not cause our dentition or digestive system to get exhausted or start to malfunction.
  • From the perspective of food quality, we call a diet mixed if besides raw vegetables, one also takes cooked ones. Following a mixed diet includes eating dairy products, eggs too, it is not only meat that makes a mixed diet.
  • Our anatomy is not capable of consuming meat on its own, especially raw meat. Our dentition and digestive system is not at all like that of a tiger or lion. Therefore, I call such a diet predan (meat-eating), not predator (carnivorous).
  • Without doubt we are not capable of consuming grass on its own – that is raw grass – like in case of a cow, horse, or elephant’s digestive system. Some vegetables humans take cooked, prepared with heat, peeled, cut, using herbs, thus making it more easily digestible.

To summarize: human anatomy does not exclude a vegan diet, especially not a vegetarian one. There is no necessity to eat meat by all means, thus follow a predan diet. A human being is capable of digesting meat, but cannot operate without vegetable foodstuff. Anatomic conditions do not determine a person’s habit of eating meat, nor do they make it impossible to give it up completely.

Characteristics of carnivorous animals

  • No fibers – meat does not contain any fibers. Meat is free of fibers so it obstructs bowel movement, defecating.

  • Short intestinal tract – this compensates the lack of vegetable fibers, this is why a tiger does not have constipation.
  • Dentition – carnivorous dentition. Humans do not have such teeth.
  • Eats raw meat – humans do not have such habits.
  • Quick digestion, special intestinal flora – putrefactive flora may cause a lot of diseases in humans, the same in tigers is considered normal.
  • Not fit for a vegetable diet – a tiger could not digest a simple salad.

Characteristics of humans

Humans need a lot of fibers and antioxidants from vegetables. The only way the human intestinal tract, which is 4.5 m long can work properly, is if it contains enough plant materials, fibers to assist spontaneous bowel movement. Antioxidants which are essential for biochemical and physiological functioning cannot be fully taken up by humans from only meat. Unfortunately, due to the past decades’ agricultural transformation, vegetable foodstuff contains significantly less nutrition, so the usual vegetable portion may not cover a person’s necessity anymore.

Humans have a medium size intestinal tract which requires enough vegetable fibers and the absence of putrefactive bacteria for food to move properly through in 1 day.

Humans would get sick by eating only meat causing poor bowel movement due to the lack of fibers, improper intestinal flora, excessive easily digestible proteins in meat, toxins, saturated fat.

Humans cook their food because that is how they can digest it well. There is no other animal on earth which would cook its food, except for swine which receives cooked leftover food from man.

Humans like various tastes: sweet, salty, spicy, sour, hot, and aromas. These can manifest both through vegetable and animal preparations.

Can a vegetarian diet supply all the nutrition we need?

Most certainly the right answer is YES. Let me emphasize however that to evaluate a diet with an appropriate dietitian perspective today is not to judge it based on the inclusion or abandonment of certain food ingredients. There is no such thing as a normal or a completely wrong, widely followed diet. There are only shortages, but those may appear in every single type of eating habit. A growing number of people are forced to give up dairy products, gluten, meat or eggs due to food allergy and even such people’s nutrition needs can be supplied.  Nutrition need of vegetarians and vegans can be fully supplied also, it only requires some knowledge as any other diets do. The same way predan diet has certain risks, deficiency symptoms, which need as much attention as risks of a vegan diet.

Risk of nutrient deficiency – vegans only?

There is no doubt or argument that a plant diet contains better quality fat, enough fibers and more complex carbohydrates. What is argued by meat-eating pros is the supply of proteins (amino acid), B12 vitamin, iron, creatin in vegan diets. Another reason in favor of vegan (instead of predan) is a more efficient supply of antioxidants, fibers and vitamins. Let’s have a look at the so-called endangered or argued nutrients in vegan diet and a diet containing a lot of meat, little vegetables.

Amino acids

Amino acids are needed to build important proteins in the body, such as structural proteins (collagen, elastin), transport proteins (hemoglobin, myoglobin), enzymes, immunglobulins, interferon, DNS and hormones (insulin, tiroxin, growth hormone). They can be divided into two groups: essential proteins (those that cannot be synthesized natively and therefore must be supplied through a diet) and nonessential proteins which the body can synthesize per type. Therefore, the key question is the supply of essential amino acids coming from outside sources.  Other than meat, all amino acids can be found simultaneously in dairy products, eggs and soy too. But we must also note that plants are full of essential amino acids, and even if not all essential amino acids are present in proper quantity in a plant, it can be compensated by eating more types of plants at the same time or at least within 2 days difference in order to gain all essential amino acids without meat. It is not prescribed in biology that we can only eat foodstuff which supply all the required essential amino acids. This top most expectation –a common fallacy – has only been formulated in the past decades.

The world’s four most popular grains – corn, wheat, rice and soy – could provide the world’s population enough proteins and adequate amino acids while their growing would take up only 4% arable land as opposed to animal husbandry which requires 30%.

According to various literatures, all essential amino acids can also be found in Brussels sprout, carrot, corn, cauliflower, cucumber, squash, potato, green peas, all types of nuts, sesame and sunflower seeds, as well as protein of tomato. It may be that they do not contain all amino acids in appropriate quantities, but we can make a good selection of them.

Essential amino acids

  • Isoleucine
  • Leucine
  • Lysine
  • Methionine
  • Phenylalanine
  • Threonine
  • Tryptophan
  • Valine

Optional essential (in case of infants, children and certain diseases – cirrhosis, cancer, renal insufficiency, sepsis etc.)

  • Arginine
  • Cysteine
  • Glutamine
  • Tyrosine
  • Serine
  • Taurine
  • Glycine
  • Histidine


  • Alanine
  • Aspartic acid
  • Asparagine
  • Glutamic acid
  • Ornithine
  • Proline

Stool analysis

I have conducted several thousand stool analyses in my medical practice to explore bacterial flora, inflamed substances and immune function. I have to say that today’s continuous consumption of animal protein changes bacterial flora to become putrefactive (clostridiums, esherichia coli, etc.). These bacteria are then extremely difficult to get rid of from the intestinal tract, even if the diet has been changed. Putrefactive flora enhances inflammatory activity, and in chronic cases reduces immune function. It can be said that an adult body cannot process, absorb and properly digest a large amount of animal proteins taken by food, and through bacterial processes its partial breakdown produces a number of harmful metabolites, toxins which inhibit recovery. Civilized people do not suffer from a lack of proteins, rather from protein poisoning! All this is nicely demonstrated by the path of recovery because if such a protein poisoned patient switches to a vegan diet, inflammation and other chronic diseases disappear already from that.

It may be concluded that a diverse selection of plant ingredients offer the human body plenty of amino acids in proper quality and quantity, and although children and expecting ladies are advised to complete their vegan diet with dairy products, in other parts of adult life animal proteins are more harmful than useful to the human body. Excess animal proteins poison the body, ideal human protein intake is closer to minimum, so the border line between minimum and maximum is very narrow.

Vitamin B12

Cobalamin participates in the synthesis process of DNS and protein, in methionine synthesis, process of the brain, the central nervous system and hemopoesis. It is often said that vitamin B12 can only be obtained from meat, but this is not true. Plant materials also contain it in significant quantities, ie.: sprouting seeds, pickled cucumber, sauerkraut (sour cabbage), various grains.

Daily requirement

  • Infant: 0,5-1,5 µg
  • Child: 2,5-5,0 µg
  • Adult: 5,0 µg
  • Pregnant woman: 6,0 µg
  • Nursing mother: 6,0 µg
  • Elderly: 5,0 µg


  • Beef liver: 65µg
  • Beef kidney: 33,4µg
  • Beef: 2µg
  • Egg yolk: 2µg
  • 1 liter cow’s milk: 4,2 µg
  • White breads: 0,13-0,24 µg
  • Brown breads: 2-3µg
  • Muesli: 4-5µg
  • Cheese: 1-2 µg
  • Manna-rax: 100µg
  • Sprouting seeds: 30-40µg
  • Yeast: 54µg
  • Pickled cucumber: 60µg
  • Sauerkraut: 65µg


Iron is responsible for transporting oxygen and electrons, it is a constituent of hemoglobin, thus its deficiency leads to anaemia. Absorption of iron greatly depends on the condition of the small intestinal flora and the concurrent presence of vitamins (C) taken by food, citric acid, organic acids and flavonoids.  Therefore, it is a fact that although animal products contain larger amounts of iron, and while plant fibers (phytates, polyphenols) may even bind iron, still it is possible to absorb similar amounts of iron from a smaller quantity found in a plant diet due to the presence of accompanying substances. We know that there are no more anaemia patients with iron deficiency among vegetarians. (Am.J.Clin.Nutr. 1994. may 59 (5 Suppl.) (1233-1237)

Loss of iron is significant in case of chronic inflammation, strong menstrual bleeding, protein deficiency or tumors. Pregnancy also requires double amounts.


Creatine plays a major role in our energy balance, in ATP synthesis. Creatine may be absorbed primarily from meat preparations and various fish. Creatine however may also be manufactured by the body from arginine and glycine (Healthy adults can produce both amino acids so they are not considered essential.). Therefore it is not necessary to derive creatine from meat.


Plant antioxidants (flavonoids, flavones, antocians, oligomer proantocianoids) are comprised of about 5000 different compounds which can be found in a broad range of edible plants. They have an extremely strong antioxidant effect, they are even able to participate in “recharging” in the regeneration of vitamin C, vitamin E, GSH. Their most well-known representatives are quercetin and rutozyd.

Meat dishes, dairy products and eggs do not contain any such plant antioxidants.

Omega 3 fatty acids

Omega 3 fatty acids play an important role primarily in the prevention and therapy of cardiovascular diseases (blood viscosity, blood pressure, cardiac cycle, arteriosclerosis, etc.), menstrual disorders, inflammation and psychological balance. It cannot be manufactured by the body so it needs to be derived from outside. There are plant and animal sources. General foodstuff – both plant and animal products are low in omega 3 fatty acids. Exceptions among meat are some sea and fresh-water fish, crayfish (herring, tuna, salmon, eel, trout, carp, mackerel), and among plants exceptions are certain vegetable oils (linseed, hemp, rape, walnut, soy, wheatgerm). Neither predans (meat-eating) eat enough of the listed fish, nor do vegetarians/vegans have enough of these oils. Therefore, it is important for both types of diets to complete their eating habits. But neither is better or worse than the other.


There are no vitamins which can be found only in animal flesh, but there are numerous vitamins which can only be derived in proper quantity from plants. Vitamin supplements are essential for both types of diets, it is not more important for vegans or predans.


Fibers are carbohydrates which do not get digested or absorbed in the digestive system, still they have an important role in preserving our health. They bind harmful materials (toxins, gases and bile acid), slow down the absorption of unnecessary carbohydrates, create bulk in the intestine, this way assuring passage. Without them one may experience constipation and numerous organic function disorders. Animal products do not contain any fibers (that is meat, dairy products or eggs), plant food on the other hand contain fibers in large quantity, except for refined grains. I know from experience that replacing insignificant meat consumption (eating meat 1-3 times a week) with a vegan/vegetarian diet may be enough to put an end to chronic constipation. We can see that eating meat even a few times a week can destroy the ideal fiber intake, thus causing constipation.


It is evident today that we need more than the main nutrients in our lives, we need secondary plant substances, saponins, flavonoids, volatile oils, tannins, etc. These substances are important catalyzers which often carry healing qualities, and they are certainly not contained (even in traces) in meat, dairy products or eggs.

Toxic waste (ptomaine)

It is produced in meat that has been left to sit. Meat however may not only be left to sit in the kitchen, it can also sit in the digestive system while several kilograms of bacteria settle on it at much higher than room temperature, at 38 °C. So nowadays, not only toxic degradation products coming from meat cells are considered to be part of ptomaines, but also toxins (neurin) produced by putrefactive bacteria settling on meat inside us.

Antibiotics, fear compounds, chemicals, steroids

Livestock tend to get sick more easily through industrial animal agriculture’s extremely cruel methods than through free-range farming. Sick animals are treated with chemical medicines (antibiotics, steroids, hormones), as the only goal is for them to reach a bodyweight and physical state ideal for their slaughtering at any cost. These medicines stay present in meat. Of course, chemicals are also there in plants due to pest control and farming, but their quantity and risk of harm to human body is much less compared to medicines used in case of animal farming. Moreover, it is a fact that animals produce a lot of fear compounds prior to their transport to slaughterhouses and their killing which remains in meat afterwards.

All in all we can conclude that the diet of those eating animal products (predans) may have some shortages, as well as that of vegans, but both may be completed by a properly selected diet, modern orthomolecular medicines, food supplements. We often hear about deficiencies of vegan diet. This is without a reason, as a meat-eating diet (predan) has many more deficiencies, it lacks for example fibers, vitamins, antioxidants, omega 3 fatty acids, phytochemicals.  It is also a fact that animal products contain a lot more harmful materials (bacteria, toxic waste, antibiotics and other medicines) than plants do.

Can we get all nutrients from meat?

Based on the above, my answer is clearly no. But generally the misunderstanding is that almost all predans (eating meat and dairy products) are convinced that they do not consume much meat (“only 2-3 times a week”, “only once a day”, “only fish and poultry”) and besides this amount all the plant foodstuff are supposed to cover deficiencies. Unfortunately this is not so. Digestion of meat increases the need for plant materials. Meat and dairy products disturb the proper ratio of plant materials by their volume, meat disturbs intestinal flora even in small quantity, not to mention an important fact that besides meat such people mainly consume milk, yogurt, cheese and eggs, even more than once a day.

Such a “mixed” diet does not carry enough fibers, antioxidants, fresh plant materials, omega fatty acids, vitamins. Due to a mixed diet the intestinal flora becomes diseased and passage slower.

Whole food vegan diet

There may be differences between vegan diets. A whole food vegan diet does not contain so-called sophisticated food ingredients like white flour, white sugar, ready-made or canned food, powders. It avoids frozen meals and does not apply heat on food too long. It uses less salt, does not use salt with potassium, only table salt or sea salt. It prefers organic foodstuff and as explained above, applies various food supplements.

Living nourishment – dead nourishment

Living nourishment refers to food which has a chemical structure and energetics that has not yet been damaged: living vegetables, fruits freshly picked. Vegetables and fruits kept in a root-cellar are considered living. Seeds which have only been cut or ground before use are living also. Dried plants or parts of them are living too, just like anything that has been freshly prepared, cooked or cooked for a short time. Cold-pressed oil is also living. Preserved food, or something that has been cut or ground a long time ago is considered dead. Frozen, over-cooked food and dishes that have been heated several times are dead, as well as conserved food, something that has been mixed with chemicals, ready-made things (powders, sauces, etc.) and meat. Bulk manufactured vegetable oil in plastic flasks which contain a lot of trans fatty acids and chemicals are also dead food. Anything that has been fried in animal fat or oil is considered dead.

Therefore, vegan diet can also be harmful if it contains too much dead matter, carbohydrates, little fresh materials, too much conserved food, or if it is not well balanced and diverse. It is not appropriate to take pasta with pasta or bread with bread in a meal (although it is plant based). Also, dishes prepared from cans or ready-made packets are harmful.

Various grains

One opinion of those advertising paleoite diet is certainly true saying that Europeans have a hard time digesting proteins of wheat and rye. I conduct numerous food tests and my experience is that avoiding food with gluten can cure digestive disorders and various other inflammatory diseases even if gluten sensitivity cannot be detected by laboratory methods. Yet, I do not share other theses of paleoites. I do not think for example that humans would not need any grains that contain carbohydrates, although the level of this need may vary according to individuals, illnesses, lifestyle, and it is possible that there is an imbalance in a person’s diet. Rice, corn, millet, amaranth, buckwheat, quinoa may be eaten more or less without any restrictions, except for those who have food intolerance for them based on tests. In case of any illnesses, I generally do not recommend eating food made of grains, rye, bulgur, durum, kamut. Those however who have consumed these without any trouble before,  should not need to avoid them.

Further reasons for eating a lot of plant food

Besides reasons listed above (full of fibers, omega 3 fatty acids, vitamins, phytochemicals, antioxidants), here are additional important reasons in support of eating predominantly plant materials:

  • it is rich in essential fatty acids
  • intake of saturated fatty acids is reduced
  • cholesterol intake and absorption is reduced
  • it supports the balance of nitrogen (it is poorer in polynucleotides)
  • acid-base balance improves (it is mostly fresh vegetables which can provide an alkalic chemical effect on the body)
  • it is lower in calories, if there is no excessive eating of grains with carbohydrates and sweets
  • it is more favorable for physiological intestinal flora (Br.J.Rheumatol. 1994.jul.33.(7)(638-43)
  • enhances intake of  L(+) jobbra forgató lactic acid
  • phytotherapy – healing-preventive nourishments

Further reasons about harmfulness of meat

Besides lacking fibers, providing too much proteins, causing intestinal flora to become putrefactive, containing medicines and lacking antioxidants, here are some more arguments against meat:

  • excessive cholesterol intake
  • ratio of saturated fat is too high (ideal is: P/S > 2)
  • purin, intake of nucleic acid ↑
  • acid base gets out of balance (acid ↑)
  • can only be taken after heat has been applied to it, or it has been preserved


A vegan/vegetarian diet which has been selected reasonably with expertise is not any less healthy than a predan diet. A changed physiological condition may require certain supplements, so during pregnancy or nursing vitamins D and B12 should be taken, for children under 5 attention should be paid to proper calorie intake, perhaps iron and vitamin D should be provided.

Taking these points into account, vegetarian diet is normal (Am.J.Clin.Nutr. 1994.may 59 (5 Suppl.) 1176-1181) (J Am Diet Assoc. 2003 Jun;103(6):748-65. ).

I apply vegan and vegetarian diets which are effective therapies for a number of chronic diseases, such as disorders of metabolic syndrome, or so-called specifically nutrition-related diseases (pl.: RA – Br.J.Rheum. 1994.Jún. 33 (6) (369-75), colon cancer, coagulopathy (Am.J.Clin.Nutr. 1993.Sept.58(3) 354-9).


Nutritional counseling is necessary for both predans and vegans/vegetarians, as deficiencies may appear in both cases. There are actually more problems with meat-eating diets.

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