Introduction - The Problem

The issue of essential amino acids is misrepresented. Essential amino acids are "essential" precisely because they are so easily provided for by our diet, thus synthesising them becomes unnecessary, as has also happened with vitamin C in humans. In Harper's Biochemistry 24th Ed., Victor W. Rodwell, PhD says:

It might be argued that the nutritionally nonessential amino acids are more important to the cell than the nutritionally essential ones, since organisms (eg. humans) have evolved that lack the ability to manufacture the latter but not the former group.

Tom K et al. (1995) have demonstrated, for the first time, that the human body will compensate for lower dietary protein intakes while still maintaining normal biological function, thus demonstrating that the human body is naturally adapted to "very low protein diets" (VLPD). In renal patients Tom K et al. found that 25 grams of protein per day plus some amino acid supplements simply reduced the wasting of excess amino acids. On VLPD the body has adaptations that mean that metabolism is more efficient:

• Amino acid oxidation is decreased, resulting in a lower requirement and more efficient utilisation of essential amino acids(10)
• if protein or amino acid intake is sufficient neutral NB is achieved by a postprandial suppression of whole body protein degradation, with or without an accompanying increase in protein synthesis(1,2)
• if amino acid intake is inadequate there is loss of lean body mass with negative NB(3,1)

By taking a bionomic perspective to diet, meaningful incites into our biological requirements are soon realised without the needs for endless years of research which can continue to produce conflicting results, therefore requiring "more research", the favourite call of the scientific research community. So long as they persue anthropocentric modes, they will never find results to questions about natural biological systems, since they do not investigate them at the outset.

In conventional nutritional paradigms, we refer to primary and secondary foods. Primary foods are those that are unprocessed such as vegetables, fruits and unprocessed meat, while secondary foods have been processed and include items such as bread, pasta, meat pies, candies and so forth. Primary foods are thought to be more desirable since processing reduces food value. Cooking itself is a form of food processing. In bionomic nutrition we consider that there is only one food type, that is uncultivated fruits (including some seeds perhaps) and vegetation to which we are suitably adapted to eat in their natural state without causing harm to us. In the bionomic paradigm feeding behaviour is also important. The human lacks real biological equipment to catch and eat meat, and the absence of any requirement to consume, or ability to process concentrated protein in protein synthesis without wasteful amino acid oxidation are all clear information that there is no requirement for humans to eat any concentrated proteins.

The hunger for protein seems to carry into vegetarian diets as well, with many popular texts extolling the need to eat seeds, nuts, grains and legumes in order to meet protein requirements. But it is unusual to find such foods forming more than a minor part in any natural diet, if at all.

It shall be shown that high protein foods are not necessary and are counterproductive in human biochemistry, and data in some popular vegetarian web pages and books about protein will be refuted and updated. Books such as "Vegan Nutrition, a survey of research", by Gill Langley MA PhD, which clearly have political slants, athough worthy, are somewhat misleading in scientific terms since it is anthropocentric to talk of vegan nutrition, when in fact the issue required for discussion is human nutrition. These books, in demonstrating the protein adequacy (and excess) of vegan diets, do not educate the reader in the valuable lesson of true human nutrition, based on our biological requirements.

Protein Requirements

The Frugivore

A popular myth is that fruits do not contain enough essential amino acids to supply requirements. Analysis of USDA Agricultural Handbook number 8, raw fruit EAA profiles produced the following tabulation. It is clear from this, that many fruits deliver "good quality" protein. Geoffrey Cannon, author of Food and Health: The Experts Agree, from the Consumers' Association, also says that fruits yield "quality" protein. Three to four kilos of some of the fruits suggested here, will supply sufficient protein and calories. If you apply nitrogen balance figures, then this requirement is reduced by about two thirds! From this it is easy to understand how popular modern food items containing many times the protein content of fruits and vegetables tend to oversupply protein. This is simply protein down the drain as urea! Only a diet of foods with a protein content less than about 0.5 grams per 100 grams will cause protein deficiency. Some fruits are low or deficient in one or more EAAs as are some grains and vegetables. Variety may be essential.

A Contradiction

So what's the daily protein requirement? Well, the average theoretical losses amount to about 0.34 g of protein per kg body weight per day. Clearly a recommendation to replace this loss has to have an adequate safety margin. With 2 standard deviations added to this value, it comes to 0.45 g/kg per day of "ideal" protein. Adding safety margins for digestibility and protein quality, the requirement is thus in the region of 0.75g/kg.*

Digestibility. We're very good at digesting protein. We can digest and absorb 70% - 90% of plant protein and 85% - 100% of animal (or human) protein. Remember, we digest human protein all the time -- our own tissues. We're very efficient at reclaiming and recycling our own protein.*

The More Is Better Myth

According to Harper's Biochemistry, the putrefaction bacteria in the large intestine convert amino acids into toxic amines or ptomaines, such as cadaverine (from lysine), agmatine (from arginine), tyramine (from tyroseine), putrescine (from orithine) and histamine (from histidine). And these amines are "powerful vasopressor substances". Tryptophan undergoes a series of reactions to form indole and methylindole (skatole), which produces the distinctive putrefying faecal smell of a high protein diet. The sulphur-containing amino acids are transformed into mercaptans such as ethyl and methyl mercaptan as well as hydrogen sulphide (H2S). All these gasses are very poisonous and unpleasant. Phosphatidylcholine, only found in meats, breaks down into choline and the related toxic amines such as neurine. This is evidence that meat is not well digested. Herbivores do not produce putrid excrement, but "dung" instead, some still contains sufficient nutrients to warrant eating again, such as with rabbits.

However, a meal of fruit with similar food energy value would yield about 2.6 g of protein of which 0.4 g would be wasted. A high protein food at least doubles the quantity of protein that is potentially subject to putrefication in the bowels. Worse still, the reason that plant protein is less digestible is because it is found in the tough cellulose walls of plant cells which pass through the gut undigested if not sufficiently masticated. These proteins are not available as soil for putrefying bacteria in the bowel. Animal protein wastes are highly bioavailable to putrefying bowel bacteria since they have no cellulose cell wall. It seems that only putrefying bacteria benefit from the "highly digestible" animal proteins.

The Unwritten Assumption

Textbook Nutrition

In the book Dirty Medicine 'Science, big business and the assault on natural health care', the author Martin J Walker says:

To reshape the public perception of science, the authority of science first had to be restored. Personal experience and popular perceptions had to be challenged. The experiential message of campaigning pressure groups and the subjectivity of unorthodox life styles had to be eroded. In relation to health and welfare, a new area of bowdlerised science was to take the place of proper scientific enquiry. The new philosophy was called 'risk management and evaluation'. This 'scientific' discipline, introduced a new relativity.

The answer is that this system based on weight is quantitative and not qualitative, so we discard it immediately and look for some scientific criteria. We need to look at physiology and comparative anatomy. The standard body weight system would compare a genuine anorexic with a very slim female marathon runner concluding that they are both "underweight". But in fact, the marathon runner will no doubt be fitter and healthier than the average person who is of standard body weight. So why not define a system based on a "healthiest body weight"?

Very briefly: From physiology we learn that a mass of protein also requires to be serviced by various organs which feed and take away waste. A lower body mass will therefore produce less strain on the organs of supply (eg. the lungs, liver and GIT) and elimination (eg. liver, kidneys, bowels). If we look at the anatomy we observe that wild land mammals are very lean (usually about 4% fat vs the humans 10%+) and their muscles are tough. We see that the areas of the body without muscle are bony and that the muscles are lean and do not bulge. This is certainly true of our primate cousins. The anatomy of the average westerner is quite unnatural, and the standard body weight concept is as useless as quantitative nutritional paradigms.

Practical Problems

To answer the above question, while still keeping a bionomic perspective, it is worth studying the provision of protein by other dietary sources and finding the nearest fit. Our prime objectives are to obtain foods with adequate nutrient contents and that are readily available and can fit in with our cultural limitations. This need can be served by a variety of vegetables, preferably eaten raw or perhaps lightly steamed. As a bonus these foods are low cost and provide an abundance of minerals and vitamins. Behaviour ideas would suggest that salt, spices and other artificial factors be eliminated so as not to pervert the appetite or sense of taste and smell which guides food selections in wild animals. Concentrated proteins such as animal products, seeds, nuts, grains and legumes are not required and should only be present at very low levels, just a few grams per day, if at all. To make more than a very small place in ones diet from these foods will continuously over supply the body with protein, and these foods are low in some vitamins. Many frugivores do include plant matter such as leaves in their diets, as well as small quantities of seeds, and insects, usually eaten accidentally. Surely a similar diet, should be ideal for supplying human protein, mineral and vitamin requirements, minus insects!?

Some non-orthodox nutritional authors suggest that human protein requirements, being about one third of baby protein requirements, are met on a diet that is one third as rich in protein as human milk. Other protein sources may not be as ideal as human milk, in terms of amino acid profile or digestibility. However this line of thought seems logical and worthy of analysis.

If we study the nitrogen balance figures (Table 2), we find that the growing infant requires about 3 times the protein per kg of body weight than the adult highest estimate of requirement to achieve NB (reviewed by FAO/WHO/UNU 1985). Human breast milk is 7% of calories or 1.5% protein. If 1.5% supports at least 3 times the requirements of an adult then adult requirements for ideal protein must be about 0.5% protein. If we accept the current nitrogen balance recommendations, and fruit protein contains about half the essential amino acids of human milk (Table 7), thus we must double the quantity eaten. This brings us to a diet of fruits with at least 1% protein content, or less when vegetables are eaten, and this will meet the highest (2 standard deviation) requirement for protein to maintain NB. The actual figure for an "average person" will be about 75% of the 1%. Thus a diet of 0.75% fruit protein is sufficient. Remember, the so called "digestibility" factor is no such thing, it is actually nitrogen lost, not protein broken down to amino acids and absorbed.

If we plot this on the graph (see Plate 1) we obtain a likely candidate for true protein requirements, and this equates to about 33 g/day from fruit, or 20 g/day from the other vegetable or grain foods. This yields the lowest figure for the study and is labeled min. required level. The maximum protein utilisation has been labeled max. utilisation level.

In order to meet the requirement and not to exceed it, one has to eat low protein fruits or vegetables. Some people suggest that since this requires eating excessive bulk of food (actually fruit and vegetables are 70-90% water) then they can replace these food items with more nutrient dense foods, containing much more protein. For every protein dense food one eats in this scenario, one will also have to eat a food that has no protein in, such as sugar or fat, to make up for the calorie shortfall. These foods are "empty calories", and present their own health problems. Eating any other food, with more than a trace of protein, will immediately have one ingesting excess protein. In practicle terms one cannot fiddle the figures to suit ones own dietary choices, it just cannot work out, because the continued eating of processed foods with one or more essential nutrients upset will not support life. If you provided all your calories from protein rich "tofu" then you would require about 20 cups per day, and this would have about 280 grams of protein in it, perhaps 14 times our requirement! This would produce much NH3 and soil for putreficative bacteria. Eating meats, nuts or seeds, eggs, cheese or fish would be as bad or worse.

Fruits will certainly provide all the protein one requires. If one wishes to use the popular % of calories as protein unit (not a true SI unit), then this study suggests that 3% to 6% of calories as protein will meet all your requirements so long as the diet is not a poor mono diet. Will you get malnutrition on a VLPD? Well certainly protein deficiency is unlikely, as we shall now see.

Kwashiorkor

Protein X-Files

Bibliography/References

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Protein and Peptide Problems

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6. Endogenous opioid systems regulate mcell proliferation in the developing rat brain,
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7. Identification of opioid peptides regulating proliferation of neurons and glia in the developing nervous system,
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   Husby et al (1985) Scand J Immunol 22:83-92
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   Gardner MLG (1994) Physiology of the gastrointestinal tract (Johnson LR : edit) Rave Press, NY pp 1795-1820
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11. 'paranoid ideation and persecutory feeling could well be human correlates of the behaviour changes noted in animals',
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13. Cereals and Schizophrenia,
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    'Increased IgE antibodies to food proteins were also found in schizophrenics'
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    Ashkenazi A et al (1979) Amer J Psychiat 136:1306-1309: - found that leukocytes reacted to a fraction of gluten in a fashion intermediate between coeliac disease and normal controls
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15. Karjalainen J et al (1992) New Eng J Med 327: 302-307
    Bovine albumin peptide as possible trigger of insulin-dependent diabetes mellitus,
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    Bovine lactoglobulin in human milk,
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    Passage of cow s milk protein in breast milk,
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