The belief that animal protein is better than plant protein appears to be based on research in 1914, when Osborn and Mendel did some of the earliest research on protein requirements. Since overt experimentation on humans is discouraged, experiments on rats were conducted. Osborn and Mendel found that rats grew faster on animal protein than they did when they ate plant protein. Of course, rat physiology is different than humans and extrapolation from one species to another is often questionable. Nevertheless, they took these results and declared that animal protein, composed of meat, eggs and dairy products, was classified as a “Class A” protein. Plant proteins were classified as “Class B” proteins. [1] These ideas of rigid classes of proteins were discarded in England in 1959, but the American public is still encouraged to accept this dogma. [2]

Scientists who really seem to understand human physiology do not totally agree on the precise figure for human daily need for protein, but established scientific research put the figure somewhere between 2% and 8% of the diet. These figures contain built-in safety margins and are recommended allowances that are more than adequate for 98% of the population. [3] Human mothers milk, containing human protein and antigens, has a maximum of 5% protein. In comparison, bovine (cow) milk has 15% protein. Rat milk has an astounding 49%.. [4]

With what we know about plant protein content, it easily provides all the protein humans require. Even if we ate nothing but potato (11% protein), we would get more than enough protein for our needs,[5] but not necessarily all the nutrients we need. The revised edition of Diet for a Small Planet by Frances Moore Lappe contains much data on food planning and meals that do not require the usage of animal protein which, for a number of reasons, creates considerable problems for human physiology.

The companies and interests who sell animal protein (meat, fish, cheese, eggs, chicken, etc.) have for many years disseminated cultural propaganda which raise the amount of protein “you need” by 30%, which of course creates a multi-billion dollar industry which also consumes more than 33% of the fresh water in the United States and leaves behind billions of pounds of animal waste and human disease in its wake.

The fact that plant protein is entirely sufficient for humans was emphasized at an annual meeting of the American Association for the Advancement in Science, at which the eminent nutritionist Dr. John Scharffenburg said, “let me emphasize, it is difficult to design a reasonable experimental diet that provides an active adult with adequate calories that is deficient in protein.” [6] This brings to mind another aspect of the propaganda of the meat and dairy industry, that an increase in human activity requires a corresponding increase in animal protein consumption. According to the National Academy of Science, there is little or no evidence that muscular activity increases the need for protein. [7]

In fact, the most imporant co-factor of osteroporosis is excess dietary protein. The correspondence between excess protein intake and bone reabsorption is direct and consistent. Even with very high calcium intake, the more protein in the diet the greater the incidence of negative calcium balance. In other words, the more protein in our diet, the more calcium we actually lose, regardless of how much calcium we take in. The result is that high-protein diets in general, and diets based on meat and dairy products in particular, lead to a gradual but definite decrease in bone density and assist the development of osteoporosis.

The general correlation between the development of osteroporosis and protein intake has also been observed elsewhere on the planet. Statistics tend to show that osteoporosis is most common in those countries where dairy products are consumed in large quantities. This tendency is present in the United States, Finland, Sweden and the United Kingdom.

Serotonin is an important substance that inhibits aggression and violence. Most proteins encouraged in the diet contain amino acids other than tryptophan. A high protein meal reduces the plasma ratio of tryptophan to the competing amino acids, and less tryptophan is carried across the blood-brain barrier to the neurons. This fact has socially developed to where those who have a high protein diet (meat, dairy, eggs) are more aggressive. Thus, the high protein diet is encouraged in various sports. Some years ago, a chemical company that made pure tryptophan for inclusion into over-the-counter tablets manufactured a contaminated lot, resulting in the death of several people. The FDA used this as an excuse to ban Tryptophan for sale to the public, removing an important modulator of aggression from public use. This had to be a set-up, because there are scores of other things out there that kill people every day and the FDA ignores them.

[1] Osborn, T., “Amino Acids in Nutrition and Growth,” Journal of Biological Chemistry 17:325,1914.

[2] Editorial, The Lancet, Journal of the British Medical Association, London, Vol.2. p.956, 1959.

[3] Scrimshaw, N., “An Analysis of Past and Present Recommended Daily Allowance for Protein in Health and Disease.” New England Journal of Medicine, Jan 22, 1976, pg. 200.

[4] Bell, G., Textbook of Physiology and Biochemistry, 4th edition, 1954, p.167.

[5] U.S.D.A. Agriculture Handbook, No.456.

[6] Scharffenburg, J., Problems With Meat, Woodbridge Press, 1982, p.90.

[7] National Academy of Sciences, Recommended Dietary Allowances, 8th edition, Washington, D.C., 1974, p.43.

[8] Coe, F., “Meat and Renal Stones.” Internal Medicine News, Vol 12. No.1, 1979.

[9] Wachman, Ammon et al, “Diet and Osteoporosis,” Lancet, May 4, 1968, pg.958; Ellis, F., et al, “Incidence of Osteoporosis in Vegetarians and Omnivores,” American Journal of Clinical Nutrition, No.25, p.555, 1972.

[10} Johnson, N., et al “Effect of Level of Protein Intake on Urinary and Fecal Calcium Retention,” Journal of Nutrition, Vol 100, p.1425, 1970; Allen, L., et al, “Protein-Induced Hypercalcuria: A longer term studu,” American Journal of Clinical Nutrition, Vol.32, p.741, 1979; Solomon, L., “Osteoporosis and Fracture of the Femoral Neck,” Journal of Bone and Joint Surgery, 50B, p.2, 1968.

Human Evolution
The Human Body