Vegan Health ArticlesA Brief History of Protein: Passion, Social Bigotry, Rats, and Enlightenment
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Rats Confuse Nutritionists

By: John McDougall M.D.

Many people have the idea that animal foods contain protein which is superior in quality to the protein found in plants. This misconception dates back to l9l4, when Lafayette B. Mendel and Thomas B. Osborne studied the protein requirements of laboratory rats and demonstrated nutritional requirements for the individual amino acids.[5] They found that rats grew better on animal sources of protein than on vegetable sources. So, investigators at that time suspected that the vegetable foods had insufficient amounts of some of the amino acids essential for the normal growth of rats. Because of these and other animal-based experiments, flesh, eggs, and dairy foods were classified as superior, or "Class A" protein sources. Vegetable proteins were designated inferior, or "Class B" proteins.

Rat Studies completed in the early 1940's by Dr. William Rose of the University of Illinois found that l0 amino acids were essential for a rat’s diet.[6] The removal of any one of these essential amino acids from the food of growing rats led to profound nutritive failure, accompanied by a rapid decline in weight, loss of appetite, and eventually death. Animal products, such as meat, poultry, milk, and eggs prevented this decline in the rats’ health, and were found to contain the 10 essential amino acids in just the right proportions for needs of growing rats. Based on these early rat experiments the amino acid pattern found in animal products was declared to be the “gold standard” by which to compare the amino acid pattern of vegetable foods. According to this concept, wheat and rice were declared deficient in lysine and corn was deficient in tryptophan.

Subsequent research has shown the obvious: the initial premise, that animal products supply the most ideal protein pattern for humans, as they do for rats, is incorrect.[7] The dietary needs of rats are considerably different from those of humans, mainly because rats grow very rapidly into adult size as compared to people. Rats are fully adult after 6 months; whereas a person takes 17 years to fully mature. This difference in need is especially clear when the breast milk of both species is examined and compared. The protein content of rat breast milk is 10 times greater than the milk intended for human babies.[8,9] Baby rats double in size in 4.5 days; an infant doubles in size in 6 months. The obvious reason for the different needs is because rats grow very rapidly into adult size as compared to humans; therefore requirements for protein to support that growth are very much higher.

Go on to: Dr. William Rose Discovers Human Needs
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We began this archive as a means of assisting our visitors in answering many of their health and diet questions, and in encouraging them to take a pro-active part in their own health. We believe the articles and information contained herein are true, but are not presenting them as advice. We, personally, have found that a whole food vegan diet has helped our own health, and simply wish to share with others the things we have found. Each of us must make our own decisions, for it's our own body. If you have a health problem, see your own physician.