What is mutual supplementation of a protein?

Answer 1

Mutual Supplementation is the concept that a diet containing no meat (including poultry and fish) can provide all of the needed amino acids to the body if the right combination of legumes and whole grains is reached. To do this the proteins must be complementary proteins (a protein that may not be used by the body by itself but in conjunction with another protein can be used by the body to provide the needed amino acids for normal metabolism).

The entire concept is actually a myth.

In 1914, Thomas B. Osborne and Lafayette B. Mendel conducted studies on rats, which suggested that they grew best when fed a combination of plant foods whose amino acid patterns resembled that of animal protein. That makes sense, as all baby mammals, rats and humans included, grow best when fed the perfect food for baby mammals: their mother's milk. The term "complete protein" was coined to describe a protein in which all eight or nine essential amino acids are present in the same proportion that they occur in animals. "Incomplete protein" described the varying amino acid patterns in plants. It's a misleading term, because it suggest that humans (and other animals, one would assume) can't get enough essential amino acids to make protein from plants.

Frances Moore Lappé' popularized the idea of protein combining in her 1971 book Diet for a Small Planet. The American National Research Council and the American Dietetic Association (ADA) soon picked it up, cautioning vegetarians to be sure to combine their proteins.

Lappé reversed her position on protein combining in the 1981 edition of Diet for a Small Planet, in which she wrote: "In 1971 I stressed protein complementarity because I assumed that the only way to get enough protein ... was to create a protein as usable by the body as animal protein. In combating the myth that meat is the only way to get high-quality protein, I reinforced another myth. I gave the impression that in order to get enough protein without meat, considerable care was needed in choosing foods. Actually, it is much easier than I thought."

The ADA reversed itself in its 1988 position paper on vegetarianism. Suzanne Havala, the primary author of the paper, wrot of the research process: "There was no basis for [protein combining] that I could see.... I began calling around and talking to people and asking them what the justification was for saying that you had to complement proteins, and there was none. And what I got instead was some interesting insight from people who were knowledgeable and actually felt that there was probably no need to complement proteins. So we went ahead and made that change in the paper. And it was a couple of years after that that Vernon Young and Peter Pellet published their paper that became the definitive contemporary guide to protein metabolism in humans. And it also confirmed that complementing proteins at meals was totally unnecessary."

The paper was approved by peer review and by a delegation vote before becoming official.

So, fortunately, the theory that plant proteins are somehow "incomplete" and therefore inadequate has been disproved All unrefined foods have varying amounts of protein with varying amino acid profiles, including leafy green vegetables, tubers, grains, legumes, and nuts. All the essential and nonessential amino acids are present in any single one of these foods in amounts that meet or exceed your needs, even if you are an endurance athlete or body builder.