Protein Quality For Vegans
What are proteins made of?
Proteins are made up of amino acids, and there are 20 different amino acids that can form the constituents of any given protein. We all need a regular supply of all 20 of these amino acids. However, our bodies are able to synthesize 11 of the amino acids on their own, without any dependency on diet. The names for these 11 amino acids are alanine, arginine, asparagine, aspartic acid, cysteine, glutamic acid, glutamine, glycine, proline, serine, and tyrosine, and they are known as the nonessential amino acids.
The other 9 amino acids can’t be produced by our bodies and so we need to get them from the foods we eat; they are known as the essential amino acids, and their names are histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine. Each of these amino acids performs a specific role in helping to maintain our health. For example, histidine and lysine can support our immune function, threonine helps to maintain skin quality and prevent bleeding, and tryptophan contributes to the production of serotonin, a neurotransmitter that helps regulate our mood and appetite.
Complete and incomplete plant protein
Most plant foods don’t contain all 9 of the essential amino acids, and in such cases the protein provided is known as incomplete protein. However, there are a few exceptions: plant foods that provide, on their own, all 9 amino acids. Examples of these complete plant protein sources include soya products, quinoa, buckwheat, pistachio nuts, chia seeds, and hemp seeds. Generally, however, it is a good idea for vegans to regularly consume multiple different plant proteins, to ensure a good intake of all the essential amino acids.
Â
Plant protein digestibility
Another aspect of plant protein is its digestibility, and some plant proteins are more digestible than others, meaning that a greater proportion of the protein will be assimilated. For example, cashew nut protein is 90% digestible, peanut protein is 69% digestible, green lentil protein is 63% digestible, and red kidney bean protein is 55% digestible.
Â
