Protein is one of the most talked about nutrients, partially because it fulfills such an important role in our body. Unfortunately, everybody seems to have their own opinion over how much protein, and what sorts of protein, offer the most benefit.
While a certain amount of debate is inevitable, many of the recommendations can be dangerous, and when scrutinized scientifically, most of them don’t hold up. Scientific literature is fairly clear about protein’s role in our diet, and while it is always open to new research and discussion, a lot of our knowledge is textbook at this point.
Protein isn’t just muscle, it fulfills many roles in every living organism alive, all the way down to bacteria. Understanding this is crucial to understanding why animal products are not the only good sources for protein, and helps to explain how protein is important in our own body as well. Unlike fats and carbohydrates, whose primary purpose is to supply fuel, protein has another, more important role. This role lies at the heart of the discussion, and it begins with amino acids.
What Is Protein?
Protein is more than a nutrient we eat, protein is one of the most essential building blocks of life. Protein forms the majority of our body, and not just the muscles we generally think about–our hair, nails, connective tissue, blood cells, and digestive enzymes are all proteins as well. In fact, there are about 50,000 different kinds of proteins in our body!
Protein is formed of chains of molecules known as amino acids. If you imagine a specific protein as being a word, like “elephant”, then the amino acids are the letters forming the word. There are twenty common amino acids in our body, and number of uncommon amino acids as well. Of those twenty, nine are considered essential because our body cannot create them itself–it must find them in food. All of the uncommon amino acids our body is capable of creating itself.
Just like a single letter of the alphabet, individual amino acids on their own have limited use. A couple may be useful individually, such as the letters ‘i’ and ‘a’ can be, but for the most part the power of amino acids is expressed when they are organized into a chain, just like words and sentences mean much more than a single letter.
If you imagine proteins as words, then our body is a dictionary with 50,000 words in it. Some of the words are much more frequently used, such as myosin and actin (the proteins our muscles are primarily composed of), but in the end, all the words are composed of the same letters, just in different orders and of different lengths. In order to form new words, we need to supply our body with letters to write them with. This is where dietary protein enters.