How do proteins work in our diet?

While arguments rage on about the role of carbohydrates and fat in our diet, proteins are still considered the cornerstone of a healthy diet. At one time, protein was synonymous with meat, but now people are looking to other sources for this life necessity, and those sources are plants.

One of the largest sources of plant-protein is soy, which has become very popular with vegans. It has the essential amino acids and is low in cholesterol, and can even lower harmful LDL cholesterol while maintaining helpful HDL cholesterol. Soy is the only common plant protein that contains sufficient quantities of the essential amino acids.

Despite that, 69% of U.S. dietary protein comes from animal sources, and this demand will rise by staggering amounts. Per capita consumption of proteins from meat, poultry and fish is 134 lb and 264 lb from dairy products. If we could switch over to plant proteins, we would reduce greenhouse gas emissions by 15% and reduce the amount of land needed to graze animals by 26%.

How is protein metabolized in the body? Hydrochloric acid in the stomach denatures (breaks down) the proteins, making them easier to digest. Pepsin (a digestive enzyme) is released by the stomach and attacks the peptide bonds (the bonds that connect two amino acids together) to make smaller peptide molecules (small protein strings) that can enter the small intestine. (Amino acids connect to make a protein by removing a molecule of water from a carboxyl COOH group and an amine NH2 group). These small peptides are digested into amino acids in the small intestine by peptidase, which is another digestive enzyme (An enzyme acts as a catalyst). Amino acids are absorbed into the bloodstream and go through the liver where they are broken down into alpha-keto acids and amino acids, and then made into non-essential amino acids needed by the body. On the other hand, the essential amino acids must be obtained by dietary intake. This liver conversion process results in the production of urea and ammonia, which is filtered out by the kidneys.

Some people are allergic to soy. Fortunately, there is another plant protein candidate: yellow peas grown in Canada and Europe. Some people think that pea-protein is easier to digest and has fewer known allergenic reactions.

Algae is another possible source of protein. Gold-colored whole algae grown in large, dark fermentation tanks is not like the green slime variety and contains 65% protein.

Another possibility is canola protein. This source is high in cysteine, an amino acid used by the body for replacing hair and skin.

Protein has several health benefits: helps sustain energy levels; manages weight and hunger; protects muscle mass as we age; and helps active people build lean muscles.

The source for this is an article in The American Chemical Society's Chemical and Engineering News magazine.

Oh, and by the way, another source of protein is crickets. Yes, the insects can be ground up and made into a shake. They call it an Oreo Mud Pie Cricket Shake, and some burger joint is offering them. Yikes!

Thanks for reading.