By: Shoshana Kosman, RD/LD
Proteins are large complex molecules that are made up of hundreds or thousands of smaller units called amino acids. There are 20 different amino acids that can be combined to make up a protein.
They consist of essential and non-essential amino acids. Essential amino acids are not produced by the human body, so they must be consumed through food. Examples of essential amino acids: Leucine, Isoleucine, Valine, Histidine, Lysine, Methionine, Phenylalanine, Threonine, and Tryptophan. Non-essential amino acids are produced by the human body, so they do not need to be consumed through food. Examples of non-essential amino acids: Alanine, Arginine, Asparagine, Aspartic Acid, Cysteine, Glutamic acid, Glutamine, Glycine, Proline, Serine, and Tyrosine
Why are Proteins Important for the Body?
- Proteins take many different forms and thus have different functions in the body.
- Different forms and functions of proteins:
- Antibodies – Bind to specific foreign particles, such as viruses and bacteria, to help protect the body.
- Enzymes – Carry out almost all of the thousands of chemical reactions that take place in cells. They also assist with the formation of new molecules by reading the genetic information stored in DNA.
- Messenger proteins – Transmit signals to coordinate biological processes between different cells, tissues, and organs. Messenger proteins are often hormones.
- Structural proteins – Provide structure for cells, supporting muscles, tendons, nails, hair, and skin. They also allow the body to move.
- Transport/storage proteins – Bind and carry atoms and small molecules within cells and throughout the body.
- You might notice that proteins are hard at work in your body when:
- Your body heals a cut on your skin, as proteins aid in the growth, repair, and maintenance of body tissues.
- You fend off a cold or recover quickly from a sickness, as proteins help build a strong immune system.
- You feel full after eating, as proteins aid in satiety (feeling “satisfied” after eating).
Protein Food Sources
- Complete sources of protein (defined as having all the essential amino acids):
- Animal protein
- Dairy protein
- Cottage cheese
- Vegetarian protein (soy)
- Soy beverage (make sure it is fortified with calcium 20%)
- Incomplete sources of protein (defined as having low levels of one or two of the essential amino acids).
- Nuts and seeds
- Peanut butter
- Animal protein
Now that you have learned many reasons why protein is important to consume daily, make an effort to include them in every meal!