Protein

One-fifth, or 20%, of the body’s weight is protein. Protein (S-Prot) is found in all cells, such as sinews, muscles, hair, and nails.

The purpose of proteins is to:

• Act as antibodies in immune defence
• Transport gases and nutrients in the blood
• Act as building blocks of hormones and enzymes
• Form new tissues during growth
• Strengthen the skin, nails, sinews,and connective tissue
• Transport fats in the blood and other body fluids
• Bind and transport oxygen in the blood
• Bind oxygen in muscle tissue

Proteins are made up of 20 different amino acids. Not all proteins contain all of the amino acids. Amino acids can be divided into essential and non-essential amino acids. The body cannot build essential amino acids itself; they are obtained from food. The body makes non-essential amino acids from essential amino acids. Excess protein obtained from the diet is stored as fat in the body.

As is commonly known, protein is found in meat, but vegetables also contain it. Vegetable proteins are present in beans, peas, seeds, nuts, and grains, for example. Animal-based sources are fish, chicken, low-fat meat, eggs, and dairy products. As a source of energy, proteins account for 10–20%, while fats account for 25–40% and carbohydrates for 45–60%.

Athletes and those who regularly do sports need higher amounts of protein to maintain the nitrogen balance of the body. Protein is available in abundance in food, so increasing meal portions guarantees a sufficient intake of proteins.

When should protein be measured?

Blood protein levels can be measured when investigating nutritional disorders, diseases of the liver and kidneys, chronic diseases involving swelling, immune deficiency, and when suspecting diseases that produce lots of proteins in the blood.

It can be a good idea to have protein tested in connection with the following symptoms:

• Fragile nails or hair
• Weak muscle mass
• Swelling
• Infection tendency
• High blood pressure
• Skin symptoms on the arms, legs, and face
• Fatigue
• Weight loss
• Fever
• Rash
• Joint symptoms

Normally, the body tries to save as much protein as possible and, if necessary, reuse the amino acids it contains. Therefore, very little protein usually accumulates in the urine.

What does a protein test measure?

Proteins can be measured from the blood or urine. Urinary protein measurement is used for assessing kidney function.