Welcome to the first, in a three-part series, which will examine the importance of macro-nutrients for your immune system. Today, we are looking at how protein supports the immune system.
As mentioned in a previous article, protein is essential for muscle growth, recovery and strength, but it can also play a critical role in supporting the immune system.
Most of the exercise responses on the immune system are controlled by hormones such as adrenalin, cortisol and pro- and anti-inflammatory cytokines. These immune responses are very much based on the intensity, duration and type of exercise you are taking part in.
The proteins that are involved with boosting our immune response include:
Cytokines – stimulate and regulate the immune system and it’s responses. These include pro-inflammatory cytokines that increase the activity of our immune cells to help fight against bacteria.
Antibodies – proteins that help the immune cells to identify and destroy pathogens.
Lysozyme – a protein that attacks and destroys the cell walls of bacteria.
Fibrin – supports blood clotting. Without fibrin, cuts and wounds would not heal, leaving us open to infections and foreign substances entering the blood.
Cell receptors. The surface of our cell membranes contains receptors made of proteins that respond to messages from hormones or other molecules.
The general population are more susceptible than their trained athletic counterparts, to the adverse effects from high-intensity exercise. Studies have reported the harmful side effects and increased upper respiratory tract infection promoted by exhaustive physical exercise. The amino acids found in protein impact key metabolic pathways in immune cells, which aids optimal immune function and recovery from these intense training sessions.
There is growing evidence in support of the immune mediating effects of the amino acid Glutamine. Glutamine, which is found in natural protein sources, is used by the liver to help detoxify the blood. Without these amino acids, we would quickly become unwell due to build-up of waste substances in our blood. Lack of glutamine in the diet is linked to intestinal permeability, which is where gaps open up between the cells of the gut lining, which should normally sit tightly together. These gaps can allow incompletely digested food and bacteria etc. to enter the bloodstream, which can then set up a negative immune response in the body.
So, in summary, a diet that supports a healthy immune system should include sensible intakes of protein and amino acids, since they are required for the optimal synthesis and concentration of a variety of immune related proteins (including cytokines and antibodies).
Check out our protein article on recommendations for hitting your protein intake and helping aid your immune response to training!