HEALTH and NUTRITION

Understanding Your Immune System

INSIDE YOUR BODY THERE IS AN AMAZING PROTECTION MECHANISM CALLED
the immune system. The human immune system has developed into a collection of 20 trillion highly specialized cells that circulate throughout the body to kill any bad bacteria, virus, yeast, or cancer cells. This highly specialized system can recognize cells as being self and non-self. If a cell is recognized as non-self, the immune system begins a serious of chemical reactions to destroy the invader cells. Inflammation is the crucial first step in fighting off infection, healing wounds, and maintaining health.

When the immune system is suppressed or distracted, we have too little inflammation to fight contagious viruses, bacteria and parasites, and we get infectious diseases such as the flu and pneumonia. When the immune system is over stimulated, we have too much inflammation and the delicate balance among all of our major systems- endocrine, central-nervous, digestive, and cardiovascular/respiratory, is disrupted by this chronic inflammation. In a healthy body, these systems communicate with and respond to one another. With chronic inflammation, that cross-talk no longer works and we develop chronic diseases, such as arthritis, diabetes, cancer, multiple sclerosis and celiac disease. Therefore, it is important to keep the body balanced, strong, and healthy.

How Does Your Immune System Work?

The immune system is a complex series of responses that protects the body from disease by attacking anything foreign to it. An antigen is any substance that causes your immune system to produce antibodies against it. An antigen may be a foreign substance from the environment such as food proteins, chemicals, bacteria, viruses, or pollen, which has been ingested, inhaled or injected into the body. An antigen may also be generated within cells, as a result of normal cell metabolism, or because of viral or intracellular bacterial infection. A third type of antigen is a normal protein or complex of proteins (and sometimes DNA or RNA) that is recognized by the immune system of patients suffering from a specific autoimmune disease. An antibody is a disease fighting protein developed by the body in response to the presence of an antigen.

When you ingest something that your immune system doesn't like and perceives as undesirable, it attacks by means of inflammation. T-cell receptors (white blood cells that help destroy infected cells and coordinate the overall immune response) interact with antigen protein molecules to recognize "self"antigens. T-cells mediate the immune response and releases a message to the B-cells (white blood cells best known for making antibodies.) to produce antibodies.

An antibody binds to an antigen and marks the antigen for destruction by other immune system cells. B-cells can only make antibodies when they receive the appropriate command from the T-cell. In some autoimmune diseases, B-cells mistakenly make antibodies against tissues of the body (self antigens) instead of foreign antigens. For example, in multiple sclerosis, the immune system targets "self" nerve tissues of the central nervous system causing paralysis.

Other types of white blood cells (such as macrophages and neutrophils) circulate in the blood and survey the body for foreign substances. When they find foreign antigens, such as bacteria, they engulf and destroy them. The antigens are destroyed by the production of toxic molecules, such as reactive oxygen intermediate molecules. If production of these toxic molecules continues unchecked, not only are the foreign antigens destroyed, but tissue surrounding the macrophages and neutrophils are also destroyed. This build up of toxic molecules contribute to inflammation.

When inflammation occurs, chemicals from the body's white blood cells are released into the blood or affected tissues in an attempt to rid the body of foreign substances. This release of chemicals increases the blood flow to the area and may result in irritation and redness. Some of the chemicals cause leakage of fluid into the tissues, resulting in swelling, stimulating the nerves and causing pain. For example, in rheumatoid arthritis, toxic molecules are made by over productive macrophage and neutrophils cells invading the joints, causing warmth and swelling, and resulting in damage to the joint.

When many antibodies are bound to antigens in the bloodstream, they form a lattice network called an immune complex. Immune complexes are harmful when they accumulate and initiate inflammation within small blood vessels that nourish tissues. Immune complexes, immune cells, and inflammatory molecules can block blood flow and ultimately destroy organs such as the kidney. This can occur in people with lupus.

Examples of Immune System (or Autoimmune) Diseases listed by human body system¹:

• Gastrointestinal System: Celiac disease, Crohn's disease, and Ulcerative colitis.
• Nervous System: Multiple sclerosis, and Peripheral neuropathies (numbness and pain).
• Musculoskeletal System: Rheumatoid arthritis.
• Skin System: Systematic lupus erythematosus, Dermatitis, Scleroderma, Psoriasis, and Sjogren's syndrome.
• Blood System: Type 1 diabetes, Pernicisous and autoimmune hemolytic anemia, and Wegener's granulomatosis.
• Endocrine Glands: Thyroid disease, Grave's disease, and Hashimoto's thyroiditis.

The most important factors affecting the immune system are our nutritional status (diet), our lifestyle (physical activity), our physical environment (toxins and stress) and genetics. Genetics are not easily changed. Our immune system is basically identical to our 40,000 year old ancestors. Our physical environment is also often difficult to change in the short term since few of us can pick up and leave our home, job, family and friends to live on a pristine island free of pollutants, toxins and stress. Therefore the only way to immediately impact our immune system is through the food we eat and the amount of physical exercise we get daily. And since 50% of the immune system surrounds the gastrointestinal tract, what we ingest daily directly affects our nutritional status; toxin levels in the body (antibiotics and poisonous chemicals); and how well we feel. Physical activity is important for good health, but if you eat a diet that weakens the immune system, you negate the benefits of exercise. Also, when you are ill or in pain, exercise becomes difficult. Therefore the quickest, simplest, and easiest way to strengthen your immune system is to have a healthy, happy gastrointestinal tract through a diet of whole foods, such as vegetables, fruits, beans, nuts, wild fish and lean meats usually found in the perimeter of the supermarket.

1. Understanding Autoimmune Disease: NIAID. 2007. Retrieved from http://www/wrongdiagnosis.com/artic/understanding_autoimmune_disease_niaid.htm.

© 2008 by Claudia Pillow and Annalise Roberts