Autoimmune Responses to Food (IgA)
Food reactions are commonly thought of as allergies or sensitivities, yet another common reaction is the stress or autoimmune reaction to food. Food allergies are due to an IgE immune response, food sensitivities are due to the IgG immune reaction and the stress or autoimmune reaction is due to IgA. IgA is also known as secretory IgA (sIgA) because it is found in secretory organs like the gut, nose, tears, milk and saliva glands. IgA has the very important task of preventing viruses and bacteria from attaching to mucous membranes. It also helps the mucous membranes trap microorganisms so that they can be prevented from causing harm. Approximately 6 to 15% of the antibodies in blood serum are IgA.
Stress and autoimmune response to food depends on two factors: personal susceptibility and exposure to the known triggers. The naturopathic assessment looks at both aspects. The stronger a person's vitality and constitution the less likely they will be affected.
The autoimmune response to food, especially when looking at lactose intolerance or celiac disease can be genetic, but this type of food reaction can also develop later in life due to a number of factors including:
- Habitual exercise at an intense level can cause suppression of mucosal immunity, while moderate exercise may have positive effects. Salivary IgA concentrations decline immediately after a bout of intense exercise, but usually recover within 24 h. Training at an intense level over many years can result in a chronic suppression of salivary immunoglobulin levels. The degree of immune suppression and the recovery rates after exercise are associated with the intensity of exercise and the duration or volume of the training. Low levels of salivary IgA are associated with an increased risk of respiratory illness in athletes.
- Measurement of salivary IgA levels over a training season may be predictive for athletes at risk of infection.
Stress and autoimmune responses to food are associated with:
Although IgG is the immunoglobulin present in greatest quantity in serum, IgA is the antibody produced in the greatest quantity in a day. In fact, 60% of the immunoglobulins produced in a day are IgA antibodies. Over half of the IgA produced is transported to secretory fluids (e.g. saliva, intestinal fluids).
- The Half-life of IgA is 5 to 6 days.
- Those deficient in IgA show increased absorption of food antigens and formation of IgA-circulating immune complexes .
- Research shows that newborns have very little IgA, because they have not been exposed to microbes. But, within the first month of life, the number of cells capable of producing IgA increases 75-fold – just because of normal exposure to microbes in the environment. Without exposure to normal amounts of bacteria, the IgA system fails to develop normally.
It is always advisable to work with a naturopathic doctor before engaging in any treatment plan.
The treatment for the stress or autoimmune responses to food involves:
- Addressing any causes of stress.
- Identifying and addressing any underlying food sensitivities
- Treat any underlying lactose intolerance or celiac disease.
- Support overall digestive health and immunity.
Reviewed by Iva Lloyd, BScH, RPE, ND 
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