Delayed-sensitivity Food Reactions
IgG antibody reactions take hours or days to develop, making it difficult to determine the reactive food by observation or elimination diet. In an IgG reaction, the IgG antibodies attach themselves to the antigen and create an antibody-antigen complex. These complexes are normally removed by special cells called macrophages. However, if they are present in large numbers and the food antigen is still being consumed, the macrophages are unable to remove all the complexes. The antigen-antibody complexes accumulate and are deposited in body tissues. Once in tissue, these complexes cause inflammation, which can contribute to a variety of diseases and health conditions.
In a food reaction, the immune system reacts by releasing cells called antibodies. Foods that cause antibodies to be released are called antigens or allergens. Two types of antibodies commonly produced in response to foods are IgE (immunoglobulin E) and IgG (immunoglobulin G). Food allergies and food sensitivities differ by the type of antibody produced and the speed of the reaction. Food allergy is an immediate reaction caused by the production of IgE antibodies, while food sensitivity is a delayed reaction caused by the production of IgG antibodies to specific foods.
Digestive disorders: Conditions like irritable bowel syndrome (IBS) and Crohn’s disease have been linked to IgG food reactions. Research has shown that elimination of IgG reactive foods can alleviate IBS symptoms.
Migraines: A 2007 research study found that 43/65 patients with migraine headaches had complete remission of headaches after one month of eliminating reactive foods. Another study in 2010 found a significant reduction in the number of headache days and migraine attacks with elimination of reactive foods.
Mood/attention deficit disorders: Deposition of antibody-antigen complexes in nervous system tissues may contribute to hyperactivity, depression, anxiety, inability to concentrate and other mood disorders. There is evidence that eliminating IgG food antigens improves attentiveness in children.
Weight gain: Antibody-antigen complexes in tissue cause inflammation, which can lead to fluid retention and weight gain. To fight inflammation, the body releases a chemical called ghrelin, which also happens to be an appetite stimulant. Thus, IgG food reactions may contribute to weight gain in two ways: fluid retention and increased appetite.
Fever, fatigue, chills, sweating and feeling weak, puffiness.
Itching, redness, swelling, and rashes (including eczema, psoriasis). Allergic individuals and those with atopy achieved 70% reduction of symptoms with elimination of IgG reactive foods. In addition, atopic children (with or without eczema) are shown to have higher IgG levels to specific foods than non-atopic children. In children without eczema, higher levels of IgG were still significantly associated with atopy, with elevated IgG antibodies most prominent to egg white, range and cow’s milk.
Bronchitis and asthma symptoms.
Asthma is a chronic inflammatory disease of the lungs marked by recurrent episodes of airway hyperresponsiveness resulting in chest tightness, wheezing, and shortness of breath. Allergic or atopic asthma is the most common form of asthma, and allergic sensitization occurs in about 80% of asthmatic children and 60% of asthmatic adults. In both human asthmatics and animal models of allergy, allergen-specific IgG can contribute to allergic inflammation. Allergic individuals and those with atopy achieved 70% reduction of symptoms with elimination of IgG reactive foods. In addition, atopic children (with or without eczema) were shown to have higher IgG levels to specific foods than non-atopic children. In children without eczema, higher levels of IgG were still significantly associated with atopy, with elevated IgG most prominent to egg white, orange and cow’s milk.
Rheumatoid Arthritis Joint pain, muscle stiffness and swelling. Some rheumatoid arthritis patients have shown improvement in symptoms when reactive foods were eliminated from the diet. It has been hypothesized that patients with occasional rheumatitis may experience delayed hypersensitivity food reactions
What can we learn from testing for sensitivities?
Because hours or days can pass between the time a reactive food is consumed and the occurrence of a reaction occurs, testing is virtually the only way to determine which foods are responsible for the reaction.
IgG reactions frequently occur to commonly consumed foods such as dairy, wheat, eggs, yeast, pork and soy. Elimination diets (remove suspect foods for a period of time and then reintroduce and check for reactions) are difficult to follow and can take months to complete.
Although still controversial in mainstream medicine, IgG food sensitivity testing is starting to accumulate research in support of its clinical utility. For example, 125 patients, identified by an allergist as likely having food allergies, were given blood tests for IgG food reactions. All positive foods were removed for a 6 month period. The allergist considered the treatment a success when a minimum 75% improvement in symptoms occurred. Of the 80 patients who completed the full course, 71% were successfully treated. In particular, there were 11 patients who had positive allergy symptoms, but had negative IgE test results. These patients were all successfully treated by eliminating the IgG food allergens. The allergist concluded that blood tests for IgG reactions to food were clinically useful and much more palatable to patients than the traditional skin prick and oral challenge tests.
Leaky gut syndrome is caused by inflammation in the gut lining. Inflammation can be caused by food allergies or sensitivities, abnormal gut flora, stress, certain drugs, and alcohol. An inflamed gut lining causes more food particles to leak into the bloodstream where they may come in contact with food-specific immunoglobulins. Therefore, a test report that shows multiple food reactions to foods regularly eaten may be an indication of leaky gut. If so, your healthcare professional may suggest treatments for your digestive system in addition to dietary changes.