Causes of Allergies

All allergies are caused by an immune response of the body toward a foreign substance. The mechanism for this response is actually quite fascinating, as it demonstrates how our bodies are self-repairing mechanisms under normal circumstances. An allergen is a protein that the body evaluates and judges to be foreign and therefore dangerous. Upon exposure, the body goes to work to defend against this invader by alerting the immune system that an antigen is present. Thus alerted, the immune system releases specific antibodies to deactivate the antigen, in the form of one or more immunoglobulin proteins designated IgG, IgA, IgM, IgD and IgE. IgE is the immunoglobulin protein most involved in the response to environmental allergens, while IgG is more often involved in the response to food allergies.

Next, mast cells, which produce the allergic response, are activated. The antibody protein signals the mast cells to produce histamine and at least 28 other chemicals that are responsible for the symptoms you experience. As this happens, the antibody proteins attach themselves to the antigens like a peg fitting into the correct hole. There are a number of sizes and shapes of each antibody protein that are specific to each type of allergen. Typically, IgE-mediated allergic response is generally immediate upon exposure to the allergen; at least after sensitization has occurred in the individual, while IgG-mediated response can take up to 72 hours after exposure.

Delayed-response allergies can appear up to 72 hours after exposure to the allergen. These responses are often associated with IgG immunoglobulin antibodies, and might present as other illnesses, leading the sufferer to misdiagnose the symptoms or not believe they are associated with an allergy. Typical symptoms of delayed allergies are lethargy, attention deficit disorder, hyperactivity, itchy skin, mood swings, fatigue, insomnia or inflammation in joints or other tissues. These symptoms are often attributed to one of the mysterious illnesses in the chronic fatigue syndrome/fibromyalgia spectrum or any of several autoimmune disorders. In fact, up to 80 different medical conditions have been associated with IgG immunoglobulin responses to food allergies. If these symptoms sound familiar and you have been diagnosed with arthritis, asthma, insomnia, psoriasis or any other hard-to-manage chronic illness, it might be worth your while to begin keeping a careful food diary and noting when flare-ups of your condition occur within 72 hours of ingesting a food that commonly causes allergic response.

The most common cause of environmental allergies are the pollens of trees, weeds, flowers and grasses, as well as dust mites, molds, tobacco smoke and pet dander. Playing an increasingly important role, however, are the thousands of chemicals that surround modern man. We now spend up to 90% of our time indoors, with many artificial substances from carpet fibers to paint exuding VOCs (volatile organic compounds) constantly. Despite efforts to reduce the chemical gasses to which we are exposed, the fact is that they are many times higher now than at any other time in the history of humankind. Chemical sensitivities are a relatively new phenomenon simply because people were not exposed to so many chemicals in past times. Nowadays, evidence is accumulating that as many as 1000 new chemicals are introduced to our environment each year.

As early as the 1980s, scientists began using the acronym SBS (for sick building syndrome) to describe a cluster of symptoms experienced by office workers when high-efficiency buildings that re-circulated the same stale air, pathogens and chemical fumes, began making dozens ill at a time. With perfect irony, the phenomenon was brought to the attention of the general public when the offices of the Environmental Protection Agency were reported by CBS to be environmentally unsafe for workers. As high profile and indignation rousing as these facts are, however, food allergies are by far the more prevalent cause of illness and in fact have been shown to exacerbate the development of environmental allergies.

Food allergies are defined as abnormal or adverse immunological responses to foods that others can eat with no reaction. The operative phrase however is ?immunological responses?. Food allergies must be distinguished from non-allergic reactions to foods caused by enzyme deficiency, poor digestion or food poisoning as well as toxic reactions that anyone would experience if they ingested a toxic substance. According to Alternative Medicine, The Definitive Guide (second edition) the USDA estimates that only about 15% of the population reacts to foods, but that of those only 1.5% experience true, immunologically-mediated reactions. The rest are a result of food intolerance, a broad category that includes food poisoning and toxicity, anaphylactoid reactions and other mediator-release reactions, pharmacologic reactions (reactions to drugs), metabolic food reactions and food idiosyncratic reactions. The latter refers to food sensitivities for which the biological mechanism is not well understood, and includes such reactions as hyperactivity in children as a response to certain food additives or sugar, headaches in response to the food additive MSG and even celiac disease, a reaction to gluten-containing foods. Metabolic food reactions include adverse reactions to foods that contain certain substances for which the individual?s body lacks the enzyme to break it down, like lactose intolerance or phenylketonuria.

This is not to say that these disorders are less important than food allergies, as they can have serious consequences ranging from failure to thrive to mental retardation to death. It is very important to distinguish between food allergies and food intolerances simply because the methods we will discuss in later sections to alleviate certain allergies will not help food intolerances based in genetic defect. It is also important to realize that traditional allergy testing may not reveal food sensitivities or intolerances that are not immunologically mediated.

Finally, you should be aware of cross-reactivity. If you determine, for example, that you are allergic to shrimp, chances are that you are also allergic to other types of shellfish, such as crabs, lobster and crayfish.

The foregoing information is widely recognized by both traditional and alternative practitioners. There are a number of additional theories that alternative practitioners have espoused, and some of them are beginning to be studied or recognized by researchers and MDs. The following sections explore these theories.