Immune System in Overdrive

Allergies

Allergies happen because our immune system responds to generally harmless substances (allergens) that it views as threatening. Allergens can be inhaled, ingested, or enter through the skin. These responses are linked to the IgE antibody and range from mild symptoms like a runny nose, asthma, or hives, to an extreme, life-threatening reaction known as anaphylaxis.^[1]

Anaphylaxis can happen within seconds or minutes of exposure to an antigen, or even a half-hour or longer. It results in a variety of widespread symptoms, including hives, swelling of the throat and tongue – resulting in difficulty breathing – dizziness, headache, pain or cramps, nausea, vomiting or diarrhea, a weak and thready pulse, decreased blood pressure, and ultimately loss of consciousness and shock^[2] If anaphylaxis isn’t treated right away, it can be fatal.

Typically, allergies are more common in children, but they can affect anyone regardless of age, gender, race, or socioeconomic status, and can begin or recur at any age. Having allergies can mean two things: 1) Your immune system is too active, and 2) Your immune system is misfiring (attacking the wrong substances). Use of the term “overactive” might give the impression that your immune system is strong, however it is misdirected and is actually an unbalanced response, thus the term “over-reactive” might be a better description. Among other things, stress can play a role in the development or severity of allergies.^[3]

Many allergies are insidious and numerous people don’t realize they have them. Environmental allergens that we inhale such as pollen, dust mites, mold and animal dander can assault us every day and cause general fatigue, headaches, red and itchy, watery eyes, and runny nose and sinus congestion.^[4]  The general nature of some of these symptoms makes it difficult to ascertain the culprit.

Undiagnosed and/or undealt-with allergies makes your immune system work overtime, causing it to be overtaxed, weakened, and potentially not available when a real pathogen comes along, leading us to be more susceptible to viral and bacterial infections.^[5] Conversely, there is considerable evidence that respiratory viral infections are associated with the development of allergies and asthma.^[6]

Food allergies and intolerances affect more than 20% of the population in industrialized countries, with the majority (15% to 20%) being non-immunologically mediated reactions.^[7]Foods that are considered healthy for the greater part of the population can cause problems for others if they have an allergy, a sensitivity, or an intolerance to them. Let’s talk about each of these in turn.

Food Allergies

Food allergies are an immune hypersensitivity initiated by an IgE reaction. As described previously, IgE allergies are immediate responses to an antigen that has entered the body. Often people who ingest an allergen have gastrointestinal discomfort (bloating and diarrhea) along with other IgE symptoms. IgE food allergies usually don’t disappear but they can improve over time, because if a person has a strong immune system and a healthy digestive system, the better their body can tolerate accidental exposure. Accidental is the key word, here, as it’s smarter to stay away from food you are allergic to.

Food Sensitivities

The term ‘food sensitivity’ is subject to a wide range of interpretation and therefore can be confusing. IgG antibodies have been implicated in delayed food allergies or food sensitivities.^[9] Delayed food allergies are called as such due to the fact that symptoms can be seen up to 72 hours after eating a problem food. These types of reactions are inflammatory in nature and are not associated with the release of histamines so you will not get the immediate hypersensitivity reactions of itching, hives, and swelling. IgG sensitivity reactions include symptoms such as headaches, anxiety, depression, bloating, constipation, acid reflux, joint pain, fatigue, and brain fog.^[10] Eliminating IgG positive foods has been shown in clinical studies to improve symptoms of diseases such as irritable bowel syndrome and migraines, and there is also ongoing research into potential benefits for those with autism and ADHD. ^{[11] [12] [13] [14]}

While you can test IgG for food sensitivities via a blood test,^[15] these tests are controversial as the results are commonly not as reliable as elimination diets for uncovering food sensitivity. However, they can give individuals a starting point to eliminate some foods and assess if it helps their symptoms or not.

Food Intolerances

A food intolerance is not triggered by the immune system. It is usually caused by a deficiency or absence of an enzyme needed to digest a food. One of the most common types of food intolerance is lactose intolerance, where an individual has a deficiency of the enzyme lactase that is needed to break down the sugar lactose found in cow’s milk. This can lead to symptoms that may look like an allergy, such as bloating and diarrhea. Other non-immune mediated intolerances include sulfites (present in wine and medications), monosodium glutamate (flavor enhancer), colorants and preservatives (such as tartrazine, benzoates, sorbates etc.), and sweeteners (aspartame).^[16]