Have you suffered with symptoms for months or years, without being able to pinpoint a specific trigger? Have you ever thought a food, or foods, might be the cause, but you couldn’t narrow it down to a specific food? Food sensitivities are a poorly understood and often overlooked common contributor to many different symptoms and medical conditions.
What is the difference between food sensitivity and food allergy? IgG food reactions are called “sensitivities,” which is a different type of reaction than food allergies. IgG is a type of antibody, which is a part of your immune system. Food allergies are mediated by a different type of antibody, called IgE. Food allergy reactions are, by definition, an immediate hypersensitivity, meaning you react very immediately when you eat a food you’re allergic to. It’s typically easy to identify a food allergy after a few exposures because of this immediate reaction. If you eat peanuts and get itching in your mouth immediately after, you only need to eat peanuts a few times to connect the reaction with the peanuts.
In contrast, IgG-mediated food sensitivities are, by definition, a delayed hypersensitivity reaction. This means you might react right away, or it may take up to three days to react. Because of this delay in reaction, it can be very difficult to figure out what food, or foods, a person is reacting to, even when someone is journaling food intake and symptoms, and working very hard to figure out food triggers for their symptoms. It is also important to keep in mind that this means eating a food you’re sensitive to even twice per week can keep the inflammatory and immune reaction going of all the time! Often when people suspect a food is causing their symptoms, they try cutting back on the food. This is often not an effective method of figuring out food reactions; just two exposures per week can cause constant or cyclical symptoms that seem unrelated to intake of the food in question.
What type of symptoms can IgG food sensitivities cause? Since IgG antibodies can circulate all throughout the body, they can cause a wide variety of symptoms. The reaction to the food in the body leads to immune activation and inflammation, which can show up just about anywhere. They can contribute to symptoms that may seem random and unrelated, as well as to chronic disease, since the root of all chronic disease is inflammation. Some of the most typical reactions include digestive symptoms, eczema or rashes, pain, sinus congestion, susceptibility to infections, acute viral infections often turning into sinus infections or bronchitis, fatigue, brain fog, lack of focus, headaches, and migraines. Food sensitivities can also increase or exacerbate seasonal or environmental allergic reactions and asthma, as well as autoimmune conditions.
A 2002 review article by Searman concluded that, “we can no longer view different diseases as distinct biochemical entities. Nearly all degenerative diseases have the same underlying biochemical etiology that is a diet-induced pro-inflammatory state. Although specific diseases may require specific treatments, such as adjustments for hypomobile joints, beta-blockers for hypertension and chemotherapy for cancer, the treatment program must also include nutritional protocols to reduce the pro-inflammatory state.” This is a testament to the importance of a whole foods, less processed, anti-inflammatory diet, but also to the role of food sensitivities in the diet as specific foods that cause inflammation.
In general, conventional medicine tends to deny the contribution of food sensitivities to symptoms, even including IBS and other digestive disorders. Unfortunately for suffering patients, there has been limited research on IgG food sensitivities, in large part due to research funding primarily being allocated to patentable pharmaceutical products that generate large profits, though there are some small studies in the medical literature
A study done by Yale in 2004 found that in those with IBS, a 12-week elimination diet based on IgG food sensitivity testing resulted in a 10-26% greater reduction in IBS symptoms as compared to a sham diet in the control group. The better the compliance with the diet, the greater the improvement in symptoms.
A condition called eosinophilic esophagitis, which causes symptoms of difficulty swallowing, food impaction, vomiting and heartburn is an allergic inflammatory condition of the esophagus that involves eosinophils, a type of white blood cell. Eosinophils are usually associated with allergies. Research has shown that IgG-mediated food sensitivities have more of an impact on this condition than actual IgE food allergies. They have found that IgG-sensitive food intake leads to specific immune reactions that then trigger eosinophils causing an allergy-like reaction, leading to inflammation and chronic symptoms. Finding and eliminating food sensitivities, along with additional treatment to eliminate inflammation and heal the gut are key strategies to not only manage, but to actually cure this condition, which is otherwise considered chronic.
Research has shown that a gluten or wheat sensitivity specifically can lead to reactions that cause abnormal immune activation and high levels of inflammation in the gut. The terms non-celiac gluten sensitivity (NCGS) and non-celiac wheat sensitivity (NCWS) are generally used to refer to this condition, when removing gluten from the diet resolves symptoms, after testing negative for celiac disease and wheat allergy. It was previously thought that sensitivity did not produce an inflammatory reaction in the gut like celiac disease does. It is now known that psycho-neurological issues such as ADHD, mood disorders and migraines are some of the most common reactions to gluten or wheat sensitivity, second only to digestive disorders and symptoms.
The following is a quick case study demonstrating how food sensitivities can pop up at any age and can cause very specific reactions. A 65-year-old woman presented with constant itching, flaking and redness all over her scalp for about nearly three months. She had no previous history of skin rashes or conditions. The condition seemed to start after a trip to Italy, though she had no idea if or how it might be connected to the travel. She had no other new symptoms. She was overall healthy with no other complaints, and on no medications. As part of her work up a blood IgG food sensitivity test was ordered. The rest of the work up was unremarkable, but her food sensitivity test showed high reaction to eggs. The patient removed eggs from her diet and within two weeks, the skin reaction was 100% resolved. The patient then found through reintroduction of eggs that if she ate eggs baked into foods occasionally, she had no return of symptoms; if she ate eggs as a meal she began to again experience itching on her scalp. Any practitioner who uses food sensitivity tests on patients will have countless similar cases, with a huge variety of symptoms and food reactions between patients.
While gluten, dairy and eggs tend to be the most common food sensitivities, any food can be the culprit. Most food sensitivity panels test anywhere from 50 to 300 foods. To have food sensitivity testing you will likely need to see a naturopathic physician, integrative/holistic physician, APRN or nutritionist, or find a way to test it yourself. Many lab companies now offer testing kits you can order yourself and complete at home. Because testing quality and reliability varies, it’s recommended to see a practitioner or physician who knows a reliable lab and orders this type of testing to avoid wasting money on a test that may not be accurate. A knowledgeable practitioner will also help create an effective plan from your results so that you get the most out of your testing and have the best chance of recovering from your symptoms.