Allergy, Sensitivity, Intolerance
If you’re sniffling, sneezing and wheezing, your throat itches, your nose is running and your eyes are watery, in all likelihood you are one of the 20 percent of North Americans who are allergic to something, and that something may be in season. An allergy occurs when the body's immune system overreacts to a substance that is normally harmless, such as mould, pollen, animal dander or dust mites. It’s easy to mistake allergies and hay fever symptoms for symptoms of an infection—a cold or sinusitis. But a cold usually lasts no more than ten days and often presents with thick green or yellow mucus as opposed to the clear and runny mucus of an allergy. The overall itch is often the clue that we’re suffering from an allergy.
These airborne triggers are familiar to almost everyone, whether we’re sufferers ourselves or not. But more complex and mysterious are our adverse reactions to the very substance that sustains us: our food. It’s been long known that the consumption of certain foods can have profound effects on our individual immune systems. But I’m not speaking here of fast food, junk food, sugar, chemicals or preservatives—substances that can erode our health over a period of years. I’m speaking about food allergies and food intolerance.
Food Intolerance
Also known as non-allergic food hypersensitivity, this a distinct category of problem not to be confused with allergies. Organic dairy products may be healthy food in moderation yet more than half of the world’s population will experience upset stomachs, intestinal cramps, gas or diarrhea when they ingest milk or milk products: this is lactose intolerance, the inability to effectively digest dairy, and nothing to do with immune dysfunction. Lactose, the sugar in milk, is digested by the enzyme lactase. It is estimated that 75 percent of adults worldwide show a significant—and perfectly healthy—decrease in lactase activity during adulthood. Most adults of Asian, African, Middle Eastern and Native American descent are lactose intolerant. In addition, half of Hispanics and about 20 percent of Caucasians do not produce sufficient lactase as adults. If a person is one of this 75 percent and drinks milk, she may to varying degrees experience bloating, upset stomach, loose bowels and mild to moderate forms of diarrhea.
A simple test for lactose intolerance is to drink at least two eight-ounce glasses of milk on an empty stomach and note any gastrointestinal symptoms that develop in the next four hours. The test should then be repeated using several ounces of cheese (which does not contain much lactose). If symptoms result from milk but not cheese, then you probably have lactose intolerance. If symptoms occur with both milk and cheese, you may be allergic to dairy products, a quite different condition. It’s rare that lactose intolerance is so severe that eating cheese causes symptoms.
Food Allergies
These are something quite different. Sometimes called food sensitivities when they are relatively mild, food allergies are a notorious cause of negative effects on the body and are based on the relationship between a food and the individual immune system. Technically speaking, a food allergy is associated with the generation of immunoglobin E (IgE) antibodies against that particular food. The symptoms may be hives, swelling or full-blown anaphylaxis. If you have a food allergy, you’re probably already carrying around an Epi-pen and wearing a MedicAlert bracelet.
If you experience digestive distress soon after eating but have never discerned the cause, then testing is the key to identifying whether you have a food intolerance or a food allergy. A food allergy is effectively evaluated by a blood test that looks at the immunoglobulins present in the body against specific foods. In fact almost everyone has some allergic reaction to some food, usually the result of repeated consumption of the same food (I had a friend who ate peanut butter several times a day for forty years until it became the trigger to terrible migraines), general overconsumption or inherited susceptibility. Most people, however, do not experience intense symptoms and get by without serious problems.
An example of overconsumption in our society is the omnipresent wheat grain. A morning breakfast cereal with toast, a sandwich for lunch, crackers as a snack, pasta for dinner with cakes and cookies for dessert is not at all an uncommon diet routine in our part of the world. Given that many people have a genetic predisposition to wheat intolerance, developing a real intolerance to wheat gluten is hardly surprising. Even a mild to moderate gluten sensitivity can produce symptoms of gas, bloating, polishing of the intestine and malabsorption. Chronic inflammation to the lining of the intestine from an overactive immune system (which attacks the intestinal mucous membrane) causes the intestine to wear down (“polish”) and eventually become unable to absorb nutrients. This is known as celiac disease, a genetically inherited allergy to the gluten component of wheat that affects the digestive system and especially the small intestine, and often produces more severe symptoms. Perhaps one in 100 people have full-blown celiac disease, and about 97 percent of those with the disease don’t know it. If you wonder whether you or a loved one has celiac, a GP can do blood work to look at readings of anti-tissue transglutaminase antibodies, total immunoglobulins (in particular IgA) and screenings for anti-gliadin antibodies and anti-endomysial antibodies. You may be referred to a gastroenterologist for a biopsy. Alternatively, there is a widely available home blood test that allows you to do the preliminary work-up in the comfort of your own home (https://www.glutenpro.com/celiacsure.html). Report the results to your family doctor. And keep in mind that, even if you don’t have celiac disease (which is what this test is looking for), you may still have a mild intolerance or sensitivity to gluten.
One way to rule in or out food intolerances and allergies is to undergo an “elimination diet” that identifies exactly what food may be causing your symptoms. The elimination diet involves entirely removing suspected food(s) from the diet for a period of time—two weeks to two months—and waiting to determine whether symptoms resolve. Then you purposely reintroduce items one at a time back into the diet while leaving three days between each reintroduced food as you chart symptoms and responses. If it’s irritable bowel syndrome you suffer from and you think dairy in particular is something you want to rule in or out, ask your doctor to conduct a hydrogen breath test (HBT). An HBT can also help determine whether or not you have bacterial imbalance in the gut.
A skin allergy test determines fixed or immediate responses to food allergies. A simple test your doctor can do involves scratching your arm and/or back with suspected allergens and then analyzing the welts left behind for their intensity.
Food sensitivity testing (very different than intolerance or allergy), however, is done when certain symptoms develop, or preexisting conditions become worse. Examples of such symptoms include acne, anxiety, arthritis, asthma, attention deficit disorder, autism, chronic diarrhea, chronic fatigue, constipation, depression, diabetes, high blood pressure, hyperactivity disorder, irritable bowel syndrome, muscle pain, obesity, panic attacks, sinusitis and weight imbalance. Again, we’re not talking about the difference between good foods and bad foods when we’re talking about these immune responses. An IgG reaction can be triggered by such wholesome foods as organic chicken, broccoli, or spinach. True, the reactions that sensitivities provoke are not as severe as allergies, but they can nonetheless damage your health through inflammation and the sort of symptoms I’ve just listed.
Testing your blood is the first step in the process to help identify the foods which may be causing symptoms. Professional laboratories use the microarray-based test that can detect IgG antibodies to more than two hundred different foods. Only a blood test can reveal hidden food sensitivity in these circumstances. If someone asks you to hold a metal rod while they figure out your sensitivities, I’d have serious doubts about the accuracy of their results and the quality of their recommendations. A well-respected and scientifically proven testing protocol called the enzyme-linked immunosorbant assay provides a useful measurement of the concentration of the antigen (the food in question) and the antibody (your immune response), thereby exposing the specific food intolerance. These factors are determined by an immune reaction governed by a molecular component of the immune system called immunoglobulin gamma (IgG). Based on test results, patients can then work with their health professionals, using an elimination diet to determine which foods should be eliminated or reduced from their diets. The old saying “one man’s meat is another man’s poison” really is true. No test is 100 percent accurate, and food allergy testing is no exception. Although highly reproducible, you can expect a few false positives and negatives (e.g., cashews may show up as sensitive, but on a subsequent test, they don’t. Pepper spice may not show up as positive, but a subsequent test might suggest a low-grade response).
In many cases, eliminating these sensitivity triggers from your diet may be enough to relax an overexcited immune system and you may find yourself symptom free. I’ve personally witnessed hundreds of cases of eczema, psoriasis, migraine headaches, fibromyalgia, irritable bowel syndrome and panic attacks that quite literally disappear once food intolerances were tested for, discovered and removed.