Food Allergies, Intolerances and Sensitivities
Indigestion. General malaise. Hives. Constricted throat. Light-headedness out of the blue. Last winter I was having periods of ill health, experiencing all of these symptoms, and I was clueless as to why. At first I thought they were all unrelated—maybe I was getting a sore throat, maybe I had touched something that was giving me hives, maybe I was having an autoimmune problem? It took me three long months and an elimination diet before I finally pinpointed what was happening: I had developed my first food allergies.
Strawberries and peanuts are no longer foods I include in my life, and food allergies are something that I have had to become a lot more knowledgeable about over the past year. In the process, I also have learned a goodly amount about food intolerances and food sensitivities as well. It was strange but also a huge relief to finally figure out food allergies were causing the symptoms I listed above. Now that I know, I can act accordingly. In case there are others out there who have been or may one day go through a similar process, I wanted to share some of the things I have learned.
One of the first things I learned was that I am hardly alone in suffering from food allergies. According to the USDA, around two to four percent of adults in the United States have some sort of food allergy. A recent study published in Pediatrics found that the incidence of food allergies in U.S. children is around eight percent, two full percentages higher than ever previously supposed. Of the children participating in the study, 39 percent had histories of severe reactions, and 30 percent had multiple food allergies.
Up to half a billion dollars is spent annually to treat food allergy reactions, according to a study published in the April 14th, 2011 Journal of Allergy and Clinical Immunology. Food allergies were a prevalent enough concern for Congress to pass the Food Allergen Labeling and Consumer Protection Act of 2004. This Act requires all food whose labeling is regulated by the FDA to identify the food source names of all ingredients that are, or contain any protein derived from, the eight most common food allergens (milk, eggs, fish, crustacean shellfish, tree nuts, peanuts, wheat and soybeans).
A food allergy occurs when the immune system mistakenly believes that a food is harmful. Specifically, the immune system creates immunoglobulin E (IgE) antibodies in response to the introduction of a particular food in the body. The next time a person eats the food, the IgE antibodies signal the immune system to release massive amounts of chemicals and histamines. In turn, these chemicals trigger the symptoms of an allergic reaction. Allergic reactions vary in intensity and expression, and can be triggered by even a small exposure to an allergen food. Allergic responses can affect the respiratory system, gastrointestinal tract, skin, or even the cardiovascular system. Common symptoms can include:
- Tingling in the mouth
- Swelling of the tongue and/or throat
- Hives and swelling
- Abdominal cramps
- Difficulty breathing
- Drop in blood pressure
- Loss of consciousness
The timeframe for symptoms to appear varies with each person and allergy. They may appear within minutes, or not until hours after a person has consumed a food to which s/he is allergic. It is not always necessary to actually ingest the food either—sometimes simply touching or breathing in an allergen will result in a reaction.
The most severe reaction to an allergy inducing food is anaphylaxis. Anaphylaxis is the systematic manifestation of an allergy, a.k.a. when the allergic reaction affects the body as a whole and not just locally. An example of a localized reaction would be eating a strawberry and getting hives on your fingers, mouth and lips. An anaphylactic response to eating strawberries would result in hives appearing throughout the entire body. The severity of anaphylaxis can be graded as mild, moderate or severe and it is a potentially life-threatening allergic reaction. According to the USDA, it is estimated that anaphylactic responses to food result in 30,000 emergency room visits, 2,000 hospitalizations and 150 deaths each year.
Why do some people develop food allergies, while others do not? At this point, no one is entirely certain. A complex interplay of genetics, hormone levels, environmental exposure and immune system development are likely the underlying factors. We do know that some allergies children experience will fade as they grow into adulthood, but not all of them. Some adults, such as myself, will develop food allergies later in life. It is less likely for reactions that appear in adulthood to fade over time, but it depends on the person, the exposure, etc. The intensity of an allergic reaction can also change over time.
Ways to diagnose
If you think that you or someone you know might have a food allergy, it is important to look into it. There are several ways to diagnose a food allergy.
Prick test: This is the most common allergy test and, performed correctly, has a high degree of accuracy. A small needle is used to scratch the skin gently through a droplet of fluid containing a known allergen. In most cases, clinics use purified liquid forms of the allergen, but sometimes you may be asked to bring a fresh sample (especially if the suspected allergen is food). The test is usually done on the forearm. It isn’t painful and results are immediately available. Children can be safely skin tested from four months of age.
A positive reaction occurs when the skin around the needle prick becomes itchy with redness and develops a white swelling called a wheal. The wheal reaches its maximum size in about 15 to 20 minutes and the reaction fades within an hour. Wheal diameter varies from 5mm to 10mm in a positive test—the larger the wheal, the more likely that you are allergic.
Blood test (RAST radioallergosorbent test): This measures the amount of specific immunoglobulin E antibodies (IgE) to inhalants and foods in your blood. IgE causes histamine to be released when you’re exposed to various environmental and food allergens. The test is safer than a skin-prick test, as you’re not directly exposed to the allergen.
Results are graded from grade 0 (negative) and grade 1 (weak positive) to grade 6 (strong positive), depending on the level of the allergen’s specific IgE antibody in your blood. The higher the grade, the more likely it is you have an allergy to that allergen. More than 400 specific allergens can be tested for in this way.
Currently there is no solid treatment available for food allergies, beyond the avoidance of the food you react to (and having medication on hand in case of an accidental exposure). There is some research being done in desensitization immunotherapy, which is when medical professionals administer small doses of the allergen to create an immune tolerance. This is a very old and controversial treatment, which absolutely should not be tried at home, especially with severe food allergies. Consult a healthcare professional.
There are a lot of resources available for those living with food allergies. The Food Allergy and Anaphylaxis Network (FAAN) has a lot of terrific resources on their website- check it out at www.foodallergy.org.
As I researched food allergies, I also learned an increasing amount about food intolerances. Contrary to what I initially thought, a food intolerance is very different from a food allergy. I asked Katy Wallace, ND RYT from Human Nature LLC what the difference was between the two. “The greatest difference between a food intolerance and a food allergy is that an intolerance does not involve the immune system, “ she explained. “Food intolerances are a digestive issue. [The food] goes into your gut and your digestive tract just can’t handle it.”
A lactose intolerance is perhaps the most common example of a food intolerance. Someone who is lactose intolerant lacks the enzyme needed to digest milk sugar. As a result, when that milk sugar enters the digestive tract it cannot be broken down properly and causes symptoms like gas, bloating, diarrhea, abdominal pain, etc. Reactions vary with the size of the dose. Food intolerances can also have more insidious effects, which may not be easily traced to the food itself. For instance, the lack of a specific enzyme might lead to the build up of indigestible byproducts, which can in turn mimic the symptoms of an allergy. Food intolerances can also lead to headaches, irritability, nervousness or even heartburn. Other common food intolerances are to wheat, alcohol and sugar.
What causes a food intolerance? There are a variety of potential causes. It might be intestinal enzyme deficiencies (like lactose intolerance), adverse reactions to naturally occurring chemicals in foods (ex: histamine, serotonin, tyramine, etc.), preservatives (e.g.: sulfites), flavorants (e.g.: aspartame) and artificial colors (e.g.: tartrazine).
Unlike allergies or food sensitivities, neither blood nor skin prick tests are available for food intolerances. Since it is a digestive issue, there aren’t any antibodies present to test. If you think you might have a food intolerance, the best way to investigate is to pay close attention to your body and how you feel after eating any suspect foods. Keep a food diary, recording how you feel immediately after, several hours after, and even the next day. Try an elimination diet and pay attention to how your body feels as you add in each additional food.
Over the past 10 years food sensitivities have become increasingly talked about in the U.S., A food sensitivity is a food that causes an adverse response in your body, but not to the level of a full-on allergy. The body can produce other antibodies (similar to but different from the IgE produced when you have an allergy) that have more subtle effects. Food sensitivities can degrade any bodily system over time, and manifest in a wide variety of ways.
The following are some of the major symptoms: fatigue; lethargy; needing to sleep after you have eaten; drowsiness; poor memory; poor concentration; mental agitation; mood swings; compulsive eating; food cravings; sugar craving; carbohydrate and starch cravings; water retention; weight problems; mood swings; depression; restlessness; irritability; headaches; migraines; swollen and painful joints; muscle pain; stiffness; gas; bloating; flatulence; indigestion; heartburn; constipation; blurry eyes; spots in front of eyes; restless sleep; broken sleep.
“When you have a sensitivity, these chemicals called cytokines are produced. The chemicals can be very acidic and can degrade any body system,” explains Katy Wallace. Sensitivities can manifest in a variety of ways over time, “because the human body is so dynamic, your level of sensitivity is affected by other variables.”
There are a couple of different tests available to detect food sensitivities in the body, both of which are offered at Human Nature. One is the ALCAT, a very sensitive blood test that looks for any kind of reaction to a wide array of foods. Another option is the ELIZA test, which is similar to the ALCAT but less sensitive. The results from ELIZA, according to Wallace, are more repeatable and consistent, because it isn’t so very sensitive.
Over the past year perhaps the greatest lesson I’ve learned (and had repeatedly reinforced) is that it is so important to pay attention to my body and its unique reactions. The body is incredibly complex, and each one is utterly unique. When it comes to food allergies, intolerances and sensitivities, there is no “one size fits all” rule, and the same person can experience each of these categories very differently over time. If you find that you do need to avoid a food for one reason or another, be sure to check out the binders in the Co-op’s Owner Resources Area. There is a lot of helpful information geared toward finding foods that are free of common allergens. Katy Wallace at Human Nature is a fabulous consultant, and we are also lucky to have the UW Allergy Clinic here in Madison as well.