Basic Differences Between an Allergy and an Intolerance

image00These days it’s fairly common to hear people announce that they are allergic to foods like wheat or dairy. But have you ever wondered how is it that so many people are developing allergies to foods that have been a part of the American diet for generations? Should we be concerned?

Food allergies have increased over the last decade, particularly among children. Still, many people who claim they are allergic to a certain food may actually have a food intolerance instead, since intolerance is the much more common condition of the two.

Here are some of the basic differences between an allergy and an intolerance:

Food Allergy

When you have a food allergy, you experience an immune response to the trigger food that can affect several different areas of your body at once. Sensing an attack, the immune system overreacts by producing antibodies that travel to the cells and produce the allergic reaction.

This histamine response can range from mild to severe. Some common reactions to food allergy are:

  • Hives or eczema
  • Itchiness in the mouth or ear canals
  • Swelling, especially around the lips and mouth
  • Wheezing or difficulty breathing
  • Stomach pain, diarrhea, or vomiting

In some cases, people develop a more severe reaction known as anaphylaxis. This condition causes constriction of the throat, making it difficult to breathe, and it slows the circulatory system. Individuals may experience a drop in blood pressure and go into shock. Anaphylaxis can be fatal if not treated immediately with an injection of epinephrine.

For some people, it only takes a miniscule amount of the food to trigger a reaction: just inhaling the steam from cooking fish can be enough to trigger a reaction in those with an allergy, for example. Parents of children who have nut allergies need to follow a special protocol for washing all traces of peanut from their hands.

Around 15 million Americans have food allergies—four percent of the adult population and roughly eight percent of children under five. Only eight foods account for 90 percent of all allergic reactions: peanuts, tree nuts, fish, shellfish, wheat, soy, milk, and eggs. Although they occur in a small percentage of the total population, food allergies cause about 200,000 emergency care visits a year—or one every three minutes.

Food Intolerance

Unlike food allergy, which is an immune response, food intolerance occurs when your digestive system is unable to break down the foods you eat. The most common symptoms of food intolerance are gas, bloating, diarrhea, and abdominal pain. Migraines and hives may also occur in some cases.

The primary reason for food intolerance is that people either lack or don’t manufacture enough of the enzyme needed to digest a particular food. For instance, those who can’t digest dairy products are lacking in lactase, which breaks down lactose into small enough particles to be absorbed through the intestinal wall. The most common foods that cause intolerance are wheat and dairy.

Other causes of food intolerance are:

  • Caffeine
  • Salicylates
  • Food additives
  • Foods naturally high in histamine, like shrimp
  • Nitrates
  • MSG
  • Sulfates

A form of food intolerance that has caused a lot of confusion and debate is celiac disease. Celiac is an autoimmune disorder in which the body’s immune system views the gluten—and some non-gluten proteins, which make up three-quarters of the overall protein content—in wheat as a threat and attacks it, causing damage to the villi of the small intestine and chronic inflammation.

Although the disease involves an immune response, unlike a food allergy it is not a life-threatening condition. Left untreated, however, celiac disease can lead to malnutrition, type 1 diabetes, rheumatoid arthritis, and liver disease.

Celiac needs to be distinguished from non-celiac gluten sensitivity, which causes inflammation and distress without permanent damage to the small intestine. Far more people suffer from non-celiac gluten sensitivity but may also benefit from a gluten-free diet.

Diagnosing Food Allergy or Food Intolerance

Because they present similar symptoms and often involve the same foods, it can be a challenge to figure out which condition you suffer from. Prick or blood testing is a reliable method of determining which foods cause an allergic reaction. If food intolerance is suspected, though, there are reliable tests for two conditions: celiac disease and lactose intolerance.

A good way to determine which foods are causing problems is to keep a diary of what you eat in order to monitor your body’s reactions. You can also undergo an elimination diet, in which you restrict all foods that you or your doctor suspect are causing the problem and then add them back to your diet one at a time to see how you respond.

Food allergies, intolerances, and sensitivities are controversial topics in the medical field. Some research connects them to recent changes in the Western diet, particularly the refinement of whole foods like wheat and rice, genetically modified foods (GMOs), and the ready availability of chemically-processed food.

Keep in mind that the human body is not designed to process synthetic or chemical substances, and when the body doesn’t know what to do with something, it can mess up the whole system. A sensible diet of whole foods rich in naturally-occurring antioxidants and omega-3 fatty acids is a good preventative step to avoid developing a food allergy or food intolerance.

The articles on this website are not to be construed as medical advice, diagnosis or treatment.