Food Intolerance VS Food Allergies

More families are being affected by food allergies and intolerances then ever. According to a study released in 2013 by the Center for Disease Control and Prevention, food allergies among children increased by ~50% between 1997 and 2011.  While most of us are aware of the signs and symptoms of an allergic reaction, intolerances are a whole different animal. Understanding the difference and being able to identify potential symptoms of both food allergies and intolerances is essential for maintaining and optimizing health and quality of life.  

What Is a Food Allergy?

Food allergies occur when your immune system identifies a food as a foreign invader. Your immune system then reacts, or rather overreacts, by producing antibodies called imunoglobulin E (IgE) which travel to cells that then release chemicals to cause a reaction. This reaction typically happens immediately and can be as mild as inflammation (hives, for example) or as severe as anaphylactic shock.

The “Big 8” most common food allergies include milk, eggs, fish, shellfish, tree nuts, peanuts, wheat and soy. These account for 90% of all allergies.

Symptoms include:

  • hives, itchiness, swelling of skin
  • vomiting
  • diarrhea
  • anaphylaxis (difficulty breathing, dizziness, loss of consciousness)

potential causes

  • Avoidance of allergens. Previous recommendations for the avoidance of allergens, particularly peanuts, during pregnancy, infancy and breastfeeding have been dispelled. New evidence supports early exposure to allergenic foods to reduce the risk. In fact, it’s predicted that following the LEAP (Learning Early About Peanut allergy) study protocol could prevent 40-60% of peanut allergies!
  • Vitamin D deficiency. Studies have suggested that infants with low vitamin D are at an increased risk for food allergies. Check out my post on vitamin D for more information on how to optimize your levels.
  • The Hygiene Hypothesis. This theory states that being too clean and lack of exposure to microbes and pathogens at an early age can increase susceptibility to allergies. Living on a farm, having a pet dog, playing in the dirt, childcare attendance, and having an older sibling may have a protective effect.
  • A history of eczema. This study demonstrated that 1 in 5 infants with eczema had an allergy by 12 months of age, compared to 1 in 25 infants without eczema. One of the primary reasons for this is due to the break in skin barrier, so maintaining skin integrity by preventing eczema is key. 

You can refer to this article on the Prevention of Food Allergies for a more in-depth review on causes and prevention strategies.

What Is a Food Intolerance?

Food intolerances are typically more difficult to diagnose than allergies because they present in so many different ways and can take up to 72 hours to occur after eating the offending food. Also unlike allergies, they don’t involve the immune system.

Symptoms may include:

  • bloating
  • asthma
  • digestive upset
  • headaches or migraines
  • arthritis
  • eczema
  • fatigue

Based on the above symptoms, you can see why it may be difficult to connect the dots between food and what you may be experiencing. Unlike IgE, which causes an immediate response, the immunoglobulin G (IgG) antibody is related to delayed reactions. Food intolerances are typically caused by increasing levels of IgG in the body.

potential causes

  • enzymatic deficiencies (e.g. lactose intolerance due to lactase deficiency)
  • nutrient malabsorption  (e.g. fructose)
  • sensitivities to certain proteins or components of food such as histamine, gluten or FODMAPs (fermented carbohydrates, oligosaccharides, disaccharides, monosaccharides and polyols)

So What Do I Do?

If a food intolerance is suspected, an elimination diet is the most cost effective way to identify foods that may be causing issues. This type of diet removes foods that could be problematic, then reintroduces them one by one. (More on this to come!)

Receiving testing is also an option. Have your doctor test for suspected food allergies or take a test such as this one to identify IgG-mediated food intolerances.