About Food Intolerances & Food Allergies

Sometimes the immune system produces antibodies called immunoglobulin to specific foods.  Depending on whether the immunoglobulins are IgG or IgE, they can cause either food intolerance or a food allergy.  There are important differences in the two reactions.

Food Intolerance (IgG) 

Food Allergy (IgE) 

   Slow onset: hours to days after eating
   reactive food

   Rapid onset: minutes to hours after eating
   reactive food

   Reactions are usually to foods eaten most 
   often 

   Reactions are relatively rare 

   Chronic disease strongly associated with
   food intolerance 

   Is an acute reaction: usually quick and
   dramatic 

   Can affect any tissue or organ in the body 

   Usually affects airways, skin or intestine 

   Difficult to detect without testing 

   Readily apparent after eating food allergen 


Why test for food intolerance?

  • Food intolerance occurs with the foods you eat most often.
  • Most people are unaware that they are eating foods that make them sick.
  • IgG reactions are much more common than IgE reactions, affecting as many as 1/3 of the general population.
  • IgG reactions that cause food intolerance take hours to days to develop; making them very difficult to uncover without testing.
  • More than 100 diseases and conditions are associated with food intolerance.
  • More than 2/3 of people with chronic health conditions have IgG reactions to food.