Food sensitivity (sometimes called intolerance) is a term used to indicate symptomatic responses when particular foods are eaten. Food sensitivities and intolerances tend to create more subtle symptoms than allergic responses, although over time, their impact on health and vitality can be dramatic.
In traditional medical circles, the lines between food allergy and food sensitivity can blur. For the sake of our discussion, we would like to make a clear distinction.
A “true” food allergy can potentially be life-threatening, eliciting an immune response that produces IgE antibodies. One common example we’ve all heard about is a child with a peanut allergy who must avoid even the tiniest amounts of peanuts in any form, or be overcome with disastrous symptoms. Thankfully, not all allergies evoke such an intense response, however IgE-mediated responses are generally observed almost immediately after the offending food is ingested.
The medical community recognizes that foods like milk, eggs and peanuts tend to trigger food allergies in children, and that peanuts, tree nuts, some fish and shellfish are common triggers in adults. The traditional doctor who doesn’t integrate nutrition into his practice tends to focus on these IgE-mediated issues when food-related symptoms are mentioned at all.
Food sensitivities are associated with IgG and sometimes IgA antibody production. The onset of symptoms in these cases may be delayed hours or even days, so associating an offending food with a subtle symptom can be elusive.
There are also some people who have reactions to foods that don’t involve the immune system and this is referred to as an intolerance. You may have heard of lactose intolerance. In this case, the person’s body doesn’t manufacture the enzyme lactase which is required to digest milk sugar, or lactose. This is entirely different from a milk sensitivity where an individual's immune system reacts to the protein casein found in dairy.
FOOD SENSITIVITIES INVOLVE A REACTION BY THE BODY AGAINST CERTAIN FOODS WE EAT.