Defining Food Allergies and Food Intolerances

I don't talk about food allergies and intolerances very much on my blog, but allergies are probably the single most influential factor in my day-to-day life. I will try to spend more time blogging about them to help spread the word about what food allergies are, what intolerances are, and how to cook with them.

(Photo by: Vu Nguyen, Creative Commons 2.0)

There is some basic vocabulary about food allergies that I thought might be helpful to learn.

1. Food Allergy: 
According to the American Academy of Allergy Asthma & Immunology, a food allergy happens when the immune system over-reacts to the protein in a certain food. The reactions can include:
- a rash, or red, itchy skin (hives/eczema)
- stuffy or itchy nose, sneezing, or itchy and teary eyes
- vomiting, stomach cramps, or diarrhea
- angloedema or swelling
- hoarseness, throat tightness, or a lump in the throat
- wheezing, chest tightness, or trouble breathing
- anaphylaxis

2. Food Intolerance:
There's a lot of conflicting information out there about intolerances. Here's the general consensus, though: if a reaction to the food involves the immune system, then it's an allergy. If a reaction to a food does not involve the immune system, then it's an intolerance. The Australian government's Better Health Channel provides a thorough list of food intolerance symptoms, which include:
- nervousness, tremor
- sweating
- palpitations
- rapid breathing
- headache, migraine
- diarrhea 
- burning sensations on the skin
- tightness across the face and chest
- breathing problems (asthma-like symptoms)
- allergy-like reactions

The best example is a milk allergy verses lactose intolerance:
- a milk allergy is when the immune system attacks the milk protein whereas lactose intolerance is when the person's body doesn't have the enzyme to process the lactose in milk. 
- The symptoms are probably similar (unless the allergy causes anaphylaxis) but the cause is completely different.