Wednesday, May 12, 2010

You Say Tomato, I Say...

This morning a kind friend forwarded along an article from the NY Times, that begins, "Many people who think they have food allergies actually do not." The piece goes on to say that allergies are IgE mediated, resulting in immune system responses ranging from sneezing and watery eyes to full-on anaphylactic shock. What many people refer to as allergies then, are actually intolerances.

Part of the confusion is over what is a food allergy and what is a food intolerance, Dr. Fenton said. Allergies involve the immune system, while intolerances generally do not. For example, a headache from sulfites in wine is not a food allergy. It is an intolerance. The same is true for lactose intolerance, caused by the lack of an enzyme needed to digest sugar in milk.

Some say allergy, others say intolerance. Really it's a question of semantics. And while there is a physiological difference between the two, I am wondering why, during Food Allergy Awareness Week a designated week intended to help people "respect every bite," the Times felt it so important to exclude people who only have food intolerances, a no less unpleasant reaction to food.

Maybe it's that the issue hits too close to home. As someone with several food intolerances, for ease sake I occasionally tell people it's an allergy. Otherwise I worry that I won't be taken seriously. Because while some less severe allergies result in symptoms like hives (an allergic response), intolerances or sensitivities can cause everything from migraines to acne, GI distress, inflammation, weight gain, mood and brain fog.

Certainly patients should be educated to understand the severity of their reactions - whether an allergy or intolerance - in order to make smarter decisions about what to eat. One of my nutrition kitchen lab partners, for example, is allergic to strawberries and develops an itchy mouth after eating them. But two weeks ago in our cooking class we made such a delicious-looking dessert with strawberries that she decided the risk of slight discomfort was worth a taste. I, on the other hand, chose not to partake when we made a wheat-full dish, unwilling to endure my gut's reaction.

While the Times article acknowledges intolerances as actual conditions, it seems to be trying to discredit their severity. Still, it does highlight two important points. The first is how inaccurate food allergy testing can be, something not too many people know about. Secondly, it mentions something called a "food challenge" where a patient is given the food they are supposedly allergic to, in a disguised form. One doctor explains the limitations of this approach as being time consuming and potentially threatening if you present a patient with a food to which they might have a very strong response.

And that brings me to the Elimination Diet, which takes the concept of food challenges to a whole other level. It was really only a matter of time before I brought it up here. If you live in Seattle or have ever seen a naturopathic physician, you likely know someone who has done an elimination diet, someone who is doing one now or maybe you've done one yourself. The idea of this "diet" is to cut out all potential allergens (or, you could argue, "intolerance-inducers?") for a few weeks and then slowly reintroduce one food at a time and closely monitor the body's response. It asks a lot of you and can be very challenging. Cutting out the usual suspects means no gluten, dairy, eggs, soy, corn, peanuts, and sometimes other possible offenders. It can put a damper on your social life - going to a potluck with 20 dishes and none that meet these criteria - going out to eat and finding maybe one suitable item on the menu. On the plus side, it can be a very effective way to identify which foods are causing your inexplicable symptoms, remove them from your diet and feel a whole lot better. And an intolerance may be temporary or it may be for life. Kind of like an allergy.


  1. This story was all over the TV news in NY as well as in the NY Times. Their message was that the idea that so many people have food allergies is probably overblown. So your take on food intolerance vs. allergy is an interesting one.

  2. Did you say, "Elimination Diet"? Arrrrgh! But as a woman who has fought the obesity battle her whole life I'd have to say that discovering the food allergy related to cravings piece was profound. Food allergies are real! I think this is a story that needs to get out a lot more.

  3. I find it strange that many people "don't believe in" food allergies. I mean, most food is from a plant, and a lot of people are allergic to plants (hi, springtime anyone?) so why no possibility of an allergy to a plant that is typically consumed as food. This was actually the subject of a recent debate between myself and a non-Bastyr amigo of mine. Coming back around to intolerance vs. allergy, the way I've heard it described (that made the most sense to me) is that an intolerance is a genetic enzymatic insufficency--your body does not make sufficient amounts of the enzyme needed to metabolize the given food--while an allergy is mediated by your immune system--the food is recognized by your body as a "foreign invader". Lactose intolerance (lacking the enzyme lactase,which is necessary to digest the lactose sugar in milk) is the most commonly referred to intolerance and is usually spoken of in terms of "I'm allergic to milk".
    I, too, have resorted to saying allergy instead of intolerance because there is a slight overtone of preference when you say you have an intolerance. Tomato/tomato...either way, every body is different and not every body can eat everything. It's just a fact.

  4. Great points!

    @Anon. Glad this is finally hitting NYC. It's important to have issues like this up for discussion. Last week the Times followed up and did a whole "debate" about it. bringing a variety of experts to comment. Check it out:

    @Molly, there are so many factors - such as food allergies that lead to cravings and inflammation - all part of the weight puzzle.

    @Jessie, I like the way you present it - very clear! And I totally agree - everybody is different. Makes nutrition a very challenging and exciting field to work in...