Elimination Diets

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“Two separate people told me I should try going gluten and dairy free to combat my arthritis and go off my medicine.  Perhaps that could be another topic: elimination diets to combat various diseases.”

In response to my request for blog topics, a friend of mine suggested the preceding idea.  My response inspired a tangential post to which you can find a link here as well as about two-thirds of the way down.

Before we get to elimination diets, let us first consider some of the various ways in which foods might have a negative impact on us: allergies, intolerances, and sensitivities.

Food allergies involve the immune system and the reactions are rapid and often acute.  Think of somebody who accidentally eats a peanut and has to use his EpiPen to keep his throat from closing.  Doctors can test for food allergies with a high degree of accuracy.

Food intolerances do not involve the immune system.   For example, consider somebody who lacks the lactase enzyme in his system necessary to digest lactose, and as a consequence he experiences symptoms like gas, bloating, and diarrhea in response to dairy ingestion.  We call this lactose intolerance, and doctors can test for it via a hydrogen breathalyzer test.

Food sensitivities differ from both allergies and intolerances.  Symptoms associated with food sensitivities tend to set in slowly, leave slowly, and are more subtle.  The range of associated symptoms is also quite wide, including headaches, fatigue, joint pain, bloating, and nasal congestion, just to name a few.

The current tests for food sensitivities are, to put it kindly, not great.  In fact, there is no immunological society in either the U.S. or Europe that considers today’s food sensitivity tests valid.  One of the problems with these tests is that they can simply reflect exposure to a food.  In other words, if you have eaten a given food recently, it is more likely to come up positive.  Even worse, the results can actually reflect tolerance (yes, tolerance) to the food in question.

The best way to determine food sensitivities is through an elimination diet, a procedure in which somebody cuts out various foods and then reintroduces them in systematic fashion in order to see how his symptoms change in response.  Elimination diets can be slow (think weeks, not days) and tedious, and they require a tremendous amount of discipline on the patient’s part.  Another issue to consider is that the patient is unblinded.  In other words, he knows when he is or is not eating a given food and this can influence the results.  If someone or something has led him to suspect that a given food is responsible for his symptoms, then he might imagine or exaggerate a reaction due to expectation.  It’s sort of a like a reverse placebo effect.  Additionally, other confounding factors exist too.  All sorts of variables exist in our life, so the onset or dissipation of a symptom cannot automatically be attributed to a change in diet.

While elimination diets can yield useful data, the challenges and downsides associated with them understandably leave people looking for alternative approaches [At this point, I went off on a tangent, which I extracted and posted here.], which brings us back to the food sensitivity tests that I mentioned a couple of paragraphs ago.  These test results should never be taken literally, but they can be used for the basis of an elimination diet.  For example, if the results indicate that Foods X, Y, and Z are problematic, one can eliminate and then reintroduce these three foods to determine which (if any) of them are indeed problems.

Also remember that cutting out foods can have consequences and should not be done casually.  I know cutting out gluten is kind of the in thing to do these days, but going gluten-free without a good reason for doing so it not such a great idea.  Gluten-free products are often lower in fiber, iron, and some of the B vitamins.  Of course it is possible to get these nutrients elsewhere, but a gluten-free individual has to pay that much more attention to the rest of his diet in order to avoid a deficiency.  Additionally, gluten-free products tend to be more expensive than their traditional counterparts, and potential social repercussions warrant consideration as well.  Unless somebody has cause for eliminating a food and has discussed it with his doctor and dietitian first, cutting it out is probably not the best idea.

Despite all of these potential downsides, elimination diets are currently our best option for determining food sensitivities.  If you are considering eliminating a food (or foods) due to a medical condition or symptom, talk with your doctor and dietitian first.  While elimination diets have their place, they are not always the appropriate first step.  Your doctor may wish to run other tests first.  For example, celiac disease can be more difficult to diagnose if somebody has already begun to reduce his gluten intake.  So, talk with your healthcare team first.  Your dietitian can help you to design the logistics of your elimination diet.  If you are going to put in the effort to do one, might as well make sure you implement it in such a way that will maximize your chances of gathering useful data.  Lastly, if and when you do start an elimination diet, keep an open mind to all possible outcomes and do not assume that a given food is going to be either benign or problematic.