How To Do An Elimination Diet


(By Bev Laumann) Many people with IC find that diet modification and an elimination diet are the most powerful tools they have to take control of their life and manage IC’s frustrating ups and downs. Soon after embarking on an IC diet though, most of us find truth in the old saying, “everyone’s different.” While the IC diet lists many foods to avoid, IC patients often find one or two “bad” foods that their bladder can tolerate. Or, they are surprised to find one or two “good” foods that others can tolerate, but they can’t. I’ve found I can eat a bit of watermelon or a few pecans now and then. Unfortunately, my IC friend Susan can’t touch even the tiniest bit of either. Yet she can eat bacon, and I can’t. Ralph can eat bananas all day, but Barbara’s bladder won’t tolerate them. And Meg says that foods don’t seem to effect her bladder one way or the other.

Dietary Differences

Why do we have these individual dietary differences? Doctors aren’t sure. One answer may be that IC is not one disease, but many. Different subsets of IC patients may have different causative factors for their bladder symptoms and this leads to differing experiences with food. The number of years one has had the disease and whether or not one’s bladder has “Hunner’s ulcers” may also be a factor in our food sensitivity. One study involving over 300 IC patients found that our sensitivity to spicy foods and tea increases with the number of years we’ve had bladder symptoms. The same study also found and that IC bladders with Hunner’s patches (also sometimes called “Hunner’s ulcers”) tend to be more sensitive to acidic and spicy foods than IC bladders without them.

Another possible explanation for our individual differences may be food intolerances or allergies. These food reactions may effect the bladder through the mechanism of bladder mast cells. In a recent broad-based survey involving thousands of IC patients, allergy (to food, airborne allergens, or medications) was found to be the most common IC-associated disease. More than 40% of those in the study had at least one allergy definitively diagnosed by a physician. According to a journal article on managing food allergy (S.C. Bischoff et al., in Allergy, 1995), “There is evidence that in subjects who are sensitized to foods, eating those foods alters their intestinal permeability and that this change in intestinal permeability allows an increased absorption of antigen. The symptoms and the severity of those symptoms at secondary target organs such as the skin or lung will be dependent upon the amount of antigen arriving at the target organs.” In other words, the irritating food substances pass through an unusually “leaky” intestinal lining and get into the blood stream, where they travel to a sensitized organ, and cause a painful reaction there. One could reasonably speculate that perhaps an IC bladder, already irritated and sensitized from other causes, may provide a target organ for this process in an allergic IC patient.

Many IC patients also have something called irritable bowel syndrome (IBS), a gastrointestinal condition that has also been linked to mast cells and increased intestinal permeability. Data from several studies have suggested that allergic reactions to food antigens may be a causative factor for at least some IBS patients.

Uncovering the Offending Foods

Whatever the medical reasons for our dietary problems and differences, as patients, we want as much control over our bladder symptoms as possible. We can do that by pinpointing which foods provoke our bladder. This may not be as easy as it first appears. Typical pin-prick allergy testing techniques will not uncover food sensitivities such as those IC patients have. What’s more, reliable tests for reactions to food additives (ie., monosodium glutamate) have yet to be developed. But there are some tests available that may be helpful, particularly if you know that you already have pollen or medication allergies. Known as RAST tests, ELISA tests, or cytotoxic tests, these blood tests for food allergies are now available through some, but not all allergists. If you have food allergies, this kind of test can not only pinpoint foods your body reacts to immediately, but can also identify foods that cause delayed reactions. (Immediate reactions appear in minutes to hours and are mediated by a substance called IgE, whereas delayed reactions are mediated in the body by IgG and can appear a day or so after ingesting the allergen.) In the past some doctors considered them unreliable, but the tests have gradually gained acceptance as physicians have seen the positive results with their allergy patients. Finding and eliminating food allergens may or may not be helpful in controlling your particular bladder symptoms though, and if you do see improvement, it may take several months to become apparent.

Food intolerances are not the same as food allergies. An intolerance is just a general term that means you get symptoms of some sort when you eat a particular food. Intolerances do not involve the same mechanisms as allergies. So your bladder may react to foods, but that reaction may not involve an allergic process at all. Doctors consider food allergy tests inappropriate or useless for diagnosing food intolerance problems that are not allergies. The tried-and-true (and least expensive) method for discovering if foods cause symptoms, remains the elimination diet. It will reliably uncover which foods cause you trouble regardless of the underlying biologic mechanism.

General Guidelines for Elimination Diets

Most elimination diets have two phases: the first phase, where foods are eliminated and symptoms will be reduced (if successful), and the second phase, where foods are gradually reintroduced while watching for the appearance of symptoms. The whole process may take months to complete. Keep in mind also, that you must pay attention to nutritional adequacy during these dietary manipulations, especially during the second phase. Rotate the food groups you test. Don’t spend weeks adding green vegetables one at a time to your diet, while neglecting meats, dairy, yellow vegetables and grains.

Throughout the time you are manipulating your diet (and for at least a week before starting your dietary changes), it is important to keep a symptom score diary. This will be time-consuming, I can tell you right now. But it is necessary to do it this way because your memory will play tricks on you. In fact, in a recent study involving more than 300 IC patients, researchers found that only about 60% of the IC patients could tell their doctor (within reasonable limits) how many times per day that they urinated. (The patients were first asked how often on average they urinated, then their real frequency was tested and recorded. Those with more severe cases were better at guessing their real frequency than those with milder cases).

Because many IC patients also have migraine headaches, irritable bowel syndrome, fibromyalgia, and other medical conditions, it is important to take note of the effect of diet on those symptoms also. Record each symptom separately, as each may be affected differently (or not effected at all) by your dietary experimentation. It is good to use a numeric severity scale (0-to-5 or 1-to-10, for instance) to rate your symptoms for the day. At the end of each day, record the numeric severity for frequency, urethral burning, backache, and fatigue separately.

Keep an open mind when embarking on an elimination diet, and watch for food additives. I remember one time I thought I couldn’t have sunflower seeds, because whenever I ate some, they bothered my bladder. As I continued to try the seeds again and again over a course of two weeks, my bladder’s reaction to them seemed to get progressively worse each time. When I went to throw out the empty jar, I noticed a white salty sediment remaining at the bottom. Suddenly it occurred to me that maybe it was something other than the seeds that caused the bladder pain. The label indicated that the seeds had added HVP (hydrolyzed vegetable protein). I figured that if the tiny amount of HVP was the real culprit, then maybe it would settle out in the jar and became more and more concentrated toward the bottom. That may expalin why my symptoms got worse each time I ate some seeds. I purchased some additive-free seeds later and they gave my bladder no problem. That experience taught me not to jump to conclusions.

Watch out also for ingredients that may not be on a food label. Sulfites, for instance, can be notorious IC pain-provokers, and are often problematic for allergic individuals too. By U.S. law sulfites must be on a food’s label only if the food contains more than 10 parts per million. (Lesser amounts and naturally occurring sulfites in non-packaged foods may provoke some IC bladders nonetheless.) Sulfites may be added to dried fruits, some processed potatoes, shrimp, and coconut. They naturally occur in wine and onions. The acidity of the food may increase the allergenic effect of the sulfite. Cooking can destroy or lessen some sulfite compounds, but if it is not completely destroyed you may still react to the remaining amount. (Baking, for instance, does not destroy enough of the sodium metabisulfite on coconut to keep my sulfite-sensitive bladder happy). It is best, for the purposes of an elimination diet, to work only with fresh foods that you know won’t confuse the issue with artificial additives. You can test additives separately later.

Watch out for certain words on packaged foods: “gluten” is wheat, “casein or caseinate” is dairy, “hydrolyzed” anything or “natural flavors” may have MSG, “surimi” contains fish, and “albumin” is egg white. One more thing to keep in mind when adding beef or other meats to your diet (as if there isn’t enough to remember) is that supermarkets sometimes illegally try to boost their profits by grinding up leftover pork, lamb and chicken trimmings with the ground beef. Pre-packaged ground turkey can also have MSG. When you wish to add meats to your diet, don’t use ground meats.

There are several kinds of elimination diets, and each person must evaluate for themselves which one is best suited for their particular situation. It is also a good idea to check with your doctor or consult a registered dietitian before embarking on any long-term dietary modifications. This is especially true if you have other serious medical conditions besides IC.

Elimination Diet Types

In general, there are three different types of elimination diets you can try (with appropriate review by your medical care provider). These are: (1) the simple exclusion diet, (2) the empirical diet, and (3) the few foods diet.

The Simple Exclusion Diet

The purpose of this diet is to firmly establish what the patient already suspects: that foods “A,” “B,” and “C” for instance, cause problems. This dietary tactic is easy t