This is a multi-part series from our dietician Laura Palazzolo. Stay tuned for additions over the next few months!
The Elimination Diet: Part 1
The elimination diet is a mainstay of treatment in the functional nutrition world. If you are not familiar with the practice of functional nutrition, it is a type of nutrition counseling that recognizes each individual’s biochemical differences. It also focuses on customizing treatment based on the subjective and objective experience (such as labs or symptoms) of the individual which creates custom treatment plans. The elimination diet allows individuals to determine specific tolerance for foods and identify which foods that may be related to symptoms. This is accomplished by eliminating a specific set of foods and reintroducing them one by one. A more detailed explanation will follow in additional posts.
Let’s get some terminology straight before we dive into the specifics:
- Food Sensitivities: broad term including both food allergies and intolerances
- Food Allergies: mediated by the immune system. It is a response to proteins. Can be IgE (a type of antibody important in the immune system) or non-IgE mediated. Sometimes it is a mix of both types.
- IgE mediated reactions generally present in the typical fashion one thinks of with food allergies (ie- hives, throat closing, facial swelling). The onset is fairly immediate; the reaction is severe and sometimes life-threatening.
- Non-IgE mediated reactions are less understood. Symptoms of the food allergy are delayed, more subtle and usually not life-threatening. I’ll review some of these symptoms later.
- Food Intolerances: Does not involve the immune system, can be metabolic, toxic or pharmacologic (related to natural chemicals found in food). Can involve proteins, carbohydrates, fats or chemical substances. Lactose (a carbohydrate) intolerance is one of the most common intolerances. Examples of other intolerances are fructose (a carbohydrate), caffeine (a chemical) and solanine (a chemical) found in nightshade vegetables. Food intolerances have been associated with irritable bowel syndrome (IBS).
Food allergies are on the rise
According to Food Allergy Research & Education, about 15 million people live with food allergies and many of them children. Recent research that tracked food allergies between 1997 and 2011 showed that, food allergy diagnoses are on the rise. It is estimated that the prevalence has increased by 18% between 1997 and 2007 and continues to increase yearly. Eight foods account for 90% of all reactions. These foods are: milk, eggs, peanuts, tree nuts, soy, wheat, fish and shellfish. The statistics reported are generally related to IgE mediated reactions. If you included non-IgE mediated reactions and food intolerances, which are harder to diagnose, you would probably see a much higher increase.
So why are we seeing this rise? Scientists are not really sure, but there are different theories. One popular theory, called the “hygiene” or “old friends” hypothesis, focuses on the gut microbiotia (colonies of bacteria within our bodies that help regulate the immune system and perform other functions). The theory goes like this: we are not as readily exposed to the variety and type of bacteria that we evolved with, therefore, our immune systems are not developing properly, thus making us more susceptible to food allergies. When it comes to wheat sensitivities, some believe the wheat breeding process over the years has increased sensitivities in those who are more susceptible to becoming gluten sensitive.
In the next part, I will discuss why you should consider doing an elimination diet, conventional food allergy testing and the research surrounding elimination diets for specific conditions.
Laura Palazzolo Kraus MS, RDN