In general, the tenets of a healthy diet can be summed up fairly easily: eat a whole-food, colorful diet, full of veggies, some fruits, limited grains, and lean meats/proteins. It’s the nuances to healthy eating that I think can be overwhelming: Can you have wheat? What about dairy? Why do some foods like these get separated from the heap and practically blacklisted? Wheat is a whole grain. Dairy can be a lean protein. Why don’t they fit into our basic tenets?

Many of these caveats to healthy eating fall in the realm of food intolerances. A basic explanation is that some foods, including wheat and dairy, are more likely to cause intolerant reactions (and unpleasant side effects) in many people. Food intolerances are common, with some estimations that as much as 95% of the population is affected. Sometimes they are common foods like wheat or dairy; however, sometimes for an individual, they are more random, like bananas or beef. So what exactly are food intolerances, and what should you do to figure out if you have any?

Food intolerances, sometimes referred to as delayed food sensitivities, can often culminate in headaches, skin changes including eczema and psoriasis, sinus congestion, and gastrointestinal complaints including gas and bloating, reflux, or irritable bowel syndrome (IBS), constipation and diarrhea. Some who suffer from food intolerance reactions can feel general malaise. Also, sensitivities have been linked to weight gain and difficulty in losing weight. For many, avoiding the offending foods can result in a decrease or complete resolution of symptoms.

Delayed food reactions are similar to food allergies in that the immune system is actually mounting a response against the offending food. However, the response is different. Food allergies cause a production of what are known as IgE antibodies. Typically, these reactions are quick and can be life-threatening. Shellfish and nut allergies are common examples. These are usually tested by skin prick testing.

Food intolerances, on the other hand, cause a response usually by producing IgG antibodies. These cause much slower reactions, with adverse symptoms occurring as much as 3-4 days after eating the offending food. You can see why it might be difficult to know your food intolerances just based on symptoms. It is unlikely that if you have a symptom, for example, a headache or gastrointestinal disturbance on Saturday, you will think as far back as food you ate Wednesday as a possible contributor. IgG testing is by blood-draw. Skin prick testing does not test for IgG responses, and if that is the only testing you have had done, then you have not been screened for food intolerances.

The other difference between allergies and intolerances is the length of memory that the immune system has for the offending food. For an IgE or anaphylactic reaction, you will likely have that allergen forever. An IgG food sensitivity, however, is limited to about 6-8 weeks. This short memory for food intolerances makes them controversial for testing and treating; therefore, your traditional doctor probably hasn’t offered to test them for you. The general traditional consensus is, “Why test when they are going to change anyway?” In Integrative medicine, we often test, especially for symptoms such as allergies, skin changes, chronic headaches, or obesity. We then have you avoid the offending foods for several weeks. At the same time, we initiate treatments to improve the integrity of the digestive tract thereby decreasing overall reactivity, IgG response, and the symptoms that ensue from the IgG response. We have, in effect, pulled out triggers leading to your symptoms while we treat for possible cause.

There are a couple of ways to determine whether or not the symptoms you might be exhibiting could be due to food sensitivities. One method is known as an elimination diet. This involves removing the most common food allergens from your diet (along with any additional foods that you might already suspect) for at least 10 days (longer, up to 8 weeks, is even better). After the initial avoidance period, you can reintroduce one food at a time, separated by at least 4 days, while monitoring for symptoms.

The most common food allergens include dairy, wheat, soy, peanuts, eggs, citrus, and chocolate. Keep a food and symptom diary during this period so you can easily look back to see what new food was introduced prior to a return of symptoms. If you localize a food, you will want to avoid having it in your diet for 6-8 weeks.

Alternatively, you can have a blood test to determine your food intolerances. The test is known as delayed hypersensitivity testing, and specifically measures your IgG antibody response to food allergens. It requires a blood draw and usually covers 100-200 different foods. Once you know your intolerances, you can pull them out of your diet. Since the IgG cells only remember the foods that were a problem for approximately two months, in most cases, the reactive foods can be gradually re-introduced into the diet and don’t require life-long avoidance.

My advice to patients that are suffering from long-term inexplicable symptoms after common causes have been ruled out, especially with skin pathologies, digestive complaints, and headaches, is to pursue either lab testing or an elimination diet to determine whether a certain food might be the culprit. Do seek a doctor to help you with this process; there are some online tests that aren’t quite up to snuff. It can be a challenging process to avoid what you discover you are intolerant to, but the improvements in how you feel can be vast, and you should eventually be able to make your way back to a more varied diet.

And, once you are aware of your food sensitivities, you can make not only generally healthy choices, but confidently make choices that are healthy for you.

Stay healthy & be well!

-Amy Whittington, NMD