Food Allergies

Are All Good Foods Good for You?

Concept of food allergies. Set of products that cause allergies: citrus, red fruits and berries, eggs, milk, white bread, nuts, chocolate, coffee, honey

A couple of weeks ago I sat down with a patient and we began discussing her nutritional habits (I have permission to call her Susan to share this story).  I was impressed by Susan’s dietary regime; it was packed full of anti-inflammatory foods like fish and flax, anti-oxidant foods including fruits and vegetables, and plenty of whole grains for fiber.  She, like many of my patients, has done a lot of research into her health and nutrition.  That is why I was surprised when she ended her report by saying, “I eat blueberries three times per week because they are so good for me, but they give me a little headache so I don’t eat them daily.”

As impressed as I was with this effort to provide her body with good nutrition, I explained to Susan that just because a food is a health-food, it doesn’t mean that it is absolutely healthy for you. Many, if not most, people have food intolerances and sensitivities that adversely affect their health, and often to foods that are otherwise considered healthy. Many are not aware of these intolerances that often culminate in headaches, skin changes including eczema and psoriasis, sinus congestion, and gastrointestinal complaints including gas and bloating, reflux, IBS, constipation and diarrhea.  For many, avoiding the offending foods can result in a decrease or complete resolution of symptoms.


Food sensitivities likely occur when for some reason your body reacts to a food as an antigen or foreign body as opposed  to recognizing it as nutritional and beneficial.  Your body then produces an antibody response to that food, just as it would to an invading bacteria or virus.  This response includes increased inflammation and an immune response that can result in many different symptoms including those mentioned above, or generalized symptoms of fatigue, behavioral disturbance, and weight gain. In addition to culminating in what can range from aggravating to life-altering acute symptoms, continually ingesting foods that cause an immune response can result in long-term issues including chronic fatigue, inflammation, and a less responsive immune system.

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 is done by removing the most common food allergens from your diet (along with any additional foods that you might already suspect) for at least 10 days.  After the initial avoidance period, you can reintroduce one food at a time, separated by at least 4 days, and monitor 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 around the time a symptom returned.

It is important to realize that food sensitivities, as opposed to true allergies, can be delayed by as much as 4 days (i.e., you could have the offending symptoms the day that you ingested the food or up to 4 days later).  This is a surprise to many, and often the reason that we don’t realize which foods we have intolerances for.  It is also the reason that foods MUST be reintroduced one at a time and separated by at least 4 days during an elimination diet.

A simpler way to determine food sensitivities and to avoid what can be a strict elimination diet is through laboratory testing.  This type of testing is different from traditional allergy testing and currently is performed mostly by holistic, integrative, and naturopathic doctors.  The test is known as delayed hypersensitivity testing, and specifically measures your antibody response to the most common food allergens (usually you are tested for around 100 of the most common foods that can cause sensitivities).  The test measures antibodies known as IgG; these are antibodies that are not produced as rapidly as the antibody group IgE, which is the antibody responsible for immediate allergies including anaphylaxis (a severe and immediate allergic reaction that can lead to a compromised airway, shock and even death).  Traditional allergy testing, using pin-testing or scratch-testing, tests for IgE as opposed to the delayed IgG antibody.   To measure IgG, I use a lab called Immunolabs.  They have some useful tools on their website ( to help you determine whether or not food sensitivities might be affecting your health.  (I have no financial affiliation to Immunolabs and there are a handful of other useful labs that measure food sensitivities as well.)

Food sensitivities likely play a role in the daily lives of many of us (it is estimated that 55 to 95% of the population reacts to some foods).  For some, like Susan, the offending food and effect is obvious; for others, the symptoms are much more insidious.  My advice to patients that are suffering from long-term inexplicable symptoms, especially skin pathologies, digestive complaints, and headaches, is to pursue either lab testing or an elimination diet to determine whether a certain food might be a culprit or a trigger.  Once you are aware of your food sensitivities, you can then determine which good foods really are good for you!