Figuring Out Food Allergies and Sensitivities
I also have this posted on my and Chef Lilly Allison Steirer's blog Health from the Hearth, but I thought it might be useful to have this here as well!
In my 12 years of seeing patients, it seems that the frequency of food intolerances has increased exponentially in all age categories. I think this is perhaps due to a combination of increased sensitivity to foods as well as greater awareness of our bodies and the potential role food sensitivities can play in various ailments. During the springtime, we focus on helping the body eliminate wastes more effectively by optimizing the function of our liver and large intestine. One of the most powerful ways we can do this is to avoid any foods to which we are sensitive. This will decrease inflammation in the digestive tract and throughout the body and improve our ability to properly utilize the nutrients in our food.
What is the difference between an allergy and a sensitivity?
I like to make this distinction because there are clear differences between different types of food reactions. This is because our immune system makes different types of antibodies. Antibodies are “flags” made by our immune cells; when these cells recognize a foreign protein in the body (from a bacteria, a virus, or an allergen like pollen or a food), antibodies are released which tells the body to make inflammation.
We have a few different types of antibodies that cause us to have different types of allergic reactions: IgE antibodies are immediate sensitivity antibodies. In people who have reactions to things like shellfish or peanuts, they react almost immediately and usually in a severe way such as vomiting, swelling, or airway restriction. IgE sensitivities are more of what we would call a true “allergy”. They tend to be more severe and immediate, and often a person with this type of allergy can not tolerate any amount of the offending food. They can be quite persistent throughout life, though kids can grow out of some severe types of food allergies.
IgG antibodies are delayed sensitivity. These produce delayed reactions that may be difficult to find the cause of such as joint pain, asthma, eczema or a chronic stuffy nose. These are more often what I would call a “sensitivity”. This is because they tend to be less severe, and can vary in severity throughout life. Also, people can often tolerate some amount of these foods before they have a reaction. The severity can also usually be reduced by using natural anti-inflammatories, periodic avoidance, and healing the lining of the digestive tract.
IgA antibodies are made in the digestive tract and are our first defense against whatever comes into our bodies. These are important because diagnosing celiac disease can be partially based upon finding an IgA type antibody called anti-endomysial antibody. Celiac disease is a genetic disease and will not change throughout life; someone with celiac will have to avoid all gluten throughout their lifetime to avoid damage to the small intestine.
How do I know if my children or I have a food allergy?
As I mentioned above, the symptoms of food allergies and intolerances can be widely variable. Generally, it tends to be much easier to diagnose an immediate sensitivity because a child will have a severe reaction to a specific food that is easy to replicate. Other types of sensitivites can be more difficult to figure out, though.The gold standard for testing for food sensitivities is an elimination diet; we take out all the possible foods for 3 weeks, see if there is improvement, and then add foods back 1 at a time for 72 hours to see if there is a reaction. This is effective but cumbersome and time consuming.
My favorite type of lab testing for this information is a blood test for IgG antibodies to specific foods. This is not perfect but gives us a very good place to start and frequently is very beneficial. I often see infants who show reactivity to something in their mother’s milk, which manifests most commonly as colic, digestive trouble or eczema. Often in this case we will test the mother because the antibodies she makes to those foods could be coming through the breast milk and causing a reaction in the child.
Check back next week for more on “I have food sensitivities, what do I do now?”