One of the worst nickel food allergy offenders is soy. Nearly all processed foods include soy or soy lecithin. I avoid ingesting foods that contain either soy or soy lecithin.
The Food Allergen Labeling and Consumer Protection Act of 2004 (FALCPA) require food manufactures to label the top 8 allergens (soy, milk, egg, fish, shellfish, tree nuts, peanuts or wheat). In my experience, soy is always identified as a potential allergen on a food label. However, soy lecithin is “highly refined oil” making it exempt from FALCPA, requiring you to thoroughly identify whether or not processed goods contains the ingredient.
To further explain the difference between soy and soy lecithin, some physicians argue that soy lecithin is created in a lab where the proteins have been removed entirely or to such a minuscule amount that would not cause an allergic reaction.
Allergic Living magazine includes the section “Doctor’s Q&A: The Food Allergy Experts” where Dr. Scott Sicherer and Dr. Hemant Sharma answer readers’ food allergy questions. In the winter 2016 edition someone asked:
“My son was diagnosed with a soy allergy following a reaction to a meal containing soy protein. On the labels of foods he regularly eats, I now notice that some contain soy lecithin and soybean oil, but my son has never reacted to these foods. Is soybean different than soy lecithin and soybean oil? Or does he need to avoid those as well?”
Dr. Sicherer’s responded noting:
“soy oil is highly processed to remove proteins and should not be a concern for those with soy allergy. It should be noted that not all oils are free from proteins, so the situation is different for many nut and see oils. Soy lecithin is a fatty derivative of soy, which has negligible protein. It appears in many packaged foods, largely because of its emulsifying properties. Speak to your allergist about your son’s allergy, but most people with a soy allergy can safely consume foods that contain soy lecithin. Allergic reactions that are attributed to soy lecithin are rare.”
The uniqueness of a nickel food allergy is that our bodies react to nickel and create a nickel protein complex when we eat something higher in nickel. Chemically, the interesting thing about soy lecithin and a nickel allergy is that nickel is used as a catalyst during the chemical creation of soy lecithin in a lab. What does that mean? When soy is hydrogenated or chemically changed to soy lecithin flakes of nickel are added to establish the higher heat source to make the chemical change. “In hydrogenation, nickel is the main metal catalyst used for saturation of double bonds.”
Despite the removal of protein when soy becomes soy lecithin, I wonder whether soy lecithin continues to contain trace amounts of nickel when it’s highly refined.
 Food Allergy Research and Resource Program. University of Nebraska-Lincoln. farrp.unl.edu/soy-lecithin, retrieved 6/15/2016.
 Sicherer, S. & Sharma, H.. (Winter 2016). Doctor’s Q&A: The Food Allergy Experts – Dr. Scott Sicherer and Dr. Hemant Sharma tackle Allergic Living readers’ questions. Allergic Living, Volume 5, Issue 4, 18-19.
 Shurtleff, W; Aoyagi, A. History of Lecithin and Phospholipids (1850-2016), page 355.