In searching for answers, others choose blood tests that guide the selection of foods to eliminate. We use a panel that includes both IgG and IgE antibodies. Normally, IgG deals with body invaders like viruses and bacteria. On the other hand, IgE interacts with allergens and parasites in our immune defense system. For some, the tests look great and the patient can mark immune food sensitivities off their list. For others, they reveal IgG sensitivities that they would never have suspected. Beyond the common food triggers noted above in the short elimination diet, our patients have shown reactions to garlic, cucumbers, curry, nuts, and many more. In these patients avoiding that food trigger frequently led to significant improvement.
What food sensitivity tests are available to functional medicine doctor besides IgG and IgE antibodies? Some labs offer IgA antibody testing in addition to these others. We use IgA for gluten sensitivity testing also, but not for all foods. Some labs look at the cell mediated response beyond antibodies. We have found these cell mediated tests to overshoot, meaning they point to more foods as reactions than are truly clinically significant. Our patients either come to us on very restricted diets or leave with enough food restrictions already. We really don’t want to make their recovery any harder than it already is. Excessive food restriction can even lead to nutrient deficiencies or outright malnutrition. With these facts in mind, we focus on elimination diets and IgG/IgE testing with a side order of gluten IgA.
Besides our office experience in seeing patients return to healthier lives with either of our options, medical research (several noted below) supports our practice. Several studies have linked different diseases back to food sensitivities. Migraine and irritable bowel syndrome are two of the more commonly studied syndromes shown to lessen with food avoidances (see below). While there is some conflicting data and complete resolution of symptoms does not occur in all, many studies show statistically significant changes. Like most of our patients hear from me, “you likely have more than one reason for your illness” Eliminating a food or two or three rarely fixes everything, but a good percentage see some benefits.
From a quick reading, these references support the clinical utility of IgG blood testing for food immune sensitivities. In migraine and irritable there appears to be benefits to testing and eliminating the foods with elevated antibodies. So if we ask you to do this blood test, we are hoping to find triggers for your symptoms or your labs (like thyroid antibodies, elevated liver tests, and more). Then we can have a little more light to peer into your health and see what is not functioning correctly. With such insight we can guide you towards a healthier more abundant life.
Short Reference list
Diet restriction in migraine, based on IgG against foods: A clinical double-blind, randomised, cross-over trial Kadriye Alpay, Mustafa Ertaş, Elif Kocasoy Orhan, …First Published March 10, 2010 Research Article https://doi.org/10.1177/0333102410361404 http://journals.sagepub.com/doi/abs/10.1177/0333102410361404
Atkinson W, Sheldon TA, Shaath N, et al
Food elimination based on IgG antibodies in irritable bowel syndrome: a randomised controlled trial
Gut 2004;53:1459-1464. https://gut.bmj.com/content/53/10/1459
Choung, Rok Son, and Nicholas J. Talley. “Food Allergy and Intolerance in IBS.” Gastroenterology & Hepatology 2.10 (2006): 756–760. Print. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5358086/