I am just recently back from my state RD meeting. It was an amazing conference. We had Dr. Janice Joneja, an immunologist and author who spoke about food allergies and sensitivities. We also had Shelley Case, a well known international expert on Celiac disease and also a published author. What a joy and gift to hear these experts. Below are a few pearls from Dr. Jonega and on the next issue of my newsletter I’ll share some pearls on Celiac disease. Read more.
- First of all, Dr. Joneja and I totally agreed that IgG testing for foods indicates that the person has been repeatedly exposed to (the) food components, which are recognized as foreign proteins by the immune system. IgG production is likely to be the first stage of development of oral tolerance to a food. Studies suggest that IgG indicates protection or recovery from a previous IgE-mediated food allergy. Its presence should not be considered as a factor which induces hypersensitivity, but rather as an indicator for immunological tolerance, linked to the activity of regulatory T cells. Those are her words, not mine, straight from her PowerPoint so I’ll explain. IgG tests are routinely being marketed but are of no value. They flag foods you tolerate (oral tolerance). Why they are marketed when technology has advanced….I don’t know. Mediator Release Testing, that I use, is not an IgG test. Rather, it identifies the quantity of chemical mediators released upon exposure to an antigen and it measures them whether they were secreted via an immune pathway or a sensitized T cell pathway. It is the mediators that make one sick. Here’s more on the subject.
- 60 year olds are now the age group experiencing the most Non-IgE food sensitivities. It explains why I’m getting a lot of new patients who are well into their life and now need help identifying food triggers. To clarify, an IgE reaction is the immediate reaction some get to peanuts, shellfish, etc. Non-IgE is what we call the other delayed reactions where you eat a tomato and the next day the joint pain is unbearable. Or you eat a food with a certain preservative and the next day you have a migraine or an irritable bowel. Non-IgE reactions cause a plethora of symptoms and it’s different for each person. It might be Eosinophilic esophagitis in one and stomach ache, bloating or vomiting in another. If you really pay attention, they even cause things like irritability, anxiety, a stuffy nose, and alter sleep. But they always involve pain and suffering on some level and they are delayed up to 3 days so figuring them out without testing is nearly impossible. Non-IgE reactions are my specialty (but you don’t have to be 60 years old to hire me!).
- I learned intricate details about Oral Allergy Syndrome which is a localized IgE reaction but only affects the mouth and throat. The real allergy is to the actual pollen but our immune system isn’t perfect and it mistakenly cross reactions to foods. If you are having odd responses to food, this might be a piece of the puzzle. We now have information to help isolate and identify which foods cross react with specific pollens.
- Dr. Joneja clarified that in food sensitivities, its not the food….it’s our immune response to it. Think about it – just because you can’t eat cashews because you get hives does not mean no one can eat cashews. It’s your immune system mistakenly attacking the food. There are many contributing factors including our digestive ability. As we age, it’s a given that we make less saliva and gastric juices. Throw more fuel on the fire with antacids and PPI’s and you’ve really got a storm brewing. Reducing our God-given hydrochloric acid has many side effects as we are now even less able to break down the food into its natural end-products. Re-read my 8 reasons not to be on an antacid long term. Long term, the risk is that the immune system is not down-regulated and it continues firing and becomes an auto immune disease now attacking its own tissue. Celiac is a non-IgE mediated, auto immune disease and the cause is gluten. We know that diet changes positively affect other auto immune diseases (Rheumatoid Arthritis, Type 1 Diabetes, Hashimoto’s…) and the key is to identify and remove the offenders, down regulate the immune system, and stop the process before one auto immune disease turns into 7. After all, its the same process, just different tissue it attacks.
- Milk and peanuts both have about 28 to 30 proteins. Peanuts have about 9 different allergenic proteins. There are differences in severity depending on which protein YOU happen to react to. I bet you know someone who has a peanut allergy and it’s truly life-threatening….but another friend has a peanut allergy and it’s no fun but it’s not typically life threatening. This is why it really takes an expert to help you sort through this process of determining reactive foods – it can be very dangerous.
- I’ve known this but I’ll still share. IgE skin tests for foods are (only) about 30 to 50% predictive. Where else can a test be (only) 30-50% accurate and yet we still use it?! Oral challenges, like what we do after finding your a safe oligo-antigenic diet with MRT is truly the best way to isolate and identify trigger foods. And, IgE reactions are much less common than non-IgE reactions. But usually when an individual feels like food is an issue, their Immunologist will run an IgE panel. Not very helpful in any regard – the reaction is likely to be non-IgE and the test isn’t all that accurate.
- If you’re a mom or mom to be: breast feeding is protective and the AAP Allergy Management guidelines recommend exclusive breast feeding for 4-6 months. Longer is better. But, once the baby is exclusively breast fed for this time period, there is no evidence to suggest that waiting to introduce foods until after 4-6 months is necessary, including gluten. In fact, Hourihane et al in 2007 published that waiting to introduce a known allergen like peanuts actually increased the incidence of peanut allergies later in life…because oral tolerance was never achieved.