I am honored to have been a guest to talk about food sensitivities on Facebook Live with NourishDoc!
We covered a lot of ground, including:
What are food sensitivity, Food Allergy, and Food intolerance?
Food sensitivity is an IgG immune response, and it can cause gut symptoms (nausea, bloating, gas, belching, stomach pain, cramps), headaches, skin rashes and flares, brain fog, irritability, fatigue, nervousness, trouble sleeping, joint aches and pains (and more), and points to gut dysfunction and leaky gut. Reactions are not life-threatening and tend to be delayed. They can be delayed by 2-3 days! Food sensitivities often are dose-related; people with food sensitivities may not have symptoms unless they eat a large portion of the food or eat the food frequently.
Food allergy is an IgE immune response, and it can cause hives, rash, itching, rashes and flares, gut symptoms (nausea, cramping, stomach pain, vomiting), trouble breathing, swelling of the airways to the lungs, and anaphylaxis (a serious and potentially fatal allergic reaction), and can be life-threatening. Reactions are typically immediate or within an hour. Food allergies can be triggered by even a small amount of food and occur every time the food is consumed. People with food allergies are generally advised to avoid the offending foods completely, depending on the severity of the allergy.
Food intolerance is a digestive system response rather than an immune system response. Food intolerance can cause symptoms like an IgG reaction and also isn’t life-threatening. It results from an inability of your body to appropriately metabolize (break down) a food or foods, and it won’t show up on IgE or IgG testing. A common example is lactose intolerance which occurs when your small intestine doesn't produce enough of an enzyme (lactase) to digest milk sugar (lactose). Food intolerances often are dose-related; people with food intolerance may not have symptoms unless they eat a large portion of the food or eat the food frequently.
What are the causes of food sensitivities?
If there are food sensitivities, there is increased gut permeability. When there are gut problems (problems with digestion and absorption and/or gut dysbiosis, which means abnormal, imbalanced gut flora, and can involve viral/bacterial/fungal/parasitic overgrowth, for example), and keep in mind there might not even be any gut symptoms, inflammation can develop in there leading to hyperpermeability of the gut lining. This allows toxins to escape from the gastrointestinal tract and enter the bloodstream (including endotoxins from gut bugs, and food proteins), leading to an environment of systemic inflammation. Once these toxins and food proteins are in the bloodstream they can trigger the immune system, and all sorts of health problems, including skin conditions, food allergies, and food sensitivities.
And because it’s not just food proteins in the bloodstream, it’s also endotoxins, we may be erroneously blaming food! A study in a 2019 paper in Nature, by Reddel and colleagues, found that higher levels of certain gut bugs lead to the ongoing production of endotoxins called lipopolysaccharides (LPS). LPS trigger those inflammatory responses and increase gut permeability, underlying problems with eczema.
Something else to keep in mind is that our bodies run off of nutrients from the foods we eat. We need nutrients in order to build and repair healthy skin, as well as to grow, develop, repair, function, and thrive. When nutrients are missing the body doesn't have the fuel it needs to do everything that it needs to do, including building and repairing healthy skin. It's counterintuitive what we're led to believe. We are led to believe that if we take more and more foods out of our diet that we will get a resolution of symptoms and health problems, and this is simply not the case.
Many clients I see, by the time I see them, have been on limited diets for extended periods of time, and their symptoms have gotten worse. This is not a coincidence. What happens is someone takes foods out of the diet and has improvements for a time. But the underlying issue which is gut hyperpermeability is still present. Over time more food sensitivities are going to develop, and the diet will get smaller and smaller. That's because food is not the root cause of the problem.
How are food sensitivities Identified?
There is a wide range of IgG tests available. An elimination diet is also often used to identify food sensitivities.
A true elimination diet is undertaken for somewhere between 21 to 30 days in order to identify foods that trigger symptoms. After that amount of time, the idea is to reintroduce foods one at a time and in a controlled manner to determine if they are symptom triggers. Because reactions can be delayed it can be tricky to identify offending foods. Keeping a food diary can help. Record what you eat and when you get symptoms, and then look for common factors.
A short-term elimination diet carried out appropriately can be helpful to identify trigger foods. You can remove triggering foods from the diet while working to address the underlying cause of the problem. I do not advocate for long-term restrictive diets of any kind. They can be devastating in children who are growing and developing. Of course, processed foods, added sugars, IgE foods are exceptions. If whole, real foods are triggering symptoms, it's important to explore why. Again food isn't the root cause of the problem, and removing food after food from the diet is not the answer!
When it comes to food sensitivity testing, I do not typically recommend it. If someone is sensitive to many different foods taking more and more of them out of the diet is not the solution to the problem, and too often I see a fear of food developing in people of all ages, including very young children. We need to set our children up from the beginning for a healthy relationship with food. We've got to look deeper, at the gut. I recommend that deeper look at gut health as the place to focus resources, rather than on food sensitivity testing. Also, I find that food sensitivity testing often picks up foods people never eat!
How are food allergies Identified?
Allergic reactions can be IgE, non-IgE (like IgG sensitivity), or both.
There’s also a difference between sensitization and actual allergy. Sensitization is when someone makes IgE antibodies against an allergen. This can be tested for by skin prick, or specific IgE in the blood. BUT the person may not actually have a clinical allergy, which is when there are symptoms when exposed to the allergen.
Skin prick testing is considered the gold standard for identifying allergens like pollen or spores. The gold standard for identifying food allergens is an oral food challenge, but doctors use skin prick and blood testing to identify food allergy too.
Blood testing for total IgE and absolute eosinophil count aren’t helpful for identifying allergies because they can be high with other health problems.
You can blood test for specific IgE allergens, BUT false positives are common because of cross-reactivity between them (proteins in different allergens resemble each other).
For skin testing, the patch test is used for identifying delayed hypersensitivity reactions like contact dermatitis. The skin prick test is used when IgE reactions are suspected, like eczema, hives, food allergies, and anaphylaxis.
What foods are good for someone with food sensitivities?
A diet of whole real foods is good for everyone! You can remove identified, only identified, trigger foods from the diet while you work to address the underlying cause of the problem. If you aren’t sure if a food is causing symptoms or not, don’t blame the food.
How do diet and nutrition help food sensitivities?
Diet diversity = microbiome diversity = gut health/gut integrity = less chance for food sensitivities!
Diet diversity means eating a variety of foods from all food groups and categories of foods. Vary protein sources (eggs, chicken, fish, beef, pork, etc.), vegetables (different colors and textures), and carbs (starchy vegetables and root vegetables, quinoa, rice, and other whole grains). A diverse diet feeds good gut bugs, and a diverse gut microbiome confers health benefits, including a healthy gut and gut integrity. This results in a lower risk for food sensitivities.