“One man’s food is another man’s poison.”

— Lucretius

The abundance of gluten and dairy free options that now line supermarket shelves have many people are wondering about food sensitivities. It’s been estimated that 15-20% of the population have some form of food sensitivity or intolerance that causes unpleasant and unwanted symptoms, whether mild or severe. And these are uniquely individual and largely undiagnosed.

In this article, we’ll take a look at the differences between food allergies, intolerances, and sensitivities. Although these three terms are often used interchangeably, their causes are quite different. To make sense of it all, it’s helpful to understand a little about our body’s IgE, IgA, and IgG immune responses.

IgE, IgA and IgG refer to immunoglobulins, or antibodies. These antibodies are part of our immune system, and are produced in response to things we come in contact with on a daily basis: foods, dust, dander, and pollen. They help the body build an immune system response to ‘fight’ against foreign invaders.

IgE Reaction: Food Allergy

An IgE reaction is an immediate hypersensitivity characterized by hives and throat swelling that accompany anaphylactic reactions some people experience when exposed to certain foods. Other symptoms can include wheezing, coughing, runny nose, vomiting, swelling of the lips or tongue, tearing or redness of the eyes, or a weak pulse and loss of consciousness. It occurs when the body mistakes an ingredient as harmful and defends itself by producing high levels of IgE. The most common foods that trigger IgE reactions are peanuts, shellfish, egg, dairy, soy, tree nuts, wheat and fish. It’s estimated that 3-7% of children and about 2% of adults have food allergies.

IgA Reaction: Food Intolerance

IgA immunoglobulins are present in our mucus and helps us fight bacteria and viruses. They increase in response to stress, disease, or alcohol, as well as to foods when the foods we eat cause inflammation. The rise of IgA immunoglobulins is followed by the fall of the enzymes needed to break down and absorb certain ingredients.

For example, those who are lactose-intolerant lack lactase, the enzyme needed to breakdown lactose (the sugar in milk). When lactose is not absorbed, it ferments in the colon and leads to symptoms like gas, bloating, nausea, and intestinal pain. People with food intolerance may experience digestive upset like nausea, constipation, or diarrhea, or skin itching and rashes including conditions like eczema and psoriasis.

IgG Reactions: Food Sensitivity

An IgG reaction to food proteins develop from a variety of health conditions, repeated exposure, inflammation, and immune reactivity that result in a vicious cycle of inflammation and food triggers. Food sensitivities contribute to leaky gut and harm the intestinal lining, causing inflammation. This is the most common as we age due to a natural "weakening" of our intestinal lining that leads to tiny leaks. The symptoms might range from digestive problems, such as abdominal pain, bloating, and gas, to other symptoms related to inflammation like headaches, fatigue, brain fog, or joint pain.

Of all three, it’s easiest to ignore food sensitivity symptoms, or worse — accept them as part of life because of the delay between food ingestion and response times. Food sensitivity responses can take anywhere from 24 to 72 hours to appear – yes, up to 3 days later. That means the random bloating, brain fog, low energy or headaches you experienced on a Tuesday might not be so random after all… that quesadilla you ate on Saturday night may have been the culprit.

What about elimination diets?

Elimination diets are all about the power of deduction to identify the trigger foods. You may have a good idea which foods your body disagrees with, but your food reaction could also be caused by specific food combinations or even certain amounts. During an elimination diet, it’s crucial to keep a concise food journal that specifies what you're eating, when you’re eating, and how you're feeling.

Depending on the severity and complexity of your food reaction, an elimination diet may not work for you for one of these reasons:

They are time consuming and can take months to go through the process of eliminating and then challenging foods. It’s a trial-and-error process, and you may have to try different foods and amounts until you find the right combination.
Symptoms of food sensitivity are generic and mimic other conditions, making diagnosis difficult and increasing unnecessary suffering.
You are busy, enjoy eating out, or don’t have time to cook, and have limited time for the shopping and meal planning that is required to follow a restricted diet.

Testing for Food Reactions

Oftentimes, your PCP can test for IgE allergic reactions with skin prick or blood testing to know what foods and other allergens must be avoided and when an Epi-pen is an appropriate prescription.

However, if you’re looking to test for IgA/IgG reactions (food intolerances and sensitivities), a functional-medicine practitioner can order a blood panel to assess your reactivity to common foods. We use a panel that detects sensitivities to up to 209 different food. (You can book a call with us here to set this up.) If you are diagnosed with or suspect intestinal permeability, autoimmune disorders, or chronic inflammation, this method is the quickest way to reduce systemic inflammation and immune system burden. This panel will allow you to get to the root of symptoms and build a personalized nutrition plan to eliminate inflammatory dietary triggers, balance your gut, and improve your lifestyle.

If food sensitivity testing sounds like it might be a good fit for you, or if you prefer to try an elimination diet to address your symptoms, we’re here to help you navigate the world of food reactions - book a free discovery call to discuss your concerns with us.