Maybe you have jokingly said that you are allergic to some particular vegetable you dislike, an activity (or duty) you despise, or even a person you can’t stand. But when it comes to food, the word allergy should not be taken lightly. It is also very important to understand the difference between allergy and intolerance. These two are not the same, even though some people use them interchangeably. If you suffer from any negative reaction to food, it is very important to properly diagnose the problem. Are you allergic? Or is it just food poisoning? Each case requires a different approach and a different management strategy. Let’s take a look at four abnormal food reactions you might experience - allergy, intolerance, sensitivity, food poisoning, and food aversion.
Allergies are driven by the immune system. An immediate reaction is called hypersensitivity and it is caused by IgE antibodies (Immunoglobulin E, a product of plasmatic white blood cells). These IgE antibodies attach themselves to mast cells, which stimulates the release of histamine and cytokines, causing an immediate allergic reaction. The delayed reaction is mediated by T-cells of the immune system and the symptoms appear a few minutes after consuming an antigen that causes the allergy. Symptoms and their intensity vary from person to person, based on the state of their immune system. Allergies usually start showing up in childhood, but in some cases, they might start later in life. You could have been allergic to something since early childhood, but symptoms might not actually show up until you are an adult. Allergies can also be caused by the damage of our microbiome (gut flora).
Usually, an allergy starts when the integrity of the gut barrier is compromised, which is critical for our immune health. When foreign proteins (like gluten) are allowed through the mucosal membrane of the gut, our immune system becomes activated, recognizes the invader as dangerous, and next time it meets the same substance, it already knows how to fight it. But sometimes, when our immune health is already compromised, our defense system fails, and the reaction can become very severe. Mast cells then start producing too much histamine, thus causing the body to go into anaphylactic shock, which causes contractions and swelling of mucous membranes so strong that it can lead to fatal suffocation (due to the throat swelling closed).
Some allergies are non-IgE related, but they are linked to elevated levels of eosinophils (another type of white blood cell and a very important component of our immune system). These cells are responsible for fighting parasites and infections, and they also help control the mechanisms associated with allergies and asthma. With these allergies, a disease called Eosinophilic Gastroenteritis can develop. This rare but serious condition affects the digestive system as well as the immune system, and can develop in children as well as adults. Symptoms include vomiting, diarrhea, blood in stool, colic, and stomach pain.
The most common allergens are dairy, eggs, soy, and gluten (wheat in particular, but also other grains containing gluten). Elimination diets are usually necessary to first determine which the offending allergen is, and then eliminate it for a certain period of time to let the gut barrier heal properly, before carefully reintroducing these foods. In some cases, allergies can go away completely after a proper healing period, but in many cases, the patient needs to stay away from the culprit for good, while still focusing on healing and maintaining the health of both the digestive and immune system.
Sometimes referred to as food sensitivity, intolerance is not mediated by immune cells. Intolerance usually shows up when the body doesn’t have the proper mechanism to deal with the particular substance that is ingested. Very often the intolerance is caused by the lack of certain enzymes that are necessary to break down the foreign substance. Lactose intolerant people are missing lactase, the enzyme responsible for breaking down the form of sugar found in dairy. People sensitive to sulfites don’t have enough sulfite-oxidase. Patients suffering from histamine intolerance lack diamine-oxidase (DAO). With histamine intolerance (HIT), symptoms are often misunderstood as an allergy, but the HIT reaction is typically delayed because the food needs to be digested first and moved through the digestive tract to reach the point where DAO usually starts doing its job. People with Mast Cell Activation Disorders may experience DAO deficiency related reactions, as well as more immediate allergy-like reactions.
Allergy is immediate and even the tiniest amount of the allergen causes the reaction. With sensitivity, you might be okay with a small or trace amount of a particular food, but your body might not be able to handle it in a larger quantity. Another example of food intolerance is fructose malabsorption, a sensitivity to the fruit sugar. Chris Kresser does a great job of explaining this condition in this post about coconut milk and why some people might not tolerate it well. Gluten intolerance is a very common problem (though it is very different from full-blown Celiac disease, which is a serious autoimmune disorder). Many people are sensitive to sweeteners, preservatives, flavorings, colorings, and other artificial ingredients in food (for example sodium benzoate, sulfites, aspartame, tartazine, monosodium glutamate, and others). FODMAPs are also a category of otherwise perfectly healthy foods many people don’t tolerate well.
Eliminating the food or substance you are intolerant to will for sure control the symptoms, but most likely will not cure the underlying problem. There are many different symptoms and causes of food intolerance, and we often overlook these chronic symptoms and take them as a part of our lives. If you eat a peanut and immediately have trouble breathing, it might be easy for you to connect the dots between your symptoms and the trigger, but we don’t always know, especially when we have allowed ourselves to get used to chronic, low-level digestive problems that don’t really limit our ability to enjoy life, but we don’t even remember what life was like before we had these issues. Remember, common doesn’t necessarily mean normal. Discovering the culprit is a necessary first step to diagnose and find an effective treatment of your particular intolerance.
Some foods are not good for us in their raw form (like potatoes or legumes) because they contain toxins that can poison us. There are compounds that are dangerous to everyone, like gluten, lectins, or heavy metals, and then there are compounds that are dangerous in larger amounts (like histamine). Eating spoiled fish is basically an example of histamine poisoning. The amount of accumulated histamine in rotting fish is dangerous even to a healthy individual without HIT problems. Botulinum toxin (BTX) also falls into this category. The severity of symptoms is again determined by the type and amount of the particular toxin and the overall state of your health, and your liver in particular due to its essential role in detoxification.
We soak our nuts, seeds, and legumes to eliminate at least some of the toxic compounds, and we cook potatoes to make them easier to digest and get rid of the saponins in them. But some other toxins in our food are not easily removable - pesticides, herbicides, and hormones that leak into our food and water, for example. Even if we are not allergic to certain foods, they will still harm us if they contain these toxins. For instance: people with Non-Celiac Gluten Sensitivity (NCGS) or Celiac disease might feel poisoned after consuming beef that was grain fed, while grass-fed meat is perfectly okay for them. It is not the meat that causes the problem, it is gluten from the cattle feed. With Celiac disease, the gut attacks itself (autoimmunity), but if you are non-Celiac but still sensitive to gluten, your body will attack the gluten itself, which still causes a reaction.
The most common toxins in our food include gluten, lectins, saponins, phytic acid, pesticides, herbicides, heavy metals, and environmental hormonal disruptors (like BPA). The only real solution is simple: to eliminate toxins, you need to avoid toxins. We have talked a lot about toxicity, so check back for our previous posts to learn more.
Some negative reactions to food might be also psychosomatic. Maybe you really, really, REALLY hate tomatoes. Depending on your disgust or hatred towards a particular food, you might actually convince your body to reject it, even with physiological symptoms (like vomiting after eating it). This doesn’t include eating disorders like anorexia, but sometimes, we can really convince our brain that this food is making us sick. It is very common amongst children who, for example, refuse to eat vegetables. When I was a child, I couldn’t stand rabbit meat (we ate it a few times a week because my grandparents bred rabbits for meat, so it was a cheap and easy option for us). This aversion later grew into me hating meat in general, and I didn’t really eat any meat until much later in life.
The connection between our brain and our gut is very strong, and food aversions with physiological manifestations are a wonderful example of this. An essential step in freeing yourself from psychosomatic reactions is realizing the role that your mind (both conscious and unconscious) is playing, and if the root cause is somewhere deeper than “my parents forced me to eat vegetables,” don’t be afraid to look deeper into the psychology of your aversion with the assistance of a skilled professional. There might be some unresolved food-related childhood trauma involved, or even an early (or already existing) eating disorder. Either way, don’t underestimate the power of your own mind in relation to physiological symptoms.
Now you know that you are not allergic to dairy because you lack lactase to break it down. You also know that gluten sensitivity is not just a mild version of Celiac disease, though a full Celiac disease can develop later if the immune system is compromised. You might also realize that you don’t feel sick because of the steak itself, but because of what the cow was fed. If you experience any unusual reactions to food, don’t immediately jump to the conclusion that you are allergic, but also do not underestimate your symptoms. Listen to your body; it always tells you exactly what it needs. Sometimes, you just need to turn down the other noises (inflammation) to hear it well. Diagnosing and living with a food allergy or sensitivity might be difficult, frustrating, and limiting, but living with untreated symptoms that can later develop into more serious conditions is even worse. Take your time, don’t ignore the little things, eliminate toxins first, give yourself plenty of time to heal, and above all be gentle, loving, and patient with yourself. The power of your mind doesn’t just cause trouble (as in the case of food aversions), your mind is also a wonderful healing tool. They say mind over matter for a reason!