Food Allergies, Sensitivities & Intolerances
Approximately 19% of the population in Australia experience an adverse reaction to one or more foods [1]. People often use the terms food allergies, sensitivities and intolerances interchangeably, however, they’re three different things. So what are the differences?
Food Allergy (immediate reaction)
Food allergies or ‘true’ allergies are an IgE-mediated immune response. The IgE antibody floats around in the bloodstream and causes an immediate reaction to an allergenic food by triggering the release of histamine. Symptoms often include hives, swelling of the lips, tongue and throat, difficulty breathing, and vomiting. An anaphylactic response is the most serious form of allergic reaction which can occur within seconds of allergen exposure. Common allergens include milk, eggs, wheat, soy, nuts, fish and shellfish.
Food Sensitivity (delayed reaction)
Food sensitivities are also an immune-mediated reaction, however, they are not a ‘true’ allergy. This is because they involve an IgA or IgG immune response which doesn’t cause an immediate release of histamine but causes a delayed reaction to a food. This reaction can occur up to 3 days after being exposed to a problematic food, unlike a ‘true’ allergy which can occur within seconds. The primary cause of food sensitivities is intestinal hyperpermeability (leaky gut). Food sensitivity symptoms can present anywhere in the body and can range from headaches, brain fog, fatigue, rashes and other skin problems, to anxiety and depression. Because the immune response is so delayed, it can be really hard to pinpoint food sensitivities.
Food Intolerance (non-immune mediated)
Food intolerance, sometimes also referred to as a food sensitivity is a group of non-immune mediated responses to food [3]. It is defined as a symptomatic reaction to a food at a dose that is tolerated by most people [1]. Symptoms can occur a few hours or up to 48 hours after eating a problematic food. There are 4 main types of food intolerance reactions: metabolic reactions include things like lactose, fructose and histamine intolerance; pharmacologic reactions include sensitivity to caffeine and MSG; Toxic reactions include food poisoning; and other adverse reactions include sensitivities to things like sulphites and other preservatives [2]. Symptoms of a food intolerance can include bloating and other IBS-type symptoms, nausea, reflux, headaches, rashes, fatigue and more. Common food intolerances include lactose, fructose, FODMAPs, salicylate, caffeine, MSG and sulphites.
Celiac disease (autoimmune)
Celiac disease is an autoimmune condition that causes an intolerance to gluten. Gluten triggers an immune response that causes massive gut inflammation and damages the lining of the small intestine. This causes digestive symptoms such as diarrhea, constipation, weight loss, bloating & abdominal pain. It also inhibits the small intestine from absorbing nutrients into the bloodstream, causing nutrient deficiencies. If left untreated, it can cause major health problems and increase the risk of cancer. People with celiac disease must avoid all gluten-containing foods, as even small amounts can cause harm.
How do I know if I have a food allergy, intolerance or sensitivity?
Food allergies are the easiest to identify because the reaction occurs quickly and symptoms are usually pronounced. If you suspect you have a food allergy, the best thing to do is see your doctor who can refer you for testing.
Food sensitivities are not as straightforward due to the delayed reaction which can occur in any part of the body. Food sensitivity testing is not always recommended as it can sometimes be misleading and misinterpreted.
The gold standard for identifying food sensitivities & intolerances is a carefully planned elimination diet. There is also testing available for certain intolerances such as the fructose breath test and celiac blood screening. I recommend keeping a food/symptom diary for 2 weeks documenting every food you eat and the symptoms you experience. This is a great starting point when it comes to identifying problematic foods. Then the best thing to do is see a naturopath or other healthcare practitioner who can take your full case history and create an individualised treatment plan for you.
Treatment
Treatment for a food allergy involves strict avoidance of the allergenic food and some people require antihistamines or an Epipen. Depending on the type and severity of the allergy you may be able to improve immune tolerance, but this should only be done with the help of a practitioner.
The treatment for food sensitivities and food intolerances usually involves an elimination diet where problematic foods are eliminated for a certain time period before being slowly reintroduced. This allows levels of IgG / IgA in the blood to decrease before the food is reintroduced and also helps to decrease inflammation in the gut. During this time it is crucial to also identify and correct the underlying cause of the food sensitivities or intolerances. Unless these are recognised and corrected, you are likely to become intolerant to more and more foods over time. Common causes include intestinal hyperpermeability (leaky gut), dysbiosis (gut bacteria imbalance), SIBO (small intestinal bacterial overgrowth), poor digestion, nutrient deficiencies and inflammation.
Treatment will often involve:
Healing the gut lining with certain herbs and nutrients
Correcting dysbiosis
Optimising digestion and increasing the production of digestive enzymes
Supporting a healthy immune response using herbs and probiotics
Improving liver detoxification
Reducing inflammation in the body.
If you have any questions or would like to work with me, please contact me.
References:
Clinical Naturopathic Medicine - Leah Hechtman (2019)
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8152468/
https://www.degruyter.com/document/doi/10.7556/jaoa.2020.008/html