Food Allergies, Intolerances & Sensitivities: What's the difference?


Food allergies, intolerances, and sensitivities are increasingly common.

Nut-free schools are commonplace, and the number of gluten-free foods are on the rise due to the fact that millions of Americans experience allergic reactions or sensitivities to foods every year. While most reactions are mild, some can be life-threatening and require emergency treatment or hospitalization.


Food Allergies

Food allergies are simply an abnormal response to food that’s triggered by your immune system. It happens when the immune system mistakes a non-harmful food, like peanuts, tree nuts or eggs for a serious invader and overreacts to it. The immune system creates a specific type of compound called an IgE antibody that is responsible for most of the symptoms seen in true allergies. In an allergic reaction, the production of IgE antibodies is triggered by a protein in the offending food. These IgE-mediated allergic reactions can be non-serious or serious and life-threatening such as in an anaphylactic reaction to food.


Severe Food Allergies: Anaphylaxis or anaphylactic shock

Anaphylaxis is typically a fast-developing and life-threatening reaction that can occur when exposed to specific foods, medications, or stinging insects (e.g., bees). Symptoms can include sneezing, coughing, itching, hives, swelling, blood pressure drop, abdominal pain, dizziness, tightness in the throat, and shortness of breath. The main treatment for an anaphylactic reaction is an epinephrine auto-injector and calling 9-1-1. Avoiding what caused your reaction and carrying an Epi pen is necessary to prevent future life-threatening reactions which may become more severe than the initial one.


Approximately 1-2% of adults and fewer than 10% of children suffer from food allergies. Most food allergies are first noticed during childhood, but they can develop at any age and may last for a lifetime. Mild allergic reactions to a food may result in more serious symptoms the next time it is eaten. So, after your first reaction—even if it’s mild—it’s important to speak with your healthcare provider to see if you should go for allergy testing or carry emergency medication.


While it’s not entirely clear what makes a person develop a food allergy, research shows that your genes and your gut microbiome may influence your chance of developing food allergies. New studies show that introducing young children to peanuts may reduce their chances of developing serious peanut allergies. (Speak with your healthcare provider before introducing your child to peanuts.)


While there is no cure for food allergies, reactions can be prevented by avoiding contact with that specific food. Although any food has the potential to cause an allergic response, there are a few foods that account for most reactions.

Common food allergens include:

● Peanuts

● Tree nuts (e.g., almonds, walnuts, pecans)

● Fish (e.g., cod, bass, flounder)

● Shellfish (e.g., crab, lobster, shrimp)

● Eggs

● Milk

● Wheat

● Soy


These common food allergens must be declared on package labels, according to the FDA.


Oral allergy syndrome or Pollen-food allergy syndrome

Oral allergy syndrome causes symptoms such as rash, itching, sneezing, and swelling occur around the mouth, lips, and tongue after eating specific types of foods. Foods commonly associated with this syndrome include raw apples, bananas, cherries, kiwis, peaches, celery, tomatoes, potatoes, melons, and hazelnuts. This type of allergic reaction is not life-threatening and is common among those who are also allergic to grass and ragweed pollen (hence the name pollen-food allergy syndrome). Cooking the fruit or vegetable often reduces the symptoms because the heat breaks down the proteins responsible for this type of non-life-threatening reaction.


Eosinophilic Esophagitis

Heartburn-like symptoms, nausea, vomiting, abdominal pain, or difficulty swallowing after eating certain foods may be eosinophilic esophagitis associated with food allergies. If this happens, it’s important to speak with your healthcare provider to see if you should get tested for allergies or need medications. Avoiding foods that cause this reaction is key to managing EE.


Food Intolerances

Food intolerances are more prevalent than food allergies with up to 20% of the general population have affected by a food intolerance. Food intolerance involves a reaction to certain food components (e.g., lactose, histamines, alcohol, etc.), but do not involve an immune system response. Rather, a food intolerance occurs in individuals who lack the ability to properly digest food particles. This can be due to the lack of either a digestive enzyme or the nutrient responsible for breaking down that food particle.


Food intolerances can cause flushing, itching, cold or flu-like symptoms,

inflammation, and digestive symptoms such as bloating or abdominal discomfort. Common trigger foods and ingredients include dairy products, sulfites, histamines, lectins, preservatives, artificial colors, fillers, flavorings, chocolate, citrus fruits, and acidic foods. Management of food intolerances can include enzyme substitution or


Food Sensitivities

Food sensitivities involve an immune response to a certain food or foods that occurs in your GI tract and result in the production of an IgA antibody.

This type of reaction can occur hours or even days after ingesting the trigger food and can elicit symptoms in your digestive tract as well as in other areas of your body. Common sources of food sensitivities are cow’s milk (and dairy products), eggs, gluten (from wheat, rye, spelt, and barley), soy, shellfish, and tree nuts.


Symptoms caused by food sensitivities can vary from person to person and can include: indigestion, nausea, vomiting, irritable bowels, bloating, diarrhea, migraines, headaches, dizziness, difficulty sleeping, mood swings, depression, anxiety, unintentional weight loss or gain, dark under-eye circles, asthma, irregular heartbeat, wheezing, runny nose, sinus problems, ear infections, food cravings, muscle or joint pain, bladder control issues, fatigue, hyperactivity, hives, rashes, dry skin, excessive sweating and acne.


Food sensitivities that are not addressed can lead to other chronic health issues. For example, the inflammation caused by an ongoing food sensitivity can lead to a condition called intestinal permeability, or “leaky gut syndrome.” In certain individuals, the presence of a leaky gut can put them at risk for developing an autoimmune illness.


Food allergies, intolerances, and sensitivities are increasingly common. While adverse food reactions can cause serious health problems, avoiding your trigger food(s) is an important part of managing food reactions. If you suspect you might be reacting to one or more foods, it's important to seek the guidance of your healthcare provider. If you believe you have a serious food allergy, it’s critical that you see your healthcare provider to determine if you need to carry emergency medication for future exposures.


For more information on how you can test for and manage

your food reactions, contact us.







References

Barbara, G et al. Inflammatory and Microbiota-Related Regulation of the Intestinal Epithelial Barrier

Front Nutr. 2021; 8: 718356.


Mayo Clinic. (n.d.). Lactose intolerance. Retrieved from https://www.mayoclinic.org/diseases-conditions/lactose-intolerance/symptoms-causes/syc-20374232


MedlinePlus. (2020, September 28). Anaphylaxis. Retrieved from https://medlineplus.gov/anaphylaxis.html


MedlinePlus. (2020, September 28). Food allergy. Retrieved from https://medlineplus.gov/foodallergy.html


Medscape. (2020, February 5). Food Allergies. Retrieved from https://emedicine.medscape.com/article/135959-overview#showall


Mu, Q. et alLeaky Gut As a Danger Signal for Autoimmune Diseases. Front Immunol. 2017; 8: 598.


National Institute of Allergy and Infectious Diseases. (2018, October 26). Identifying Causes of Food Allergy & Assessing Strategies for Prevention. Retrieved from https://www.niaid.nih.gov/diseases-conditions/food-allergy-causes-prevention


National Institute of Allergy and Infectious Diseases. (2019, September 11). Treatment for Living With Food Allergy. Retrieved from https://www.niaid.nih.gov/diseases-conditions/treatment-living-food-allergy


National Institute of Allergy and Infectious Diseases. (2018, October 25). Characterizing Food Allergy & Addressing Related Disorders. Retrieved from https://www.niaid.nih.gov/diseases-conditions/food-allergy-characterizing


NIH News in Health. (2017, March). Understanding Food Allergies. Retrieved from https://newsinhealth.nih.gov/2017/03/understanding-food-allergies


United States Food and Drug Administration. (2018, September 26). What You Need to Know about Food Allergies. Retrieved from https://www.fda.gov/food/buy-store-serve-safe-food/what-you-need-know-about-food-allergies


Tuck, CJ et al. Food Intolerances. Nutrients. 2019 Jul; 11(7): 1684.


The contents of this blog are intended for educational purposes only. The information presented here is not a substitute for proper medical attention, diagnosis, or treatment by a qualified healthcare professional. Always seek the advice of your healthcare provider before starting or making any changes to an existing treatment plan, exercise program or dietary regimen, and before using nutritional supplements.

~ Dr. Sarah Williams ~ Concord, Massachusetts ~


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