Dr. Sarah Giardenelli, ND, MSOM, LAc
Most of my patients are fascinated to learn that there is a connection between their seasonal allergies and their food allergies. An allergy is an immune response to any substance or molecule. That substance or molecule that the immune system responds to in an allergic response is the allergen. Similar or identical molecules can be found in foods, plants, molds, and human tissues. When the immune system is triggered by an allergen in a food for example, the immune system becomes heightened to a certain molecule or molecules in that food which might appear similar to others in pollens or even tissue in the human body. This response is known as allergen cross-reactivity and is a relatively newer field of study within the field of allergy. Fellow Virginian and allergy cross-reaction researcher, Sue Killian, MS, has helped me gain new insights and appreciation to the fact that allergens goes to the molecular level. As she puts it, “An allergen is simply a molecule, not the whole ragweed plant, the whole dust mite, or even the whole pollen.”1
The importance of being aware of these allergen cross-reactions is that they can significantly impact quality of life for patients. Imagine being a professional gardener or chief and not being aware that the plants or foods you were working with on a daily basis were exacerbating your allergic symptoms. The immune system is a dynamic system and responses in one person can vary widely from the next. It is important to realize that immune responses are not limited to skin reactions, itchy eyes, nose or throat or to the more extreme response of anaphylaxis. If an allergic response was that clear they would certainly be much easier to diagnose! Below is a chart that highlights the variety of possible symptoms related to allergy.2
What is not always appreciated in medicine by providers or patients is the frequency of these cross-reactions. The majority of individuals with food allergies have seasonal allergies, such as hay fever. Of the 15 to 20% of the population with hay fever, 50% have oral allergy syndrome or contact dermatitis (skin rash from direct contact to allergen) or less commonly gastrointestinal symptoms.3 The most common form of hay fever is birch allergy and oral allergy syndrome occurs in up to 80% with birch allergy after eating a wide variety of vegetables, fruits, and nuts.4 Dust mites allergens are well known to cross react with shellfish allergens. Conventionally the link between seasonal allergies and asthma is well known, however the link between cow dairy and dermatitis/eczema and asthma, although well known in some communities, is not always as appreciated. At least 30% of children with atopic dermatitis/ eczema have food allergies and about 6% have food induced asthma, most commonly to cow’s milk, egg, and peanut.3 Although this link between certain foods to dermatitis/ eczema and asthma doesn’t represent a cross-reaction, it is a good example of how one allergy can exacerbate another. The concept of total body burden is important in relation to allergy, because if you can reduce the body burden of one allergen by avoidance, rotation, or allergy shots/ drops (immunotherapy), then often the body is able to tolerate the other allergens and symptoms do often resolve.5 I cannot tell you how often my patients happily report, “I cleaned up my diet and my seasonal allergies disappeared”.
Oral allergy syndrome occurs when a person with hay fever or allergic rhinitis develops an itchy or swollen mouth, throat or lips and less commonly gastrointestinal symptoms, after eating certain foods. Oral allergy syndrome is specific to pollen cross-reactions to foods.6 According to www.foodintolerances.org, those with hay fever typically have cross reactions to two or more foods3:
Birch pollen: apple, carrot, celery, pear, tomato, cherry, tree nuts (infrequently: many more fruit and spices)
Goosefoot pollen: banana, melon, peach (infrequently: nectarine, asparagus, kiwi, potato, olive, onion)
Mugwort pollen (weed): carrot, celery, aniseed, peach (infrequently: many more fruit, vegetables and spices)
Ragweed pollen: melon, cucumber, banana, sunflower
Timothy grass: apple, litchi, tomato, celery, corn, bell pepper, paprika3
Diagnosing food and seasonal cross-reaction allergies takes detective work. While the various types of food allergy testing can be revealing, they may not be clinically relevant. Clinical history, testing, and oral food challenge done together with a provider trained in food and environmental allergy and familiar with cross-reactivity issues provides the most useful information. Any type of food testing without a food challenge will be of limited utility, because the patient will not be aware of their unique response to that food or if they are even having one, because the body can mask allergic symptoms when the allergy sufferer is continuously eating a trigger. The elimination period of an elimination-challenge diet helps to lower the immune response enough so that the allergy can be unmasked when the food is reintroduced during the food challenge. In terms of detecting the cross reactions, if environmental allergy testing reveals a trigger, cross reactivity charts, such as this one from the American Academy of Allergy Asthma and Immunology https://www.aaaai.org/conditions-and-treatments/library/allergy-library/outdoor-allergies-and-food-allergies-can-be-relate.aspx can be referenced to help determine foods that might possibly be aggravating the allergic symptoms related to that allergen.6 To help reduce seasonal allergy symptoms avoiding cross-reactive foods, at least seasonally when the immune system is most reactive to these might be helpful or for some life changing.
Sarah Giardenelli, ND, MSOM, LAc was born and raised in upstate New York. She completed her undergraduate studies in pre-medicine and psychology at the State University of New York at Buffalo. Knowing from an early age that she wanted to help people achieve optimal health naturally, she found her calling at the National College of Natural Medicine, in Portland, OR. After six years of study, Sarah earned both a Doctorate in Naturopathic Medicine with Honors in Research and a Master of Science in Oriental Medicine. She then completed her naturopathic residency at Clifton Springs Hospital & Clinic, outside of Rochester, NY.
Sarah integrates both Naturopathic and Chinese medicine in her practice. She has special interest in integrative medicine, nutrition, environmental medicine/toxicity, pain and chronic disease management, Chinese and Western herbs, community health, women’s health, gastrointestinal health, and geriatric health. Sarah also has additional training in the prescription of Chinese formulas and in bio-therapeutic drainage, an individualized, whole systems approach to wellness through detoxification.
Sarah sees her service in the healthcare profession as an honor; part of the change to provide a better healthcare system for the community. Her passion for integrative and natural medicine stems from both her own personal expereince of relief of years of digestive and intestial chaos and family experiences of healing with natural medicine.
Sarah is nationally certified in naturopathic medicine by the Association of Accredited Naturopathic Medical Colleges and in acupuncture by the National Certification Commission for Acupuncture and Oriental Medicine. She is a licensed acupuncturist in the Commonwealth of Virginia and is a member of the American Association of Naturopathic Physicians. Other interests include rowing, hiking, gardening, and consuming (and cooking) delicious foods.
- Killian, Sue. Hidden Allergens. Allergy Support Consulting.[Online] 2016. [Cited: April 15, 2016.] http://www.allergysupportconsulting.com/hidden-allergens-2.
- Giardenelli, Sarah M. Food Allergy vs Food Intolerance. NOVA Medical & Urgent Care Center.[Online] NOVA Medical Group, May 1, 2015. [Cited: April 15, 2016.] http://www.novamedgroup.com/food-allergy-vs-intolerance/.
- http://www.foodintolerances.org/non-food-allergies.aspx. Food Intolerance Diagnostics.[Online] 2014. [Cited: April 15, 2016.] http://www.foodintolerances.org/non-food-allergies.aspx.
- Allergic cross-reactivity: from gene to clinic.Ferreira F, Hawranek T, Gruber P, Wopfner N, Mari A. s.l. : Allergy, 2004, Vols. 59:243-267 .
- Patel, Kalpana D. Overview of the Principles of Environmental Medicine Diagnosis and Treatment. AAEM.[Online] [Cited: April 15, 2016.] https://www.aaemonline.org/pdf/principles.pdf.
- Pongdee, Thanai . Oral Allergy Syndrome. American Academy of Allergy, Asthma & Immunology.[Online] AAEM, 2016. [Cited: April 15, 2016.] https://www.aaaai.org/conditions-and-treatments/library/allergy-library/outdoor-allergies-and-food-allergies-can-be-relate.aspx.