The Food Allergen Labeling and Consumer Protection Act of 2004 (FALCPA), which addresses the issue of the labeling of foods that contain certain food allergens, requires all food products that are regulated by the FDA to be labeled in a specific way. This is to enable the consumers to check for the presence of the eight major food allergens (milk, egg, fish, crustacean shellfish, tree nuts, wheat, peanuts, and soybeans). According to the FDA, tree nuts include almonds, beech nuts, Brazil nuts, cashews, chestnuts, Chinquapin nuts, coconut, hazelnuts, ginkgo nuts, hickory nuts, lichee nuts, macadamia nuts, pecans, pine nuts, pili nuts, pistachios, shea nuts, and walnuts. It must be noted that the FDA recognizes coconut as a tree nut for the purposes of labeling, although coconut is not a tree nut in the strictest sense.
The scientific name of coconut is Cocos nucifera, and it belongs to the Arecaceae family. It is a dry drupe and is only distantly related to tree nuts. It has a smooth exocarp (outer layer), fibrous mesocarp (middle layer), and a hard endocarp (layer that surrounds the seed). The reason behind the recognition of coconut as a food allergen might be due to the documentation of a few cases of allergic reaction (especially anaphylactic shock) on consumption of coconut.
Cross-reactivity Between Coconut and Walnut
In terms of allergic reactions, cross-reactivity is said to occur when an allergic reaction develops on exposure to substances containing structurally similar proteins. A common example of cross-reactivity can be explained with reference to tree nuts. There have been instances where some individuals who are allergic to one of the tree nuts developed an allergic reaction on consuming other tree nuts. In the U.S., the incidence of allergic reaction to walnut (34%) is much higher than any other tree nut, whereas a coconut allergy is quite rare. However, a few cases regarding cross-reactivity between coconut and walnut/hazelnut have been documented. The proteins that are believed to cause allergies after ingestion of coconut include:
➠ Coc n 7S globulin
➠ Coc n 11S globulin (Cocosin)
➠ Coc n Profilin (protein isolated from coconut tree pollen)
In a study conducted by Teuber and Peterson, two patients with primary walnut allergy and secondary coconut allergy were studied. The tests that were conducted suggested substantial IgE cross-reactivity between walnut and coconut. This study also suggested that it was IgE resulting from primary walnut exposure that contributed to a secondary cross-reaction to coconut.
There have been cases where the allergic reaction occurred only due to the ingestion of coconut, as the affected individual could tolerate other tree nuts, seeds, dates, etc. However, allergic reactions to coconut alone is quite rare. Most people who are allergic to tree nuts can safely eat coconut, but an allergic reaction could occur in rare cases due to the cross-reactivity between coconut and some other tree nuts.
Oils from both coconut, as well as palm contain 7S globulin proteins. These oils are commonly used in cosmetic products such as creams, lotions, soaps, shampoos, etc. It is believed that the slight increase in the incidence of allergic reactions to coconut could be due to the sensitization to these proteins due to the topical exposure through the skin.
Coconut Allergy Symptoms
Coconut allergy is a type 1 hypersensitivity, wherein the immune system produces a response, as it considers the presence of certain proteins in coconut as a threat. The response involves the activation of the immune cells which produce Immunoglobulin E (IgE) antibodies to defend the body. These antibodies bind to the proteins in the coconut, thereby stimulating the mast cells to release histamine. It is the release of histamine that causes the blood vessels to dilate, thereby causing the untoward symptoms that are associated with allergic reactions.
The symptoms of coconut allergy include:
➠ Watery eyes
➠ Red, itchy eyes
➠ Runny nose
➠ Vomiting, nausea, and diarrhea
➠ Wheezing or asthma-like symptoms
➠ Breathing problems
➠ Flushed face
➠ Low blood pressure
In extreme cases, one could even develop an anaphylactic shock. This condition is characterized by the following symptoms:
➠ Swelling of the throat/tongue/lips/face
➠ Shortness of breath
➠ Breathing difficulties
➠ Difficulty in swallowing
➠ Heart palpitations
➠ Drop in blood pressure
➠ Skin turning blue
➠ Loss of consciousness
Prevention and Treatment
Every individual who has had an allergic reaction to any food needs to identify the food that he/she might be allergic to. This can be done with the help of skin prick tests, food challenges, and blood tests that check the blood for antibodies. In case of an allergy, the avoidance of the food is the best treatment option. Thus, individuals who are allergic to coconut should avoid food products that contain coconut in any form.
➠ Coconut milk, coconut cream, or shredded coconut might be used in some cake mixes, bread, baked goods, pastry products, dough, chocolate, soups, ice creams, sauces, puddings, salad dressings, dumplings, etc. So, make sure that you read the food labels.
➠ In case of recipes wherein coconut flour is used, unprocessed bran, tapioca flour, or almond flour (avoid almonds, if you are allergic to them) can be used as a substitute for coconut. Clarified butter can be used instead of coconut butter. In case of any doubts, consult a dietitian or a nutritionist to learn about the best substitutes.
➠ Be very cautious while eating out. Make it a point to ask about the ingredients used in dishes. Avoid any dish that contains coconut.
➠ While antihistamines or corticosteroids help alleviate the symptoms of an allergic reaction, it would be best to keep an epinephrine injection ready, so as to tackle an anaphylactic reaction.
Though some people who are affected by tree nut allergies could develop an allergic reaction on consuming coconut, coconut allergy is quite rare. It must be noted that some people might develop allergic dermatitis on coming in contact with coconut oil. Such individuals should avoid the use of cosmetics, shampoos, soaps, or other products that contain coconut diethanolamide, cocamide sulfate, cocamide DEA, and CDEA. On a concluding note, avoidance of the allergen is the only way to avoid the untoward symptoms associated with allergies.