A look at the cross-reactivity of common Thanksgiving ingredients.

The Thanksgiving Holliday is nearly upon us! Now is the time to start menu planning and thinking about our guests, and what they can and cannot eat. It can be challenging to accommodate everyone’s tastes and needs, especially when food allergies and sensitivities are involved. Most people are aware of their own allergies and perhaps their sensitivities if they’ve had a dietary antigen test (if not, they should try the gold standard in DATs, the Precision Point Diagnostics P88).

Some of your family, friends, and patients may not realize that they can cross-react to certain foods that may be sensitive or allergic to. They may have an identified allergy or sensitivity which causes them to avoid certain triggers, but they may not be as vigilant about cross-reactive triggers. These “secret” triggers may spark more readily around the holidays for a few reasons.

1) People are eating a larger variety of foods than usual because they are feasting. They may not realize they have a sensitivity or allergy to a certain food that they consume rarely (another reason for a DAT test).

2) Someone else may be preparing the meal. Whether at a restaurant or at a family members house, there may not be clear knowledge of everything in every dish. This is particularly true when meals are served “family style”- even with instructions, people help themselves and may consume a trigger. Guests may also eat more than they usually do, and for that reason may consume more of a trigger food than would usually be the case.

3) Cross-reactive foods may be eaten because of a lack of knowledge. This can compound the other problems above because the consumptions of triggers may stack- couple this with consumption of high histamine foods often served while feasting, and it may not be the tryptophane in the Turkey causing your guests to crash, but food triggers.

So how to food triggers work? Basically, genetically related foods have a chance to trigger food allergies and sensitivities because they share certain proteins that the body reacts to. An allergic reaction is an IgE reaction, an immunologic reaction that can cause severe symptoms, including anaphylaxis. A food sensitivity is an IgG reaction, which is usually more subtle, but left neglected can cause symptoms ranging from brain fog, skin conditions, and extreme fatigue. Left long enough undiagnosed allergies and sensitivities can turn into autoimmune conditions- where they body’s immunological defenses attack its own cells when triggered.  There are also reactions between environmental allergens and food allergens, sometimes known as oral allergy syndrome. Pollens can cross-react with related foods (like tree nuts), and environmental pests can cross-react with foods as well (a common cross-reactivity is between cockroach and clam- they share enough common proteins that detritus from cockroaches often triggers clam showing up as an allergy or sensitivity). These are all reasons why anyone who has the slightest reaction to a food should at least have a baseline DAT.

Below you’ll find a list of common ingredients used in Thanksgiving meals in The United States. The list is ordered in the degree of severity of common reactions, and includes the ingredient, the food family, common Thanksgiving dishes the ingredient is found in, and common cross-reactivities for the allergen/sensitivity.  This list is shared in the hope both host and guest will recognize the hidden triggers they should look out for especially during the holidays.

Peanuts

Food Family: Legumes

Common Allergies/Sensitivities: Highly allergenic, can cause severe reactions (anaphylaxis)

Common Dishes: Some stuffing recipes, snacks

Cross-Reactivity: Legumes like soybeans

Tree Nuts

Food Family: Nuts

Common Allergies/Sensitivities: Includes almonds, walnuts, pecans, etc.; common allergens

Common Dishes: Pecan pie, stuffing, salads

Cross-Reactivity: Other nuts like hazelnuts, almonds

Milk (Dairy)

Food Family: Dairy Products

Common Allergies/Sensitivities: Lactose intolerance, milk allergy

Common Dishes: Mashed potatoes, gravy, mac and cheese

Cross-Reactivity: Other dairy products like cheese, yogurt

Eggs

Food Family: Animal Products

Common Allergies/Sensitivities: Egg allergy

Common Dishes: Stuffing, casseroles, pies

Cross-Reactivity: Poultry meat, certain vaccines

Wheat (Gluten)

Food Family: Grains

Common Allergies/Sensitivities: Celiac disease, gluten sensitivity

Common Dishes: Stuffing, bread rolls, pies

Cross-Reactivity: Barley, rye

Soy

Food Family: Legumes

Common Allergies/Sensitivities: Soy allergy

Common Dishes: Sauces, some gravies, tofu dishes

Cross-Reactivity: Peanuts, other legumes, high in histamines

Shellfish

Food Family: Seafood

Common Allergies/Sensitivities: Shellfish allergy

Common Dishes: Oyster stuffing, seafood appetizers

Cross-Reactivity: Other shellfish like crab, shrimp

Fish

Food Family: Seafood

Common Allergies/Sensitivities: Fish allergy

Common Dishes: Gravlax, fish appetizers

Cross-Reactivity: Other fish like cod, salmon

Sesame Seeds

Food Family: Seeds

Common Allergies/Sensitivities: Sesame allergy

Common Dishes: Some bread rolls, salad toppings

Cross-Reactivity: Nuts, kiwi

Mustard

Food Family: Brassicaceae family

Common Allergies/Sensitivities: Mustard allergy

Common Dishes: Mustard-glazed hams, dressings

Cross-Reactivity: Other Brassicaceae family members like broccoli, cabbage

Sulphites

Food Family: Preservatives

Common Allergies/Sensitivities: Sulphite sensitivity

Common Dishes: Dried fruits in stuffing, wine

Cross-Reactivity: Other preservatives, red wines, some vinegars

Corn

Food Family: Grains

Common Allergies/Sensitivities: Corn allergy

Common Dishes: Cornbread, corn pudding

Cross-Reactivity: Rice, wheat

Poultry (Turkey)

Food Family: Poultry

Common Allergies/Sensitivities: Less common, but poultry allergy exists

Common Dishes: Roast turkey, turkey gravy

Cross-Reactivity: Chicken, duck

Potatoes

Food Family: Nightshade

Common Allergies/Sensitivities: Rare, but potato allergy exists

Common Dishes: Mashed potatoes, potato casserole

Cross-Reactivity: Other nightshades like tomatoes, eggplants

Carrots

Food Family: Apiaceae family

Common Allergies/Sensitivities: Rare, but carrot allergy exists

Common Dishes: Roasted vegetables, soups

Cross-Reactivity: Celery, parsley

Green Beans

Food Family: Legumes

Common Allergies/Sensitivities: Rare, but green bean allergy exists

Common Dishes: Green bean casserole

Cross-Reactivity: Peanuts, soybeans

Cranberries

Food Family: Heather

Common Allergies/Sensitivities: Rare, but cranberry allergy exists

Common Dishes: Cranberry sauce, salads

Cross-Reactivity: Other heaths like blueberries, and lingonberries

Pumpkin

Food Family: Gourd Family

Common Allergies/Sensitivities: Rare, but pumpkin allergy exists

Common Dishes: Pumpkin pie, soups

Cross-Reactivity: Other gourds like squash, cucumbers

Sweet Potatoes

Food Family: Morning Glory

Common Allergies/Sensitivities: Rare, but sweet potato allergy exists. Sensitivity is more common.

Common Dishes: Sweet potato casserole, roasted sweet potatoes

Cross-Reactivity: latex, cassava, yam

Butternut Squash

Food Family: Gourd Family

Common Allergies/Sensitivities: Rare, but butternut squash allergy exists

Common Dishes: Roasted squash, soups

Cross-Reactivity: Other gourds like pumpkin, zucchini

Brussels Sprouts

Food Family: Brassicaceae Family

Common Allergies/Sensitivities: Cross-reactivity with other members of the Brassicaceae family like broccoli and cauliflower

Common Dishes: Roasted Brussels sprouts

Cross-Reactivity: Cabbage, kale

Celery

Food Family: Apiaceae Family

Common Allergies/Sensitivities: Celery allergy, cross-reactivity with other Apiaceae family members like carrots and parsley

Common Dishes: Stuffing, soups

Cross-Reactivity: Carrots, parsley, dill

Onions

Food Family: Allium Family

Common Allergies/Sensitivities: Cross-reactivity with other alliums like garlic and leeks

Common Dishes: Stuffing, gravies, casseroles

Cross-Reactivity: Garlic, leeks, scallions, shallots

Butter

Food Family: Dairy Products

Common Allergies/Sensitivities: Lactose intolerance, milk allergy

Common Dishes: Mashed potatoes, pastries, casseroles

Cross-Reactivity: Other dairy products like cream, cheese, milk

Cream

Food Family: Dairy Products

Common Allergies/Sensitivities: Lactose intolerance, milk allergy

Common Dishes: Mashed potatoes, whipped cream toppings, sauces

Cross-Reactivity: Other dairy products like milk, butter, cheese

Brown Sugar

Food Family: Sugars

Common Allergies/Sensitivities: Rare, but can cause issues for individuals with sugar sensitivities

Common Dishes: Desserts, glazes, sweet potatoes

Cross-Reactivity: White sugar, honey

Chitlins

Food Family: Pork

Common Allergies/Sensitivities: Cross-reactivity with other pork products like bacon and sausage

Common Dishes: Southern (African-American) dishes

Cross-Reactivity: Other pork products like bacon, sausage

Collard Greens

Food Family: Brassicaceae Family

Common Allergies/Sensitivities: Cross-reactivity with other leafy greens like kale and spinach

Common Dishes: Southern sides

Cross-Reactivity: Mustard greens, kale

Maple Syrup

Food Family: Sugars

Common Allergies/Sensitivities: Rare, but can cause issues for individuals with sugar sensitivities

Common Dishes: Glazes, desserts, sweet potatoes

Cross-Reactivity: Honey, other syrups

Marshmallows

Food Family: Confectionery

Common Allergies/Sensitivities: Gelatin allergy, cross-reactivity with other gelatin products

Common Dishes: Sweet potato casserole, desserts

Cross-Reactivity: Other gelatin products, beef

Fried Onions

Food Family: Allium Family

Common Allergies/Sensitivities: Cross-reactivity with other alliums like garlic and leeks, gluten sensitivity if breaded

Common Dishes: Topping for green bean casserole