A few foods account for the majority of food allergies.
To be sure, experts say, it’s at least theoretically possible that any food could cause an allergic reaction in some people (though certainly not all foods have been documented to do so). But eight types of foods tend to be allergens — or cause an allergic reaction — far more frequently than others. The so-called “Big-8”– including foods such as peanuts, milk and shellfish like shrimp — account for more than 90% of food allergies in the U.S. In addition, sesame is being increasingly recognized as a top food allergy, rounding out the top nine, notes Dr. Pooja Varshney, a pediatric allergist at Dell Children’s Medical Center and clinical assistant professor of pediatrics at the University of Texas at Austin Dell Medical School.
Taking food allergies seriously
“I think there’s a lot of public misunderstanding of the importance of food allergies — like a little bit is probably OK, or people will just have a tummy ache — it’s not that big a deal,” says Dr. Brian Vickery, the founding director of the Food Allergy Center at Children’s Healthcare of Atlanta and an associate professor of pediatrics at Emory University. The reality, he and other experts say, is far more serious. Even small — or trace — exposures to the food people are allergic to can lead not only to symptoms like itching and skin rash, or hives, but swelling of the face and throat, as well as difficulty breathing. In the most severe instances, an allergic reaction can be fatal.
Recognizing food allergies
Given the seriousness of food allergies, it’s important to heed any of a broad range of possible symptoms after food is consumed, and seek medical attention for adults or kids to ensure proper diagnosis and allergy management. Symptoms may include skin redness around the mouth or eyes, itchy mouth, vomiting, diarrhea, lightheadedness, chest pain and trouble swallowing. “Once we confirm the diagnosis of food allergy, then the current standard of care is to strictly avoid that food,” Vickery says. Admittedly, experts say, that’s a tall order, but it’s critical to take measures like reading labels and talking to restaurant staff about ingredients, even as there’s no foolproof way to know if that food has been contaminated by an allergen.
Where the standard medical advice had been for parents to wait to give their kids certain commonly allergenic foods, the example of this legume has turned that on its head. Landmark research found, in fact, that early introduction of peanut products significantly decreased how frequently babies at high risk for peanut allergy actually developed it. If a child isn’t already allergic to peanuts, it’s advantageous to start peanut products in the first year of life to help reduce the risk of a peanut allergy, Varshney says. However, experts caution, make sure to introduce safe, developmentally appropriate forms of peanut, like smooth peanut butter thinned with water, rather than whole peanuts or even straight peanut butter, which are choking hazards for infants and small children.
Another very common food allergy, especially in kids, milk allergy differs from lactose intolerance. “Lactose intolerance is a problem digesting the sugar in milk,” Varshney explains. Sufferers typically develop abdominal pain, gas, diarrhea and upset stomach as a result. With a milk allergy, the immune system attacks the food, causing an allergic reaction. So in addition to some overlapping symptoms like abdominal pain, it triggers other symptoms such as hives and swelling of the lips, tongue or throat, and can even cause a potentially life-threatening allergic reaction called anaphylaxis.
While more research is needed, experts say it’s likely peanut-related findings apply to other foods that have also been commonly withheld from the youngest children like eggs. “We don’t quite have that data yet for the other foods, like milk or egg or seafood or even tree nuts,” says Dr. David Jeong, an allergist at Virginia Mason Medical Center in Seattle. “But the belief is that earlier introduction — even of those foods — will likely decrease the risk of becoming allergic down the road.” For those who do have an egg or milk allergy, a majority can actually tolerate either of these in baked goods (though that’s not the case for cooking other allergens). Still, not everyone can, so check with a doctor before serving those up.
Fish — or specifically finned fish such as tuna, halibut or salmon — are another common source of food allergy. And cooking that aerosolizes fish, like boiling it, can actually be a hazard. That was highlighted by headlines about an 11-year-old boy who tragically died on Jan. 1 this year from an allergic reaction after smelling cod that was being cooked at his grandmother’s home in Brooklyn, New York. To those who are allergic to seafood of any kind, “we caution people to beware of the potential for an inhalational reaction,” Vickery says.
Shellfish allergy is the most common food allergy in adults. Shellfish include shrimp, lobster, crab and mollusk — like clams, mussels, oysters and scallops. But where boiling shrimp, for example, could present an exposure hazard to a person with a shellfish allergy, for those with other food allergies, simply smelling it or an aerosolized exposure doesn’t typically cause issues. However, some who are allergic to milk report having trouble with boiled milk. “There’s been some recent reports of people having trouble in places like coffee shops where they are foaming lattes and release milk protein into the air,” Vickery says — where some described symptoms like chest tightness, coughing and difficulty breathing. “But these kinds of reactions are not typically common.”
Whereas the peanut ripens underground, you’ll find another potent allergen up higher. Tree nuts, including walnuts, almonds, hazelnuts, pecans, cashews and pistachios, are a common source of food allergy. Along with peanuts and shellfish, tree nut allergies are among the food allergies most frequently linked with anaphylaxis — the rapidly occurring allergic reaction that can kill. Besides avoidance of the allergen, for any food allergy, it’s recommended people carry epinephrine — which can reverse life-threatening effects like a dangerous drop in blood pressure during anaphylaxis — as well as keeping other allergy medications on hand to manage an unexpected allergic reaction.
Just as a milk allergy differs from lactose intolerance, a wheat allergy is different from gluten sensitivity, or the immune disease that prevents people from eating wheat, celiac disease. So before removing wheat from your diet or otherwise trying to self-diagnose or self-treat, experts say it’s imperative — as with any potential food allergy — to get a proper diagnosis. That means seeing a clinician, such as an allergist, with significant experience diagnosing food allergies, who — once a diagnosis is made — can also advise on how to avoid eating wheat. Frequently, registered dietitian nutritionists also provide advice to help patients develop an everyday game plan for meals and snacks.
It’s hard to miss all the products in supermarkets today with soy in them. In many respects, dietitians caution, it’s overconsumed — kind of like corn can now be found in overabundance in forms that are far from healthy, like high-fructose corn syrup. Soy is frequently found in infant formula — which is often soy-based — and the allergy often develops in infancy. (Similarly, a baby’s allergy to dairy may be first discovered when the child is given cow’s milk-based formula.) That makes due diligence in reading labels and inquiring about this ingredient critical.
Food manufacturers must list — using plain terms the consumer can understand, like “peanut” — any of the Big-8 that are in food products, as required by the Food Allergen Labeling and Consumer Protection Act. And given the growing prevalence of sesame allergy, the Food and Drug Administration is considering extending that requirement to sesame. The edible seeds are found in everything from hummus and sushi to buns. But even if labeling does change, it will still be important to inquire about the ingredient in freshly baked goods — which aren’t covered under the labeling law. The law also doesn’t require manufacturers to list if foods could potentially be contaminated by allergens processed in the same facility, though some voluntarily disclose that.
To recap, the most common food allergies are:
— Tree nuts
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