Introducing major food allergens

What to Know

  • Learn the major food allergens
  • Get the latest research around and implications of allergies
  • Recognize food allergy symptoms

Keeping up with the latest food allergy recommendations can seem daunting, as new research (sometimes contradicting old research) continues to emerge. What causes food allergies and why they’re on the rise remains unclear, but the fact that they are rising cannot be disputed. Roughly 4% of American children have at least one food allergy, an 18% increase over a decade. An allergic reaction to food occurs when the body’s immune system misinterprets or overreacts to a protein in food, identifying it as harmful or dangerous and triggering a protective response.

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Any food has the potential to cause an allergic response and so far, over 160 foods have been identified! However, only these eight foods account for about 90% of all reactions:

  • Milk
  • Eggs
  • Peanuts
  • Tree Nuts (walnuts, pecans, almonds, cashews, pistachios)
  • Soy
  • Wheat
  • Fish
  • Crustacean Shellfish (shrimp, crab and lobster)

Also be aware that certain seeds, including sesame and mustard seeds, are common food allergy triggers and are considered major allergens in other countries.

The latest research has shown that there is no benefit in delaying the introduction of allergy-causing foods. Therefore, the American Academy of Pediatrics (AAP) recommends not delaying introducing foods such as eggs, dairy, soy, peanuts or fish (in the texture your baby can safely handle) when you introduce solids (around 6 months). See Introducing solids: Signs of readiness for more information as to when your baby is ready to start solids.. However, if you suspect your baby has an allergic reaction to a food or if you have a history of severe eczema or food allergies, talk to your doctor on how best to introduce allergy-causing foods.

As you’re introducing a new potential food allergen to your baby, how do you know if he has an allergy? Symptoms of an allergic reaction may involve the skin, the digestive system, the cardiovascular system and/or the respiratory tract and can vary from person to person, and from incident to incident. It’s important to know that a mild reaction can occur on one occasion and a severe reaction to the same food may occur on a subsequent occasion. This range of reactions may include:

  • Hives (red spots that look like mosquito bites)
  • Itchy skin rashes (eczema, also called atopic dermatitis)
  • Swelling to the lips and face
  • Sneezing, stuffy or runny nose
  • Repetitive coughing or wheezing
  • Throat tightness
  • Difficulty breathing
  • Nausea
  • Vomiting
  • Diarrhea
  • Cramping
  • Pale skin
  • Light-headedness
  • Loss of consciousness
  • Anaphylaxis, which requires immediate medical treatment. Anaphylaxis is a severe and potentially life-threatening allergic reaction that can occur within seconds to minutes of exposure to an offending allergen. It can, among other things, cause a sudden drop in blood pressure and impair breathing. If your child has known allergies, make sure you speak to your physician or allergist to get an emergency plan in place so that you are always prepared.

What to Do

Inform and prepare yourself

Discuss your plan to introduce solid foods with your physician or allergist, especially if you have a family history of allergic diseases (like food allergies, eczema, asthma, hay fever or atopic dermatitis).

Introduce major allergens alongside safe, already well-tolerated first foods

Unless otherwise instructed by your physician, give your baby one major allergen at a time at a rate not faster than one new food every 2-3 days.

Note that when introducing nuts, peanut and tree nut butters are safe at younger ages, but shelled whole peanuts and tree nuts carry choking risks.

You may offer dairy products like cheese and yogurt before age one, but whole cow’s milk should be avoided until after one year of age (while this is unrelated to allergies, it is worth noting because your baby cannot digest whole cow’s milk easily, not to be confused with an allergic reaction).

Watch for any signs of an allergic reaction after introducing each new food

If any of the previously noted reactions occur, stop feeding your child the new food and consult with your child’s doctor for evaluation. If your baby experiences any severe reactions (like difficulty breathing, swelling or severe vomiting or diarrhea) call 911 immediately.

Practice allergy prevention strategies

While there’s no certainty, research indicates the following strategies can be helpful in reducing the risk of allergies in your child:

  • Eat a wide variety of foods while you are pregnant and breastfeeding. Now is not the time to restrict certain foods, as no correlation has been shown between moms avoiding foods and allergies in their children. Plus, you need the full range of nutrients to grow a healthy baby!
  • Breastfeed. The best step you can take to reduce the incidence of allergies is to breastfeed your baby exclusively for six months. The antibodies, nutrients and various health-protecting substances found in breast milk help promote the development of a balanced intestinal flora, protect against infections and boosts your baby’s immune system (among many other benefits).
  • Get plenty of omega-3’s while you’re pregnant and breastfeeding.
    Focus on foods like low-mercury oily fish (salmon and sardines), algae (seaweed and kelp), and nuts and seeds (especially walnuts, chia and flax seeds). If you’re having a hard time incorporating these foods into your diet, check with your doctor about taking a supplement. Either way, your baby’s developing immune system will reap the benefits of omega-3 and DHA during development in utero and as he continues to mature in infancy.
  • Nourish your baby with probiotics and prebiotics found in foods. Probiotics are live, non-pathogenic microorganisms that improve or maintain intestinal flora balance by repressing and replacing harmful bacteria. They are found in fermented foods such as live-cultured yogurt, sauerkraut, kimchi, miso, kombucha tea and dark chocolate! Prebiotics are indigestible fiber compounds that “feed” on beneficial intestinal bacteria. Breast milk is rich in prebiotics, though you can boost your supply by eating bananas, garlic, onions, leeks and tomatoes. Oligosaccharide prebiotics in particular, found in some of these foods, are thought to help program a healthy immune system. Making sure your baby has enough can help ensure a healthy ratio of “good” to “bad” bacteria in his gut.

Research shows that both pre and probiotic ingestion can have beneficial effects on your baby’s developing gastrointestinal and immune systems and may be helpful in preventing allergies.

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Avoid smoking and second-hand smoke. Smoking and exposure to second-hand smoke may increase your baby’s risk for allergic diseases and food allergies. In general, it is recommended to avoid any form of tobacco exposure during pregnancy and during childhood (and thereafter!).