How (and Why) to Introduce Allergens to Your Infant

In the last decade, prevailing beliefs about timing the introduction of highly allergenic foods to babies have undergone a sea change.

For decades, parents were advised to delay introducing allergenic foods until 12 months (cow's milk dairy), 24 months (eggs) or even 36 months of age (fish, tree nuts, peanuts). Then, in 2008, the American Academy of Pediatrics (AAP) retracted its previous guidelines on the matter, acknowledging that there was insufficient evidence to support delayed introduction of allergens as a strategy to reduce the risk of food allergy. But beyond that, the organization did not offer specifics as to whether there was an ideal window during infancy to introduce these foods, nor did it comment on whether delaying introduction of foods might actually increase risk of developing food allergies.

[See Food Intolerance: Fact and Fiction]

As a result, pediatricians and parents have been in limbo since 2008, lacking clear guidelines as to whether early or delayed food introduction could help prevent babies from developing food allergies. As more observational research on solid food introduction and risk of food allergy became available, the body of evidence began to point in a relatively consistent direction: Early introduction of common food allergens seemed associated with a lower risk of developing food allergies compared to delayed introduction. Some pediatricians found these studies compelling enough to start advising parents to stop delaying the introduction of allergens past 12 months. But lacking sufficient evidence that met the "gold standard" of scientific research--randomized, controlled trials--other pediatricians continued to feel it was prudent to follow the delayed introduction approach until better evidence was available or official guidelines were issued.

This past January, however, the American Academy of Asthma, Allergy and Immunology (AAAAI) released a new set of recommendations on infant feeding practices to help prevent food allergy. The recommendations are based on the available observational research to date, and are the first guidelines to state that delaying introduction of foods like wheat, cow's milk dairy, eggs, fish and nuts may actually result in an increased risk of food allergy or eczema.

The AAAAI recommendations state that once an infant over 4 months old has tolerated a few non-allergenic solid foods (think common early solids like rice cereal, oatmeal, sweet potatoes, carrots, bananas, apples or pears), parents can proceed with introducing other more allergenic foods without delay, ideally at home rather than in day care or a restaurant. As with introducing all new solids, only one new food should be introduced every three to five days to help isolate triggers of any allergic reaction.

Importantly, the guidelines also note that exclusive breast-feeding for at least four months may be protective against cow's milk allergy in infants. Lastly, they found no significant protective benefit against food allergy when mothers avoided allergenic foods like dairy, egg and peanuts during pregnancy or lactation.

[See How to Breast-Feed Twins]

Ultimately, how to introduce allergens is a personal decision you'll make in consultation with your pediatrician. If your infant already has eczema or signs of a food allergy--or if a sibling has a peanut allergy--your pediatrician may refer you to a pediatric allergist for testing and individualized guidance.

If you do decide to introduce allergens to your infant between the ages of about 5 to 12 months, I offer some texture-appropriate ideas for doing so--many of which I road-tested on my own two kids:

Wheat

Yes, even though I have Celiac disease, I introduced wheat to my kids at around six and a half months of age. My personal decision was based on some evidence which suggested four to six months may be the optimal time to promote tolerance of gluten in babies with a family history of type 1 diabetes or Celiac disease.

[See What is Gluten, Anyway?]

-- Cooked wheat cereal: Cream of Wheat and farina are both iron-fortified cooked cereals that are texture appropriate for infants just starting out on solids; use breast-milk or formula to thin it out as needed. Wheatena is a whole-wheat version of farina that is not iron-fortified. Bob's Red Mill offers organic versions of all these products. Gerber and Beech-Nut make multi-grain infant cereals that contain wheat.

-- Dry cereal: Plain Cheerios contain some wheat starch and are a low-salt, low-sugar, high-iron vehicle for exposing infants to some wheat as they learn to self-feed. Sugar-free, salt-free puffed wheat cereals are available in conventional (Quaker) and organic versions (Arrowhead Mills); these also make good early finger foods.

-- Pastina: Those itty-bitty pasta stars can be added to low-sodium soup or any baby food once your infant advances to lumpier, more textured purees.

-- Crackers: Beware: Most teething biscuits contain added sugar, not exactly what you want an infant gnawing on. Zweiback toast was the standard teething biscuit of my generation, but it's almost impossible to find nowadays. Most other wheat crackers are too crispy to be safe for infants just starting on finger foods ( at around 8 months), though crumblier options like saltines may work well.

I found the soft and crumbly texture of Carr's Whole Wheat Crackers perfect for my kids at this age. Unfortunately, they too contain a bit of sugar; however, it turned out to be 50 percent less than several wheat teething biscuits I checked out from organic brands that are explicitly marketed to infants (1.5 grams per cracker vs. 3 grams per teething biscuit). In the context of an otherwise extremely low-sugar diet, I found one cracker every few days to be an acceptable compromise until my kids could handle crunchier textures. At that point, I switched them to sugar-free, whole-wheat crackers.

Fish

-- Puréed fish: Mild white fish or salmon can be cooked simply (steamed, baked, poached or broiled) and puréed into baby food with a touch of breast-milk or formula for infants as young as six months old. Freeze leftovers in 1-ounce ice cube trays, and defrost as needed. Pureed fish goes well with baby favorites like mashed avocado, green beans, peas, sweet potatoes and carrots.

-- Salmon croquettes (pancakes): My grandma had a recipe for crab-cake-like croquettes that use boneless canned salmon; search for it on my personal blog. For infants and children, I advise only using canned foods with BPA-free can liners; look for Wild Harvest or Vital Choice brands. Mixed with either buttermilk or kefir along with some bread crumbs, an egg, baking soda and some seasoning, the salmon is transformed into a soft, spongy pancake that older infants can self-feed. (They also make a great topping for mom's lunch salad!)

-- Table food: Fish's soft and flaky flesh renders it a perfect table food for infants (starting around 8 months) to share with the rest of the family. Avoid using any honey-containing marinades or sauces until baby is more than 1 year old to reduce the risk of infant botulism.

Peanuts

-- Bamba: It's been speculated that this popular Israeli snack food is the reason why Israeli children are 10 times less likely to have a peanut allergy as their Jewish counterparts in the United Kingdom; Israeli infants routinely eat it in their first year of life. Bamba is essentially a puffed corn snack coated with powdered peanut and fortified with iron; it has no added sugar and very little sodium. I introduced Bamba to my twins at 8 months, pending their ability to handle stickier peanut butter without choking two months later. You can order it online or find it in kosher supermarkets, but be aware that the export version is not iron-fortified like the Israeli version.

-- Creamy peanut butter: Many older infants (between 10-months to 1-year old) are able to handle a thin layer of smooth peanut butter melted on toast. Brands with no added sugar, oil and/or salt are widely available, as are organic versions. As with all sticky foods, keep a close eye to make sure baby doesn't choke. Other options are homemade baked goods with no added sugar that contain peanut butter; quick cooking oats mixed with peanut butter and mashed banana can be baked into a soft "cookie" that older infants can self-feed.

[See Are All Nut Butters Created Equal?]

-- Powdered peanut butter: Powdered peanut butter, which is essentially defatted peanuts turned into a flour-like powder, can be added to plain whole-milk yogurt and spoon fed to baby. Powdered peanut butters do contain small amounts of added sugar, though much less than a fruit-flavored baby yogurt would.

Tree nuts

-- Pancakes: Almond flour or hazelnut flour can be used to make pancakes--soft, perfect finger food that most infants can handle in the seven- to 10-month range. Elana Amsterdam, the veritable queen of baking with almond flour, has many recipes on her blog; her silver-dollar pancakes remain in our repertoire to this day.

[See Taking Teff Flour to the Test Kitchen]

-- Sliced almonds: Sliced almonds are soft and paper thin; many older infants should be able to handle them just fine if they are chopped and cooked into a veggie dish. Sautéed and tossed with well-cooked green beans, they make a family-friendly side dish that can be shared with older infants at the family table.

Eggs

-- Cooked egg: The AAAAI recommendations suggest that cooked egg may be a better way to expose infants to egg protein than baked egg; that's presumably because the protein remains more intact. I introduced egg with recipes like "Cereal with Egg Breakfast" and "Sweet Potato Custard" from the book Baby Bites by Bridget Swinney.

-- Baked egg: Pancakes or other baked goods are another convenient way to expose baby to trace amounts of egg. As my kids transitioned to finger foods, I used up leftover frozen veggie purees like beets, pumpkin and sweet potato by adding them to store-bought whole-grain pancake mixes prepared with eggs.

Dairy

While a little bit of liquid cow's milk in a mixed dish or baked food is fine for infants six to 12 months, the AAAI and AAP caution against offering liquid cow's milk as a beverage until after baby turns 12 months old. This is because cow's milk, unlike the breast-milk or formula it displaces, contains no iron and can therefore increase a child's risk for developing anemia.

-- Yogurt: Whole-milk plain yogurt is an easy early dairy food to introduce to younger infants. I offered it either au natural or mixed with puréed beets ("baby borscht"). Avoid flavored yogurts--even ones marketed to babies--as they all contain added sugar that infants do not need.

-- Ricotta Cheese: Whole-milk ricotta was another early dairy food in our rotation once my kids could handle thicker purées. It has a soft, creamy texture and tends to be lower in sodium than other cheeses. My favorite combos were mixing ricotta cheese with mashed sweet potato and cinnamon or pure tomato sauce and puréed broccoli or spinach ("baby lasagna").

Hungry for more? Write to eatandrun@usnews.com with your questions, concerns, and feedback.

Tamara Duker Freuman, MS, RD, CDN, is a NYC-based registered dietitian whose clinical practice specializes in digestive disorders, Celiac Disease, and food intolerances. Her personal blog, www.tamaraduker.com, focuses on healthy eating and gluten-free living.