When should you introduce children to allergenic foods?

If you are a parent of an infant, you probably feel lost at times trying to wade through all of the various theories, thoughts and recommendations for when to introduce allergenic foods. Is it better to introduce early or late? If I am breastfeeding, should I eat these foods in my own diet or is that dangerous? All of these questions come up on a regular basis for both first-time and seasoned parents. Dr. Jay Lieberman, a Le Bonheur allergist/immunologist, weighs in on this topic below.

The main reason for all the confusion around introduction to allergenic foods is that . . . we just don't know for sure.

What does research say?

While past research suggested that early introduction of allergenic foods may actually lead to allergies, newer research is telling us that this may not be the case. In fact, in the most recent guidelines published by the American Academy of Pediatrics state, “Although solid foods should not be introduced before 4 to 6 months of age, there is no current convincing evidence that delaying their introduction beyond this period has a significant protective effect on the development of atopic disease regardless of whether infants are fed cow milk protein formula or human milk. This includes delaying the introduction of foods that are considered to be highly allergic, such as fish, eggs, and foods containing peanut protein.” This was a change from past guidelines that recommended delayed introduction of allergenic foods.

When should you introduce these foods? What foods do you recommend?

For my patients who are not at high risk for allergy, I recommend introduction of foods starting at 4-6 months of age. I do not limit the type of foods, so long as they are not a choking hazard or health hazard for other reason. Meaning, peanut butter or other nut butters (whole nuts may be choking hazards), fish, eggs, and other allergenic foods are fair game from an allergy standpoint. In fact, some studies suggest that the more diverse the diet, the better off the child may be from an allergy standpoint. As testament to this, my own little one had tried peanut butter, eggs, fish, shrimp, and anything else that she could get her little hands on long before 12 months of age. Now, I do not recommend just throwing all of these to a 6 month old in a big soup. New foods are best introduced alone, with one new food at a time over a few days. This is simply to see if the food leads to any reactions. Worrisome reactions will occur within minutes of ingestion and occur every time the food is ingested. If you introduce five new foods at once, and the child reacts, you will never know which food is the culprit. Clearly, I can never guarantee that a child will not react on the first ingestion of any of these foods. That being said, if they are allergic at 6 months, they are likely still allergic at 12 months. Therefore, delaying the introduction until 12 months is not likely to alter the outcome, rather only delay it a few months.

Are there exceptions?

Of course, the above recommendation is for average or low-risk children. If the child already has moderate to severe eczema or reactions to formula as an infant, they are already at higher risk for food allergies, and perhaps more careful introduction of allergenic foods may be warranted. Hypoallergenic formulas may be needed to treat symptoms in infants, but should not be used to prevent allergic diseases (food allergy, eczema, asthma). It’s best to ask your pediatrician in these cases.

What do you recommend for breastfeeding mothers?

As for pregnant and breastfeeding mothers, I have no specific recommendations (other than breastfeeding is recommended and may be protective for allergic diseases). I have no convincing evidence that any food you eat (even in excess) at any time during your pregnancy will have any effect on your child’s allergic outcome. My approach is to simply recommend a diverse and healthy diet for all expectant and breastfeeding moms. I recommend all moms to breastfeed exclusively for 3‐4 months if possible, and then start adding in solid foods as possible and tolerated by the infant. In addition, the amount of specific food protein that may be transferred (unchanged) to your breastfeeding infant is probably not enough to matter, unless he or she has severe eczema.