Q It seems like food allergies are becoming increasingly common. I have a seven-month-old baby whom I'm breast feeding and a two-year-old. Is there anything I can do to prevent them from developing food allergies?
AYour question is an excellent one that has left parents and physicians alike scratching their heads in recent times. In fact, some recommendations on ways to prevent allergies that physicians have been giving parents for over a generation turn out not to be "evidence based" and therefore have come into question recently. One thing is certain: Allergic illnesses are on the rise.
For years, pregnant and breastfeeding mothers have been cautioned against eating certain foods (such as peanut and sometimes shellfish) as a way of helping to prevent allergies in their offspring . At present, there isn't enough evidence to draw firm conclusions as to whether this will make a difference. The only caveat is that there may be a place for breastfeeding mothers to avoid highly allergic foods in the prevention of eczema.
Evidence exists to support exclusive breastfeeding for at least the first three to four months of life to prevent eczema, cow milk allergy, and wheezing in the early years. If you are unable to exclusively breastfeed and your infant is at high risk for allergies (essentially meaning that a parent or sibling have allergies, asthma or eczema) then it is advisable to feed your baby specialized formula. These formulas have had their proteins partially or fully broken down, or hydrolyzed, to make them hypoallergenic. However, they offer no benefit over exclusive breastfeeding. It's also important to note that soy formula does not appear to offer any benefit over cow milk formula for the prevention of allergies. If your child is at high risk for allergic illness, talk to your health care provider for advice on appropriate formula choice.
Many parents have been told to delay the introduction of certain solid foods in order to prevent allergies. There is not convincing evidence to delay the introduction of solid food beyond six months of age, even with foods that are considered highly allergic, like fish, eggs and foods containing peanut protein. The recommendation comes from a report published in January 2008 by the Committee on Nutrition and the Section on Allergy and Immunology of the American Academy of Pediatrics.
You may have heard of the "hygiene hypothesis" which suggests that if a child is kept too clean, that he will have a higher risk of developing allergic disease. The idea is that if a child is exposed to certain bacteria and viruses early on in life, his immune system will be stimulated to fight diseases rather than to develop allergies. Thus, it seems that children who attend daycare, have multiple siblings, are exposed to animals, and come from a lower socioeconomic background seem to have a lower risk of allergic disease. There is still much to be learned about the hygiene hypothesis, but it is certainly food for thought.
If your child develops wheezing, cough, hives or facial swelling immediately after eating, she should be assessed by a doctor immediately. While delaying the introduction of a highly allergic food does not seem to prevent an allergic reaction, it would seem reasonable to wait to introduce highly allergic foods to a high-risk child until she is old enough to let you know if she feels unwell after eating.
Dr. Cheryl Mutch appears every Sunday in Live It! Dr. Mutch is a consultant pediatrician in Burnaby and the co-author of The Good Food Book for Families (Random House Canada).
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