February 27, 2015
From The Expert: What You Need To Know About New Peanut Research
Despite the promise of new research that says giving infants peanuts may actually prevent an allergy, it’s not clear how the new findings will play out over the larger population and what they might mean for other types of allergies.
We asked Georgetown’s Sally Joo Bailey, one of the panelists on our Feb. 25 show about the research, to answer some of the most popular questions we received from listeners.
Question: I was eating peanut butter sandwich and nuts excessively during pregnancy. My first daughter has strong peanut allergy and I feel that consuming peanut butter contributed to her allergies. Her allergist told me to exclude peanuts with my second pregnancy and so far my toddler seems to have no allergies. What effect does a mother’s diet have on her child’s allergies?
Sally Joo Bailey: I typically recommend you don’t eat any of the highly allergic foods in excess, as that is not what your body is used to. We don’t fully understand why and how or even if what a mother eats during pregnancy affects the baby. Typically if there is a child with food allergies, especially to peanuts, we recommend removing peanuts from the home since there is an increased risk of the sibling developing peanut allergies. In the past, we had also recommended mothers avoid peanuts with the next pregnancy. This study may change what we recommend in terms of during pregnancy, breastfeeding and infancy in regards to exposure to peanuts.
Q: Do you think there is a connection between the use of certain pesticides and the development of peanut or other food allergies?
SJB: Not that I am aware of.
Q: A friend has a grandson who is in his early teens who has had a serious peanut allergy all his life. Does the study hold out any hope for him? Is there evidence that desensitizing through the introduction of minuscule portions of peanuts help?
SJB: Other studies at food allergy research centers, such as Johns Hopkins, have been conducting studies on peanut oral tolerance. There seems to be some desensitization: About 50 percent of patients in the study are able to tolerate peanuts, however, they must continue ingesting peanuts three times a week . Unfortunately once they stop ingesting peanuts, the majority regain their allergy.
Q: Are there any cases of patients with a peanut allergy naturally overcoming the allergy or seeing the allergic reaction reduce itself over time?
SJB: Yes, about 20 percent do outgrow their peanut allergy. There’s also new testing that is able to identify people with mild reactions, caused by a pollen allergy cross reaction and not a true severe allergic reaction.
Q: I have read that some doctors think there is a link or connection between the great increases in so many vaccines and the growing number of allergies in the U.S. What do you think?
SJB: There aren’t any allergies associated directly with vaccines. There is a hygiene hypothesis that states that allergies in general have increased perhaps because we as a Western society — with clean running water, sewer systems, antibiotics and vaccines — have too clean of a living environment compared to those living in very rural, undeveloped areas without those things. These are areas where families often live in the home with pigs and chickens wandering inside in and out of their bedrooms and kitchens. They believe that perhaps because they are constantly exposed to bacteria from animal fecal matter, and fighting viral and bacterial infections without antibiotics and vaccines, that their immune systems are “too busy” fighting infections and germs to develop into allergic antibodies. Thus the body is spending its immune efforts on fighting infections and not developing allergies.
Q: I’ve read that breastfeeding and delaying cow’s milk from your infant actually decreases the risk of susceptibility to any food allergies, including peanuts. Have you found that information?
SJB: Breastfeeding in general is recommended for all infants and we believe it may help those with eczema and food allergies.
Q: Is the advice to avoid peanuts to prevent peanut allergy related to common advice to not feed kids gluten before a certain age to prevent gluten allergy?
SJB: The way gluten sensitivity develops is different than the way a peanut allergy develops.
Q: Does eczema in babies foretell of other allergies, or just peanut allergy?
SJB: Yes, actually, the most frequent food allergy associated with infant eczema is eggs.
Q: Is there a connection between allergies and the rise of the use of soy-based infant formula and other soy products?
SJB: I am not aware of a rise in soy allergies. Most milk allergic infants are not recommended to switch to a soy formula but rather a hydrolysated cow’s milk formula.
Q: For a typically developing child — no eczema, no family history of peanut allergy — does it seem reasonable to introduce a tiny amount of peanut butter, perhaps at a pediatric visit, just in case?
SJB: For low risk patients — meaning no family history of environmental allergies, like pollen, cat, dog, asthma or eczema — the American Academy of Pediatrics recommends introduction of all foods.
Q: Are peanut allergies common in other countries?
SJB: In most Western countries allergies exist. They’re not as common in Asian and African countries.
Q: Should infants with eczema be tested for food allergies before solid food is introduced?
SJB: We know that up to 40 to 60 percent of infants with moderate to severe eczema have a food allergy. If a child has persistent eczema that develops before the age of 1, I would recommend an allergy evaluation with an allergist.
Q: Would highly refined foods and additives in foods contribute to susceptibility of food allergies?
SJB: There is a higher risk of contamination to peanuts and tree nuts in these foods, which is a risk for patients who already have a food allergy and is trying to avoid them, but there is no direct correlation of additive, preservatives or highly refine foods causing more food allergies.
Want more? Listen to our full hour on the new research.