When my four-year-old daughter, Maya, was diagnosed with a peanut allergy, I was pregnant with my second child. I was curious to know if there was any way to prevent life-threatening food allergies in baby number two.
Dr. Douglas Mack, a pediatric allergist, asthma and immunology specialist in Burlington, Ont., tested Maya. He says even though researchers have yet to discover exactly why allergies have doubled in the last decade or so, (Health Canada estimates that food allergies affect five to six percent of children under three in Western countries), and exactly what causes them, there has been some promising research linking simple precautionary measures to a decreased incidence of food allergies and eczema.
The “sunshine vitamin” has received a lot of press lately, perhaps due to the discovery that every cell in our bodies contains a vitamin D receptor. Since breast milk usually only contains between four to 40 IU of the vitamin per litre, the Canadian Pediatric Society (CPS) recommends a daily 400 IU vitamin D supplement for breastfed infants during the first year of life. (Breastfeeding or pregnant women can take a supplement of up to 1,000 IU a day).
Dr. Mack reiterates the importance of this practice, citing a study from Australia linking food allergies to less sun exposure, and therefore, lower levels of vitamin D. Researchers found that as you move further away from the equator, prescriptions for EpiPens and hypoallergenic formulas increased, as did food allergy-induced anaphylaxis in children.
“Vitamin D can modulate the immune system,” says Dr. Mack. “How it does this is still not very clear. But what is evident, is that by having lower exposure and lower levels of vitamin D, we see more allergies.”
Some research is showing probiotic supplements could help children outgrow or lessen their food allergies.
Probiotics – microorganisms found in the gut that contribute to healthy digestive function – show a lot of promise for both preventing and treating food allergies and atopic tendencies. Several commercial yogurts now boast added probiotics, and supplements can be easily found in health food stores and drugstores.
“Likely the chemicals produced by these bacteria modify the gut in some way,” says Dr. Mack, “so we’re even seeing a lot more use of probiotics to treat other diseases such as colic and diarrhea in mainstream medical practice. It used to be something you’d only hear from naturopaths, but today, even before official recommendations are made, it appears to be safe and quite promising.”
The Journal of Allergy and Clinical Immunology cites a 2012 study where an extensively hydrolyzed (i.e., broken down) cow’s milk formula was given to babies with a cow’s milk allergy. Some babies received the formula only, and others had the formula and a lactobacillus probiotic supplement. “With the probiotic there was a dramatic outgrowing of the cow’s milk allergy,” says Dr. Mack. “We have to look at this some more.”
Does delaying the introduction of allergenic foods make a difference?
- In 2000, the American Academy of Pediatrics recommended avoiding cow’s milk until 12 months, eggs until 24 months and peanuts until 36 months. However, despite these recommendations, there still was a significant increase in allergies to these foods.
- In 2008, the AAP stopped making such recommendations, and now notes that many children may in fact tolerate a much earlier introduction of some allergenic foods.
- The AAP guidelines now say that although solid foods should not be introduced before four to six 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. This includes delaying the introduction of foods that are considered to be highly allergic, such as fish, eggs and foods containing peanut protein.
- “Should we be introducing our babies to peanuts at five, six, or seven months?” asks Dr. Mack. An oft-cited UK study supporting this practice compared incidence of peanut allergies in Israel to the UK. In Israel, six-month-old babies were routinely given a peanut-containing snack to promote weight gain, yet they were found to have a 10-fold lower incidence of peanut allergy than their counterparts living in the UK, who typically don’t start eating peanuts until much later in life.
Originally published in ParentsCanada magazine, July 2012.