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Canada’s MDs Take Position on Infant Diet and Food Allergy

In a joint position statement, the Canadian Pediatric Society and the Canadian Society of Allergy and Clinical Immunology declare that there is no convincing evidence that delaying the introduction of allergenic foods protects babies against food allergies.

The December 2 statement recommends breastfeeding for six months and introducing solid foods by six months. When it comes to key allergens, the two Canadian medical bodies say: “Later introduction of peanut, fish or egg does not prevent, and may even increase, the risk of developing food allergy.” (The statement stresses that the newer advice only applies to infants at higher risk of developing an allergic condition, and definitely not to children who already have a confirmed food allergy.)

The position is in keeping with the American Academy of Pediatrics’ advice. In a statement [1] in 2008, the AAP reversed its previous guidance, which used to counsel parents to hold off feeding children: dairy products until 1 year of age, eggs until 2 years, and peanuts, nuts, and fish until 3 years of age.

Like the AAP, the Canadian doctors are now officially stating that there was no convincing evidence to support those prior recommendations. The old advice “was actually based on expert opinion; it wasn’t based on rigorous scientific study,” says Dr. Edmond Chan, pediatric allergist and co-author of the statement. “But what we’ve learned in the past few years about the immune system is the opposite of that thought.”

Of the delay of a Canadian statement on the subject, Chan says: “We felt that this would be an opportune time, after there has been a few years of having the general public have this message disseminated by the AAP. The advantage now is that we have more evidence to cite steering us in that direction.” Another reason for a statement was that “we still have a sense that many parents are adhering to [older] recommendations to delay introduction,” he says.

There is still no definitive study to prove that earlier introduction of allergenic foods may help a child’s immune system and avoid the onset of allergies. But a number of research papers are pointing to some protective effect. The CPS-CSACI statement notes a recent study from Australia demonstrated that delaying egg introduction for the first year of life resulted in a 3.4-fold higher risk of developing egg allergy, compared with egg introduction at any time between four and six months of age.

As well, the surge in food allergies from a rare condition to about 8 percent of American children [2] and about 6 percent of Canadian children occurred during the period when the guidance was to delay introducing certain solid foods, leading scientists to suspect that avoidance may have contributed to food allergy’s rise.

While the Canadian statement explains current research on why the delay of feeding foods has been unhelpful to allergy prevention, Allergic Living finds the statement less than clear on whether that means foods should always be introduced early in high-risk children or whether there would be discretion according to the child’s family and own symptom history.

On one hand, the statement notes that early introduction “cannot be recommended at this time” because more research is needed to confirm whether any benefit truly exists. But it also directly recommends: “Do not delay the introduction of any specific solid food beyond six months of age.”

The Canadian statement differs from the U.S. one on a couple of points. In accordance with World Health Organization guidelines, the CPS-CSACI statement recommends exclusive breastfeeding [3] for the first six months, while the AAP statement recommends it for the first four to six months.

Also, the Canadian position includes a note that “the total duration of breastfeeding (at least six months) may be more protective than exclusive breastfeeding for six months.” This is an approach in which the mother still breastfeeds for six months, but begins introducing solids along with breastfeeding from four months.

The statement also states that pregnant or nursing women should not restrict their diet in an attempt to reduce food allergy risk. “While the evidence that restricting maternal diet during pregnancy and lactation helps to prevent allergy is weak, the risks of maternal under-nutrition and potential harm to the infant from avoiding these foods may be significant,” reads the statement.

Chan acknowledges that early introduction of potentially allergenic solids is far from a sure-fire way to prevent allergy. “Our understanding of the immune system right now suggests there is more than just the age of introduction,” he told Allergic Living. “There’s likely quite an impact from the regularity of exposure.” So once a food has been introduced, it should be eaten on a regular basis.

Of course, the concern that remains for parents of food-allergic infants is what happens if the six-month-old goes into anaphylaxis after having a new food introduced to their diet.

“There is an inherent irony in this question, because there is this huge emphasis on these recommendations being directed at high-risk infants [defined as having a first-degree relative with an allergic condition]. All these recommendations could actually have the most benefit for that infant, and yet the parents are potentially the least likely to follow them, because of this worry about anaphylaxis,” says Chan.

“There’s this interesting dilemma, there’s this irony, that those who might benefit most are the most afraid.”

Next: Managing fears; the official recommendations

To temper these fears, Chan points out that the prevalence of anaphylaxis to a newly introduced food is very low.

“Even if we were to be quite generous with the numbers, that high-risk infant, if there was peanut allergy in the older sibling, would be at just under 10 percent chance of having a peanut allergy. That describes peanut allergy – it doesn’t have anything to do with anaphylaxis. We’re talking below a 1 percent type of chance of anaphylaxis.”

For parents who still feel uneasy about introducing a new food, Chan has a simple solution: schedule a food challenge with an allergist. “If it can’t be done in a home setting, then maybe it needs to be done in a physician-supervised setting.”

As for parents who may be especially nervous because they feel their six-month old infant won’t be able to communicate the fact they are experiencing anaphylaxis, Chan notes: “It’s always not easy to determine from the parents’ perspective what a reaction might fully represent in an infant, because infants can’t fully verbalize what they’re feeling.” But he says this does not just apply to food allergies; a six-month old can’t tell the parents of symptoms of other serious conditions either.

The statement closes with these general recommendations:

Do not restrict maternal diet during pregnancy or lactation. There is no evidence that avoiding milk, egg, peanut or other potential allergens during pregnancy helps to prevent allergy, while the risks of maternal under nutrition and potential harm to the infant may be significant.

Breastfeed exclusively for the first six months of life. Whether breastfeeding prevents allergy as well as providing optimal infant nutrition and other manifest benefits is not known. The total duration of breastfeeding (at least six months) may be more protective than exclusive breastfeeding for six months.

Choose a hydrolyzed cow’s milk-based formula, if necessary. For mothers who cannot or choose not to breastfeed, there is limited evidence that hydrolyzed cow’s milk formula has a preventive effect against atopic dermatitis compared with intact cow’s milk formula. Extensively hydrolyzed casein formula is likely to be more effective than partially hydrolyzed whey formula in preventing atopic dermatitis. Amino acid-based formula has not been studied for allergy prevention, and there is no role for soy formula in allergy prevention. It is unclear whether any infant formula has a protective effect for allergic conditions other than atopic dermatitis.

Do not delay the introduction of any specific solid food beyond six months of age. Later introduction of peanut, fish or egg does not prevent, and may even increase, the risk of developing food allergy.

More research is needed on the early introduction of specific foods to prevent allergy. Inducing tolerance by introducing solid foods at four to six months of age is currently under investigation and cannot be recommended at this time. The benefits of this approach need to be confirmed in a rigorous prospective trial.

Current research on immunological responses appears to suggest that the regular ingestion of newly introduced foods (eg, several times per week and with a soft mashed consistency to prevent choking) is important to maintain tolerance. However, routine skin or specific IgE blood testing before a first ingestion is discouraged due to the high risk of potentially confusing false-positive results.

Read the full position statement here [4].