The Canadian Pediatric Society and the Canadian Society of Allergy and Clinical Immunology have issued new guidance on when high-risk infants can safely be exposed to foods commonly associated with food allergies, reversing their previous advice to avoid some foods early in a baby's life.
The groups said there is no need to shield these children from foods like peanuts, eggs or shellfish in the early months after they begin eating solid foods. In a statement, the groups said babies can be exposed to potential food allergens as early as six months of age.
It had been thought that keeping foods commonly associated with allergic reactions out of the diets of at-risk babies would protect them from developing allergies. But it has since been shown the technique does not work.
In fact, the American Academy of Pediatrics reversed their advice on this issue nearly six years ago, in a statement published in its journal Pediatrics in January 2008. Similar advice has also been issued in Britain.
Babies considered at high risk of developing food allergies are those who have a parent or sibling with a food allergy, asthma, allergic rhinitis or an allergic condition such as atopic dermatitis.
"Delaying dietary exposure to potential allergens like peanuts, fish or eggs will not reduce your child's risk of developing a food allergy," Dr. Edmond Chan, a pediatric allergist and co-author of the revised Canadian policy, said in a statement.
"However, once a new food is introduced, it is important to continue to offer it regularly to maintain your child's tolerance."
The advice also extends to the diet of pregnant women and nursing mothers.
"We also don't recommend avoiding milk, egg, peanut or other foods while pregnant or breastfeeding," said Dr. Carl Cummings, who is also a co-author of the statement.
"There is no evidence to support the theory that avoiding certain foods during this time will prevent allergies in children."
The statement said that while foods like eggs and peanuts can be introduced into the diets of high-risk babies, the decision about timing can be based on the parents' comfort level. Parents who are unsure should talk to their doctor, the Canadian Pediatric Society said.
Dr. Anne Ellis, chair of the allergy and immunology division at Queen's University in Kingston, Ont., welcomed the policy revision, saying it will be useful for Canadian clinicians to have made-in-Canada guidance.
In 2000, expert panels in a number of countries recommended delaying the introduction of foods with high-risk allergenic potential for various durations post-birth. For whole milk, it was suggested waiting until nine months, Ellis said. The recommended delay for fish and eggs was one year, and peanuts two years, she said, noting the times were rather arbitrary.
But studies have subsequently shown that this approach hasn't protected against the development of food allergies. There have even been concerns that they might have had the opposite effect, Ellis acknowledged.
"For example, in the case of peanut allergy, the incidence of peanut allergy has clearly doubled in the last decade. So obviously these recommendations were not something that were helping," Ellis, who is a practising allergist, said in a phone interview.
She said that parents should still use caution introducing new foods into a baby's diet, making sure not to try more than one new food per day and watching for signs of an allergic reaction. Those could include hives, itchy red welts around the mouth, vomiting or severe food refusal on the part of the baby.
Food allergies affect about seven per cent of Canadians. The pediatric society said some research suggests food allergy in babies is increasing, affecting more than 10 per cent of one-year-olds.