Feeding solid foods to infants before 6 months of age can increase the risk of allergies

Jul 26 2006

Feeding solid foods to infants before 6 months of age can increase the risk of allergies, while exclusive breastfeeding for at least 6 months may prevent the onset of allergic symptoms later in life, according to a paper published in the Annals of Allergy, Asthma and Immunology.

The paper is the first consensus document published in a peer-reviewed journal to recommend allergy-avoiding strategies for introducing solid foods to the infant diet.

"This report reinforces the consensus of organizations such as the American Academy of Pediatrics and the World Health Organization, which recommend exclusive breastfeeding for at least six months as optimal for infant and maternal health," said lead author Alessandro Fiocchi, M.D., University of Milan Medical School, Milan, Italy. Dr. Fiocchi is chair of the Adverse Reactions to Foods Committee of the American College of Allergy, Asthma and Immunology (ACAAI), which prepared the consensus document.

Specific recommendations of the committee include:

• Exclusive breastfeeding (with no cow's milk formulas or any supplemental food) is indicated during the first six months of life because it has a preventive effect against the onset of allergic symptoms that extends far beyond the period of breastfeeding.
• Supplemental foods should not be introduced during the first four months of life, as it is associated with a higher risk of allergic diseases up to the age of 10 years.
• The avoidance of cow's milk in the early months of life has been shown to be an effective means of preventing allergies. "We concluded that delayed exposure to solid foods should be similarly useful in preventing food allergies," said co-author Amal Assa'ad, M.D., Cincinnati Children's Hospital Medical Center, Ohio.
• The main foods that pose a high allergy risk include cow's milk, eggs, peanuts, tree nuts (such as hazelnuts, walnuts, cashews, almonds, chestnuts, macadamias and pistachios), fish and other seafood. "Other foods – even staples such as fruits, vegetables, meats, soy and cereals – also have the potential to cause allergies if introduced too early," said co-author Sami L. Bahna, M.D., Dr.Ph., Louisiana State University School of Medicine, Shreveport. The authors noted that it seems "reasonable that foods should be introduced selectively, individually and gradually" to lessen the risk of allergy.
• Mixed foods containing a variety of potential food allergens should not be given to infants until tolerance to every ingredient has been evaluated individually.
• Cooked, homogenized foods are preferred to their fresh counterparts when a reduced potential for causing allergies has been clinically demonstrated, such as in the cases of beef, vegetables and fruit.

"The timing after age 6 months at which specific foods should be introduced depends on a number of factors, including the individual infant's nutritional needs and risk for allergies," Dr. Fiocchi said. It is generally considered prudent not to introduce hen's eggs, fish, peanuts and nuts before the age of 12 months, or later in infants at high risk of allergy, the authors said.

The committee reached its consensus based on an evidence-based review of published research related to food allergies in infants.