The World Health Organization (WHO), the American Academy of Pediatrics (AAP) and other groups recommend that parents delay introducing solid foods for 4 to 6 months to curb children's allergy risk.

However, the new findings, published in the journal Pediatrics, question the effectiveness of this strategy.

German researchers found that among the 2,073 children with complete records and 6-year follow-up, those who received no solid foods before 4 to 6 months of age did not have a lower risk of nasal allergies, asthma or sensitization to common food allergens.

"We found no evidence to recommend a delayed introduction of solids beyond 4 or 6 months for the prevention of asthma, allergic rhinitis, and food or inhalant sensitization at the age of 6 years," write the researchers, led by Dr. Anne Zutavern of the GSF-National Research Center for Environment and Health in Neuherberg.

While the WHO, AAP and other groups recommend delaying the introduction of solid foods to prevent allergies, there has been "scarce" scientific evidence to back this up, according to Zutavern's team.

The one possible exception was the skin condition eczema. When the researchers looked only at children who'd had no skin or allergy symptoms in the first 6 months of life, those who'd had solid foods before 4 months of age were more likely to develop eczema later in life.

The researchers suggest that could be because parents who noticed skin or allergy symptoms early in their baby's life may have been more careful to delay solid foods.