While nursing has been shown to help prevent allergies in babies, other common practices, such as avoiding certain foods during pregnancy, using soy formula, or waiting until a baby is six months old to introduce solid foods have not shown any benefits, according to a new report published in the journal Pediatrics.

In this latest advisory, the American Academy of Pediatrics updates earlier suggestionsBaby getting Breast-fed that might have made some parents feel as if they weren’t doing enough to prevent allergies and asthma. in 2000, the group advised mothers of infants with a family history of allergies to avoid cow’s milk, eggs, fish, peanuts and tree nuts while breast-feeding. This advice has been tossed out, along with the suggestion to delay a child’s introduction to certain foods.

The only surefire advice remaining is to breast-feed. Exclusive breast-feeding for at least three months protects against wheezing in babies, but it is unclear whether it prevents asthma in older children.