Old Thinking: Breastfeeding moms should avoid eating allergenic foods such as peanut butter and eggs.
New Thinking: There's no clear evidence that what you eat while nursing affects your child's allergy risks.
Old Thinking: Soy-milk formula can prevent allergies.
New Thinking: Soy milk has no benefit when it comes to allergy prevention (and soy protein is itself allergenic). A better choice? Hypoallergenic or hydrolyzed formulas, which, research shows, may offer some protection against allergies, though breastfeeding is still preferred.
Old Thinking: Hold off on giving all tykes allergenic foods (such as nuts, egg whites, wheat, corn, shellfish, and citrus fruits) for at least one year, and possibly three if there's a family history of food allergies.
New Thinking: The only reason to wait beyond the first six months to introduce potential allergens is if there's a family history or your baby has had a previous allergic reaction. (But still watch for choking hazards.)