Released this week, the set of guidelines from the National Institute of Allergy and Infectious Diseases recommends that doctors begin introducing some infants to peanut-containing foods as early as four months of age to reduce their chances of peanut allergy. The sweeping recommendation follows a seminal paper published in 2015 that showed early introduction of peanuts can desensitize the immune systems of children who are particularly susceptible to the allergy, preventing many from ever developing a dangerous and often-isolating condition which, in extreme cases, can cause deadly anaphylactic shock.