Southwest Airlines to Stop Serving Peanuts on Flights Southwest Airlines says it will stop serving peanuts on its flights next month. The airline says it’s making the change to help protect passengers who have severe peanut allergies. Peanuts have historically been the one snack perhaps most linked to airline service. The move comes as awareness of peanut allergies has increased, especially in confined spaces like airplane cabins. Even trace amounts can cause major complications for those with the most extreme nut allergies. The FDA lists peanuts as one of the eight food types that account for 90 percent of all food allergies in the United States.